ORIGINAL ARTICLE White-to-white corneal diameter, pupil diameter, central corneal thickness and thinnest corneal thickness values of emmetropic subjects Juan A. Sanchis-Gimeno • Daniel Sanchez-Zuriaga • Francisco Martinez-Soriano Received: 29 November 2010 / Accepted: 11 October 2011 / Published online: 22 October 2011 Ó Springer-Verlag 2011 Abstract Purpose This report assesses white-to-white corneal diameter, pupil diameter, central corneal thickness and thinnest corneal thickness values in a large sample of emmetropic subjects. Methods Three hundred and seventy-nine eyes of 379 young healthy emmetropic subjects were analyzed by means of scanning-slit corneal topography. The age of the subjects ranged from 18 to 53 years (mean ± SD = 29 ± 7). The mean of five consecutive measurements of the central corneal thickness, the thinnest corneal thickness, the white- to-white corneal diameter, and the photopic pupil diameter was recorded. Results The central corneal thickness ranged from 528 to 588 lm; the thinnest corneal thickness ranged from 504 to 574 lm; the white-to-white corneal diameter ranged from 11.5 to 12.3 mm; and the pupil diameter ranged from 3.0 to 4.7 mm. The central and the thinnest corneal thickness were positively correlated (r = 0.94, p \ 0.001), and the pupil diameter was significantly higher in females (p \ 0.001). Conclusions This study shows that there are no differ- ences in white-to-white corneal diameter, central corneal thickness, and thinnest corneal thickness between emme- tropic females and males. However, pupil diameters are greater in emmetropic females. Keywords Corneal thickness Á White-to-white diameter Á Pupil diameter Á Scanning-slit corneal topography Á Ocular surface Introduction An anatomist’s ‘‘definition of the normal eye’’ is different from an ophthalmologist’s. From an ophthalmologist’s point of view the normal eye is the non-pathological eye, not the emmetropic eye as accepted by anatomists [21]. Assessment of ocular dimensions is essential for oph- thalmic surgeons, because it must be measured before scheduling excimer laser refractive surgery and cataract surgery [8, 16]. Cataract is the world’s leading cause of blindness [28], and excimer laser refractive surgery has been reported to be performed on more than six million people worldwide [10]. This is why studies of ocular dimensions are usually carried out in these patients and not in emmetropic subjects. The analysis of distribution of refractive errors has detected that emmetropia may be more prevalent than myopia and hyperopia in European populations [14] although different studies carried out in Asian populations have found that hyperopia and myopia are more prevalent than emmetropia [13, 27]. Previous studies analyzed the ocular axial length values and corneal thickness values of the emmetropic and non- emmetropic eye [19, 20, 22, 23], but based on a biblio- graphic search using MEDLINE, we have found no study dedicated exclusively to the white-to-white corneal diam- eter and pupil diameter in healthy emmetropic eyes (i.e., those subjects with spherical equivalent refraction of ±0.5 diopters). Thus, currently, there is a lack of information on the quantitative ocular anatomy of J. A. Sanchis-Gimeno (&) Á D. Sanchez-Zuriaga Á F. Martinez-Soriano Department of Anatomy and Human Embryology, Faculty of Medicine, University of Valencia, Av. Blasco Iba ´n ˜ez, 15, Valencia 46010, Spain e-mail: juan.sanchis@uv.es 123 Surg Radiol Anat (2012) 34:167–170 DOI 10.1007/s00276-011-0889-4