Abstract:AIM: To explore the effects and mechanism of vascular endothelial cadherin (VE-cadherin) on experimental corneal neovascularization (CRNV). METHODS: Mouse corneas were burned with sodium hydroxide to build a CRNV model. The burned corneas were locally administrated with anti-mouse VE-cadherin neutralizing antibody. Annexin V and cluster of differentiation 31 (CD31) double staining was used to measure vascular endothelial cell apoptosis with the use of flow cytometry (FCM). The protein expression of NADPH oxidase 2 (Nox2), caspase-3, and protein kinase C (PKC) in the burned corneas were examined by Western blot. Human retinal endothelial cell (HREC) proliferation was detected using a Cell Counting Kit 8 (CCK-8) assay in vitro. RESULTS: The amount of CRNV peaked two weeks after the alkali burn. FCM confirmed that VE-cadherin neutralizing antibody treatment increased CD31 positive cell apoptosis. Western blot revealed that the intracorneal protein expression of Nox2 and caspase-3 were up-regulated, while PKC was down-regulated in the VE-cadherin neutralizing antibody administrated group. CCK-8 assay showed that VE-cadherin neutralizing antibody markedly inhibited HREC proliferation. CONCLUSION: VE-cadherin exhibited an anti-apoptosis effect through enhanced PKC signaling and an enhanced cell proliferation pathway.

Abstract:AIM: To utilize tissue micro measurement to study the effect of transient high intraocular pressure (IOP) induced by different durations of suction during laser in situ keratomileusis (LASIK) on rabbit retina thickness. METHODS: Sixty healthy New Zealand white rabbits were randomly divided into a control group, and 3 negative-pressure suction groups (20s group, 45s group, and 3min group) and each group was comprised of 15 rabbits (30 eyes); the latter 3 groups were the transient high IOP models. The retinal tissue around the papilledema was separated. Hematoxylin and eosin (HE) staining was carried out to generate slices for light microscopy. The changes in the retina thickness values of each layer were measured for all animals in each group at different postoperative recovery periods and compared with the values recorded for the animals in the control group. The thickness of the retinal tissue showed a normal distribution. The ANOVA was performed by using SPSS13.0 statistic software. RESULTS: In the comparison between the 20s and 45s negative-pressure suction groups and the control group, no significant differences were observed, except at 14d. Significant difference was observed between the 3min negative-pressure suction group and the control group, and the retina thickness value of each layer reached a peak at 14d after repair. CONCLUSION: Conventional negative suction during LASIK may not lead to significant changes in retinal tissue thickness; however, if the suction duration is increased to 3min, it will cause significant changes in retinal tissue thickness.

Abstract:AIM: To evaluate effects of Danhong Huayu Koufuye (DHK, a Chinese medicinal formulae) alone or combined with metformin on diabetic retinopathy (DR) in Zucker diabetic fatty (ZDF) rats, an animal model of obese type-2 diabetes, and then to investigate the mechanisms. METHODS: ZDF (fa/fa) rats were administered with vehicle (distilled water), metformin, DHK, and DHK plus metformin. Electrophysiological and histological analysis were applied to evaluated effects of DHK alone or combined with metformin on DR. The levels of fasting blood glucose (FBG) and glycosylated hemoglobin (HbA1c) in blood were measured to evaluate the antihyperglycemic activity of DHK. Furthermore, levels of nitric oxide (NO), malondialdehyde (MDA) and activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) in serum were measured to study effects of DHK on oxidative stress in ZDF rats. In addition, body weight, lipidic indexes and insulin level were also assessed. RESULTS: DHK combined with metformin significantly reversed the prolongation of latency times of flash electroretinogram (FERG) and oscillatory potentials (OPs) in diabetic rats. Furthermore, DHK alone or combined with metformin showed a remarkable suppression of retinal neovascularization and amelioration of retinal internal limiting membrane morphology. Moreover, DHK alone or plus metformin reduced FBG (P<0.05), HbA1c (P<0.01) and MDA (P<0.01) levels in diabetic rats. In addition, reductions in levels of triglycerides (TG) (P<0.01) and low density lipoprotein cholesterol (LDL-c) (P<0.01 and P<0.05, respectively) were also observed in diabetic rats treated with DHK alone or plus metformin. CONCLUSION: DHK in combination with metformin had a preventive and therapeutic effect on DR in type-2 diabetic rats, and the possible mechanisms may be alleviating hyperglycemia, reducing oxidative stress and improving lipid metabolism.

Abstract:AIM: To investigate the effect of DSX, an active component extracted from Erigeron breviscapus, on the voltage-gated outward K+ channel currents in rat retinal ganglion cells (RGCs) by using electrophysiological method, and to explore the possible mechanisms of DSX on optic nerve protection. METHODS: Outward K+ currents were recorded by using whole-cell patch-clamp techniques on acutely isolated rat RGCs. Outward K+ currents were induced by a series of depolarizing voltage pulses from a holding potential of -70 mV to +20 mV in an increment of 10 mV. RESULTS: Extracellular application of DSX voltage-dependently suppressed both the steady-state and peak current amplitudes of outward K+ currents in rat RGCs. Furthermore, DSX reversibly and dose-dependently inhibited the amplitudes of outward K+ currents of the cells. At +20 mV membrane potential DSX at the concentrations of 0.02 g/L and 0.05 g/L showed no significant effects on the currents. In contrast, DSX at higher concentrations (0.1 g/L, 0.2 g/L and 0.5 g/L) significantly suppressed the current amplitudes. CONCLUSION: These results suggest that DSX reversibly and dose-dependently suppress outward K+ channel currents in rat RGCs, which may be one of the possible mechanisms underlying Erigeron breviscapus prevents vision loss and RGC damage caused by glaucoma.

