Agreement between intraocular pressure measurement using Goldmann applanation tonometry with and without fluorescein in consecutive Ghanaian patients

Abstract

Objective. The interchangeability of Goldmann Applanation Tonometry (GAT) with or without fluorescein requires clarification among African populations. The present study aimed to determine the agreement between IOP measurement using GAT with and without fluorescein in consecutive patients in Ghana. Design: A prospective cross-sectional clinic-based study design. Setting: The study was conducted at the Ophthalmology and Optometry units of the UCC Eye Clinic, Cape Coast, Ghana. Participants: A convenient sample of 104 consecutive patients who visited the clinic. The participants were randomised into two groups, where those in the first had their IOPs first measured without fluorescein and later with fluorescein on GAT; participants in the second group had their IOPs first measured with fluorescein and later without fluorescein after a 10-minute washout period. The central corneal thickness was measured using the Anterior Segment model of Zeiss Cirrus HD-OCT. Results: There was no agreement between the unadjusted IOP measures with and without fluorescein with GAT using the Bland Altman analysis (p < 0.0001, Lower limit: -0.9433, Upper limit: 6.8914; 95% CI = -1.6097 to -.02769). There were no statistically significant differences in gender between unadjusted IOP measurements with (Mann Whitney U test, p = 0.110) and without (Mann-Whitney U test, p = 0.083) fluorescein. Conclusion. Unadjusted IOP measurement without fluorescein was approximately 3 mmHg significantly lower than with fluorescein. We recommend practitioners maintain the gold standard GAT with fluorescein to guide accurate glaucoma diagnosis and management decision-making.