Purchase this article with an account.
Vinod K. Maseedupally, Paul Gifford, Helen A. Swarbrick; Hemi-meridional Differences In Corneal Topography In Relation To Ethnicity And Eyelid Morphometry. Invest. Ophthalmol. Vis. Sci. 2011;52(14):4191.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To study hemi-meridional differences in corneal topography of East Asians and non-East Asians and relate these to eyelid morphometry.
External eye photographs were captured with the Nikon D5000 digital SLR camera. Corneal topography was determined using the Medmont E300 topographer. The corneal geometric center was taken as the reference center for corneal topographic variables. Asphericity (Q) for eight hemi-meridians was determined from topographic raw data using the least squares method. Eyelid morphometric variables were quantified from external eye images using I-Metrics software. Analysis of variance (ANOVA) was used to compare hemi-meridional Q-values within ethnic groups. To analyse differences in corneal topography and eyelid characteristics between ethnicities, independent sample t-tests were used. Pearson correlation was used to relate corneal parameters and eyelid morphometry.
Thirty-five East Asians (22.4±2.3 yrs) and 35 non-East Asians (24.1±3.6 yrs) were enrolled in the study. For East Asians the nasal hemi-meridian was the most prolate (Q=-0.39±0.21), whereas the supero-nasal hemi-meridian was the most prolate (Q=-0.38±0.25) in non-East Asians. The least prolate hemi-meridians were supero-temporal (Q=-0.11±0.19) and infero-temporal (Q=-0.15±0.15) for East Asians and non-East Asians respectively. ANOVA showed significant variation in mean hemi-meridian Q-values for both East Asians (p<0.001) and non-East Asians (p=0.003), but only supero-temporal and temporal hemi-meridians showed statistically significant differences between ethnic groups. Most eyelid morphometry features showed significant differences between ethnic groups. Significant correlations were found between lower eyelid and corneal parameters in East Asians, whereas correlations were less consistent in non-East Asians.
Differences were found in hemi-meridional corneal topography between East Asians and non-East Asians. Corneal topography parameters correlated with eyelid morphometry, particularly in East Asians.
This PDF is available to Subscribers Only