Analysis of retinal nerve fiber layer thickness in cognitive impairment

Introduction: Cognitive impairment may be present at birth or can occur later in adulthood. Few studies have shown correlation of cognition with retinal nerve fiber layer thickness (RNFL). The present study was planned to analyse RNFL thickness in disorders of cognition. Materials and Methods: 60 eyes of cognitive impairment were included. All patients underwent RNFL thickness measurement by OCT at initial visit and after 3 months. Statistical analysis was done with a p value less than 0.05 to be significant. Results: 60 eyes of cases of cognitive impairment were included. 16 (53%) cases had cognitive impairment following traumatic brain injury and 14 (47%) cases were secondary to Alzheimer's disease. The mean RNFL thickness in the superior quadrant was 105.92 µm ±28.343µm at initial visit and at 3 months follow up was 105.72 µm±27.916 µm, in the nasal quadrant was 69.17 µm ± 13.199µm at initial visit and at 3 months follow up was 68.97 µm± 13.119 µm, in the inferior quadrant RNFL thickness was 111.03 µm±22.558 µmat initial visit and at 3 months follow up was 110.92 µm±22.372 µm, in the temporal quadrant was 59.35 µm ±11.333 µm at initial visit and at 3 months follow up was 59.18 µm ±11.247 µm but the difference was not statistically significant. Subgroup analysis of cases also did not show any statistically significant difference in RNFL thickness. Conclusion: RNFL thickness remains unaffected in cognitive disorders. However studies on a large sample of patients with a longer follow up are needed.