Study of ganglion cell complex and retinal nerve fibre layer in perichiasmatic brain tumour patients: A prospective observational study

Koyel Chakraborty, Sucheta Parija

Meeting:  2022 RANZCO


Date:      -

Session Title: FREE PAPERS – Glaucoma/Neuro-Ophthalmology

Session Time:      -

Purpose: Compressive lesions of anterior visual pathway can cause severe and permanent visual loss. Optical coherence tomography can pick up ganglion cell complex (GCC) thinning, even with normal retinal nerve fibre layer thickness and subtle visual field changes. We aim to find an association of GCC thickness with visual parameters in such patients.

Method: A prospective study was conducted on 37 patients with perichiasmatic brain tumour, operated between February 2019 and June 2020 at a tertiary care institute. Patients with ocular comorbidities were excluded. A comprehensive neuro-ophthalmological work-up was done. Documentation of demographic, clinico-radiological, and surgical profile with 6 months follow-up, was done. Statistical analysis was significant at p < 0.05. Results: Mean age was 35.14 ± 11.98 years. Preoperative GCC thickness in 63.7% eyes measured 65.67 ± 14.85 μ and final post-operative GCC thickness in 53.6% eyes measured 66.19 ± 15.62 μ. Improvement in mean visual acuity was noted at the final visit, the differ- ence being statistically significant (p = 0.03). GCC thick- ness showed clinically positive correlation with visual acuity (r = -0.48, p < 0.001) and field defect (r = -0.27, p = 0.04) at six months post-operative period. The cut-off value beyond which blindness could be prevented was found to be GCC thickness of 92 μm. Conclusion: Optical coherence tomography, a non- invasive tool, can aid in early diagnosis, monitoring, and detection of recurrence in perichiasmatic brain tumour patients. Apart from thinning of GCC, there is a positive correlation between GCC thickness, visual acuity, and field changes. Pre-operative GCC thickness >92 μm is a strong predictor of visual recovery.