Results from 1 year of follow-up in a multicenter clinical trial show that an add-on lens (Scharioth Macula Lens [SML], Medicontour) increases near vision without affecting distance vision in pseudophakic patients with age-related macular degeneration (AMD).
“Treatment of neovascular AMD has been revolutionized, but if you look at methods for rehabilitation of near vision in patients with AMD, we still have primitive aids,” said Sathish Srinivasan, MD.
“Therefore, there has been tremendous interest in the use of magnifying IOLs for a subset of patients,” said Dr. Srinivasan, who is an investigator in the prospective clinical trial and consultant ophthalmologist, University Hospital Ayr, Ayr, Scotland.
Reviewing other IOLs/telescopic systems that have been approved or are under investigation, Dr. Srinivasan noted that they have a number of downsides.
“Most of the other technologies require a large incision and involve difficult surgery,” he said. “Some of these devices also affect distance vision and visual field, and all can be used only in patients undergoing cataract surgery. This means there is an underserved population of previously pseudophakic patients.”
Other techanologies are also extremely expensive, have limited reversibility, and with an intraocular Galilean telescope design, have limited magnification, he noted.
Back to the drawing board
The aims for developing a better alternative are to achieve sufficient magnification with a device that can be implanted in an easy and safe procedure independent of lens status. It should also not reduce the visual field or distance vision and be both reversible and affordable.
Design of the SML
The SML was invented by Gabor Scharioth, MD, PhD, who published a proof of concept paper in the Journal of Cataract and Refractive Surgery in August 2015.
The single-piece hydrophilic IOL has a 13 mm overall diameter and 6 mm optic that features a +10 D add in the central 1.5 mm. The rest of the optic is refractory neutral.
The SML is an add-on lens for implantation in the ciliary sulcus. It features a convex-concave optic, 4-point fixation with flexible haptics, a non-torque and square design, and can be implanted through a 2.2 mm incision. The lens is not available preloaded, but is delivered using a standard cartridge.
The features of the lens allow for safe and easy surgery, perfect fit in the ciliary sulcus with rotational stability, and avoidance of both iris capture and touch with the pseudophakic IOL.
“A great advantage of this lens is that its implantation is reversible,” Dr. Srinivasan said.
Multicenter clinical trial
Recruitment in the multicenter clinical trial started in October 2015. The trial is under way in seven centers in six European countries. Planned enrollment is 60 eyes. So far, 35 eyes have been implanted, and Dr. Srinivasan presented data from 25 eyes that had completed 1 year of follow-up.
Patients were eligible for enrollment if they were at least 55 years old, were pseudophakic, and had dry or inactive, stable wet AMD. They had to have corrected distance visual acuity (CDVA) of 0.1 to 0.4 (decimal) and show improvement in corrected near visual acuity (CNVA) of ≥3 lines when tested with a +6.0 D reading addition at 15 cm, compared to a +2.5 D add at 40 cm. The testing was performed at all centers with standardized ETDRS near vision charts.
Patients were excluded if they had active wet AMD, severe zonulopathy, iris neovascularization, uveitis, anterior chamber depth <2.8 mm from the endothelium, or had previous complicated cataract surgery.
The SML was implanted in the patients’ better-seeing eye. Vitreous loss occurred in one eye during implantation, but did not affect visual acuity.
Mean CDVA was 0.18 (decimal) preoperatively and remained unchanged at 3, 6, and 12 months of follow-up. Mean UCNVA at 15 cm improved from 0.25 (decimal) preoperatively to 0.68 at 1 year.
“These data provide proof of concept that the SML does not affect distance vision but helps to increase near vision,” Dr. Srinivasan said. “But patient selection is key, and postoperative visual training to help patients to read at a distance of 15 cm rather than the traditional 40 cm really seems to help.”
Mean IOP was 15 mm Hg preoperatively and the same at 1 year after surgery.
Three patients experienced distance vision issues with halos and glare, and the SML was explanted in two of those patients. There were no cases of dislocation, chafing effect, iris capture, visual field loss, or other complications.
Dr. Srinivasan has no relevant financial interest in the SML.