Purpose Ascertain the demographic characteristics and interocular features of right and left eye in Chinese and Pakistani group. Estimate the average RNFL thickness and the difference between right and left eye in both groups and to determine the cutoff values for intraocular difference in Retinal Nerve Fiber Layer (RNFL) thickness measured with Cirrus HD-OCT (Carl Zeiss Meditec, Inc) in Chinese and Pakistani subjects, aged 18-28 years.
Methods A cross sectional comparative study was conducted in healthy Chinese and Pakistani subjects (n=100) . Participants were explained the nature of study and subjects willingness was documented with signature on consent and filling a questionnaire regarding their general health, life style and ophthalmic history. RNFL thickness was measured by HD-OCT Optic Disc Cube.
Results Measuring optic nerve head difference between the two eyes showed that most parameters are the same except horizontal cup to disk ratio (HCDR) and retinal nerve thickness. For quadrant thickness in each eye, inferior quadrant is thicker than the superior quadrant, presenting a double hump appearance and nasal quadrant is thicker than the temporal quadrant thickness, following “ISNT” rule.The average RNFL thickness difference between the right and left eye is (2.18±6.95)µm and right eye was thicker than left eye and the difference was statistically significant .For RNFL quadrant thickness, all quadrants are similar excluding temporal quadrant with mean difference of (7.01±19.58)µm in right and left eye and their difference is also statistically significant. Clock hours difference showed variable different values between the two eyes in the above study groups.In Chinese group, average RNFL difference thickness (3.88±6.9)µm between the two eyes is statistically significant). In Pakistani group the average RNFL thickness is (0.48±6.6)µm with no difference between right and left eye. Nasal quadrant showed significant difference for RNFL thickness between the two eyes in Chinese and Pakistani population. The RNFL thickness measured at different clock hours varied but the RNFL thickness values measured other than clock hours showed similarity. 
Conclusion Posterior pole in Chinese subjects is thinner and more expanded while Pakistani subjects have thicker oval shaped ONH. Average RNFL thickness is greater on right eye than left eye and their difference is statistically significant in the above age subjects. In Chinese group, the RNFL thickness difference in right eye is significant while in Pakistani group both eyes have no statistical difference in their average RNFL thickness between right and left eye.