The Evaluation of Peripapillary Retinal Nerve Fiber Layer Thickness Changes in Patients with Retinitis Pigmentosa and Patients with Early-Late Stage Glaucoma

Objective: The aim of the study is to evaluate the peripapillary retinal nerve fiber layer (RNFL) thickness of patients with retinitis pigmentosa (RP) and patients with early- and late-stage glaucoma using spectral domain optical coherence tomography (SD-OCT), and investigate the similarity and differences of RNFL thickening and thinning regions between these groups. Methods: This cross-sectional study was carried out in Nigde Omer Halisdemir University Training and Research Hospital. The patients were divided into three groups; retinitis pigmentosa (group 1), early-stage glaucoma (group 2), and medium- and advanced-stage glaucoma (group 3). The RNFL thickness of all patients were measured. Each group consisted of 20 patients. Results: RNFL thinning was most frequently detected in the inferior quadrant, and then in the superior quadrant in all 3 groups and thickening was not detected in these 2 quadrants in glaucoma groups. The thickening was most frequently detected in the temporal quadrant, and in the 9 o' clock segment in all groups. In groups 1 and 2, the nasal quadrant was second after the temporal quadrant in RNFL thickening. RNFL thickening and thinning regions were found to be similar in these 2 diseases, which progress with ganglion cell damage. The horizontal quadrants were less affected and vertical quadrants were more affected regardless of the disease. Conclusion: The similar changes in the RNFL layer in these 2 different diseases with different mechanisms suggest that ganglion cells might have a specific response to various disease processes.