# Intraocular lens calculation for cataract surgery in high myopia: a case report of an extreme axial eyeball length of 35.7 mm

## TL;DR

This case report describes successful cataract surgery in a patient with an extremely long eyeball (35.7 mm), highlighting the importance of special intraocular lens calculations for high myopia.

## Contribution

The paper presents a rare case of cataract surgery in an eye with extreme axial length and demonstrates successful outcomes using specific intraocular lens considerations.

## Key findings

- A 35.7 mm axial length eye underwent cataract surgery with a minus-power IOL and achieved stable postoperative results.
- Using a larger-diameter IOL (Bigfoot IOL) and careful calculations led to improved binocular vision and quality of life.
- Special considerations in IOL selection and calculation are crucial for eyes with extreme myopia to avoid refractive errors.

## Abstract

Extreme axial eyeball length is a known risk factor for decreased accuracy of intraocular lens calculations. We report a case of a 35 years-old male with anisometropic amblyopia and an axial length of 35.7 mm in his right eye. To the best of our knowledge, this is a case of one of the longest eyeballs ever scientifically reported. The patient presented with presenile cataracts in the right eye, hand movement visual acuity, and required cataract surgery. Due to his high anisometropia, he was unable to wear spectacle correction prior to surgery in the amblyopic eye. The left (non-amblyopic) eye had moderate myopia and corrected to 20/20 with no signs of cataracts. Various intraocular lens (IOL) calculations were compared, aiming for a slight postoperative residual myopia in the right eye (approx. −1.50 D). The patient required a minus-power intraocular lens, and an IOL with a larger overall diameter (model 92S “Bigfoot IOL” manufactured by Morcher GmbH, Stuttgart, Germany) was selected. On the last available visit at 6 months, his refractive error was −1.50 to −0.75 D × 179° with a corrected visual acuity of 20/63. The large IOL was stable in the capsular bag, and there were no postoperative complications. The patient was able to wear spectacles with correction in both eyes and reported significant improvement in binocular vision and quality of life. Negative power IOLs typically have different optic configurations and require special considerations during IOL calculation. Care should be taken to avoid postoperative hyperopic refractive error. Nowadays, surgeons can choose from a selection of traditional formulas, newer-generation formulas, and axial length adjustment techniques to improve refractive predictability of eyes with extreme axial myopia. With this case report, we would like to demonstrate that even in rare cases of extreme, high myopia and eyeball length > 35 mm, good results can be achieved with correct IOL power implantation if certain considerations are made prior and during the procedure. Special considerations should be taken into account to maximize patient satisfaction.