TELE-IOL

An implantable miniature telescope can provide useful visual function in carefully selected patients with end-stage age-related macular degeneration (AMD), Irish researchers report.

Speaking at the 2014 Irish College of Ophthalmology Annual Conference in Limerick, Kirk Stephenson MB, BCh, BAO, Mater Private Hospital, Dublin, presented the results of a six-month follow-up study on the use of the implantable miniature telescope (IMT, Visioncare Ophthalmic Technologies, Inc.) for the treatment of end-stage AMD in the Irish population.

For the study, the AMD patients of one consultant in the Mater Private Hospital were screened for eligibility. Those with geographic atrophy or stable disciform scars, and were phakic were selected. Motivated suitable patients without any limiting co-morbidities were shortlisted for the procedure, Dr Stephenson told the conference.

Five patients, with a mean age of 81 years, underwent IMT implantation between March 2013 and March 2014. The baseline best corrected distance visual acuity ranged from 1/60 to 6/24.

The three IMT patients that had reached six months' postoperative follow-up point at the time of the conference had a mean improvement of 3.3 lines (range one to seven lines, no lines lost) on the ETDRS chart. Of the two patients who were three months post-op, none had lost any lines, Dr Stephenson said.

These findings are in keeping with the IMT002 study (Hudson et al. 2006), where at one year there was a mean three line improvement in patients who received the device, he reported.

One patient – the one who had only gained a visual improvement of one line – had a reactivation of her wet AMD. This patient was subsequently started on a course of intravitreal anti-VEGF treatment but has since stopped attending follow-up appointments.

“This really highlights the importance of rigorous patient selection. You have to be very careful in assessing these patients. Motivation and compliance with rehabilitation and treatment is a critical factor,” Dr Stephenson told the conference.

Patients who have received an IMT implant require ongoing monitoring and potentially treatment for macular disease, Dr Stephenson added.

Visual benefits

In addition, the costs for the device are high, though the visual benefits of the procedure really have to be considered, he stated.

Speaking to EuroTimes, Dr Stephenson acknowledged the data presented was just for six months for three patients and a longer period of at least a year would be needed for better analysis. However, so far the results for the implant are promising and offer real visual benefits, he stressed.

“It is one of a few intraocular devices available for implantation in AMD and can give these patients some degree of visual repair. It won’t bring them back to previous visual levels but it is a way to improve visual function, and so allow them to do basic daily tasks like cooking and cleaning, as well as continue some hobbies,” he concluded.

The IMT is the most advanced medical device so far to be implanted inside the eye for AMD patients missing their central vision. It is implanted only in one eye, replacing the natural crystalline lens. Once implanted, the device magnifies images, which are projected onto the healthy area of the retina not affected
by AMD.

The IMT patient selection process includes testing vision using external telescope simulators, Dr Stephenson explained. There are also quite stringent exclusion criteria, he noted, including active retinal disease, any history of retinal detachment or retinal vascular disease, high myopia or hyperopia, any evidence of low corneal endothelial cell count (<1600cells/mm2), as well as serious medical morbidities such as stroke or dementia.

The telescope implant allows patients to use natural eye movements to see better and be able to regain independence and carry out everyday tasks like cooking, recognising people, reading activities and leisure activities. “This is a significant advantage over external magnifying devices, which can frustrate patients and lead to poor compliance. In this way, with the appropriate visual rehabilitation, patients can get real visual benefits in their daily lives,” Dr Stephenson concluded.

Kirk Stephenson:
kirkstephenson@hotmail.com