Abstract:AIM: To explore changes and possible communication relationship of local potential signals recorded simultaneously from retina and visual cortex I (V1). METHODS: Fourteen C57BL/6J mice were measured with pattern electroretinogram (PERG) and pattern visually evoked potential (PVEP) and fast Fourier transform has been used to analyze the frequency components of those signals. RESULTS: The amplitude of PERG and PVEP was measured at about 36.7 µV and 112.5 µV respectively and the dominant frequency of PERG and PVEP, however, stay unchanged and both signals do not have second, or otherwise, harmonic generation. CONCLUSION: The results suggested that retina encodes visual information in the way of frequency spectrum and then transfers it to primary visual cortex. The primary visual cortex accepts and deciphers the input visual information coded from retina. Frequency spectrum may act as communication code between retina and V1.

Abstract:AIM: To identify the disease-causing gene mutation in a Chinese pedigree with autosomal dominant cone-rod dystrophy (adCORD). METHODS: A southern Chinese adCORD pedigree including 9 affected individuals was studied. Whole-exome sequencing (WES), coupling the Agilent whole-exome capture system to the Illumina HiSeq 2000 DNA sequencing platform was used to search the specific gene mutation in 3 affected family members and 1 unaffected member. After a suggested variant was found through the data analysis, the putative mutation was validated by Sanger DNA sequencing of samples from all available family members. RESULTS: The results of both WES and Sanger sequencing revealed a novel nonsense mutation c.C766T (p.Q256X) within exon 5 of CRX gene which was pathogenic for adCORD in this family. The mutation could affect photoreceptor-specific gene expression with a dominant-negative effect and resulted in loss of the OTX tail, thus the mutant protein occupies the CRX-binding site in target promoters without establishing an interaction and, consequently, may block transactivation. CONCLUSION: All modes of Mendelian inheritance in CORD have been observed, and genetic heterogeneity is a hallmark of CORD. Therefore, conventional genetic diagnosis of CORD would be time-consuming and labor-intensive. Our study indicated the robustness and cost-effectiveness of WES in the genetic diagnosis of CORD.

Abstract:AIM: To investigate whether the abnormal differentiation of the pterygium epithelium is related to the extracellular signal-regulated kinase (ERK) signaling pathway in vitro. METHODS: The expression levels of phosphorylated ERK (P-ERK), keratin family members including K19 and K10 and the ocular master control gene Pax-6 were measured in 16 surgically excised pterygium tissues and 12 eye bank conjunctiva. In colony-forming cell assays, the differences in clone morphology and in K10, K19, P-ERK and Pax-6 expression between the head and body were investigated. When cocultured with the ERK signaling pathway inhibitor PD98059, the changes in clone morphology, colony-forming efficiency, differentiated marker K10, K19 and Pax-6 expression and P-ERK protein expression level were examined by immunoreactivity and Western blot analysis. RESULTS: The expression of K19 and Pax-6 decreased in the pterygium, especially in the head. No staining of K10 was found in the normal conjunctiva epithelium, but it was found to be expressed in the superficial cells in the head of the pterygium. Characteristic upregulation of P-ERK was observed by immunohistochemistry. The clone from the head with more differentiated cells in the center expressed more K10, and the clone from the body expressed more K19. The P-ERK protein level increased in the pterygium epithelium compared with conjunctiva and decreased when cocultured with PD98059. The same medium with the ERK inhibitor PD98059 was more effective in promoting clonal growth than conventional medium with 3T3 murine feeder layers. It was observed that the epithelium clone co-cultured with the inhibitor had decreased K10 expression and increased K19 and Pax-6 expression. CONCLUSION: We suggest ERK signaling pathway activation might play a role in the pterygium epithelium abnormal differentiation.

Abstract:AIM: To explore whether genetic variations in the MFN1 gene are associated with low to moderate myopia in Chinese population. METHODS: The case-control association analysis was used. The study included 100 independent myopia patients (-0.75 D ≤ spherical refraction ≤-8.00 D) and 100 sex-matched healthy controls (with binocular spherical equivalent ranges between -0.50 D and +0.50 D). Four single nucleotide polymorphism (SNP) tags (rs3976523, rs13098637, rs6762399 and rs7618348) were selected for genotyping by direct sequencing. The frequencies of genotypes and their alleles were calculated based on the number of SNP genotypes in each sample. The Chi-square test was used to examine the difference in the frequency between the myopia cases and controls. RESULTS: Genotype distributions in the four SNPs were all in accordance with the Hardy-Weinberg equilibrium; analysis showed that rs13098637 was significantly associated with low to moderate myopia (P=0.003 and empirical P=0.010). There were no statistically significant differences observed for the genotype or allele frequencies of the other three SNPs between the myopia cases and controls in the Chinese population in this study. CONCLUSION: The current study has revealed that the C allele of rs13098637 in MFN1 had a significant association with low to moderate myopia.

