Association Between Visual Acuity and the Corneal Area Occupied by Granular Lesions, Linear Lesions, or Diffuse Haze in Patients With Granular Corneal Dystrophy Type 2

Purpose: In granular corneal dystrophy type 2 (GCD2), corneal deposits containing fragments of transforming growth factor-b–induced protein appear in sequence as granular lesions (GLs), linear lesions (LLs), and diffuse haze (DH). We aimed to investigate the association between visual acuity and age-related changes in lesion types in patients with GCD2. Methods: We retrospectively evaluated the medical records and slit-lamp photographs of 533 patients (1066 eyes) with genetically confirmed GCD2 (heterozygous). Deposits were classified into GLs, LLs, and DH, after which the area occupied by each lesion type was measured. The associations between visual acuity and each lesion area were also evaluated using univariable and multivariable models. Results: The area occupied by GLs increased beginning in the teen years, whereas the area occupied by DH began to increase after age 40. However, the area occupied by LLs increased until patients had reached their 40s, after which no further increases occurred. Multivariable analyses revealed no association between GLs and low visual acuity after adjusting for age and sex. Increases in the LL area were associated with lower odds for low visual acuity (adjusted odds ratio = 0.4 for the third tertile, 95% confidence interval, 0.2–0.97), whereas increases in the DH area were positively associated with low visual acuity (adjusted odds ratio = 3.3 for the third tertile of the DH area, 95% confidence interval, 1.3–8.3). Conclusions: Our findings indicated that LLs associated with GCD2 do not produce significant decreases in visual acuity, whereas DH exerts the most significant negative impact on visual acuity. Late-onset DH may be associated with the termination of LL formation.