Correlation between retinal nerve fiber layer thickness and anterior segment parameters in patients with
Nithya Rathinam1, Nirupama Kasturi1, Subashini Kaliaperumal1
1Department of Ophthalmology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India.
Purpose:
The purpose of this study was to assess the retinal nerve fiber layer (RNFL) thickness in patients with pseudoexfoliation (PXF) and to correlate it with anterior segment parameters such as intraocular pressure (IOP), central corneal thickness (CCT), pigments in angle structures, and grades of PXF.
Methodology:
This was a cross-sectional comparative study in a tertiary care center. Patients having unilateral PXF were categorized as group 1. Age- and sex-matched healthy controls were categorized as group 2. All subjects underwent IOP measurement, CCT measurement, and retinal nerve fiber thickness measurement. Subjects in group 1 also underwent gonioscopy and perimetry. Data were entered and analyzed using the IBM-SPSS program (version 20.0); Chicago, IL.
Results:
Mean RNFL thickness in group 1 was 85.91 ± 22.237 μ and in group 2 was 106.65 ± 6.1 μ. The mean RNFL thickness in patients with PXF syndrome was 103.38 ± 5.815 μ and in patients with PXF glaucoma was 67.82 ± 17.984 μ. The mean CCT in patients with PXF syndrome was 516.41 ± 23.03 μ and in patients with PXF glaucoma was 507 ± 33.05 μ and control group was 526.6 m. The mean IOP in patients with PXF syndrome was 8 ± 6.01 mmHg; in patients with PXF glaucoma was 17.21 ± 7.33 mmHg; and in the control group was 14.12 ± 2.693 mmHg. There was a negative correlation between IOP and RNFL thickness, and a positive correlation between CCT and RNFL thickness, but it was not statistically significant. A statistically significant correlation was found between grades of PXF and RNFL thinning with a correlation coefficient of 0.437 (P = 0.001).
Conclusion:
Patients with PXF have a lower CCT, higher mean IOP, and RNFL thinning compared to normal subjects. The presence of grade 3 PXF (on the lens surface edge) showed a statistically significant correlation with RNFL thinning.