Abstract:AIM: To conduct a comparative study of effectiveness of silicone hydrogel contact lens and hydrogel contact lens, which are used in patients after laser-assisted subepithelial keratomileusis (LASEK). METHODS: Sixty-three patients (121 eyes) with a spherical equivalent ≤-5.0 D were chosen after undergoing LASEK in 2012 at Guangdong General Hospital. They were randomly divided into 2 groups. The silicone hydrogel group included 32 cases (61 eyes) that wore silicone hydrogel contact lenses for 4-6d after the operation, while the hydrogel group included 31 cases (60 eyes) who wore hydrogel contact lenses for 4-6d after the operation. Patients’ self-reported postoperative symptoms (including pain, photophobia, tears, and foreign body sensation) were evaluated. The healing time of the corneal epithelium, the visual acuity of patients without contact lens after epithelial healing, and the incidence of delayed corneal epithelial shedding were also assessed. The follow-up time was 1mo. RESULTS: Postoperative symptoms were milder in the silicone hydrogel group than in the hydrogel group. There were significant differences in pain, foreign body sensation, and photophobia between the 2 groups (P<0.05), although there was no significant difference in postoperative tearing (P>0.05). The healing time of the corneal epithelium in the silicone hydrogel lens group was markedly shorter than that in the hydrogel group (4.07±0.25 vs 4.33±0.82d, t=2.43, P=0.02). Visual acuity without contact lenses after healing of the corneal epithelium was better in the silicone hydrogel group compared with the hydrogel group (χ2=7.76, P=0.02). There was no significant difference in the occurrence of delayed corneal epithelial shedding between the 2 groups (P>0.05). CONCLUSION: Patients with LASEK using silicon hydrogel contact lenses had less discomfort and shorter corneal epithelial healing time compared with those using hydrogel contact lenses, suggesting that silicon hydrogel contact lenses may be considered to be a better choice of bandage contact lens after LASEK.

Abstract:AIM: To evaluate the diagnostic efficiency of basic indicators and find characteristic indicators for keratoconus (KC) at adjacent stages, and to assess the progression pattern of KC. METHODS: One hundred and eight (41 subclinical, 40 moderate, and 27 severe) keratoconic patients (108 eyes) and 105 myopic patients (105 eyes) as controls were recruited in this prospective, comparative case series study. Pentacam topography was performed. Receiver-operating-characteristic curves were used to get the characteristic indicators. RESULTS: The most efficient distinguishing index between the subclinical KC and the controls was posterior elevation value (PEV, AUC=0.882), with the highest specificity being 93.8%. Corneal thickness (AUC=0.852) and posterior inferior-superior value (I-S) ranked second and third (AUC=0.776). When KC became moderate, PEV remained to be of the highest diagnostic efficiency (AUC=0.988), followed by the anterior elevation value (AUC=0.986) and other parameters of anterior surface. The diagnostic value increased significantly in the anterior curvature indices (all AUC>0.900) and appeared in the anterior best fitting sphere radius (AUC=0.919) when KC developed into the severe stage. CONCLUSION: In the subclinical stage of KC, PEV, thickness, and posterior I-S had important diagnostic values, and elevation values remained most efficient when KC developed to the moderate stage. The anterior curvature indices were most characteristic when KC became severe. KC first appeared in the inferior cornea of posterior surface, but the feature of protrusion formed at the moderate stage.

Abstract:AIM: To evaluate and compare corneal biomechanical findings measured by ocular response analyzer, topographic and pachymetric findings in patients with unilateral keratoconus patients and healthy controls. METHODS: This is an observational, case-control study. Patients with keratoconus in one eye and forme fruste keratoconus in the fellow eye were compared with sex and age matched with controls healthy subjects. All subjects were evaluated with rotating scheimpflug imaging system. The receiver-operating-characteristic curves were analyzed to evaluate the sensitivity and specificity of the parameters. RESULTS: Twenty-seven patients with keratoconus in one eye and forme fruste keratoconus in the fellow eye were compared with 40 eyes of 40 normal subjects. Corneal hysteresis (CH) was 8.0±1.7 mm Hg in keratoconus group, 8.3±1.6 mm Hg in forme fruste keratoconus group, and 9.8±1.6 mm Hg in control groups (P=0.54 between keratoconus and forme fruste keratoconus groups, P<0.01 between control group and other groups). Corneal resistance factor (CRF) was 7.1±2.2 mm Hg in keratoconus group, 7.8±1.2 mm Hg in forme fruste keratoconus group and 9.9±1.5 mm Hg in control group (P<0.001 between control group and other groups). Using receiver-operating-characteristic analysis, the area under curve values of the parameters to distinguish forme fruste keratoconus from control subjects were: CH (0.768), CRF (0.866). Best cut-off points were 9.3 mm Hg and 8.8 mm Hg for CH and CRF respectively. CONCLUSION: Ocular response analyzer parameters (CH and CRF) are found to be significantly lower in forme fruste keratoconus patients compared to normal control subjects.

Abstract:AIM: To study the potential reasons of increased straylight in pseudophakic eyes. METHODS: Cross-sectional study. Seventy patients diagnosed as bilateral age-related cataract and implanted with Tecnis ZA9003, Sensar AR40e, SA60AT, XLSTABI ZO or Akeros AO intraocular lens (IOL) were enrolled in this research. Straylight was measured by a C-Quant straylight meter three to four weeks postoperatively. Five different modalities of IOL, including spherical/aspherical optics and hydrophobic/hydrophilic material were tested in this study. Normal as well as dilated pupils were used. The main outcome variable for straylight measurement was the logarithmic straylight parameter, log(s). RESULTS: The straylight parameter increased significantly after pupil dilation (P<0.05). Straylight of aspherical IOL was significantly higher after pupil dilation (P<0.05) compared to spherical IOL. In normal pupil, straylight of hydrophobic IOL was significant higher when compared with hydrophilic IOL (P<0.05). CONCLUSION: Straylight and visual acuity stand for the different aspects of visual function. Several factors including pupil diameter, optic material, aspherical design of IOL influence intraocular light scattering in pseudophakic eyes. Further investigation was needed to study the impact of optic material and optic surface design on pseudophakic straylight.

