title: Evaluation of 30- and 25-diopter intraocular lens implants in equine eyes after surgical extraction of the lens.
abstract: OBJECTIVE
  To determine appropriate intraocular lens (IOL) implant strength to approximate emmetropia in horses.
  
  
  METHODS
  16 enucleated globes and 4 adult horses.
  
  
  METHODS
  Lens diameter of 10 enucleated globes was measured. Results were used to determine the appropriate-sized IOL implant for insertion in 6 enucleated globes and 4 eyes of adult horses. Streak retinoscopy and ocular ultrasonography were performed before and after insertion of 30-diopter (D) IOL implants (enucleated globes) and insertion of 25-D IOL implants (adult horses).
  
  
  RESULTS
  In enucleated globes, mean +/- SD lens diameter was 20.14 +/- 0.75 mm. Preoperative and postoperative refractive state of enucleated globes with 30-D IOL implants was -0.46 +/- 1.03 D and -2.47 +/- 1.03 D, respectively; preoperative and postoperative difference in refraction was 2.96 +/- 0.84 D. Preoperative anterior chamber (AC) depth, crystalline lens thickness (CLT), and axial globe length (AxL) were 712 +/- 0.82 mm, 11.32 +/- 0.81 mm, and 40.52 +/- 1.26 mm, respectively; postoperative AC depth was 10.76 +/- 1.16 mm. Mean ratio of preoperative to postoperative AC depth was 0.68. In eyes receiving 25-D IOL implants, preoperative and postoperative mean refractive error was 0.08 +/- 0.68 D and -3.94 +/- 1.88 D, respectively. Preoperative AC depth, CLT, and AxL were 6.36 +/- 0.22 mm, 10.92 +/- 1.92 mm, and 38.64 +/- 2.59 mm, respectively. Postoperative AC depth was 8.99 +/- 1.68 mm. Mean ratio of preoperative to postoperative AC depth was 0.73.
  
  
  CONCLUSIONS
  Insertion of 30-D (enucleated globes) and 25-D IOL implants (adult horses) resulted in overcorrection of refractive error.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: McMullen
authors.forename: Michael G
authors.initials: MG
authors.lastname: Davidson
authors.forename: Nigel B
authors.initials: NB
authors.lastname: Campbell
authors.forename: Jacklyn H
authors.initials: JH
authors.lastname: Salmon
authors.forename: Brian C
authors.initials: BC
authors.lastname: Gilger
mesh_terms: D000818:Animals; D000867:Anterior Chamber / Q000601:surgery; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use; D037901:Euthanasia, Animal; D015353:Eye Enucleation / Q000379:methods / Q000662:veterinary; D006734:Horse Diseases / Q000601:surgery*; D006736:Horses; D019654:Lens Implantation, Intraocular / Q000379:methods / Q000662:veterinary*; D007908:Lens, Crystalline / Q000033:anatomy & histology / Q000601:surgery*; D007910:Lenses, Intraocular / Q000662:veterinary*; D012029:Refraction, Ocular / Q000502:physiology; D012030:Refractive Errors / Q000628:therapy / Q000662:veterinary*; D054140:Refractive Surgical Procedures / Q000379:methods / Q000662:veterinary*
chemical_list: D000900:Anti-Bacterial Agents