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Michael C Knorz

Publications and source records attributed to Michael C Knorz.

2 recordsLinked to original sources

[Refractive benefit and incremental costs of LASIK: results of a cost benefit study in two universities' LASIK departments].

BACKGROUND: No data is available to date on the cost effectiveness of laser in situ keratomileusis (LASIK) with regard to the German-speaking health care system. Hence we compared the clinical outcome and cost data of two German LASIK centres in respect of procedure cost effectiveness from the patient perspective. MATERIAL AND METHODS: A retrospective cohort study was implemented at the University Hospitals of Mainz and Mannheim. Data on refractive outcome were obtained from the LASIK centres' patient documentation, cost data on the surgery as well as on eyeglasses etc. before and after the surgery were obtained from patient interviews. The primary endpoint of this investigation was the individual incremental cost effectiveness ratio linking direct cost with the LASIK associated refractive gain. RESULTS: Clinical and economical data of 178 patients (Mainz: 45, Mannheim 133) was evaluated. After biplanar simultaneous LASIK 71% (Mainz) and 73% (Mannheim) reported, that they did not need eyeglasses etc. any longer after surgery; 31% (Mainz) versus 13% (Mannheim) had to undergo LASIK re-treatment. Median direct cost for the surgery was reported to be 3000 euro; (Mainz) versus 3910 euro; (Mannheim); the corresponding LASIK associated refractive gain was +5.6 D (median Mainz) versus +4.2 D (median Mannheim), resulting in median incremental cost effectiveness ratios of 667 euro; (Mainz) versus 831 euro; (Mannheim) per gained refractive unit. This investment has to be related to median annual cost of 250 euro; for eyeglasses etc. before surgery and 0 euro; afterwards. CONCLUSION: Depending on the performing surgical centre, German LASIK patients have to face a median investment of 667-831 euro; per gained refractive benefit unit. This incremental cost benefit ratio can be regarded as a surrogate parameter for comparison with alternative surgical or conservative treatment strategies in myopia.

Adolescent↗

Flap and interface complications in LASIK.

Flap complications using first-generation microkeratomes, such as the Automated Corneal Shaper, were reported in 2.5% (27 of 1,062 eyes). With modern microkeratomes, such as the Hansatome, keratotomy-related complications dropped to 0.16% (46 of 28,201 eyes). Postoperative flap complications, such as flap slippage, occurred in 1.42% (21 of 1,418 eyes), most of them during the first hour after surgery. Interface complications are a new diagnostic entity as the interface between flap and stroma presents an empty space where fluid or cells can accumulate. Diffuse lamellar keratitis usually occurs within the first postoperative days but may also develop later on, triggered, eg, by recurrent corneal erosion. Epithelial ingrowth is a rare complication caused rather by postoperative invasion than by intraoperative implantation, which suggests that the quality of the flap edge and its apposition are very important. Interface fluid is a rare but important phenomenon related to steroid-induced glaucoma but presenting with falsely low tonometry readings.

Corneal Diseases↗