Vision improvement in patients with bilateral macular scars remains a major challenge faced by retinal surgeons.
“For patients with bilateral macular scars, either from age-related macular degeneration (AMD) or from any other disease, there are limited options. Usually, these patients are sent to a low vision clinic, where they are provided with low vision devices, which in many cases, do not meet the patients’ needs,” said Dr. Abhishek Kothari, director and chief vitreoretinal surgeon at the Pink City Eye and Retina Institute, a super-specialty center dedicated to the treatment, research and prevention of eye diseases in Jaipur, India.
According to Dr. Kothari, currently, there are limited surgical options for patients with bilateral macular scarring. One option is the implantable miniature telescope (IMT) developed by Dr. Isaac Lipchitz from Israel (IMT; VisionCare Ophthalmic Technologies, CA, USA). However, this implantable telescope is very difficult to insert and requires a large 7-8 mm incision for insertion.
The other option is the Scharioth macular lens (SML; Medicontur, Zsámbék, Hungary). The SML is a sulcus lens, flat design, with zero power optics except for a central 1.5mm diameter circle which has +10D power. In the spectacle plane, the SML acts like a +6 magnifying glass, which is optimal for patients with small macular lesions. “However, in patients with large macular lesions, the SML does not provide significant improvements in vision,” noted Dr. Kothari.
“The SML is very expensive, not readily available for patients in India, and has limitations in the range of power available. Therefore, we have developed the Sulcus Implantable Vision Aid (SIVA) lens for these patients. It has significant improvements over the existing SML, including increased power from +10D to +12D and +14D. These three varieties offer more options for patients,” he explained.
In addition, Dr. Kothari says that compared to the SML, where insertion requires good pseudophakia with no iridocapsular adhesions, the SIVA lens can be inserted in patients with capsular adhesions where the sulcus space is small, by utilizing 2 small pockets. This device is easy to implant in the sulcus by both anterior segment and retinal surgeons.
Furthermore, Dr. Kothari explains that the SIVA lens has wider indications as compared to the SML, which is indicated primarily for patients with bilateral macular scars. “For example, when the SIVA lens is inserted bilaterally in younger individuals with nystagmus, their reading ability increases, and they can continue school and perform learning activities. This is a major advantage of this lens,” he shared.
In addition to individuals with bilateral low vision secondary to nystagmus, Dr. Kothari also said this new lens has added benefit for patients with AMD and macular scars, as well as patients with geographic atrophy involving the fovea, for which there is no treatment.
“A key advantage of the SIVA lens is the availability of wider range of powers: 10D, 12D and 14D. In addition, due to the vault design, as opposed to the flat design of the existing lens, the SIVA lens can be used in both pseudophakic and younger, phakic patients,” Dr. Kothari further explained. “The SIVA lens can give hope to patients who have bilateral low vision due to a variety of pathologies, who are unable to use or unsuited to routine optic devices.”
“Notably, elderly patients with tremors or other motor disabilities, find existing low vision devices difficult to use, but with the SIVA lens, they can see improvements in near vision without using cumbersome low vision devices,” he concluded.
Editor’s Note: The SIVA lens was developed by Dr. Abhishek Kothari in partnership with several ophthalmic companies in India (currently Biotech Visioncare and Appasamy Associates). The reason for giving the design to multiple companies, according to Dr. Kothari, is that they do not want to patent or have financial interest in the lens. The intention was to lower the cost of the IOL. Once more affordable, more patients can benefit from the lens.
