Pattern of Idiopathic Intracranial Hypertension in Indian Population

Change in contrast sensitivity and OCT parameters in idiopathic intracranial hypertension

Background:

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

Objectives:

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.

Design and Methods:

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).

Results:

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.

Conclusion:

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.

Idiopathic intracranial hypertension and visual function in North Indian population

BACKGROUND

Idiopathic Intracranial Hypertension (IIH) is a neurological disorder with varied presentation, visual morbidity being the most important one. Literature is sparse as regards the effects of IIH on the visual system in Asians.

OBJECTIVE

Assessment of visual morbidity and change with treatment in IIH patients in North India through a prospective interventional study.

MATERIALS AND METHODS

Sixty eyes of newly diagnosed IIH patients were evaluated for functional and structural tests of visual system. Lumbar puncture was performed to establish IIH diagnosis and received oral Carbonic anhydrase inhibitor thereafter. Change in visual function was studied from baseline to 6-month follow-up visit.

RESULTS

Mean age of participants at presentation was 33.27 ± 10.68 years and majority were females (73.3%). Seventy percent eyes (n = 42) had visual acuity 20/20 at presentation. Average Pelli Robson contrast sensitivity (CS) improved from 1.86 ± 0.34 to 2.11 ± 0.24 (Friedman Test: X2 = 59.2, p ⩽ 0.001) while number of eyes with detectable visual field deficits reduced from 70% to 43.7%. Retinal nerve fibre layer (RNFL) thickness reduced from 176.27 to 114.97 µ (Friedman Test: X2 = 69.3, p ⩽ 0.001).

CONCLUSIONS

The socio-demographic profile in our study showed higher male incidence than noted in previous studies. Visual function deficits were present in patients, even in those with 20/20 visual acuity. Significant improvement was seen after lumbar puncture and initiation of medical treatment. CS and RNFL thickness showed significant improvement even after 1 month of treatment and can be used for monitoring IIH patients.