Abstract:AIM: To assess lens thickness measurements with anterior segment-optical coherence tomography (AS-OCT) in comparison with A-scan ultrasonography (A-scan US). METHODS: There were 218 adult subjects (218 eyes) aged 59.2±9.2y enrolled in this prospective cross-sectional study. Forty-three eyes had open angles and 175 eyes had narrow angles. Routine ophthalmic exam was performed and nuclear opacity was graded using the Lens Opacities Classification System III (LOCS III). Lens thickness was measured by AS-OCT (Visante OCT, Carl Zeiss Meditec, Dublin, CA, USA). The highest quality image was selected for each eye and lens thickness was calculated using ImageJ software. Lens thickness was also measured by A-scan US. RESULTS: Interclass correlations showed a value of 99.7% for intra-visit measurements and 95.3% for inter-visit measurements. The mean lens thickness measured by AS-OCT was not significantly different from that of A-scan US (4.861±0.404 vs 4.866±0.351 mm, P=0.74). Lens thickness values obtained from the two instruments were highly correlated overall (Pearson correlation coefficient=0.81, P<0.001), and in all LOCS III specific subgroups except in grade 5 of nuclear opacity. Bland-Altman analysis revealed a 95% limit of agreement from -0.45 to 0.46 mm. Lens thickness difference between the two instruments became smaller as the lens thickness increased and AS-OCT yielded smaller values than A-scan US in thicker lens (β=-0.29, P<0.001) CONCLUSION: AS-OCT-derived lens thickness measurement is valid and comparable to the results obtained by A-scan US. It can be used as a reliable noncontact method for measuring lens thickness in adults with or without significant cataract.

Abstract:AIM: To correlate corneal variables (determined using the Pentacam) with optic nerve head (ONH) variables determined using the Heidelberg retina tomograph (HRT) in healthy subjects and patients diagnosed with primary open angle glaucoma (POAG). METHODS: Measurements were made in 75 healthy eyes and 73 eyes with POAG and correlations examined through Pearson correlation coefficients between the two sets of variables in the two subject groups. The corneal variables determined were corneal volume (CVol), central corneal thickness (CCT), overall corneal thickness (OvCT), the mean thickness of a circular zone centered at the corneal apex of 1 mm radius (zone I) and the mean thickness of several concentric rings, also centered at the apex until the limbus, each of 1 mm width (zones II to VI respectively). The ONH variables were determined using the HRT. RESULTS: The following pairs of variables were correlated in the control group: CCT-disc area (DAr) (-0.48; P<0.0001), Zone I-DAr (-0.503; P<0.0001) and Zone II-DAr (-0.443; P<0.0001); and in the POAG group: CCT-cup-to-disc area ratio (CDRa) (-0.402; P<0.0001), Zone I-CDRa (-0.418; P<0.0001), Zone II-CDRa (-0.405; P=0.006), Zone I-cup shape measure (CSM) (-0.415; P=0.002), Zone II-CSM (-0.405; P=0.001), Zone IV-height variation contour (HVC) (0.378; P=0.002); Zone V-HVC (0.388, P<0.0001).CONCLUSION: AS-OCT-derived lens thickness measurement is valid and comparable to the results obtained by A-scan US. It can be used as a reliable noncontact method for measuring lens thickness in adults with or without significant cataract.

Abstract:AIM: To evaluate the long-term efficacy and safety results of viscocanalostomy and phacoviscocanalostomy. METHODS: The charts of 49 glaucoma patients who underwent viscocanalostomy or phacoviscocanalostomy surgery between February 1999 and August 2004 were reviewed retrospectively. Thirty-one eyes of 21 glaucoma patients who underwent filtering procedure with a postoperative follow-up of at least 5y were included in the study. Results of complete ophthalmologic examinations were recorded and statistically analyzed. Long-term surgical outcome was defined as an overall success when intraocular pressure (IOP) was found as ≤20 mm Hg with or without antiglaucomatous medication at the last follow-up visit, while it was defined as a complete success when IOP was measured ≤20 mm Hg without antiglaucomatous medication. RESULTS: Mean age was 68.1±9.6y (range: 32-81y). Mean follow-up time was 101.5±27.3mo (range: 60-144mo). Viscocanalostomy was performed in 8 eyes (25.8%) and phacoviscocanalostomy was performed in 23 eyes (74.2%). The mean preoperative IOP was 23.1±7.6 mm Hg with 2.1±1.0 medications, while mean IOP was 16.8±3.8 mm Hg with 0.9±1.1 medication at the last follow-up visit. Both the IOP decrease and the reduction in the antiglaucomatous medication were statistically significant (P<0.001 and P<0.001). No case required further glaucoma surgery. Overall success and complete success were found as 87.1% and 51.6%, respectively. Complete success rate was statistically higher in phacoviscocanalostomy group compared with the viscocanalostomy group (P=0.031), however there was no significant difference in overall success rate between two groups (P=0.072). CONCLUSION: Both viscocanalostomy and phacoviscocanalostomy provide good IOP reduction in the long-term period.

Abstract:AIM: To compare the intraoperative performance and postoperative outcome after microcoaxial torsional phacoemulsification using either a Kelman or balanced phaco tip. METHODS: Cataracts were treated using 2.2 mm microcoaxial torsional phacoemulsification using either a 45-degree mini-flared Kelman® or a 45-degree Intrepid® Balanced phaco tip. Intraoperative measurements included total ultrasound (US) time, cumulative dissipated energy (CDE), torsional US time, and balanced salt solution (BSS) use. The central endothelial cell density (ECD) and central corneal thickness (CCT) were evaluated preoperatively and postoperatively 1, 7, and 30d after surgery using noncontact specular microscopy. RESULTS: The 116 enrolled eyes (116 patients) were divided equally between the Kelman and balanced tip groups. Intraoperative measurements showed significantly less total US time, torsional US time, CDE, and BSS use in the balanced group than in Kelman group (P<0.05). The total US time, torsional US time, CDE, and BSS use were 17.45±14.53s, 16.63±13.97s, 6.38±5.26, and 48.21±17.21 mL in the Kelman group and 11.39 ± 9.60s, 10.90 ± 9.25s, 4.04 ± 3.42, and 41.36 ± 12.70 mL in the balanced group, respectively. CONCLUSION: Torsional phacoemulsification performed with a balanced tip provided more effective lens removal with less total US time, torsional time, CDE, and BSS use, as well as similar changes in ECD with a Kelman tip in all cataract grades. This special designed phaco tip for torsional phacoemulsification provides an alternative phaco tip for many surgeons' preference with straight phaco tip.

