Changes of subfoveal choroidal thickness after treated by Ranibizumab for choroidal neovascularization secondary to pathologic myopia

Abstract:

AIM:To observe the change of subfoveal choroidal thickness(SFCT)after intravitreal injections of anti-vascular endothelial growth factor monoclonal antibody Ranibizumab in patients with choroidal neovascularization(CNV)secondary to pathologic myopia(PM)and to research the relation between visual acuity and SFCT.

METHODS:This was a prospective, contrast, open-label study.Fifty pathologic myopia patients with CNV(50 eyes)were recruited in this study. Before the injection,best-corrected visual acuity detected by visual chart from Early Treatment of Diabetic Retinopathy Study(ETDRS),non-contact tonometer,ophthalmoscope,fundus photography, fundus fluorescein angiograph(FFA)and optical coherence tomography(OCT)examination were necessary. All affected eye were treated with intravitreal ranibizumab 0.05mL. Following up for 12mo, the changes of visual acuity and SFCT were compared before and after treatment, also the relation between them.

RESULTS:All eyes received an average of 2.47±2.23 injections,the final vision of follow-up increased by 13.62±8.98 letters than that before(t=6.69,P<0.05). The SFCT before therapy, 1, 6 and 12mo after treatment were 81.48±61.62, 79.63±60.98, 77.92±61.26 and 78.34±59.48μm and respectively decreased by 2.09±8.93, 3.68±7.42, 3.16±6.95μm compare to pre-treatment.The difference on SFCT at 1mo was not significant compared to before treatment(t=0.95, P>0.05).While after 6 and 12mo,the differences were significant(t=2.34, 2.61; P<0.05). Twenty-four eyes(48%)were with recurrence, mean recurrence times were 1.39±1.23. The SFCT increased from 75.7±51.6μm at 1mo to 84.4±55.9μm(by 11.5%)when recurred, there were significant differences(P<0.05). Twenty-six eyes(52%)were not with recurrence. The SFCT at 1, 6 and 12mo after treatment were 85.3±52.7, 83.6±50.5 and 84.2±54.2μm, there were no significant differences with multiple comparison(P>0.05).There were no serious systemic or local side effects during the follow up.

CONCLUSION:Intravitreal ranibizumab for CNV secondary to pathologic myopia is safe and can improve the visual acuity.Intravitreal injections of ranibizumab can induce SFCT reduction for CNV secondary to pathologic myopia.We hypothesized that increase of SFCT may be one of evaluation index for CNV activity.

Key words:pathologic myopia; ranibizumab; choroidal neovascularization; subfoveal choroidal thickness; optical coherence tomography; Early Treatment of Diabetic Retinopathy Study