Abstract
Purpose: :
To establish a realistic and practical model for teaching the continuous curvilinear capsulorhexis (CCC) in cataract surgery.
Methods: :
Whole enucleated rabbit eyes were subjected to intraocular perfusion using one of three fixative treatment conditions, 2% paraformaldehyde (PFA) for 6 hours, 4% PFA for 30 minutes, and 4% PFA for 1 hour. Separately, explanted rabbit lenses were extracted and subjected to immersion in the same treatment conditions. Custom rabbit eye and lens holders were used to secure the preparations. Five cataract surgeons each with a minimum of 5 years experience performed a CCC on treated eyes and lenses per their usual fashion. The treatment conditions for the various specimens were masked, and the surgeons rated the lens capsule biomechanical properties encountered in each specimen in terms of similarity to that encountered in infants, children, adults, or the elderly. Surgeons also commented on how the performance of the CCC in fixative-treated enucleated rabbit eyes compared to a CCC performed in human eyes in vivo.
Results: :
Explanted lenses treated with the 2% PFA for 6 hours, 4% PFA for 30 minutes, and 4% PFA for 1 hour were judged to resemble performance of a CCC on patients roughly 20, 70, and 50 years of age, respectively. The eyes treated with 4% PFA for 30 minutes were graded as most resembling the elderly human capsule. Whole eyes treated with 2% PFA for 6 hours, 4% PFA for 30 minutes, and 4% PFA for 1 hour were judged to resemble performance of a CCC on patients roughly 10, 20, and 50 years of age, respectively. Both explanted lenses and enucleated eyes were judged as providing realistic capsule biomechanical properties, with enucleated eyes additionally providing anterior chamber dimensions resembling those of the human eye. However, enucleated eyes exhibited variably dilated pupils and corneal clarity.
Conclusions: :
The majority of cataract surgery teaching models described in the literature focus on lens removal. Few have been developed explicitly for teaching the CCC, and none have involved model assessment by a panel of experienced surgeons. The model described is inexpensive, easy to prepare, and mimics the range of elasticity encountered in various patient populations, including the elderly human. As such it provides a realistic CCC practice model for the beginning cataract surgeon and may also have utility in teaching pupil expansion techniques.
Keywords: training/teaching cataract surgery • anterior segment