Topographic screening of donor eyes for previous refractive surgery.
OBJECTIVE
To determine whether donor eyes had previous refractive surgery using Orbscan (Bausch & Lomb Surgical) corneal topography.


METHODS
Lions Eye Bank of Oregon, Portland, Oregon, USA, and Maisonneuve-Rosemont, Hospital, Montreal, Quebec, Canada.


METHODS
Orbscan corneal topographies of 50 donor eyes from the Lions Eye Bank of Oregon were obtained; 10 eyes had previous refractive surgery (6 laser in situ keratomileusis, 2 photorefractive keratectomy, 2 radial keratotomy) to correct myopia, and 40 had not had surgery. Algorithms based on corneal anterior and posterior elevations and anterior tangential curvature were developed: The difference in curvature (DC) was based on the difference in the mean anterior tangential curvature between central and midperipheral areas; difference in elevation (DE) represented the difference between the anterior and posterior central elevations. Receiver-operating characteristic (ROC) curves for each algorithm were obtained, and sensitivity values at fixed specificities were calculated.


RESULTS
The mean area under the ROC curve, which corresponds to the probability of correctly identifying the presence of a previous refractive surgery, was 0.853 +/- 0.079 (SE) for DC and 0.933 +/- 0.057 for DE. The DC algorithm resulted in a sensitivity of 80% for a specificity of 87.5%, and DE yielded a sensitivity of 90% for a specificity of 92.5%. There was a strong correlation between the value of the DE and DC algorithms and the amount of previous refractive surgery (DC: r = 0.84, P = .008; DE: r = 0.76, P = .028).


CONCLUSIONS
The results led to a proposed criteria-based system using Orbscan corneal topography to screen eye-bank eyes for previous refractive surgery.
Department of Ophthalmology, University of Montreal, Montreal, Quebec, Canada.
Sandrine
S
Hick
Jean-François
JF
Laliberté
Jean
J
Meunier
Paula J
PJ
Ousley
Mark A
MA
Terry
Isabelle
I
Brunette
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D003315:Cornea / Q000473:pathology; D019781:Corneal Topography / Q000379:methods*; D005125:Eye Banks; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D007646:Keratotomy, Radial; D054018:Lasers, Excimer; D008875:Middle Aged; D009216:Myopia / Q000175:diagnosis* / Q000601:surgery*; D018903:Photorefractive Keratectomy; D011300:Preoperative Care; D011336:Probability; D012372:ROC Curve; D012680:Sensitivity and Specificity; D014019:Tissue Donors