Intraocular Polyimide IOL Haptic Breakage Long-Term Postoperatively: Report of 2 Cases
Narrative Responses:
Purpose
We present two cases of 3-piece silicone lenses with polyimide haptic breakage. The breakage in both cases occurred long term postoperatively. The purpose of this study is to describe these cases and provide laboratorial analysis, including scanning electron microscopy (SEM).
Methods
In the first case, an 86-year-old male underwent cataract surgery with implantation of a 3-piece silicone lens into the anterior chamber after posterior capsule rupture. Twelve years later, the patient was noted to have pseudophakic bullous keratopathy, and the lens was vaulted anteriorly. It was exchanged, but during explantation, one haptic broke into multiple pieces with only slight manipulation.
In the second case, initial implantation of the lens was uneventful; however, fifteen years later, the lens dislocated into the anterior chamber as a result of spontaneous haptic breakage. Both lenses were sent to our laboratory for analysis.
Results
By gross and microscopic evaluations, both lenses appeared to have jagged breaks at the optic-haptic junction, close to the insertion points of the loops into the optic. Manipulation of both specimens with forceps caused further haptic breakage in both loops of each lens. Under SEM, the broken edges of the haptics of both lenses appeared asymmetrical, with no pattern of breakage. Inspection of the surface of the loops in both cases revealed a smooth surface with surface deposits which appeared to correspond to protein deposits and salts. No signs of obvious degradation were found on the surface of all loops.
Conclusion
The degradation of nylon and PVDF has been extensively studied; however, to the best of our knowledge, this is the first report describing loss of elasticity of polyimide loops leading to breakage and associated clinical consequences. More research is needed to determine the cause of this phenomenon.