Visual Acuity in Pathological Myopia Is Correlated With the Photoreceptor Myoid and Ellipsoid Zone Thickness and Affected by Choroid Thickness

Abstract

PURPOSE. To quantify the thickness of the outer retinal sublayers and choroid in pathological myopia and examine associations between these factors and best-corrected visual acuity (BCVA). METHODS. The cohort was composed of 21 eyes with emmetropia and 70 eyes with high myopia (49 simple high myopia; 21 pathological myopia). Optical coherence tomography images were segmented to determine macular thicknesses of the choroid and the following outer retinal sublayers: outer plexiform layer (OPL), Henle fiber layer and outer nuclear layer (HFL þ ONL), myoid and ellipsoid zone (MEZ), outer segment of photoreceptors (OS), and interdigitation zone and RPE/Bruch complex (IZ þ RPE). Correlations between BCVA and thickness of the outer retinal sublayers and choroid were determined. RESULTS. In pathological myopia, the choroid, HFL þ ONL, MEZ, and IZ þ RPE were thinner than in emmetropia and simple high myopia (P < 0.05). Simple and multiple regression models showed that MEZ thickness was correlated with BCVA (both P < 0.001). The relationship between MEZ thickness and BCVA varied with choroidal thickness (P ¼ 0.006). For a constant MEZ thickness, thinner choroids were associated with worse vision. In the final multiple regression predictive model, MEZ thickness, choroidal thickness, and interaction between MEZ and choroidal thickness (all P < 0.001) were predictors of BCVA. CONCLUSIONS. Outer retinal alterations, especially thinning of the MEZ, occurred in pathological myopia. The MEZ thickness was associated with BCVA, and this relationship was affected by choroidal thickness.

Photoreceptor Degeneration is Correlated With the Deterioration of Macular Retinal Sensitivity in High Myopia

“…Photoreceptor morphological and functional degeneration in myopia has been reported in previous studies 6- 13 and was hypothesized to be the main reason for visual impairment. 6 For instance, ERG examinations have documented decreasing bwave amplitudes in myopic eyes, indicating photoreceptor dysfunction.…”

“…Custom-developed software was used to analyze the OCT images. 13,16,17 Bennett's formula, t ¼ p 3 q 3 s, was used to correct the image magnification before calculating the thickness of outer retina and choroid. Based on the AL, the calculation shows the relationship between the OCT-imaged measurement and the actual scan range, where t indicated the actual scan length, p was the magnification factor of the OCT imaging system camera, q was the magnification factor related to the eye AL, and s indicated the original measurement value from the OCT image.…”

“…The development of high-resolution imaging techniques, such as adaptive optics (AO) and optical coherence tomography (OCT), has enabled noninvasive imaging and in vivo analysis of retinal structure. 10,[13][14][15][16] In previous studies of HM, decreased cone packing density was assessed with AO, 10,15 and thinning of the outer retinal thickness was measured with OCT. 13,14,16 In the current study, we used both imaging modalities in myopia eyes to assess photoreceptor morphological alterations. The associations in myopia between macular light sensitivity (MLS), photoreceptor morphology, choroidal thickness, axial length (AL), and other variables were further analyzed to estimate visual function from the fundus structural information acquired by AO and OCT.…”

Characterization of the Three Distinct Retinal Capillary Plexuses Using Optical Coherence Tomography Angiography in Myopic Eyes

“…The position of the MCP was lower in the super-high myopia group than in the control group. Liu et al 27 and Ye et al 39 found that the Henle fiber layer and ONL, which comprise the largest portion of the retina, became thinner with the progression of myopia, and the inner nuclear layer showed the same changes. This change may explain why the position of the MCP declined.…”

“…This lack of a difference may be related to thickening of the outer plexiform layer (OPL) as myopia progresses. 27,39 Although the thickness of the Henle fiber layer and ONL decreases with the progression of myopia, the thickening of the OPL counteracts some of these effects, and the reduction in the inner nuclear layer, which affects the location of the MCP, does not influence the location of the DCP.…”