Change in contrast sensitivity and OCT parameters in idiopathic intracranial hypertension

Deterioration in peripheral contrast sensitivity (CS) can be an indicator to detect progressive deterioration of visual function in patients with idiopathic intracranial hypertension (IIH).

The aim of this study was to evaluate the changes in central and peripheral CS and optical coherence tomography (OCT) parameters and in patients with IIH.

In this pilot observational study, data of 20 eyes of 10 'treatment-naïve' IIH patients were analyzed. Detailed ocular examination was performed including CS assessment using both Pelli-Robson (PR) test and Spaeth-Richman Contrast Sensitivity Test (SPARCS) along with the OCT for macular and optic nerve head (ONH) parameters. A comparative analysis was done for CS and OCT parameters from baseline to a follow-up visit > 12 months (range: 18-24 months).

The study population had a female preponderance (80%, n = 8), and mean age at diagnosis was 31.9 ± 10.3 years. Mean follow-up period was 21.2 months (range: 15-24 months). At presentation, 6/6 visual acuity was noted in 75% eyes (n = 15) while all eyes had 6/6 vision at the last follow-up. Average PR score increased from 1.96 ± 0.36 to 2.30 at the last visit (Wilcoxon test: V = 0.0, p ⩽ 0.001) while average SPARCS score (total) increased from 71.85 ± 9.10 to 77.55 ± 6.20 (Paired t-test: t = -2.3, p = 0.035). Change in SPARCS score was significant in average total score (p = 0.035), and quadrant-wise score in superonasal (p = 0.014), inferonasal (p = 0.001), and inferotemporal (p = 0.021) quadrants. Same trend in SPARCS scores was observed when eyes with and without recurrence were analyzed. Statistically significant difference in retinal nerve fiber layer (RNFL) thickness (p = 0.007) and macular thickness (MT) in nasal quadrant (p = 0.006) was seen between the eyes with recurrence and without recurrence.

Peripheral CS showed significant difference in all eyes over time. It showed significant change in eyes with recurrence, even in the presence of intact visual acuity and preserved central CS. Changes in RNFL thickness and nasal MT could differentiate eyes which developed recurrence from normal eyes.