Abstract
Purpose: :
To evaluate higher order aberrations induced by different types of early senile cortical and nuclear cataracts.
Methods: :
Hartmann-Shack aberrometer WASCA Wavefront Analyzer (Carl Zeiss Meditec) was used to measure total and higher order aberrations including the third and the fourth Zernike (Z) polynomials of 124 eyes with early senile cataracts (62 patients) prior to phacoemulsification. Patients were divided into two groups based on the type of their cataract: 84 eyes (42 patients) had typical cortical cataract (group I), and 40 eyes (20 patients) had typical nuclear cataract (group II). Patients’ age ranged from 33 to 72 years.
Results: :
Mean (±Standard Deviation) total aberrations (PVOPD) were similar in both groups: 7.98±1.12 micron in group I and 7.62±1.32 microns in group II. RMS PVOPD were 1.96±0.88 and 1.85±0.98 microns, respectively. Mean (±Standard Deviation) higher order aberrations (PVOPDHO) were 3.22±1.06 and 3.18±1.15 microns, respectively. Mean (±Standard Deviation) horizontal coma (Z3, Z1) was 0.620±0.234 microns in group I, and 0.162±0.261 microns in group II (p<0.01). Spherical aberration (Z4, Z0) was 0.220±0.214 microns in group I, and 0.580±0.198 microns in group II (p<0.01). <BR>
Conclusions: :
Different types of senile cataracts caused different changes of wavefront aberrations. Nuclear cataracts induced higher levels of spherical aberrations, than cortical cataracts. On the contrary, cortical cataracts induced more significant coma aberrations, than nuclear cataracts.
Keywords: aberrations • cataract • anterior segment