Progression of Primary Open Angle Glaucoma on Optical Coherence Tomography of the Optic Nerve Head

Aims: To describe the progression of Primary open angle glaucoma (POAG) on Optical Coherence Tomography (OCT) of the optic nerve head and retinal nerve fiber layers (RNFL). Method: We conducted a descriptive retrospective study from January 1, 2015 to December 31, 2019, a period of 5 years from the files of patients followed for POAG and having carried out at least two OCT examinations of the optic nerve head (ONH), one automated visual field and Intraocular pression (IOP). The variables studied were: age, sex, mean IOP, glaucoma stage, progression of ONH parameters, and progression of RNFL parameters. Results: During the period, 112 eyes of 56 patients were included. The mean age was 48.96 ± 16.57 [12 - 83] years with a sex-ratio of 1.33 (32 M/27 F). The mean IOP was 21 ± 4.54 [10 - 36] mm Hg. According to the mean deviation (MD) of the visual field, 98 eyes or 87.5% were stage 1 of POAG, 10 eyes or 8.9% at stage 2 and 4 eyes or 3.6% at stage 3. The mean time between the 1st and 2nd OCT examination was 28.91 ± 11.07 [6 - 56] months, corresponding to an average of 2.18 OCT per patient in 5 years of follow-up. There was an average increase of 6.2% of the Cup area and an increase in the vertical Cup/Disc ratio of 1.79% per year. The thinning average of neuro-retinal ring area was 1.64% per year. The RNFL thickness had decreased on average by 4.28 μ or 0.93% per year. The lower quadrant had the highest fiber loss with 1.08% per year followed by the upper quadrant with a loss of 1.05% per year. Conclusion: OCT of the ONH and RNFL proves to be an essential tool in the follow-up of POAG. A subsequent study taking into account the OCT of the macular ganglion complex will enable to study its contribution in the follow-up of glaucomatous patients in the same population.