Purpose:
Compare keratometrically and topographically in patients diagnosed with keratoconus. Assess the characteristics and differences between patients with clinical keratoconus, subclinical and healthy patients candidates for LASIK surgery
Methods:
Observational, prospective, transversal. From April 5, 2010 to October 31, 2010, patients with clinical keratoconus (KC), subclinical keratoconus (KS) and controls (C) candidates for LASIK surgery were selected; through medical record, with refraction and elevation topography (Orbscan ®), female or male.
Results:
Out of a total of 7060 medical records, which was obtained a sample of 783 patients (85 patients being eliminated by incomplete records), being analyzed a total of 1376 eyes of 688 patients. Distributed in: KC 552 patients, 88 patients KS and C 48 patients. 353 patients being male (25.7%), with an average age of 27.97 years (Std Dev 11.93) ranging in age from 7-75 years. Right eyes studied: KC 556, KS 81, C 48, left eyes studied: KC 560, KS 83, C 48. With an average age of diagnosis of keratoconus to 23.38 years, with an age range at diagnosis of 5-73 years (mean 2.82 years). The keratometry were: in the KC group.- 52.31 DK (Std Dev 5.57) with ranges of 41.21-69.00 DK; in the KS group.- 45.95 DK (Std Dev 2.40) with ranges of 42.37- 53.26 DK; in the C group.- 45.95 DK (Std Dev 2.40) with ranges 42.37-53.26 DK [p = 0.0000]. The posterior BFS were: in the group KC 59.93 DK (Std Dev 2.59) with ranges of 47.00-56.7 DK; in the KS group.- 54.01 DK (Std Dev 2.33) with ranges of 47.20-60.50 DK; in the C group 54.01 DK group C (Std Dev 2.33) with ranges of 47.20-60.50 DK [p = 0.261]. The BFS ratio posterior / anterior were: in the KC group 1.27 (Std Dev 0.431) ranging from 1.09-1.52; in the KS group 1.24 (Std Dev 0.026) with ranges of 1.19-1.36; in the group C 1.24 (Std Dev 0.026) with ranges of 1.19 - 1.36 [p = 0.051].
Conclusions:
Patients diagnosed with keratoconus accounted for 11.09% of the consultation valued for 6 months. The keratometry are more indicative value among patients with clinical keratoconus, subclinical and controls. The coefficient BFS and posterior BFS are not specific for diagnosing patients with subclinical keratoconus and healthy. The posterior BFS helps to differentiate patients with clinical keratoconus and healthy patients candidates for LASIK.
Keywords: keratoconus • clinical (human) or epidemiologic studies: risk factor assessment • topography