Abstract:AIM: To investigate the application of optical coherence tomography angiography(OCTA)in observing the relationship between corneal topographic changes and retinal vessel density and thickness in myopic adolescents after wearing orthokeratology lenses.
METHODS:Myopic adolescents who treated and wore orthokeratology lenses in our hospital between January and December 2023 were selected for the study, and their clinical data were retrospectively analyzed. Totally 50 cases(50 eyes)of toric orthokeratology lenses(toric group)and 50 cases(50 eyes)of spherical orthokeratology lenses(spherical group)were selected. Changes in corneal topographic indices, retinal vascular density and retinal thickness were examined in the two groups before and at 3 and 6 mo after wear. The relationship between corneal topographic indexes and retinal vessel density and thickness was analyzed.
RESULTS: Compared with the pre-wear, average value of ks and kf(Avek)was significantly lower(all P<0.05), and surface regularity index(SRI)and surface asymmetry index(SAI)were significantly increased(both P<0.05)in the two groups at 3 and 6 mo post-wear. Compared with the pre-wearing period, deep retinal vessel density in whole macular area and superficial retinal vessel density in paracentral retina of macula were significantly higher in the two groups at 3 and 6 mo after wearing(both P<0.05), and the superficial retinal vessel density in macular fovea and paracentral fovea of macula of the toric group was significantly higher(all P<0.05), and the superficial retinal vessel density in paracentral macular fovea of the spherical group was significantly increased(all P<0.05). Compared with the pre-wearing period, the thickness of retina in whole macula and paracentral retina of the macula was significantly increased in the both groups at 3 and 6 mo post-wearing(all P<0.05). After wearing lenses for 3 mo, the Avek of the toric group was negatively correlated with the deep vascular density in whole macular area and paracentral macular fovea, the superficial vascular density in macular fovea and paracentral macular fovea, and the thickness of whole macular and paracentral macular fovea(all P<0.05). The SRI and SAI were positively correlated with the superficial retinal vascular density in macular fovea and paracentral macular fovea, and the retinal thickness in whole macular area and paracentral macular fovea(all P<0.05). The spherical group showed a negative correlation between Avek and the deep retinal vessel density in whole macular area and paracentral macular fovea, as well as the superficial retinal vessel density in paracentral macular fovea after wearing lenses for 3 mo(all P<0.05). SRI and SAI were positively correlated with the deep retinal vessel density in whole macular area, macular fovea and paracentral macular fovea, and the superficial retinal vessel density in paracentral macular fovea(all P<0.05). SRI was positively correlated with the retinal thickness in whole macular area(P<0.05), and SAI was positively correlated with the retinal thickness in paracentral macular fovea(P<0.05).
CONCLUSION: After wearing toric and spherical corneal orthokeratology lenses, the corneal topography of myopic adolescents changes, and the retinal blood flow density and retinal thickness increase significantly, improving retinal blood circulation. Moreover, there is a significant correlation between changes in corneal topography and retinal blood flow density and retinal thickness, which has certain guiding significance for the control of myopia.
