The Iris Thickness in a Healthy Saudi Population

Abstract

Purpose Iris thickness (IT), a known risk factor for angle closure glaucoma, has not been evaluated in the normal Saudi population. Methods Quantitative information on IT was evaluated in healthy Saudi eyes using anterior segment optical coherence tomography (ASOCT). IT and iris volume was measured with the room ‘light on’ (LON) and ‘light off’ (LOFF) using Image J software. IT in the nasal and temporal iris was measured at 500 µm (IT500) and 750 µm (IT750) from the scleral spur (SS). Differences in IT measurements by age, gender and type of refractive error were evaluated. Results We included 100 eyes of 50 healthy adult Saudis without ocular disease other than refractive errors. The mean age of 56 males and 44 females in the study group was 41.7 ± 14.5 years. The refractive status was as follows: emmetropia (35 eyes), mild/moderate myopia (33 eyes), high myopia (17 eyes) and hyperopia (15 eyes). The IT750 with LON was significantly more than IT500 both nasally (P = 0.03) and temporally (P < 0.001). The difference in IT750 and IT500 with LOFF was significantly more nasally (P = 0.03), temporally (P = 0.02), and with LON nasally (P = 0.005). IT was thicker in males when compared to females and variation of IT by refractive error was significant but not by age. The mean pupil diameter and anterior chamber depth decreased with age (P < 0.001). Anterior chamber width was not affected by age or illumination. Conclusion The baseline iris thickness in the Saudi eyes could be used to compare iris thickness in eyes with angle closure glaucoma among the Arab population.

Optical Coherence Tomography Based Choroidal Thickness and Its Determinants in Healthy Saudi Population: A Cross-Sectional Study

“…However, studies from Denmark and Japan reported greater choroidal volume in males compared with females [11,20]. Interestingly, in healthy Saudi adults, the iris is thicker in males than in females [13].…”

“…However, studies from Denmark and Japan reported greater choroidal volume in males compared with females [ 11 , 20 ]. Interestingly, in healthy Saudi adults, the iris is thicker in males than in females [ 13 ]. Differences in CT by sex in the Arab race in our study and studies on Asian and European populations need further confirmation with a larger sample size.…”

“…Choroidal thickness (CT) in healthy eyes, as measured by OCT, is influenced by several factors, including scanning location (sub-foveal, nasal, and temporal to the fovea), age, sex, the refractive status of the eye, and diurnal variability [6][7][8][9][10][11][12]. Based on anterior OCT, iris thickness in healthy eyes was studied to evaluate a nomogram for the Saudi population [13]. However, to the best of our knowledge, no study has been published on CT and its determinants in the healthy Saudi population.…”

Anterior Ocular Biometrics as Measured by Ultrasound Biomicroscopy

“…Normal data (biometrics) about the anterior component of the eye globe including anterior segment depth, ACA, iris thickness, and ciliary body thickness are needed before deciding if this eye is normal or abnormal, and these data are missing in the literature [ 31 ]. These structures can be evaluated by either UBM or anterior segment OCT [ 32 , 33 ], and differences may exist between different populations [ 34 , 35 , 36 ], and may exist with special ocular diseases including intraocular tumors, glaucoma, myopia, and retinal detachment [ 37 , 38 , 39 , 40 ].…”