Exploring IOL Options for Yamane Scleral Fixation

Findings from a bench study investigating haptic tensile strength support the suitability of the Light Adjustable Lens (LAL) for Yamane scleral fixation.

“After our experiment, I performed my first case of Yamane scleral fixation with a LAL and can report a slight increase in difficulty handling the silicone material,” said Dr Wyche T Coleman III. “However, the result was excellent overall, with great IOL position at two weeks postoperatively. We are looking forward to reporting results after refractive adjustment in these cases.”

Dr Coleman told EuroTimes that interest in using the LAL for the Yamane technique is multifactorial.

“We were prompted to look for new options for Yamane fixation because of cases of ‘rotisserie rotation’ (rotation on one of the haptic-optic junctions) with the CT Lucia, which was our IOL of choice. It would be a bonus to find a lens with better stability and the chance of improving refractive outcomes with a non-invasive technique,” he said.

“In our practice, we have seen patients with a subluxated toric or multifocal IOL who had been glasses-independent prior to the dislocation. Although we performed LASIK for refractive correction post-scleral fixation in a few such patients, we consider that approach less than ideal for an eye that has already been through so much surgery.”

The bench study conducted by Dr Coleman and colleagues evaluated the LAL and two other three-piece IOLs—CT Lucia 602 (Zeiss) and AcrySof MA60AC (Alcon). Each IOL was held with stable haptic orientation using a custom device, and an attached tensiometer exerted force on one haptic. The recorded endpoint was maximum haptic tensile strength, defined as the force at which the optic stopped maintaining tension or broke.

The experiment used ten 24-D lenses for each IOL model. The results showed mean maximum haptic tensile strength was significantly greater for the CT Lucia 602 compared to the MA60AC and LAL (156 versus 103 and 84 g, respectively). Imaging for characterising the IOL fracture mechanism revealed 40% of the MA60AC IOLs had a fractured haptic versus none of the CT Lucia or LAL lenses. Optic fracture occurred only with the LAL (40%). The haptics were pulled out of the optic without any damage in 100% of the CT Lucia IOLs, 60% of the LALs, and 60% of the MA60AC IOLs.

“Although the LAL haptics separated at the lowest tensile force, approximately half that of the CT Lucia, the mechanism of separation with the LAL commonly involved a piece of the optic being torn off with the haptic. We believe this is most conducive to long-term stability of a Yamane-fixated lens,” said Dr Coleman.

“Our finding of haptics completely dislodging from the MA60AC optic is consistent with clinical experience. We believe this separation mechanism makes the MA60AC undesirable for the purpose of Yamane scleral fixation because it increases the likelihood of optic-haptic separation from stress caused by eye movement over time.”

The team plans to repeat their experiment with the three-piece Tecnis ZA9003 lens, as some surgeons use it to perform Yamane scleral fixation.

Dr Coleman presented his study at ARVO 2023 in New Orleans, Louisiana, US.

Wyche T Coleman III MD is an ophthalmologist in the Willis-Knight on Health System, Shreveport, Louisiana, US. wychetcoleman@gmail.com