title: Comparison of Ocular Monochromatic Higher-order Aberrations in Normal Refractive Surgery Candidates of Arab and South Asian Origin.
abstract: OBJECTIVE
  To compare the ocular monochromatic higher-order aberration. (HOA) profile in normal refractive surgery candidates of Arab and South Asian origin.
  
  
  METHODS
  This cross-sectional, observational, comparative study was performed in the cornea department of a specialty hospital. Normal refractive surgery candidates with no ocular morbidity except refractive error were recruited. Refractive surgery candidates underwent a preoperative evaluation, including wavefront aberrometry with the iDesign aberrometer (AMO, Inc., Santa Ana, California, United States). The HOA from right eyes were analyzed for HOA signed, absolute, and polar Zernike coefficients.
  
  
  RESULTS
  Two hundred Arab participants (group 1) and 200 participants of South-Asian origin (group 2) comprised the study sample. The age and refractive status were comparable between groups. The mean of the HOA root mean square (RMS) was 0.36 ± 17 μ and 0.38 ± 18 μ for Arab and South-Asian eyes, respectively (P < 0.05, rank sum test [RST]). Of the 22 higher order signed Zernike modes, only Z3 (-3), Z3 (-1),3 (1), Z4 (-4), Z4 (-2), Z4 (0), Z4 (4), and Z5 (-5) were significantly different from zero (one sample t-test, P < 0.002, with a Bonferroni correction of 0.05/22). All the signed and absolute Zernike terms were comparable between groups (RST, P > 0.002 [0.05/22]). The polar coefficients for coma, trefoil, spherical aberration, and tetrafoil were comparable between groups (P > 0.05, RST). Combined RMS values of third, fourth, fifth, and sixth order also were comparable between groups (P > 0.05, RST).
  
  
  CONCLUSIONS
  Preoperative whole eye HOA were similar for refractive surgery candidates of Arab and South-Asian origin. The values were comparable to historical data for Caucasian eyes and were lower than Asian (Chinese) eyes. These findings may aid in refining refractive nomograms for wavefront ablations.
authors.affiliation: Department of Cornea and Refractive Surgery, NMC Eye Care, New Medical Center Specialty Hospital, Abu Dhabi, United Arab Emirates.
authors.forename: Gaurav
authors.initials: G
authors.lastname: Prakash
authors.affiliation: Department of Cornea and Refractive Surgery, NMC Eye Care, New Medical Center Specialty Hospital, Abu Dhabi, United Arab Emirates.
authors.forename: Dhruv
authors.initials: D
authors.lastname: Srivastava
authors.affiliation: Department of Cornea and Refractive Surgery, NMC Eye Care, New Medical Center Specialty Hospital, Abu Dhabi, United Arab Emirates.
authors.forename: Sounak
authors.initials: S
authors.lastname: Choudhuri
authors.affiliation: Department of Cornea and Refractive Surgery, NMC Eye Care, New Medical Center Specialty Hospital, Abu Dhabi, United Arab Emirates.
authors.forename: Ruthchel
authors.initials: R
authors.lastname: Bacero
mesh_terms: D057128:Aberrometry; D000328:Adult; D018912:Arabs / Q000208:ethnology*; D044466:Asian People / Q000208:ethnology*; D019781:Corneal Topography; D057108:Corneal Wavefront Aberration / Q000208:ethnology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D054140:Refractive Surgical Procedures
keywords: Arab Eyes; Ethinic Origin; Higher-Order Aberration; Refractive Surgery; Zernike Polynomials