Role of optical coherence tomography in early detection of glaucoma suspect.

Abstract

Objective: To evaluate role of OCT in early detection of Glaucoma Suspect by measuring inferior retinal nerve fiber layer thickness by Optical Coherence Tomography in relationship with visual field analysis by Humphery visual field analyser. Study Design: Prospective Cross-sectional Observational Analytical Study. Period: 15 May 2024 to 15 May 2026. Setting: Department of Eye, Independent University Hospital and Ibrahim Eye Centre, Faisalabad. Methods: 50 patients aged between 18 to 50 years with best corrected snellen visual acuity of 6/24 or better and with no secondary ocular or neurological ailments or any retinal problems were enrolled from out patient eye department of independent university Hospital and Ibrahim eye centre, Faisalabad. The enrolled patients were suspected having un-diagnosed primary open angle Glaucoma. The complete systemic systemic including history of diabetes, hypertension, arthritis, trauma, family history and medical history was recorded. Slit-lamp examination was done for status of cornea, anterior chamber, lens, iris, pupil, vitreous and fundus. Applanation tonometry was perfomed and recorded. Pachymetry, Gonioscopy, humphery visual field analysis and then OCT was done for Optic disc analysis, Ganglian Cell Complex and retinal nerve fiber layer thickness analysis. The whole record of history, examination and investigations was saved in a specific proforma. Results: Total 50 patients, aged between 18 to 50 years (mean 41.00+9.48), Male patients were 35 while Female were 15. The family history of glaucoma was 57.14 % while cup-to-disc ratio (CDR) was from 0.4 to 0.8 (mean 0.59+0.10) and intraocular pressure was from 14 to 25 mmHg (mean 20.09 +2.11). The pachymetry ranged between 470 to 572 mm (mean 520.20+22.82) and inferior RNFL from 36.40 to 96.10 um (mean 69.32+12.52). Conclusion: This study proved that RNFL thickness by OCT has a significant and potential diagnostic role in detection of early glaucoma and glaucoma suspect. At the same time, the OCT proved to be equally effective in monitoring progression of glaucoma. While considering the other OCT parameters as measuring GCC, analysing ONH and measuring RNFL thickness are also important in detection and monitoring of glaucoma but we proved that thickness of RNFL at inferior quadrant was more important in detection of glaucoma suspect. The OCT derived RNFL and particularly inferior RNFL thickness is a sesitive, and objective indicator for identifying the glaucoma suspect while detecting it at preclinical stage even before visual fields loss by perimetry.