Telescopic IOLs helpful for AMD patients, study shows
The IOL provides better vision than external telescopes, according to an experienced surgeon.
ALICANTE, Spain – Telescopic IOLs can restore some vision to patients with age-related macular degeneration. A surgeon here has implanted these lenses in 11 patients with more than 1 year follow-up.
Jorge L. Alió, MD, PhD of the Instituto Oftalmologíco de Alicante, said the lens is the first fully implantable telescope for patients with age-related macular degeneration (AMD). It is an intraocular low-vision aid that provides 3× magnification. The implant is 4.3 mm in height with haptics 13.5 mm in width. It is inserted through an 11-mm incision.
“When the lens is implanted in the eye, the optics become much better for this device [than external telescopes]. The lens follows the visual axis of the patient, while external telescopic lenses are fixed in a plane,” Dr. Alió said.
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Once implanted, the lens is permanent. Because the lens is large, the posterior capsule is kept taut and the IOL is isolated from epithelial cell growth. If posterior capsular opacification occurs, it cannot be treated with a laser but must be needled. None of Dr. Alió’s patients has developed PCO at 1-year follow-up, he said.
The telescopic IOLs can provide 3× to 8× magnification, which Dr. Alió said is comparable to external telescopic lenses of 4.5 cm.
VisionCare Ophthalmic Technologies, the company that manufactures the IOLs, makes lenses with two powers of magnification: 2.2× and 3×. Dr. Alió said that in cases with less visual loss, the 2.2× IOL has been preferable. With the lower power, less peripheral vision is lost in the implanted eye and patients can use their sight from both eyes. With the 3× lenses, the patient loses more peripheral vision and must be trained to adjust to having ambulatory vision in one eye and magnified vision in the other.
“They provide a narrow visual field and get 3× magnification of the image. That is a high magnification, allowing the patient with some training to adjust to the lens,” Dr. Alió said.
Visual improvement is moderate, and rehabilitation takes 3 to 6 months with an adjustment period of 1 to 2 months.
Dr. Alió’s patients have been able to achieve improved vision. For example, from patients with preoperative visual acuity of 20/180, 20/90 has been achieved after implantation and rehabilitation.
According to Dr. Alió, the main disadvantage is the training period. Patients most likely to adjust to the IOL are selected for implantation. Many elderly AMD patients may not be able to adjust to the magnification.
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Patient results
Over the past two years, Dr. Alió has implanted 11 patients with the telescopic IOLs. Only three cases have been problematic, in that the vision of the patient was overestimated or the disease was not stable enough.
Patients with stable AMD are selected. Although the disease is expected to evolve, these patients have a better chance of maintaining improved vision for a period of time, Dr. Alió said.
At his institute, patients with the IOL are trained postoperatively by low-vision specialists. Before implantation, patients wear external telescopic lenses to see how the magnification will change their vision. After implantation, they are taught how to walk and read using the IOL. The more adjustment they achieve during training, the better the postop results.
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For Your Information:
- Jorge L. Alió, MD, PhD, can be reached at Instituto Oftalmológico de Alicante, Adva, Dénia 111, 03015 Alicante, Spain; (34) 96-515-4062; fax: (34) 96-515-1501; e-mail: jlAlió@oftAlió.com.
- VisionCare Ophthalmic Technologies can be reached at 3a Geron St., Yehud 56101, Israel; (972) 3-632-3055; fax: (972) 3-632-3058; e-mail: mail@visioncare.co.il.