Abstract:AIM: To compare the visual outcomes (distance and near) in patients opting for three different types of monofocal intraocular lens (IOL) (Matrix Aurium, AcrySof single piece, and AcrySof IQ lens). METHODS: The present study is a cross-sectional analysis of secondary clinical data collected from 153 eyes (52 eyes in Matrix Aurium, 48 in AcrySof single piece, and 53 in AcrySof IQ group) undergoing cataract surgery (2011-2012). We compared near vision, distance vision, distance corrected near vision in these three types of lenses on day 15 (±3) post-surgery. RESULTS: About 69% of the eyes in the Matrix Aurium group had good uncorrected distance vision post-surgery; the proportion was 48% and 57% in the AcrySof single piece and AcrySof IQ group (P=0.09). The proportion of eyes with good distance corrected near vision were 38%, 33%, and 15% in the Matrix Aurium, AcrySof single piece, and AcrySof IQ groups respectively (P=0.02). Similarly, The proportion with good “both near and distance vision” were 38%, 33%, and 15% in the Matrix Aurium, AcrySof single piece, and AcrySof IQ groups respectively (P=0.02). It was only the Matrix Aurium group which had significantly better both “distance and near vision” compared with the AcrySof IQ group (odds ratio: 5.87, 95% confidence intervals: 1.68 to 20.56). CONCLUSION: Matrix Aurium monofocal lenses may be a good option for those patients who desire to have a good near as well as distance vision post-surgery.

Abstract:AIM: To compare the effectiveness and safety of pars plana capsulotomy and vitrectomy using 25-gauge tansconjunctival sutureless vitrectomy system and 20-gauge vitrectomy system for posterior capsule opacification (PCO) in pseudophakic children. METHODS: Retrospectively study. Pars plana capsulotomy and vitrectomy using 25-gauge sutureless vitrectomy system was performed for PCO in the study group (32 eyes). Patients in the control group (34 eyes) underwent capsulotomy and vitrectomy using standard 20-gauge vitrectomy system, providing a comparison between 2 groups with regard to preoperative and postoperative best corrected visual acuity (BCVA), intraocular pressure (IOP), and intraoperative and postoperative complications. The two groups were performed consequentially. The patients ages ranged from 2 to 13y (means: 6.61±2.73y). Surgical technique, intraoperative and postoperative complications, visual acuity, IOP, and recurrent PCO were recorded. RESULTS: The surgical procedure was performed uneventfully in all patients. Visual acuity improved significantly in both groups. BCVA improved in 22 eyes (81.5%) in the study group and in 28 eyes (87.5%) in the control group. There was no statistical difference of visual acuity that were attainable in two groups (H=0.115, P=0.909). Mean postoperative IOP showed no significant difference between the groups at 1wk. All sort of PCO were accomplished by 20-gauge system, while 25-gauge system was effective for pearls style and 2 grade of fibrous PCO, and was insufficient to grade 3 of PCO. In the study group two cases were not accomplished by 25-gauge system while 20-gauge system conquered them. Compared with the control group, mean operative time for opening and closing the sclerotomy in the study group was considerably reduced. The mean follow-up was 38.2mo (range: 8-79mo). During the follow-up period, no incision leakage, corneal edema, vitreous loss, IOL damage, retinal detachment, recurrent PCO, or other complications were noted. CONCLUSION: Pars plana capsulotomy and vitrectomy using 25-gauge transconjunctival sutureless vitrectomy appeared to be a safe and effective approach for PCO in pseudophakic children. Combined sutureless surgery needed shorter setup time for sclerotomy and caused less surgical trauma than combined surgery with 20-gauge vitrectomy. Therefore, this type of procedure would be a good option for selected cases with PCO in pseudophakic children.

Abstract:AIM: To determine the risk factors for acute endophthalmitis after cataract extraction in a tertiary care centre in India. METHODS: We performed a nested case control study within a retrospective cohort. The surgical records of all patients with clinically diagnosed endophthalmitis within one month after cataract surgery, performed between January 2006 and December 2009, were reviewed. These were compared with randomly selected age and gender-matched controls, from patients having routine cataract surgery within ±1wk of the endophthalmitis case. Univariable and multivariable analysis were performed to identify risk factors for endophthalmitis. RESULTS: Of the total 33 856 cataract surgeries performed during this period, there were 57 cases of postoperative acute endophthalmitis that met our study criteria. Thus, the overall incidence of endophthalmitis in our cohort was 1.6 per 1000 cataract extractions performed. Mean age of cases was 55.9y (SD: 10.9y) and for controls was 55.6y (SD: 9.8y). Thirty-five cases (61.4%) and 133 controls (59.6%) were males. Median time of onset of endophthalmitis was 4d (IQR 2-9d; range: 1-30d). Thirty-nine cases (68.4%) presented within 7d and 27 cases (47.4%) were culture positive. Two hundred and twenty-three age and gender matched controls were selected. In multivariate analysis, endophthalmitis was associated with posterior capsular rupture (PCR) during surgery (OR 6.98, 95%CI: 2.22-21.98), phacoemulsification via scleral incision with a foldable intraocular lens (IOL) implantation (OR 3.02, 95%CI: 1.13-8.04) and ocular co-morbidity (OR 2.32, 95%CI: 1.11-4.87). CONCLUSION: PCR, presence of ocular co-morbidity, and phacoemulsification via scleral incision with foldable-IOL were found to be independent risk factors for acute endophthalmitis.

