Anterior and posterior corneal curvature: normal values in healthy Iranian population obtained with the Orbscan II

• Published in: International ophthalmology Vol. 34; no. 6; pp. 1213 - 1219
• Main Authors: Gharaee, Hamid, Abrishami, Mojtaba, Abrishami, Mostafa, Mirhosseini, Seyyed Mohammad, Mehrabi Bahar, Mohammad Reza, Eghbali, Pardis
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.12.2014; Springer Nature B.V
• Subjects: Adult; Anterior Eye Segment - anatomy & histology; Asian Continental Ancestry Group; Cornea - anatomy & histology; Corneal Topography - methods; Cross-Sectional Studies; Female; Humans; Iran; Male; Medicine; Medicine & Public Health; Ophthalmology; Original Paper; Posterior Eye Segment - anatomy & histology; Reference Values; Young Adult; Iran; Orbscan II; Corneal curvature; Best fit sphere; Population based study
• ISSN: 0165-5701; 1573-2630
• DOI: 10.1007/s10792-014-0005-y

The objective of study was to determine the normative values of anterior and posterior best fit sphere (A-BFS and P-BFS) measured with Orbscan II Topography System. In this cross-sectional study, patients (age range: 18–40 years) referred to the Khatam Eye Hospital (Mashhad, Iran) were put in an observational cross-sectional study. The A-BFS and P-BFS were measured with the Orbscan II. The differences between genders, between right and left eyes, and age-related changes were evaluated. A total of 977 healthy participants consisted of 614 female and 363 male subjects aged 18–35 years participated. The average A-BFS in our study population was recorded as 43.060 ± 1.541 D (median: 43.00 D, mode: 43.10 D, range: 38.80–55.80 D). The average P-BFS in our study population was recorded as 52.702 ± 2.190 D (median: 52.60 D, mode: 53.10 D range: 46.9–62.20 D). The A-BFS and P-BFS were respectively 42.753 ± 1.629 and 52.327 ± 2.376 D in males and 43.242 ± 1.457 and 52.924 ± 2.041 D in females, which were statistically different between the genders ( P  < 0.001). However, A-BFS and P-BFS were not statistically different between right and left eyes ( P  = 0.649 and P  = 0.688 respectively). In addition, A-BFS and P-BFS were not correlated with the age ( r  = 0.038, P  = 0.096 and r  = −0.142, P  = 0.178 respectively). Considering 95 % confidence interval, A-BFS less than 43.13 D and greater than 42.99 D and P-BFS less than 52.80 D and greater than 52.60 D would be considered abnormal. Detailed description and analysis of A-BFS and P-BFS with Orbscan demonstrated that the obtained average value of BFS were higher in male than female and did not change with increasing age.