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Performance of a temperature-controlled shape-memory pupil expander for cataract surgery
Royston K Y Tan1, Shamira A Perera, Tin A Tun
1From the Department of Biomedical Engineering, Ophthalmic Engineering & Innovation Laboratory (Tan, Tun, Boote, Girard), National University of Singapore, Singapore Eye Research Institute, Singapore National Eye Centre (Perera, Tun, Girard), Duke-NUS Medical School (Perera), Singapore; and Structural Biophysics Research Group, School of Optometry & Vision Sciences (Boote), Cardiff University, Wales, United Kingdom.
A novel shape-memory pupil expander demonstrated safe and effective pupil expansion in ex vivo and in vivo models. This innovative device showed no iris tissue damage, unlike existing surgical aids.
Area of Science:
- Ophthalmology
- Biomaterials Engineering
- Medical Device Development
Background:
- Pupil expansion is crucial for various ophthalmic surgical procedures.
- Existing iris expansion devices can cause complications such as iris pigment epithelial loss and sphincter tears.
- There is a need for safer and more effective pupil expansion technologies.
Purpose of the Study:
- To validate a newly manufactured, optimized shape-memory pupil expander.
- To compare the performance of the shape-memory expander against established devices.
- To assess the safety and efficacy of the shape-memory expander in ex vivo and in vivo models.
Main Methods:
- Shape-memory pupil expanders were fabricated using overmolding techniques.
- Ex vivo porcine eyes and in vivo monkey eyes were used for device validation.
- The shape-memory expander was compared to the Malyugin ring, OASIS iris expander, and iris hooks.
- Iris tissue integrity was analyzed post-device insertion and removal.
Main Results:
- The shape-memory expander successfully achieved pupil expansion in both ex vivo and in vivo settings.
- Compared to other devices, the shape-memory expander showed no observable iris tissue irregularities.
- Existing devices resulted in complications: iris pigment epithelial loss (20.0-36.4%) and sphincter tears (10.0-27.3%).
Conclusions:
- The optimized shape-memory expander effectively expands the pupil with minimal stress on iris tissue.
- Experimental validation confirms the device's efficacy and engineering design.
- This study highlights the potential of smart materials in developing advanced ophthalmic implants for improved patient outcomes.
