Comparison of retinal nerve fiber layer thickness in patients having pseudo exfoliation syndrome with healthy adults.

Naila Yasmeen,Nauroz Fatima,Qamar Ul Islam

doi:10.12669/pjms.326.11075

Abstract

Objective:To compare mean retinal nerve fiber layer (RNFL) thickness in patients having pseudo exfoliation (PXF) with normal age matched controls using spectral domain optical coherence tomography (SD-OCT).Methods:This was a case control study conducted at Armed Forces Institute of Ophthalmology (AFIO) Rawalpindi from 12 June 2013 to 12 January 2014. Seventy eyes (Group A - 35 patients with PXF and Group B - 35 healthy age matched subjects) of more than 40 years of age were included in the study. Intraocular pressure (IOP) was measured with Goldmann applanation tonometer (GAT) and peripapillary RNFL thickness was measured in four quadrants with SD-OCT (Topcon 3D OCT-1000 Mark II) in all subjects. Data was analyzed using the SPSS version 14.Results:Mean age of group A (PXF patients) was 65.63 ± 8.47 years and of group B (Healthy subjects) was 64.31 ± 6.51 years (p = 0.470). Both groups were gender matched with male preponderance (p = 0.673). Mean IOP in each group was 13.80 ± 2.59 mm Hg, and 13.49 ± 2.07 mm Hg respectively (p= 0.578). Mean average peripapillary RNFL thickness was 77.46 ± 12.17 µm in group A and 83.96 ± 10.58 µm in group B. Statistically significant differences were detected between two groups for mean average RNFL thickness (p= 0.020) and mean RNFL thickness in inferior quadrant (p=0.014).Conclusion:PXF patients with normal IOP and visual fields have thin RNFL as compared to healthy age matched controls. Therefore routine assessment and follow up of PXF patients with OCT may help in early diagnosis of PXF glaucoma.

Highlights

The objective of this study was to compare mean retinal nerve fiber layer (RNFL) thickness in patients having pseudo exfoliation (PXF) syndrome with normal age matched controls using spectral domain optical coherence tomography (SD-OCT). This case control study was conducted at Armed Forces Institute of Ophthalmology (AFIO) Rawalpindi from 12 June 2013 to 12 January 2014 after approval of hospital ethics committee
Subjects with refractive error > ± 5 diopters, previous intraocular surgery, trauma or laser treatment, media opacities interfering with visualization and OCT image capturing, retinal pathology, family history of glaucoma and history of diabetes mellitus or hypertension were excluded
Our study revealed significantly thinner mean average peripapillary RNFL thickness (77.46 μm vs. 83.96 μm) and mean RNFL thickness in inferior quadrant (88.43 μm vs. 100.46 μm) in patients having PXF with normal Intraocular pressure (IOP) as compared with age matched healthy adults using standard deviation (SD) OCT

Summary

INTRODUCTION

Pseudo exfoliation (PXF) syndrome is one of the commonest cause of secondary open angle glaucoma accounting for 20-25% of all open angle glaucomas worldwide.[1,2,3] Prevalence of PXF increases markedly with age and has considerable racial variations with reported incidence between 4.48% to 6.45% in Pakistani population.[4,5] Apart from elevated intraocular pressure (IOP), various pressure independent factors represent the main risk factors for loss of retinal nerve fiber layer (RNFL) with subsequent glaucomatous damage in PXF syndrome. The objective of this study was to compare mean RNFL thickness in patients having PXF syndrome with normal age matched controls using SD-OCT

METHODS

RESULTS

DISCUSSION

CONCLUSION