Session Title: Surface Ablation I
Session Date/Time: Sunday 06/10/2013 | 08:00-09:30
Paper Time: 09:18
Venue: Main Lecture Hall (Ground Floor)
First Author: : A.Muzychuk CANADA
Co Author(s): : E. Sanders W. Astle P. Huang
Purpose:
The purpose of this pilot study is to investigate the effects of pediatric refractive surgery (LASEK) on corneal endothelial cell counts and morphology.
Setting:
Although laboratory evidence suggests human corneal endothelial cells retain the ability to proliferate, if this does occur in vivo it is at such a slow rate that researchers in the past have been unable to detect it. Damage to the endothelium is repaired predominantly by migration and enlargement of existing cells. Endothelial cell counts decrease with age, from approximately 5000 cells/mm2 at birth to 1500-2000 cells/mm2 in adulthood. Damage to the endothelium at a young age could theoretically lead to devastating consequences that may not manifest until later in life. All of these pediatric eyes underwent LASEK at a non-hospital laser surgical center.
Methods:
A retrospective chart review was conducted. Patients who underwent LASEK under the age of 18 with Confoscan imaging at the pre and post refractive surgery office visits were included. A single blinded observer chose the three clearest images on each patient which were subsequently imported into Konan Cell Analysis Software (Konan Cell Chek XL) 100 cells on each image were manually identified in keeping with standard optimal cellular analysis procedures. The average readings of the three images were collected. Images yielding a coefficient of variation greater than 99 were excluded with the average of the remaining readings included.
Results:
15 eyes of 11 patients were included in the study. Mean age at LASEK was 12.3 years (r =6.8-17.0) with 4 males and 7 females. Pre laser the mean central corneal thickness was 554±59.4µm. (r= 431-625µm) The baseline mean endothelial cell count was 6322±721cells/mm2 (r= 5241-7434cells/mm2) with a mean coefficient of variation of 53.6. Patients had on average 52.3±11.8% (r=36.0-74.3%) hexagonal cells with a mean cell size of 160.52±18.5µm2 (r=134.7-191.0µm2) and a mean standard deviation in cell size of 88.17µm2. Post laser the mean cell count increased slightly to 6354±857cells/mm2 (r=5140 - 7888cells/mm2) with a mean coefficient of variation of 55.0. The percentage of hexagonal cells increased slightly to 52.7±10.7%, mean cell size slightly increased to 160.99±22.7µm2 with a mean standard deviation in cell size of 90.9µm2.
Three patients who underwent the largest spherical equivalent laser corrections of -8.00, -13.00 and
-17. 00 had changes in cell counts from baseline of +899.7, +1699.7 and -649.7cells/µm2 respectively.
Conclusions:
Advances in amblyopia treatment modalities have demonstrated that children with complex forms of amblyopia can be effectively treated with combinations of glasses, contact lenses, patching and atropine penalization. There is, however, a subset of these patients who fail these more traditional forms of treatment. Detractors of pediatric refractive surgery as an emerging treatment modality for this subset of patients often cite safety concerns, although no major complications have been borne out in the pediatric refractive literature beginning nearly two decades ago.
In agreement with data from adult refractive surgery, our study suggests that advanced surface ablations such as LASEK, in pediatric populations, do not have an obvious adverse effect on the health of the corneal endothelium.
Financial Interest:
NONE
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