Abstract:
Purpose. To determine normative values of retinal nerve fibre layer thickness (RNFL) and optic nerve head (ONH) parameters and
their association with routine clinical tests such as refractive error (RE), stereoacuity (SA), and contrast sensitivity (CS) in an
African population. Methods. In a cross-sectional observational study, 100 normal subjects aged 20 to 78 years were evaluated
using the Cirrus HD-OCT 5000 and matched with 200 glaucoma patients. Results. Average (±SD) RNFL thickness for normal
subjects was found to be 102.37 ± 7.45 (range, 82–119 microns) compared with 90.74 ± 14.50 found for glaucoma subjects. Females
had higher average RNFL values (104.84 ± 6.90) compared with males (99.80 ± 7.18). Significant associations were calculated
between quadrant RNFL thickness and SA, SE, and CS (all p < 0.05). +e mean cup to disc ratio (CDR) was 0.49 ± 0.12, and mean
optic disc area (DA) was 2.08mm2 ± 0.40. Smaller DA was recorded for participants aged 60+ years (1.86 ± 0.25), followed by
40–59 age group (2.01 ± 0.41) and then 20–39 age group (2.19 ± 0.41). Significant associations were calculated between SA and
ONH parameters, except rim area (all p < 0.01), and RE was significantly associated with DA and average CDR (all p < 0.05).
Conclusion. RNFL thickness in healthy black Ghanaian population was significantly higher than that reported in other races. +e
values and associations reported in this study can inform clinical decision on the normal variation in RNFL and optic
disc parameters.
