Topographic Monitoring And Progression In Patients With Keratoconus In A 4 Years Follow Up

Abstract

 

Purpose:

 

To establish the follow-up time and progression rate through topographic changes with Orbscan IIz® in a large cohort study of in keratoconus.

 

Methods:

 

Observational, prospective, comparative and transversal study. Patients with keratoconus of the Cornea and Refractive Surgery Department at the Fundación Hospital "Nuestra Señora de la Luz" I. A. P., from May 2007 to August 2011 were included. Topographic and clinical signs of keratoconus, two or more corneal topographies of both eyes from 6 months between each study, adjusted anterior and posterior BFS (best-fit sphere) were included. Patients with incomplete clinical studies and corneal topography were excluded. The corneal topograph used was Orbscan IIz ® Bausch & Lomb. Patients, were divided into 4 study groups: Group 1 (First Study Right Eye (R)), Group 2 (second study Right Eye (R)), Group 3 (First study left eye (L)), Group 4 (second study Left eye (L)).

 

Results:

 

We reviewed 15 325 corneal topographies from these 80 studies of 20 patients were included and analyzed. Forty right and 40 left eyes , 9 female and 11 male with a mean age of 30.9 years (19 to 59 years old). Average time between studies was 17.3 months. The adjusted anterior BFS: eye R were 43.54 K and eye L were 43.73; and adjusted posterior BFS: eye R 54.28K and eye L 54.67K. The difference posterior Value was: Group 1 0.077mm to Group Group 2 0.097mm; Group 3 0.0837mm to Group 4 0.1402mm, respectively. The average keratometry: Group 1: 48.0165DK, Group 2: 48.455DK, Group 3: 48,847, Group 4: 48,328. The average pachymetry: Group 1: 474.15 µm to Group 2: 463 µm to Group 3: 468 µm to Group 4: 456.3 µm, respectively.

 

Conclusions:

 

Corneal topography with Orbscan IIz® is a useful tool to assess progression in patients with keratoconus. These patients should have a topographic control every 6 months until progression data is not present. Patients with a refractive adaptation of contact lenses should have a topography every 12 months. The posterior BFS is a reliable parameter to assess progression data, but both anterior and posterior BFS must be set to the first area of the older study, to be comparable and correlated with consecutive studies.

 

Keywords: keratoconus • topography • clinical (human) or epidemiologic studies: natural history