Corneal Topographic Patterns in Healthy Eyes in a Sample of Iraqi Population Using Pentacam

Abstract

Background: Corneal topography is computer assisted diagnostic tool, used to characterize the shape of cornea . Originally, topographic map was only used to describe the anterior corneal surface, devices as Pentacam now are able to characterize both anterior and posterior corneal surfaces, creating three dimensional map. It's essential in determining the quality of vision and the state of cornea and assess diseased from normal cornea.
Aim: The purpose of this study is to determine the distribution of corneal topographic patterns in Iraq, to make a corneal topographic database of our local people.
Subjects and methods: Five hundred and twenty healthy eyes of two hundred and sixty subjects coming to Ibn AL-Haitham Teaching Eye Hospital at Baghdad, Iraq, selected to be included in the study, (134) males and (126) females with age range of 18-60years. Data collection conducted between May 2018 and March 2019.Sample randomly selected and determine inclusion and exclusion criteria for each subject, proper history taking from all, then do corneal topography using Pentacam (oculus) for each eye in the included subjects after complete ophthalmological examination (Best corrected visual acuity, refractive error, Intraocular pressure measurement, slit lamp examination, Break up time and fundoscopic examination).
Results: Analysis of data was carried out using the available statistical package of SPSS-25, we analyzed (520) healthy eyes of (260) subjects. Abnormal patterns (Asymmetrical bowtie, irregular) were seen in (23.6_36.5 %) of people and normal patterns (Symmetrical bowtie, round, oval) were seen in (63.5_76.4%) of people. There was statistical difference toward older age group (≥ 40 years), that is to mean significant difference with age; also there was significant difference with gender with females highest proportion for most of the patterns. Patterns not affected by laterality (between right and left eye).

Conclusion: Elderly persons tend to have more change in topographic mapping and affect pattern of corneal topography, due to physiological aging process involve corneal surface curvature, than that in younger population, so there is significant difference with aging. Also gender affects topographic patterns with female's highest proportion for most of the patterns. Also we conclude that the patterns not affected by laterality. By using Pentacam (Oculus) for healthy eyes in Iraqi sample of 260 participants found that normal patterns about 75.4% and abnormal patterns about 23.6%, that's to mean 1 out of 4 subjects with healthy eyes have abnormal topographic pattern