Authors: Imran Jivraj, Ahsen Hussain, Yaping Jin, Dan DeAngelis, Asim Ali
Author Disclosure Block: I. Jivraj: None. A. Hussain: None. Y. Jin: Funded grants or clinical trials; Glaucoma Research Society of Canada, Kensington Eye Institute Research Fund. D. DeAngelis: None. A. Ali: Membership on advisory boards or speakers’ bureaus; Consultant for Santen.

Abstract Body:

Purpose: Knowledge of the dimensions of the pediatric conjunctival fornix would be invaluable in the management of cicatricial ocular surface disease and reconstruction of congenital and acquired orbital disorders. While measurements of the adult conjunctival fornix among South Asian and Caucasian populations have been described, normative pediatric data have not been reported. The present study aims to describe the dimensions of the pediatric conjunctival fornix in the pediatric population using two measuring devices.
Study Design: Cross-sectional study.
Methods: Fifty-seven subjects of varied ethnicities who were less than 18 years of age undergoing ophthalmic procedures under general anesthesia were recruited. Patients with diseases affecting the conjunctiva or fornices were excluded. Measurements of the intercanthal distance (ICD), upper (UVF, UHF) and lower (LVF, LHF) vertical and horizontal fornix depths, and lateral fornix depth (LF) of both eyes were performed by two surgeons pre-operatively using a sterile plastic ruler and a Scott ruler. Linear regression and correlation analyses were used to assess if fornix measurements increased with age. Differences between plastic ruler and Scott ruler were assessed using the paired t test.
Results:
The mean age of participants was 7.4 years (range: 0.5-17.0 years) and there was no statistically significant differences between male and female participants (p=0.90) or between Caucasians and non-Caucasians (p=0.93). Mean measurements and standard deviations using the plastic ruler were as follows: ICD: 28.4mm±3.0, UVF: 16.9mm±1.4, LVF: 12.6mm±1.7, UHF: 30.3mm±3.7, LHF: 28.5mm±3.4 and LF: 5.2mm±0.8. There was a statistically significant (p<0.05) increase in in ICD, UVF, LVF, UHF, and LHF with age as measured with the plastic ruler; LF did not change significantly with age. Measurements obtained with the Scott ruler were significantly greater (0.9mm) for UVF (p<0.0001) and smaller (-0.6mm) for LHF (p=0.0069), but not significantly different for UHF, LVF, and LF.
Conclusions: This is the first study to define the dimensions of the conjunctival fornix in an ethnically diverse pediatric population under general anesthesia. As would be expected, there was a statistically significant increase in various dimensions of the fornix with age. In comparison with the upper and lower fornix depths previously described among healthy adult South Asians (Khan et al, 2014) and healthy Caucasians (Jutley et al, 2007), we found slightly larger vertical fornix dimensions in the pediatric population. It is possible that greater elasticity of pediatric connective tissue, variable measurement technique, and the impact of eye position under general anesthesia may explain these differences.