Impact of weight reduction on structural and functional parameters of the optic nerve in idiopathic intracranial hypertension.

Purpose: To evaluate the effect of weight reduction on the structural and functional parameters of the optic nerve in established cases of papilledema in Idiopathic Intracranial Hypertension (IIH).

Methods: A prospective observational study in early and established cases of papilledema in IIH presenting from December 2019 to February 2021. Functional parameters (visual acuity, contrast sensitivity, mean deviation, VER), structural parameters (RNFL, GCL-IPL, and optic disc height), and clinical grading of papilledema were measured at baseline and every 6 weeks for 6 months. All patients underwent medical (oral acetazolamide) and diet therapy.

Results: Mean body mass index (BMI) at presentation was 26.32 ± 3.52 kg/m² and the mean change in BMI over 6 months was 1.27 ± 0.50 kg/m². 67% of eyes had papilledema of grades 2-3 at the presentation. At the end of 6 months, 75% of eyes had grade 1 papilledema while 13% showed complete resolution. A reduction of 5.32 ± 3.58 in mean deviation (r = 0.316; p-value 0.01) and gain in VER P100 amplitude of 4.2 ± 2.7 µV (r = 0.40; p-value 0.003) were noted over 6 months with reduction in BMI over 6 months. A statistically significant reduction in optic disc height (ODH) was noticed with BMI reduction over 6 months (p = 0.0007; r = 0.45).A reduction of 1.72 ± 0.90 kg/m² (equivalent to 6.53% weight loss) in BMI was associated with a four-grade change in clinical grading of papilledema.

Conclusion: Reduction in BMI had a significant impact on both structural and functional parameters of the optic nerve in IIH. The involvement of a well-certified dietician should be an integral part of treatment in IIH.