Abstract
Purpose :
Evaluating anti-scarring therapies requires objective assessment of scarring, and knowledge of normal fornix anatomy. Measurement of conjunctival scarring has focused on inferior fornix shortening, whilst reduction in superior fornix depth (FD) is often overlooked. There is data on normal FD in South Asians, but no studies investigating normal conjunctival FD in Caucasians.
We designed a custom- made fornix depth measurer (FDM) for objective measurement of upper and lower conjunctival FD. The purpose of this study was to evaluate intra- and inter-observer variability, and to establish a reference for normal conjunctival FD measurements in a Caucasian population.
Methods :
Prospective epidemiologic cross-sectional study evaluating conjunctival FD in 252 clinically normal Caucasian participants aged 20 to 80 was undertaken. Paired observers evaluated inter-and intra-observer variability. Data was analysed using Bland-Altman plots and analysis of variance.
Results :
For Caucasian subjects, mean upper and lower conjunctival fornix depths were 15.6mm (95% CI, 12.5 – 18.8) and 10.9mm (95% CI, 8.0 – 13.7) respectively. Females have smaller FDs than males (mean upper FD 15.3mm ± 1.6 females, 16.2mm ± 1.4 males p < 0.001; mean lower FD 10.6mm ± 1.3 females, 11.3mm ± 1.4 males, p<0.001). There was a progressive decline in FD with age (upper fornix depth 16.3mm ± 1.2 at age 20-29, and 15.0mm ± 1.8 at age 80+ (p = 0.04). There was 94 -100% intra-observer and inter-observer agreement for upper and lower fornix measurements.
Conclusions :
Using an alternative custom-designed FDM, central conjunctival fornix depth in Caucasian eyes appears to be similar to data previously reported in South Asian eyes. Fornix depth measurements were repeatable and reproducible.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.