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Intraocular lens power calculation for the equine eye
Ulrike Meister1, Christiane Görig2, Christopher J Murphy3
1Stiftung Tierärztliche Hochschule Hannover, Klinik für Pferde, Bünteweg 9, 30559, Hannover, Germany. Ulrike.Meister@t-online.de.
BMC Veterinary Research
|April 5, 2018
Summary
An 18.5 D intraocular lens (IOL) is recommended for equine cataract surgery to achieve optimal vision. Accurate IOL power calculation using retinoscopy, keratometry, and biometry is crucial for successful outcomes in horses.
Area of Science:
- Veterinary Ophthalmology
- Equine Surgery
Background:
- Cataract surgery with intraocular lens (IOL) implantation is increasingly common in horses.
- Accurate IOL power calculation is essential to minimize postoperative refractive errors.
Purpose of the Study:
- To determine the appropriate intraocular lens (IOL) power for horses undergoing cataract surgery.
- To evaluate the influence of breed, height, gender, and age on refractive measurements.
Main Methods:
- Retinoscopy, keratometry, and ultrasonographic biometry were performed on 98 healthy equine eyes.
- IOL power was calculated using Binkhorst and Retzlaff theoretical formulas.
- Statistical analysis was conducted to assess influencing factors and compare left/right eyes.
Main Results:
- The mean refractive state was +0.32 ± 0.66 D.
- Corneal curvature varied by breed, ranging from 20.02 D (Friesian) to 23.77 D (Shetland pony).
- Calculated IOL power ranged from 18.03 D to 19.55 D, with a mean of 18.73 D (Binkhorst) and 18.54 D (Retzlaff).
Conclusions:
- An 18.5 D IOL appears most suitable for achieving emmetropia after cataract surgery in horses.
- Performing retinoscopy, keratometry, and biometry is recommended for all affected horses.
- Postoperative visual outcomes should be systematically determined to ensure surgical success.
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