Abstract:AIM: To measure the macular pigment optical density (MPOD) in healthy Chinese people and patients with early age-related macular degeneration (AMD). METHODS: Cross-sectional population based study. Demographic and lifestyle characteristics were ascertained by questionnaire. A food frequency questionnaire was completed for all participants. Participants underwent general physical and ophthalmic examinations and MPOD was measured by heterochromatic flicker photometry. Foveal architecture was measured by optical coherence tomography. RESULTS: MPOD of 225 participants (122 healthy and 103 early AMD) was 0.48±0.18. Patients with early AMD (0.52±0.19) tended to have higher MPOD levels than healthy people (0.47±0.17), but the difference was not statistically significant (P=0.06). Participants with carrot or corn oil intake every week tended to have higher levels of MPOD (P=0.002 and 0.008 respectively) while those with corn intake had relatively lower level of MPOD (P=0.01). MPOD increased with the center foveal thickness (P=0.01). CONCLUSION: Our findings show that there is no statistically significant association between MPOD and early AMD in the studied population. MPOD is related to center foveal thickness and diets would influence MPOD levels.

Abstract:AIM: To investigate the difference of macular thickness measurements between stratus optical coherence tomography (OCT) and Cirrus OCT (Carl Zeiss Meditec, Dublin, CA, USA) in the same myopic patient and to develop a conversion equation to interchange macular thickness obtained with these two OCT devices. METHODS: Eighty-nine healthy Chinese adults with spherical equivalent (SE) ranging from -1.13 D to -9.63 D were recruited. The macular thickness was measured by Cirrus OCT and Stratus OCT. The correlation between macular thickness and axial length and the agreement between two OCT measurements were evaluated. A formula was generated to interchange macular thickness obtained with two OCT devices. RESULTS: Average macular thickness measured with Stratus OCT (r=-0.280, P=0.008) and Cirrus OCT (r=-0.224, P=0.034) were found to be negatively correlated with axial length. No statistically significant correlation was found between axial length and central subfield macular thickness (CMT) measured with Stratus OCT (r=0.191, P=0.073) and Cirrus OCT (r=0.169, P=0.113). The mean CMT measured with Cirrus OCT was 53.63±7.94 μm thicker than with Stratus OCT. The formula CMTCirrus OCT=78.328+0.874×CMTStratus OCT was generated to interchange macular thickness obtained with two OCT devices. CONCLUSION: Macular thickness measured with Cirrus OCT were thicker than with Stratus OCT in myopic eyes. A formula can be used to interchange macular thickness measured with two OCT devices in myopic eyes. Studies with different OCT devices and larger samples are warranted to enable the comparison of macular values measured with different OCT devices.

Abstract:AIM: To evaluate the relationship between intravitreal bevacizumab (IVB) treatment and the levels of vitreous vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and vitreous-retina surface fibrosis in patients with proliferative diabetic retinopathy (PDR). METHODS: This study was a prospective, open-label, controlled, randomized clinical trial. Sixty-eight eyes of PDR patients (n=53) and macular hole patients (n=15) were enrolled in this study. Thirty-four eyes of the PDR patients received IVB before vitrectomy. Twenty-three of the 34 PDR patients received IVB treatment 5d before vitrectomy (subgroup a), and 11 of the 34 PDR patients received IVB treatment greater than 2wk prior to vitrectomy (subgroup b). Nineteen of the PDR patients did not receive IVB treatment at any time prior to vitrectomy. The levels of bFGF and VEGF in vitreous samples were measured using enzyme-linked immunosorbent assay (ELISA) and the degree of vitreoretinal fibrosis was characterized using clinical data and data obtained intra-operatively. RESULTS: In PDR patients, VEGF and bFGF levels were significantly increased compared to non-PDR (control) subject’s eyes (P<0.01). In PDR patients, vitreous VEGF levels were significantly decreased following IVB treatment compared to PDR patients that did not receive IVB treatment (P<0.01). The degree of vitreoretinal fibrosis was significantly increased in subgroup b compared to subgroup a(P<0.05) and to patients that did not receive IVB (P<0.05). Vitreous bFGF levels were significantly greater in subgroup b than subgroup a (P<0.01) or in patients who did not receive IVB treatment (P<0.05). A Spearman’s rank correlation test indicated that higher levels of vitreous bFGF, but not VEGF, correlated with the degree of vitreoretinal fibrosis. CONCLUSION: We found that bFGF levels increase in PDR patient’s vitreous after IVB treatment longer than two weeks prior to vitrectomy and correlated with the degree of fibrosis after IVB treatment. These findings suggest vitreous fibrosis is increased in PDR patients after IVB treatment may be due to increased levels of bFGF.

Abstract:AIM: To analyze the low weight gain (WG) from birth to 4 and 6wk of life to predict the development of retinopathy of prematurity (ROP) among very low birth weight (VLBW) preterm babies. METHODS: Three hundred and three newborns with VLBW were analyzed. Body weight measurements were recorded weekly. In all patients, the proportion of the WG was defined as the preterm weight measured at the 4th and 6th weeks of life minus the birth weight (BW) divided by the BW. Other risk factors for ROP were also analyzed. RESULTS: Mean gestational age and mean BW of the whole cohort were 29.56±1.44wk and 1270.58±176.18g respectively. WG proportion at 4wk postnatal age (18.89%±13.58%) were significantly lower in infants with ROP (P=0.003). WG proportion at 6wk was not different between ROP and no ROP group (42.48%±20.36% vs 46.43%±15.65% P=0.118). When all the other risk factors signi?cant for ROP were included in the logistic regression poor WG did not arise as an independent risk factor. Area under the ROC curve was 0.591 (95%CI: 0.515-0.666; P=0.016). For ROP, the best discriminative cutoff of 18.06% of the proportional WG at the 4th week over the BW, sensitivity and specificity values were 67.3% and 50.0% respectively. CONCLUSION: Low WG proportion in the first 4wk of life is maybe an additional predictor of ROP in very low BW infants. Preterm babies with low BW and low WG proportion should be followed closely for ROP.

