To characterize peculiarities of the corneoscleral geometry in healthy eyes.
This is a prospective case series including 88 healthy eyes of 88 patients with an age ranging from 21 to 73 years. A complete ocular examination was performed with emphasis on the analysis of the corneoscleral topographic profile with the Fourier transform profilometer Eye Surface Profiler (Eaglet-Eye BV, Houten, the Netherlands). The distribution of different topographic parameters was evaluated, as well as the correlations between corneal and scleroconjunctival parameters.
Mean values of 8.64±0.37 (range, 7.81–9.50 mm), 6.06±0.52 (4.88–7.63 mm) and 11.93±1.32 mm (8.17–15.89 mm) were obtained for inner, limbal, and outer best-fit sphere, respectively. Mean values of 8.54±0.38 (7.86–9.66 mm) and 13.35±1.29 mm (11.05–17.31 mm) were obtained for mean corneal and scleral radius, respectively. Regarding tangent angles at limbus, mean values of 35.31±6.55°, 38.76±5.90°, 32.75±7.04°, and 25.91±8.99° were obtained for nasal, temporal, superior, and inferior angles, respectively. Mean difference between temporal and nasal sagittal heights increased from −1.48±120.70 μm for a chord of 11 mm to 73.53±236.55 μm for a chord of 14 mm. A weak but statistically significant correlation was found between corneal and scleral radii (r=0.325, P=0.004). The maximum sagittal height for a diameter of 12 mm was significantly correlated with flattest keratometry, astigmatism, corneal diameter, and corneal eccentricity (R2: 0.77, P<0.001).
The scleroconjunctival surface in the healthy eye presents some level of nasotemporal asymmetry that is higher with increasing diameters of analysis.
Group of Optics and Visual Perception (D.P.P., A.M.-A.), Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain; Department of Ophthalmology (OFTALMAR) (D.P.P., R.S.-N.), Vithas Medimar International Hospital, Alicante, Spain; Aragón Institute for Engineering Research (i3A) (M.A.A.-G.), University of Zaragoza, Zaragoza, Spain; and Department of Optics II (G.C.), University Complutense of Madrid, Madrid, Spain.
Address correspondence to David P. Piñero, Ph.D., Department of Optics, Pharmacology and Anatomy, University of Alicante, Crta San Vicente delRaspeig s/n 03690, San Vicente del Raspeig, Alicante, Spain; e-mail: email@example.com
The authors have no funding or conflicts of interest to disclose.
D. P. Piñero has been supported by the Ministry of Economy, Industry and Competitiveness of Spain within the program Ramón y Cajal, RYC-2016-20471.
Accepted September 24, 2018