Axial length, myopia progression, and myopic maculopathy in Stickler syndrome

We lack knowledge on the potentially progressive nature of and the prevalence of complications to myopia as a characteristic trait of Stickler syndrome.

This cross-sectional study combines ophthalmic examination and medical record data on Danish patients with genetically confirmed Stickler syndrome type 1 (COL2A1) and type 2 (COL11A1). The main outcomes are axial length, spherical equivalent refraction (SER), SER over time, and myopic maculopathy category by fundus photography.

The study includes 71 patients with type 1 (age: median = 29 years, IQR = 15-49 years; 44% male) and 13 with type 2 Stickler syndrome (age: median = 27 years, IQR = 9-33 years; 69% male). For type 1, the median SER was -6.00 dioptres (D) (IQR = -8.88 to -2.19 D) and -6.75. (IQR = -10.88 to -1.94) for type 2, (p = 0.52). Mean axial length was 25.99 ± 1.99 and 26.55 ± 3.45 mm, respectively (p = 0.57). SER was nonprogressive in childhood in both subtypes. Myopic maculopathy was present in 28 (43%) type 1 and five (42%) type 2 patients. The odds for higher category myopic maculopathy increased by a factor of 2.15 with each mm of axial elongation (95% CI = 1.14 to 4.04, p = 0.02) but not with age (odds ratio = 1.02 per year, 95% CI = 0.97 to 1.09, p = 0.39) in type 1.

We find myopia in our cohort is nonprogressive. We find no difference in axial length or refractive error between subtypes. Myopic maculopathy is common, its severity depending on axial length, not age. These findings are relevant for risk stratification of vision-threatening myopia.