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Position-dependent accommodative shift of retropupillary fixated iris-claw lenses
1Department of Ophthalmology, University Medical Center of the J.-Gutenberg University, Langenbeckstr. 1, 55131, Mainz, Germany. kilian.schoepfer@unimedizin-mainz.de
Summary
Head position significantly impacts objective refraction and anterior chamber depth after retropupillary iris-claw lens implantation. These changes, affecting pseudophakic accommodation, are crucial for understanding visual outcomes with these intraocular lenses.
Area of Science:
- Ophthalmology
- Optics
- Biomedical Engineering
Background:
- Retropupillary fixated iris-claw lenses (e.g., Artisan®/Verisyse®) are used for refractive correction.
- Patient head position can influence intraocular lens (IOL) position and optical outcomes.
- Understanding these positional effects is vital for predicting visual performance.
Purpose of the Study:
- To evaluate and quantify changes in objective refraction after retropupillary iris-claw lens implantation.
- To identify factors influencing these refractive and positional changes.
- To correlate head position with anterior chamber depth and refractive error.
Main Methods:
- Retrospective analysis of 51 eyes (49 patients) with retropupillary iris-claw lenses.
- Measurement of refraction, visual acuity, and anterior chamber depth in primary, forward-tilted, and backward-tilted head positions.
- Utilized mobile auto-refractometer, acoustic biometry, IOL-Master, and other devices.
Main Results:
- Significant, position-dependent changes in anterior chamber depth were observed (median difference: 0.155 mm).
- Refraction showed a significant difference (0.37 D) between forward- and backward-tilted head positions.
- A smaller spherical equivalent was noted with forward head tilt (mean: -0.438 D) compared to backward tilt (mean: -0.065 D).
Conclusions:
- Iris-claw lens position shifts significantly alter anterior chamber depth and objective refraction.
- These shifts explain phenomena like pseudo-myopia and pseudo-hyperopia, contributing to pseudophakic accommodation.
- No significant influence on visual acuity based on head position was found.
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