Generating a new lens
New technique uses lens epithelial cells in paediatric patients
An innovative technique for generating a new transparent, functional and accommodating crystalline lens following cataract removal is already producing promising results in paediatric patients, reported Thomas Kohnen MD, PhD, FEBO, University of Frankfurt, Germany, at the XXXV Congress of the ESCRS in Lisbon.
The technique involves removing the cataract through a tiny 1.5mm capsulorhexis in the periphery of the anterior capsule and leaving the lens epithelial cells on the inside of the capsular bag intact in order to regenerate the lens, explained Prof Dr Kohnen.
In a series of experiments, the researchers showed that the procedure resulted in the regeneration of functional lenses in rabbits, macaques and finally in a series of paediatric patients (H Lin et al., Nature 2016;531(7594):323-338), he reported.
The research was conducted by investigators at the University of California in San Diego and colleagues in China. The clinical study involved 24 eyes of 12 paediatric cataract patients who underwent the minimally invasive surgery to promote lens regeneration, and another group of 50 eyes of 25 paediatric cataract patients, serving as a control group, that underwent the current standard-of-care treatment that left them aphakic, Prof Dr Kohnen said.
The researchers found that in the new treatment group, the capsule healed within one month after surgery, and by three months a regenerated transparent biconvex lens structure had formed, which by eight months was comparable to a native lens, he noted.
In addition, there was no significant difference in visual acuity between eyes that received minimally invasive surgery (n=24) and those that received the current surgical technique (n=50), except at three months, when the control group had capsular opacities prior to undergoing laser capsulotomy.
Furthermore, evaluation at eight months with an open-field autorefractor showed that in eyes with regenerated lenses the mean accommodative response increased to 2.5 dioptres, compared to virtually no accommodation (0.10D) in the aphakic controls (P<0.001). Moreover, retinoscopy and slit-lamp microscopy showed that the visual axis was clear in all but one patient. In fact, compared to the current standard of care for cataract surgery, the new technique decreased visual axis opacification by more than 20-fold (84% versus 4.2%). In addition, the authors note that eyes that underwent the novel treatment had a significantly lower complication rate by almost every measurement, including corneal oedema (p=0.04), anterior chamber inflammation p<0.001), ocular hypertension and visual axis opacities. Furthermore, while 84% of eyes undergoing standard-of-care surgery required capsulotomy and 16% required anterior vitrectomy, none of the eyes undergoing the new technique required either intervention. Thomas Kohnen: firstname.lastname@example.org