[Pathogenetic basis for treatment of primary keratoconus by a combined method of excimer laser surgery (combination of photorefraction and phototherapeutic keratectomy)].
Bearing in mind that the pathological process in keratoconus starts with anterior corneal layers and is gradually progressing into inner corneal parts we put a question whether a pathological process can be stopped by affecting the anterior layers of the cornea. This paper presents the results of 5-year experience excimer laser surgery, a combination of photorefractive and phototherapeutic keratectomy (PRK + PTK) in the treatment of the initial keratoconus. The diagnosis of early keratoconus was based upon computed tomographic data, pachymetry in 5 points, and biomicroscopy of the cornea. The "firework" symptom a stromal ramification area that corresponds to the future apex of the keratoconus is described. PRK was performed with an ablation zone of 6 mm, and the transitional zone of 7 mm. The ablation zone in PhTk was dislocated towards the most ectasia--conical apex, topography and the apex site were predetermined of computed tomography. The PTK was performed with ablation zone of 8.00 mm and transitional zone of 9 mm. The described method allowed the authors to increase average uncorrected acuity of vision from 0.07 +/- 0.003 to 0.76 +/- 0.03. At the same time the acuity of vision was 1.0 in 69.2% of the eyes to enhance the mean corrected acuity of vision from 0.70 +/- 0.03 to 0.83 +/- 0.04. 2 by gradually progressing significantly to decline the degree of ametropia. The spherical component of refraction--myopia--decreased from 5.32 +/- 0.62 to 1.55 +/- 0.3 D. The cylindrical component of refraction myopic astigmatism reduced from 3.25 +/- 0.53 to 1.75 +/- 0.25 D. 3 to stop the progression of keratoconus in 91.3% of cases at a follow-up of 40.8 +/- 1.5 months (3 years 4 months) and at the maximal follow-up of 5.5 years. Thus, PRK + PTK with pathogenetically based, effective method in the treatment of the patients with initial keratoconus.
Kasparova
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D006801:Humans; D007640:Keratoconus / Q000601:surgery*; D054018:Lasers, Excimer; D018903:Photorefractive Keratectomy