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Late-onset refractive shift after small-aperture corneal inlay implantation
Alfredo Amigó1, Paula Martinez-Sorribes1, Margarita Recuerda1
1From Instituto Oftalmológico Amigó, Santa Cruz de Tenerife, Spain.
Journal of Cataract and Refractive Surgery
|June 13, 2018
Summary
Small-aperture corneal inlays may cause late refractive changes, such as hyperopic or myopic shifts, potentially due to reduced fluid diffusion at shallower implantation depths. Further investigation is warranted.
Area of Science:
- Ophthalmology
- Corneal Surgery
- Visual Optics
Background:
- Small-aperture corneal inlays are devices used to improve vision.
- The Kamra ACI7000PDT is a specific type of small-aperture corneal inlay.
- Previous approvals noted a low incidence of late refractive changes after implantation.
Observation:
- Five cases of Kamra inlay implantation at depths of 200-250 μm were reviewed.
- Initial outcomes were favorable with good visual results and stromal healing.
- Late refractive shifts (hyperopic and myopic) occurred between 6 and 19 months post-surgery in 4 out of 5 patients.
Findings:
- Late hyperopic shifts were observed in 4 patients, and a myopic shift in 1 patient.
- Topical steroid treatment was ineffective in managing these refractive changes.
- Inlays were explanted in 2 cases due to adverse refractive events.
Implications:
- A higher frequency of late refractive changes than previously reported suggests a potential issue.
- The study hypothesizes that decreased nutritional fluid diffusion to the anterior stroma, exacerbated by shallower implantation depths, may cause these changes.
- This warrants further investigation into optimal inlay placement depth and potential biomaterial interactions.
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