Abstract:AIM: To investigate the difference of retinal nerve fiber layer (RNFL) thickness and macular fovea thickness/volume between multiple sclerosis (MS) patients and healthy normal individuals using optical coherence tomography (OCT) and assess its association with visual field parameters. METHODS: Thirty consecutive MS patients and 28 healthy controls were recruited in this prospective study. Comprehensive standardized ophthalmic examinations included visual acuity, cycloplegic refraction, intraocular pressure, gonioscopy, visual field, and RNFL thickness and macular fovea thickness/volume detection using Humphrey OCT. Mean values for the thickness of the peripapillary RNFL and macular volume were calculated. Associations between visual field parameters and RNFL thickness/macular volume were analyzed by Pearson correlation analysis. RESULTS: The RNFL thicknesses in each quadrant, the average macular thickness, and the average macular volume in MS patients were all less than those in healthy controls, with statistically significant differences. The RNFL thickness and macular fovea thickness/volume were greater in eyes without optic neuritis than in eyes with optic neuritis. The average visual field parameters had positive correlations with the RNFL thickness and negative correlations with macular parameters in MS patients. CONCLUSION: OCT measurements can effectively identify the nerve changes of MS patients, which provide more data for the diagnosis of MS.

Abstract:AIM: To describe the clinical features, systemic associations, treatment and visual outcomes in Saudi patients with scleritis. METHODS: A retrospective chart review was performed for patients with scleritis presenting to two tertiary care eye hospitals in Riyadh, Saudi Arabia, from 2001 to 2011. Data were collected on the clinical features of scleritis, subtypes of scleritis, associated systemic disease, history of previous ocular surgery and medical therapy, including the use of immunosuppressants. Treatment outcomes were evaluated based on best-corrected visual acuity (BCVA) and response to treatment. RESULTS: Of the 52 patients included in the study, non-necrotizing anterior scleritis was the most common type of scleritis in 22 patients (42.3%), followed by posterior scleritis in 14 patients (26.9%). The majority of cases, 31 patients (59.6%), were idiopathic in nature. Systemic associations were present in 12 patients (23.1%). Infectious scleritis was confirmed in 6 patients (11.5%): 3 with bacterial scleritis after pterygium excision, 2 patients with scleritis related to tuberculosis and 1 patient with scleritis resulting from herpes simplex infection. For the various subtypes of scleritis, BCVA values after treatment and time to remission significantly differed (P<0.05, all cases). Systemic immunosuppressive therapies in addition to steroids were administered to 46.2% of all patients. The T-sign was present on B-scan ultrasonography in 9 (64.3%) of the 14 posterior scleritis patients. CONCLUSION: Non-necrotizing anterior scleritis was the most common subtype of scleritis. Final visual outcome and time to remission differed among the various scleritis subtypes.

Abstract:AIM: To compare the conjunctival epithelial toxicities of three newer-generation fluoroquinolones without preservatives. METHODS: In a prospective, randomized, double blind comparative study, 47 eyes of 47 patients with a primary pterygium were enrolled, and divided randomly into three groups (levofloxacin 0.5%, gatifloxacin 0.3%, and moxifloxacin 0.5%). After pterygium surgery with the same conjunctival autograft technique, each patient maintained a regimen with a randomly assigned fluoroquinolone eye drop. Patients were examined every other day after surgery until the epithelium had completely healed. Photos were taken and used to measure the area of residual epithelial defects. Conjunctival healing time and speed (initial defect area/healing time (mm2/d) compared in each group using Kruskal-Wallis tests. RESULTS: There were no significant differences in mean age, gender, and conjunctival defect size of the donor site between these groups. However, the mean of conjunctival healing time and speed were statistically different in each group. The mean of conjunctival epithelial healing time was 8.93±2.69d (levofloxacin group), 10.31±2.96d (gatifloxacin group), and 13.50±4.10d (moxifloxacin group), P=0.006. The mean conjuctival epithelial healing speed was 6.18±1.39 mm2/d (levofloxacin group), 5.52±1.68 mm2/d (gatifloxacin group), and 4.40±1.30 mm2/d (moxifloxacin group), P=0 .003. CONCLUSION: Without the influence of preservatives, levofloxacin and gatifloxacin might be less toxic to the regeneration of conjunctival epithelial cells and cause a faster conjunctival wound healing relative to moxifloxacin.

Abstract:AIM: To investigate the influencing factors of visual field improvement after trans-sphenoidal resection of pituitary macroadenomas. METHODS: This retrospective cohort study included 201 patients (366 eyes) with visual field defect induced by pituitary macroadenomas. All of them were treated with trans-sphenoidal surgery. Ophthalmologic evaluation, best-corrected visual acuity (BCVA), and visual field examination were performed before and 3mo after surgery. BCVA, visual field defect index mean deviation (MD), duration of symptoms, age, sex, and volume of tumors were compared. Expression of vascular endothelial growth factor (VEGF) and Ki-67 of tumor tissue were detected by immunohistochemical technique. RESULTS: The mean age of patients was 44.23±1.29y. Ninety-three patients were female and 108 were male. The mean tumor volume was 14.36±6.23 cm3. The mean duration of preoperative symptoms was 11.50±0.88mo. Mean preoperative MD was -17.50±0.82 dB. Mean Preoperative visual acuity was 0.64±0.04. Postoperative visual field improved in 270 (73.77%) eyes, unchanged in 96 (26.23%) eyes. Multivariate logistic regression displayed that the factors independently influencing visual field improvement were young age (OR=1.71, 95%CI: 1.325-2.387, P=0.013), low preoperative MD absolute value (OR=1.277, 95%CI: 1.205-1.355, P<0.001), small volume of tumor (OR=1.458, 95%CI: 1.060-4.289, P<0.001), low expression of VEGF in tumor tissue (OR=1.554, 95%CI: 1.089-2.457, P=0.022), and low expression of Ki-67 in tumor tissue (OR=1.552, 95%CI: 1.161-2.847, P=0.026). CONCLUSION: After pituitary macroadenomas trans-sphenoidal resection, the independent influencing factors of the visual fields recovery were low preoperative MD absolute value, young age, small volume of tumor, and expression levels of VEGF/ Ki-67.

