RESUMO
To measure the corneal thickness and the depth of the precorneal tear film of contact lens wearers with keratoconus or keratoplasty and to reconfirm the identification and classification of the keratoconus with optical coherence tomography (OCT). The cornea and precorneal tear film of 123 eyes with keratoconus, of 39 eyes after keratoplasty and 8 eyes after LASIK were examined with an OCT (Zeiss Visante) and a keratograph (Oculus). Visual acuity was determined. The mean age of all patients was 42.7 years (sigma = 9). There were 35% female patients and 65% were male patients. The central corneal thickness of 123 eyes with keratoconus was 467 +/- 73 microm. The nasal and especially the inferior corneal periphery exhibit a 9% lesser thickness (426 +/- 83 microm). The cornea with keratoconus is thinner in the 90 degrees meridian, than in the 180 degrees meridian (p < 0.01). This could be a clinically relevant result for the reduction of astigmatism after keratoplastic surgery. The central corneal thickness of 39 eyes with keratoplasty was 555 +/- 65 microm. These eyes showed peripheral parts with even less thickness. The thickness of the precorneal tear film of 114 contact lens wearers with keratoconus was 89 +/- 42 microm in the horizontal meridian, 113 +/- 56 microm in the vertical meridian. All the comparative results in case of keratoconus, keratoplasty and the depth of the precorneal tear film had high statistical significance (p < 0.001). Optical coherence tomography is particularly suitable for the examination of eyes with keratoconus and keratoplasty. It delivers new insight into corneal thickness of eyes with keratoconus and keratoplasty.
