Study shows feasibility of customized lenticules in eccentric keratoconus
Key takeaways:
- Ex vivo models of eccentric keratoconus and different types of lenticules were created.
- More investigation is needed to develop customization algorithms.
ATHENS, Greece — Implantation of customized lenticules could offer a tailored solution for corneal remodeling in eccentric keratoconus, according to an ex vivo study.
“From 28 eye bank donor corneas, we took 12 corneas to produce two models of eccentric keratoconus and the other 16 corneas to create different types of lenticules,” Mona El Zarif, PhD, said at the ESCRS winter meeting.
For the two models of keratoconus, an off-centered –18 D myopic ablation was performed on the posterior surface of all 12 corneas. The anterior surface was then treated with a +5 D hyperopic ablation for model one and a phototherapeutic keratectomy 4-mm masked ablation for model two. A femtosecond laser stromal pocket was then created in all corneas.
Femtosecond laser dissection was used to create four types of lenticules: planar shape , negative meniscus shape with a +8 D hyperopic treatment, customized planar shape with masked excimer laser ablation and asymmetric negative meniscus shape with masked laser ablation.
Topography, aberrometry and MS-39 anterior segment OCT (CSO Italia) analysis were performed in all recipient corneas before and after lenticule implantation.
“Model two showed higher Kmax and steeper curvature progression, more accurately replicating the real keratoconus profile,” El Zarif said.
With all lenticules, regularization of the corneal surface with reduction of cone apex curvature and peripheral steepening was obtained, with differences according to shape. Planar lenticules induced a homogeneous thickening, while customized planar lenticules induced higher thickening in the inferior half of the cornea. Negative lenticules determined maximal thickness increase at the periphery, gradually diminishing toward the center, and customized negative lenticules showed asymmetric peripheral thickening.
“Customized planar lenticules show the best regularization effect, ideal for eccentric keratoconus, while the customized negative lenticules show the best flattening effect, ideal for paracentral keratoconus,” El Zarif said.
The study showed that customized lenticules for asymmetric and tailored effects in eccentric cones is feasible, taking into account that ex vivo models can only partially replicate keratoconus impairment, El Zarif said.
“Further investigation is needed to develop customization algorithms to obtain better lenticules for keratoconus and eccentric keratoconus,” she said.
Reference:
- Nubile M, et al. Invest Ophthalmol Vis Sci. 2024;doi:10.1167/iovs.65.10.9.
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El Zarif M. Ex-vivo lenticule customization for stromal lenticule addition keratoplasty (SLAK). Presented at: ESCRS winter meeting; Feb. 28-March 2, 2025; Athens, Greece.
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