title: Porcine cataract creation using formalin or microwave treatment for an ophthalmology wet lab.
abstract: OBJECTIVE
  Wet labs are an important part of ophthalmology residency training in order to develop intraocular surgical proficiency. The purpose of this study was to compare the effectiveness of formalin versus microwave treatment to produce porcine cadaveric cataracts.
  
  
  METHODS
  This study was a comparative observational study at a single centre.
  
  
  METHODS
  Cataracts were created through the injection of 0.1 mL of 100% ethanol into the anterior chamber followed by the infiltration of 0.1 mL of 37% formalin using a short 30-gauge needle into the lens by introduction through the pars plana. The comparison group investigated porcine eyes treated with a microwave for 5-13 seconds using a 700 W power setting. Two observers used a validated nuclear opalescence and corneal clarity scale to independently grade the treated eyes.
  
  
  RESULTS
  In total, 70 eyes were treated with either formalin or by microwave. The formalin eyes had an average lens opacity score of 0.04 ± 0.03 and 1.91 ± 01.10 pre- and post-treatment (p < 0.001). Microwaved eyes had an average pretreatment lens opacity of score 0.10 ± 0.31, which increased to 2.86 ± 0.1.08 post-treatment (p < 0.001). Post-treatment lens opacity was significantly greater in microwave eyes than in formalin-treated eyes (p = 0.003). Pretreatment corneal clarity was 3.65 ± 0.73 in the formalin group, and 3.70 ± 0.93 in the microwave group. After treatment, there was a significant reduction in corneal clarity within the formalin (3.01 ± 1.04, p = 0.0012) and microwave groups (3.03 ± 1.07, p < 0.001).
  
  
  CONCLUSIONS
  Porcine eye models provide a realistic way to simulate cataracts and so residents can practice the basics of cataract surgery. Both microwave and formalin-based treatments are able to opacify the porcine lens with acceptable reductions in corneal clarity.
authors: Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, Alta. Electronic address: rwa.machuk@gmail.com.
authors: Robert William Andrew
authors: RWA
authors: Machuk
authors: Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, Alta.
authors: Sourabh
authors: S
authors: Arora
authors: Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, Alta.
authors: Morley
authors: M
authors: Kutzner
authors: Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, Alta.
authors: Karim F
authors: KF
authors: Damji
mesh_terms: D000818:Animals; D002386:Cataract / Q000209:etiology*; D004195:Disease Models, Animal; D004503:Education, Medical, Graduate; D005557:Formaldehyde / Q000633:toxicity*; D007908:Lens, Crystalline / Q000187:drug effects* / Q000528:radiation effects*; D008872:Microwaves; D009885:Ophthalmology / Q000193:education*; D011833:Radiation Injuries, Experimental / Q000209:etiology*; D000066908:Simulation Training; D013552:Swine; D013663:Teaching
chemical_list: D005557:Formaldehyde