Fixation characteristics among subjects with diabetes: SN-DREAMS II, Report No. 5

To evaluate fixation and scotoma characteristics among subjects with diabetes in a population-based study.

Cohort study.

A subset of 357 subjects was recruited from follow-up cohort of Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular Genetics Study I.

All subjects underwent detailed ophthalmic evaluation including microperimetry and spectral domain optical coherence tomography. Fixation parameters such as stability of fixation, fixation location, and presence of scotoma were evaluated. A p value less than 0.05 was considered statistically significant.

The mean age of the study sample was 56.86 ± 8.63 years. Relatively unstable fixation was observed in 73 and poor central fixation in 25 subjects. Among subjects with poor central fixation, 72% (18 subjects) had relatively unstable fixation. Poor central and relatively unstable fixation were significantly associated with best corrected visual acuity (BCVA; p = 0.002 and p = 0.017, respectively). Prevalence rate of scotoma was 24.4%, which was highly prevalent in females (p = 0.035) and among subjects with reduced BCVA (p < 0.001), reduced contrast sensitivity (p < 0.001), cataract (p < 0.001), impaired retinal sensitivity (p < 0.001), and presence of sight-threatening diabetic retinopathy (STDR; p < 0.001). Presence of scotoma was significantly associated with abnormal foveal contour (p = 0.046) and altered inner retinal layers (p < 0.001).

We report that fixation characteristics are independent of ocular characteristics except for BCVA. Female sex, reduced visual acuity and contrast sensitivity, cataract, and STDR were significantly associated with presence of scotoma.