Evaluation of 30- and 25-diopter intraocular lens implants in equine eyes after surgical extraction of the lens

Am J Vet Res. 2010 Jul;71(7):809-16. doi: 10.2460/ajvr.71.7.809.

Abstract

Objective: To determine appropriate intraocular lens (IOL) implant strength to approximate emmetropia in horses.

Sample population: 16 enucleated globes and 4 adult horses.

Procedures: 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 and clinical relevance: Insertion of 30-D (enucleated globes) and 25-D IOL implants (adult horses) resulted in overcorrection of refractive error.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anterior Chamber / surgery
  • Anti-Bacterial Agents / administration & dosage
  • Anti-Bacterial Agents / therapeutic use
  • Euthanasia, Animal
  • Eye Enucleation / methods
  • Eye Enucleation / veterinary
  • Horse Diseases / surgery*
  • Horses
  • Lens Implantation, Intraocular / methods
  • Lens Implantation, Intraocular / veterinary*
  • Lens, Crystalline / anatomy & histology
  • Lens, Crystalline / surgery*
  • Lenses, Intraocular / veterinary*
  • Refraction, Ocular / physiology
  • Refractive Errors / therapy
  • Refractive Errors / veterinary*
  • Refractive Surgical Procedures / methods
  • Refractive Surgical Procedures / veterinary*

Substances

  • Anti-Bacterial Agents