TNOA Journal of Ophthalmic Science and Research (Jan 2019)

Correlation between retinal nerve fiber layer thickness and central corneal thickness in ocular hypertension

  • Aditya Mahadevan,
  • Kirti Nath Jha,
  • Srikanth Krishnagopal,
  • G Ezhumalai

DOI
https://doi.org/10.4103/tjosr.tjosr_68_18
Journal volume & issue
Vol. 57, no. 4
pp. 285 – 288

Abstract

Read online

Aim: The aim of the study is to determine correlation between the retinal nerve fiber layer thickness (RNFL) and central corneal thickness (CCT) in patients with ocular hypertension (OHT) and age-matched control. Materials and Methods: This was a prospective, observational study, done between January 2016 and June 2017 at a rural tertiary care eye center. Participants diagnosed with OHT, defined as an intraocular pressure (IOP) of 21 mm Hg or higher, with normal optic disc and visual field, in the absence of any other ocular disease, were included in the study. The control group included age- and sex-matched participants with normal IOP, optic discs, and visual fields. Patients with OHT were subdivided into thin (CCT ≤555 μm) and thick (CCT >555 μm) corneas. RNFL was measured with spectral-domain optical coherence tomography and CCT with ultrasound pachymetry. Statistical Analysis: Mean, percentage, and standard deviation were used for descriptive values. Mean, standard deviation, and 95% confidence interval were utilized for the analysis of IOP, CCT, and RNFL. Mean was compared using the independent t-test. P < 0.05 was taken as statistically significant. Results: We examined 65 eyes of 35 OHT patients and 73 eyes of 40 controls. The mean IOP was 23.48 ± 2.47 mmHg, mean CCT was 553.81 ± 38.3 μm, and the mean RNFL was 102.12 ± 12.28 μm in the OHT group. Mean RNFL in OHT was 101.14 ± 10.68 μm in thin corneas, 103.21 ± 13.92 μm in thick corneas, and 104.23 ± 8.37 μm in the controls. There was no significant difference in the average (P = 0.502) or quadrant-wise (superior, nasal, inferior, and temporal) RNFL, comparing the two (thin and thick cornea) OHT groups (P = 0.247, 0.882, 0.897, and 0.551) or the control group. Conclusion: There is no correlation between CCT and RNFL thickness in patients with OHT. Mean retinal nerve fiber thickness in OHT and control revealed no difference.

Keywords