The primary objective was to evaluate whether postoperative alterations in corneal shape (as reflected by keratometry values) affect endothelial cell profile measurements after deep anterior lamellar keratoplasty (DALK) in a group of patients with keratoconus. Secondary objective was to describe the pattern of changes in corneal endothelial cell profile measurements during the first 3 years after DALK.
In this prospective interventional case series, we enrolled patients who had significant keratoconus and were scheduled for DALK (Melles technique). Cases with concomitant intraocular surgeries, intra-/postoperative complications, and poor quality of images were excluded.
Two hundred one eyes and 45 eyes (of the original 201) were enrolled for evaluating the primary and the secondary objectives, respectively. At 3 months post DALK, the mean endothelial cell density (ECD) had significantly increased and the mean cell area had decreased compared with preoperative measurements (2721 vs. 2823 cells/mm2, P = 0.015; and 378 vs. 362 μm2, P = 0.005, respectively). Regression analysis revealed a weak but significant nonlinear association between changes in mean keratometry and ECD changes at 3 months (R 2 = 0.039, P = 0.02). Standard deviation of mean cell area had significantly decreased at 12 months after DALK compared with measurements taken at 3 months after surgery (P = 0.023) and remained stable thereafter.
Apparent measurements of ECD may not show a decrease but instead even a slight increase in some cases after uncomplicated DALK (Melles technique) for keratoconus. This finding along with a later decrease in standard deviation of mean cell area suggests that notable postoperative changes in corneal biomechanical forces may affect endothelial cell profile measurements.
*Department of Ophthalmology, Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
†Netherlands Institute for Innovative Ocular Surgery, Rotterdam, the Netherlands.
Reprints: Mohammad H. Nowroozzadeh, Department of Ophthalmology, Poostchi Ophthalmology Research Center, Poostchi Clinic, Shiraz University of Medical Sciences, Zand St, Shiraz, Fars 1357867534, Iran (e-mail: email@example.com).
Dr. G. R. J. Melles is a consultant for D.O.R.C. International/Dutch Ophthalmic, USA.
The authors have no funding or conflicts of interest to disclose.
Received December 16, 2011
Accepted July 22, 2012