Classification of early dry-type myopic maculopathy with macular choroidal thickness

Purpose: To compare the macular choroidal thickness in 2 types of early dry-type myopic maculopathy.

Design: Prospective, observational, comparative study.

Methods: Patients with a refractive error of less than -8 diopters were included and were classified into 2 groups. Group 1 consisted of 24 eyes with a tessellated fundus, and group 2 consisted of 33 eyes with diffuse chorioretinal atrophy, but not to the extent of patchy chorioretinal atrophy. These 2 groups were compared with regard to their clinical characteristics, refractive error, axial length, macular choroidal thickness, and best-corrected visual acuity (BCVA). Linear regression was used to evaluate the explanatory variables in terms of macular choroidal thickness and BCVA.

Results: Patients in group 1 were significantly younger and had better BCVA, less myopia, shorter axial length, and less staphyloma than those in group 2. Refractive error, axial length, and BCVA correlated significantly with macular choroidal thickness in group 2. However, no such significant correlations were observed in group 1. Multiple linear regression analysis showed that age and macular choroidal thickness were the variables that associated most strongly with BCVA, whereas neither refractive error nor axial length was a significant predictor of BCVA. In group 2, eyes with lacquer cracks showed worse BCVA and thinner macular choroidal thickness than eyes without lacquer cracks.

Conclusions: Macular choroidal thickness is an important factor in myopic maculopathy and can be a better indicator of its severity. These findings suggest that BCVA reduction in eyes with dry-type myopic maculopathy can be related to a thinner macular choroidal thickness and to the development of lacquer cracks.