Influence of Posterior Corneal Asphericity On Power Calculation Error After Laser In Situ Keratomileusis or Photorefractive Keratectomy for Myopia.

Objectives: To assess the impact of posterior corneal asphericity on postoperative calculation error using the Haigis-L and the Barrett formulas for eyes after laser in situ keratomileusis or photorefractive keratectomy (PRK).

Methods: We assessed the mean absolute error (MAE) of two power calculation formulas, Barrett true-K and Haigis-L formulas, in a retrospective analysis of 34 eyes of 34 patients who underwent cataract surgery. We performed a regression analysis between corneal parameters (anterior and posterior Q values, Kmax, K1, and K2) and the MAE of each formula.

[Frequency of reoperations after amniotic membrane transplantation].

Background: Retrospective evaluation of the frequency of reoperations after amniotic membrane transplantation for different pathologic entities.

Material And Methods: We included 81 cases of amniotic membrane transplantation (AMT), which were operated on at the university eye clinic Tübingen since 1997 and which had been followed up for at least 12 months. Patient diagnoses were subdivided as follows: conjunctival defects after tumour excision (N = 2), bullous keratopathy (N = 5), external fistula after glaucoma filtering surgery (N = 3), recurrent pterygium (N = 5), symblepharon (N = 6), corneal ulcer with descemetocele (N = 3), non-perforated corneal ulcer (N = 51), perforated corneal ulcer (N = 1), other (n = 5).