Visual Acuity, and Macular and Peripapillary Thickness in High Myopia

Abstract

Purpose: To investigate best corrected visual acuity (BCVA), and choroidal and retinal thickness values between high myopes without myopic maculopathy and emmetropes.

Materials and methods: Case control study where 53 myopes with axial length (AL) above 26 mm without myopic maculopathy and 53 age-matched emmetropes with AL between 21.50 and 24.50 were included as controls. Complete ophthalmological examination and biometry were performed. Choroidal and individual retinal layer thickness maps using spectral domain optical coherence tomography were obtained in the macular and peripapillary area with enhanced depth imaging. Peripapillary retinal nerve fiber layer (pRNFL) thickness was obtained using the circular 12°diameter scan.

Results: Mean age was 31.9 ± 9.9 and 32.5 ± 9.3 years in the myopes and controls, respectively (p > 0.05). Mean BCVA was 55.32 ± 2.50 versus 57.04 ± 2.27 ETDRS letters, in the myopes and controls, respectively (p = 0.0004). AL was the principal predictive factor for macular and peripapillary CT in myopes and macular CT in controls. BCVA was not influenced by choroidal thickness (CT). BCVA positively correlated with global pRNFL, following correction for age and AL, in both groups (r = 0.38, p = 0.008 and r = 0.38, p = 0.007 in the myopic and control groups, respectively). Statistical analysis following correction for the potential confounding factors of age, gender, AL, gender, AL, macular CT, and peripapillary CT, showed no significant differences in macular and peripapillary thicknesses between the two groups.

Conclusions: AL is the principal predictive factor for macular and peripapillary CT in high myopes without maculopathy, and CT is not an independent predictor of visual acuity. Global pRNFL thickness is the only independent predictive factor of BCVA.

Keywords: Axial length; choroidal thickness; macular thickness; myopia; peripapillary thickness; retinal nerve fiber layer; spectral domain optical coherence tomography.