Abstract:AIM: To determine the visual outcomes in adult patients who sustained open globe injuries and to determine whether the visual prognosis following an eye injury in an African setting differs from the predicted outcomes according to the Ocular Trauma Score (OTS) study. A secondary aim was to establish the evisceration rate for these injuries and assess how this form of intervention affected outcomes in comparison to the OTS. METHODS: A prospective case series of all patients admitted with open globe injuries over a two-year (July 2009 to June 2011) period. Injuries were scored using the OTS and the surgical intervention was recorded. The best corrected visual acuity at three months was regarded as visual outcome. RESULTS: There were 249 open globe injuries, of which 169 patients (169 eyes) completed the 3-month follow-up. All patients underwent primary surgery, 175 (70.3%) repairs, 61 (24.5%) eviscerations and 13 (5.2%) other procedures. Globe eviscerations were mainly done on OTS Category 1 cases, but outcomes in this category were not found to be different from OTS outcomes. Outcomes were significantly worse in Category 2, but when the entire distribution was tested, the differences were not statistically significant. The overall association between OTS outcomes and the final visual outcomes in this study was found to be a strong (P<0.005). CONCLUSION: Reliable information regarding the expected outcomes of eye injuries will influence management decisions and patient expectations. The OTS is a valuable tool, the use of which has been validated in many parts of the world-it may also be a valid predictor in an African setting.

Abstract:AIM: To compare the effects of intravitreal injection of bevacizumab (IVB) with intravitreal triamcinolone acetonide (IVTA) on the treatment of cystoid macular edema (CME) secondary to retinal vein occlusion (RVO). METHODS: A literature search was conducted using PubMed, the Cochrane Central Register of Controlled Trials, Web of Science and the Chinese Biomedical Database. The comparison was divided into two groups, group 1 conducted comparison in branch RVO (BRVO) or central RVO (CRVO), group 2 conducted comparison in ischemic-RVO or nonischemic-RVO. Pooled mean differences (MDs) for changes in visual acuity (VA), central macular thickness (CMT) and intraocular pressure (IOP) were calculated in groups at 4, 12 and 24wk after treatment respectively. RESULTS: Eight studies comparing the efficacy of IVB with IVTA were included in the Meta-analysis. In group 1, in BRVO, significant difference was shown on the comparison of CMT at 24wk (MD, -45.66; 95% CI, -76.03 to -15.28; P=0.003), IVB was effective on BRVO for at least 24wk; no significant differences were found in the comparison of VA at each time points (P>0.05 respectively). In CRVO, no significant differences were found in the comparison of VA or CMT between IVB and IVTA at each time points (P>0.05, respectively). In group 2, in ischemic-RVO, significant differences were shown in the comparison of VA (MD, -0.28; 95% CI, -0.42 to -0.14; P<0.0001) and CMT (MD, -86.50; 95% CI, -151.18 to -22.43; P=0.008) at 24wk; In nonischemic-RVO, no significant differences were demonstrated in the comparison of VA or CMT between IVB and IVTA at each time points (P>0.05, respectively). The occurrence of high IOP was much lower in IVB group. CONCLUSION: This Meta-analysis suggested that IVB was effective in decreasing CMT in BRVO for at least 24wk, IVB is more effective on improving VA and reducing CMT in ischemic-RVO. IVB is more promising on RVO than IVTA.

Abstract:AIM: To measure optic nerve sheath diameters (ONSD) in different locations by computer tomography (CT) and to recommend the best location for cases when ONSD is used for intracranial pressure monitoring. METHODS: In a prospective cohort study, CT data of 300 healthy adults were analyzed (600 eyes). In all cases, the CT investigation was performed at the Emergency Department because of the various conditions that proved not to be connected with ophthalmological or neurological pathology. The ONSD were measured at 3 mm and 8 mm distance from the globe, and 3 mm from the anterior opening of the optic canal. The correlation analysis was performed with gender, age, and ethnic background. RESULTS: The right/left ONSD are 4.94±1.51/5.17±1.34 mm at 3 mm, 4.35±0.76/4.45±0.62 mm at 8 mm from the globe, and 3.55±0.82/3.65±0.7 mm at 3 mm from the optic canal. No significant differences correlated with gender of the patients, their age, and ethnic background were found. CONCLUSION: In healthy persons, the ONSD varies from 5.17±1.34 mm to 3.55±0.82 mm in different locations within the intraorbital space. The most stable results with lesser standard deviation can be obtained if it is measured 8-10 mm from the globe.

Abstract:Dark adaptation is a highly sensitive neural function and may be the first symptom of many status including the physiologic and pathologic entity, suggesting that it could be instrumental for diagnose. However, shortcomings such as the lack of standardized parameters, the long duration of examination, and subjective randomness would substantially impede the use of dark adaptation in clinical work. In this review we summarize the recent research about the dark adaptation, including two visual cycles-canonical and cone-specific visual cycle, affecting factors and the methods for measuring dark adaptation. In the opinions of authors, intensive investigations are needed to be done for the widely use of this significant visual function in clinic.

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