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Retinal thickness evaluation in healthy eyes from north-west Punjab through optical coherence tomography.

OBJECTIVE
To determine the mean retinal thickness in healthy eyes from north-west Punjab through commercially available optical coherence tomography (OCT) mapping software, version 3.0, from the Stratus OCT (OCT3).


STUDY DESIGN
Descriptive study.


PLACE AND DURATION OF STUDY
Al-Shifa Trust Eye Hospital, Rawalpindi, from August 2008 to February 2009.


METHODOLOGY
One hundred and two eyes of 75 healthy north-west Punjabis, fulfilling inclusion criteria were enrolled from OPD of Al-Shifa Trust Eye Hospital. After informed consent, demographic detail was taken. Best-corrected Snellen visual acuity was recorded. OCT was performed by using Stratus Carl Zeiss OCT through dilated pupil by an experienced operator. The retinal thickness was divided into 9 sections and displayed as three concentric circles including a central circle at fovea (1 mm), an inner ring (3 mm) and an outer ring (6 mm), each ring being divided into four quadrants. OCT parameters of macular thickness were analysed with baseline variables including age, gender and best corrected visual acuity.


RESULTS
The mean central foveal thickness (at foveola) was 166.30 ± 24.95 μm while the mean foveal thickness (in central 1000 microns) was 194.89±21.33 μm. There was no correlation between macular thickness and either age (r=0.109, p=0.275) or gender (Eta=0.128) or best corrected visual acuity (Eta=0.234).


CONCLUSION
Reference values were determined for mean retinal thickness in healthy eyes from north-west Punjab through OCT. These measurements were upto 54-μm higher and upto 29 μm lower than some previously reported healthy retinal thickness values. Therefore, normative database should be determined for the population under study based on regional and ethnic differences.