Purpose: To investigate foveal morphologic parameters related to visual acuity and the stages classified in this study reflect the severity of the macular pseudohole (MPH).
Methods: Seventy-eight eyes of 78 consecutive patients diagnosed with MPH were studied. Quantitative optical coherence tomography (OCT) parameters including central foveal thickness, parafoveal thickness, parafoveal inner and outer retinal thickness (PIRT and PORT), pseudohole depth, pseudohole diameter, and inner nuclear layer (INL) angulation were measured and the morphologic features of the inner retina (disorganization of retinal inner layers (DRIL)) and the photoreceptor layer (external limiting membrane (ELM), ellipsoid zone (EZ), interdigitation zone (IZ), and cotton ball sign) were determined. Associations between OCT parameters and best-corrected visual acuity (BCVA) were analyzed. Based on the location of the inner margin of INL, all patients were divided into three stages and the mean comparison between the three stages was analyzed.
Results: PIRT (r = 0.6489; p < 0.0001) and pseudohole depth (r = 0.5266; p < 0.0001) had a statistically significant correlation with BCVA. Statistically significant visual acuity differences were found in eyes with DRIL (p < 0.001) and IZ disruption (p = 0.018), but not in ELM disruption (p = 0.916), EZ disruption (p = 0.581), and cotton ball sign (p = 0.075). According to the univariate and multivariate regression analyses, PIRT was associated with BCVA in both univariate (p < 0.001) and multivariate (p = 0.002) regression analyses. Defect diameters of both ELM (p = 0.025) and IZ (p = 0.006) were associated with BCVA in univariate regression analysis, but not in multivariate regression analysis. INL angulation and the ratio of the IZ disruption was significantly different in the three groups. Stage 3 (95.8%) had significantly higher disrupted IZ ratio than stage 1 (40%) and stage 2 (65.5%). The BCVA of stages 1, 2, and 3 were identified as 0.06 ± 0.07 (20/23 Snellen equivalent), 0.23 ± 0.17 (20/34 Snellen equivalent), and 0.48 ± 0.23 (20/60 Snellen equivalent), respectively, and the differences in BCVA between the three groups were significant (p < 0.0001).
Conclusion: The parameters related to visual acuity were PIRT, pseudohole depth, DRIL, and IZ. The stage classification proposed in this study included morphologic changes of the inner retina and photoreceptor layer and is likely to be clinically useful for showing the severity of the MPH.
Keywords: Epiretinal membrane; Inner nuclear layer angulation; Macular pseudohole; Parafoveal inner retina.