Purpose: 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.
Methods: 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.
Results: 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 (R2 = 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.
Conclusions: 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