Comparison of Endothelial Cell Loss After Phacoemulsification Performed by Third Year Residents and Anterior Segment Surgeons Alexandra Braunstein, MD Eric Wolf, MD Columbia University Harkness Eye Institute New York, New York . Neither author has any financial interest in the material presented.
Purpose To present a case series of endothelial cell loss secondary to uncomplicated phacoemulsification with posterior chamber intraocular lens implantation performed by third year residents at various points in their training and anterior segment surgeons at a university teaching hospital in order to examine the rate at which resident surgical skills approach that of attendings
Background Adequate function of the endothelial cells is necessary for a perfectly clear cornea. It is thought that if a critical number of cells do not remain the lose of function will result in pathology such as edema and bullous keratopathy. Specular microscopy helps to estimate the morphology and cell count of the corneal endothelium in vivo long before clinical signs of decompensation occur. Endothelial Cell count has utility in the selection of eyes for intraocular surgery and for evaluating donor corneas. It is generally accepted that there is a gradual decline in endothelial cell count with age. The average child has ~3500 cells/mm2. The average adult has ~ 2400 cells/mm2 (1500-3500).
Methods Prospective Case Series Fifteen patients who underwent uncomplicated phacoemulsification with PCIOL from July 2008 thru December 2008. 11 surgeries were performed by third year residents and 4 by an anterior segment attending. There was no randomization or masking of patients. Resident cases were selected from patients at the resident clinic with visually significant cataracts. The attending cases were selected from his private practice.
Methods Patients had endothelial cell counts performed prior to surgery and at three months post-operatively. Cell Density was used to calculate data. Endothelial cell loss in each eye was analyzed and an average number was obtained for all cases, as well as, an average over predetermined time period of three two month blocks for the residents. Block One: July and August 2008 Block Two: September and October 2008 Block Three: November and December 2008
Exclusion Criteria: History of corneal disease in the studied eye. History of prior ocular surgery in the studied eye. Patients who had additional surgery performed at the time of cataract extraction, such as glaucoma filtering surgery or vitrectomy. Complications during the surgery, such as posterior capsule tears. Use of iris expansion devices during surgery, such as iris hooks.
Results Average endothelial cell count loss for the attending physician was 701 Average of all resident case endothelial cell count loss was 566.32 Block One Block Two Block Three Avg. ECL 874.3 648 364.6
Trend of ECL over six months
Study Limitations Small sample size Classification and severity of cataracts extracted were not taken into account. The residents endothelial cell counts were obtained from a different specular microscope than the attending. Specular microscope operator variability. Type of IOL was not taken into account. (ie. Accommodative v. toric) Polymegethism and Pleomorphism were not taken into account. Limited follow up time of three months.
Conclusions The study did demonstrate a trend that residents The sample size was too small to provide statistically significant data. Further studies with longer follow up, larger sample size and more detailed analysis of patient variability is needed to support the trend of improvement noted in this study. The study did demonstrate a trend that residents showed a considerable decrease in the loss of endothelial cells as they gained surgical experience
References Effect of age on the endothelial cell count in the normal eye.R S Wilson and M J Roper-Hall, Br J Ophthalmol. 1982 August; 66(8): 513–515. Changes in the corneal endothelial cell count as a function of age. Panda A, Venkataswarlu K, Angra SK, Mohan M. Indian J Ophthalmol 1985;33:221-3 Normal Endothelial Cell Density Range in Childhood Paolo Nucci, MD; Rosario Brancato, MD; Marilyn B. Mets, MD; Steven K. Shevell, PhD Arch Ophthalmol. 1990;108(2):247-248. Risk factors for endothelial cell loss after phacoemulsification surgery by a junior resident, ,Journal of Cataract & Refractive Surgery, Volume 30, Issue 4, Pages 839-843 Comparison of endothelial cell loss and phacoemulsification energy during endocapsular phacoemulsification surgery Zetterstrom C., Laurell C.-G. Journal of Cataract & Refractive Surgery, 1995, vol. 21, no1, pp. 55-58