[Characteristics of corneal topography in candidates for surgery for myopia].
BACKGROUND
Videokeratography analyses the corneal anterior topography. It is necessary in refractive surgery to estimate the anatomical effect of the surgery and to eliminate early Keratoconus.


METHODS
Corneal anterior topography was studied on 70 consecutive patients (140 eyes) candidates for low myopia surgery (-1 to -6); 87 eyes were wearing regularly contact lenses. With the topographic analysis machine of EYESYS compagny, keratometry (Km) at 3 mm, astigmatism (delta K) at 3 mm, I-S value at 3 mm and 5 mm according to Rabinowitz method were measured in each eye.


RESULTS
The average keratometry was 43.50 +/- 1.87 D. The average astigmatism was 0.909 +/- 0.75 D. 51 eyes presented an asymmetric corneal and among them 32 ware contact lenses regularly; 8 eyes out of 140 (6%) presented the association of an high central Keratometry value (> or = 47 D) and corneal asymmetry (I-S > 0.5 value).


CONCLUSIONS
The incidence of Keratoconus is higher in a candidate population for refractive surgery by self-selection. Its frequency is difficult to evaluate accurately because of the present limits for the diagnostic measures. In this population, it seems to represent about 6%.


CONCLUSIONS
The videokeratography before refractive surgery is necessary to reveal corneal anterior topography abnormalities and to eliminate early Keratoconus.
Agossou
K
K
Service d'Ophtalmologie, Unité 86 de l'INSERM, Paris.
Saragoussi
J J
JJ
Assouline
M
M
David
T
T
Abenhaim
A
A
Pouliquen
Y
Y
D001251:Astigmatism / Q000473:pathology; D003315:Cornea / Q000473:pathology*; D003936:Diagnosis, Computer-Assisted; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000517:prevention & control; D008297:Male; D008838:Microcomputers; D009216:Myopia / Q000473:pathology* / Q000601:surgery; D019721:Ophthalmoscopes; D009887:Ophthalmoscopy
Caractéristiques de la topographie cornéenne des candidats à la chirurgie de la myopie.