Abstract
Purpose :
This study aims at analysing the characteristics of the optic nerve and at measuring retinal thickness in macular region in different ethnic groups with a high resolution SD-OCT (spectral domain-optical coherence tomography) and verifying possible differences between different ethnic groups.
Methods :
With SD-OCT (spectral domain-optical coherence tomography) werw analysed:162 eyes of 89 healthy volunteers with average age of 43 years (22 Caucasian, 23 Asian, 20 Hispanic, 24 of African descendent) by assessing Disc Area (DA), RNFL Thickness and C/D Area Ratio; and 247 eyes of 141 healthy volunteers (39 Caucasian, 33 Asian, 32 Hispanic, 37 of African descendent) by assessing full Central Thickness (F-CT), full average CT (CT-AVG) and central, upper, temporal, lower and nasal sectors of inner (I) and outer retina (O).
Results :
Results analysis shows that people of African descendent have the highest Disc Area value (average value 2.34 mm2) and RNFL Thickness (average value 106,20 µ) and Hispanics have the highest C/D Area Ratio (average value 0.45). On the contrary, Caucasians show the lowest Disk Area value and RNFL thickness (2,02 mm2 e 97,92 µ average values, respectively) and African people have the lowest C/D Area Ratio (average value 0.27). Different dimensions of the optic disk and the RNFL thickness result statistically significant only between African and Caucasian people (p<0.05). On the contrary, differences of the C/D Area Ratio result statistically significant between African and Hispanic people. The study of the macular region, shows that, as regards CT (FULL-INNER-OUTER), Caucasians have statistically significant thicker retinal layers (p<0.05) than all other . People of African descendent present reduced thickness of F-CT and I-CT if compared with Asians as well as with Caucasians. Asian people, beside showing statistically significant differences if compared with Caucasians (in all layers) and African people (only for F-CT and I-CT), have thicker retinal layers than Hispanic people except for O-CT.
As regards results analysis of the different sectors, Hispanics have a statistically significant lower thickness in sectors T and I of the inner retina if compared with Asia
Conclusions :
Those observations are of fundamental importance for defining the normal variation interval in different ethnic groups and should be considered for the execution of the mentioned exams and parameters analysis.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.