CASE PRESENTATION
A 77-year-old man presents for a surgical consultation. The patient, a retired dentist, is well informed about the severe dry age-related macular degeneration (AMD) in each of his eyes (Figure 1).
Figure 1. The patient has advanced dry AMD that is more severe in the left eye.
His UCVA and BSCVA are 0.2 (decimal scale) with a manifest refraction of +0.25 -1.00 x 169º OD and 0.13 with a manifest refraction of -0.25 -0.25 x 144º OS. Crocodile shagreen with minimal peripheral thinning and some guttae is evident in each cornea, but the cell density is normal (> 2,400 cells/mm2). The corneal condition is not affecting his central visual acuity. The anterior chamber angle and IOP are normal. Both crystalline lenses exhibit slight nuclear sclerosis that may or may not affect his vision.
The patient has no history of ocular surgery. He has a strong desire for improved vision, especially at near. How would you proceed?
— Case prepared by Suphi Taneri, MD, PhD, FEBOS-CR
UDAY DEVGAN, MD, FACS, FRCS
Cataract surgery with a monofocal IOL and a refractive target of emmetropia in each eye would be a reasonable and safe approach. Although macular atrophy limits his potential for significant visual improvement, removing the mildly sclerotic lenses might enhance the patient’s contrast sensitivity and optimize the quality of his remaining vision.
Given the extent of macular damage, multifocal and extended depth of focus (EDOF) IOLs are contraindicated because they could reduce contrast sensitivity and degrade image quality. Instead, once the patient recovers from surgery, his ability to perform near tasks could be supported with external magnification aids such as high-powered reading glasses, handheld magnifiers, and electronic devices. These tools offer flexible, adjustable options for close work and are often more effective in patients with advanced AMD than intraocular solutions. Postoperative care would include a referral to low vision services for device selection, training, and regular monitoring for AMD progression.
It would be essential to set realistic expectations preoperatively. Although cataract surgery could optimize his remaining vision, it cannot reverse the effects of AMD.
THOMAS KOHNEN, MD, PHD, FEBO
This clinical scenario is not uncommon, but the options for treatment are limited. Although cataract surgery would likely improve the patient’s visual acuity, his visual potential and IOL choices are limited by his dry AMD. Multifocal or diffractive IOLs are contraindicated. Because the eyes are quiet and all other ocular parameters are within normal limits, I would offer cataract surgery with a monofocal IOL and a refractive target of emmetropia, -1.00 D, or a monovision strategy. The latter two approaches could improve his near visual acuity. A nondiffractive EDOF IOL might be an alternative, but published data on the technology’s utility in this setting are limited.
My colleagues and I are currently enrolling patients in a study of the SING IMT (Samsara Vision), a Galilean telescopic implant designed to improve the visual acuity and quality of life of patients with late-stage AMD. The patient might benefit from the device, but I would clearly explain to him preoperatively that spectacle independence is not the primary goal of surgery.
CATHLEEN M. MCCABE, MD
The most important part of the preoperative evaluation and surgical planning would be setting realistic expectations and discussing the patient’s current disease state, likelihood of future disease progression, needs, and goals. His BCVA limits his reading vision but would permit functional vision with a magnifier. He has a mild refractive error and is dissatisfied with his BSCVA, especially at near.
Multiple ocular comorbidities affect the patient’s visual acuity; they are not modifiable and are likely to progress. For this reason, the balance between the risks and benefits of surgical intervention favors avoiding even minimal or unlikely risks if a meaningful benefit is unlikely to be achieved. Central macular disease (dry AMD) is affecting his ability to read, and it is important that he understand this limitation will persist after surgical intervention.
Mild nuclear sclerosis may be affecting the patient’s visual function and is the only modifiable ocular pathology in this situation. Because the cataract will progress over time and the recommended lens design will not change, it would be reasonable to offer surgery with a monofocal IOL. Any lens design that decreases contrast sensitivity should be avoided.
After a comprehensive discussion of likely outcomes (mild improvement of near vision with readers and/or magnifiers), cataract surgery could be considered.
TIM SCHULTZ, MD, FEBO
The patient has a functional level of vision, particularly in the right eye, which is useful for the activities of daily living. Before recommending surgical intervention, a detailed assessment of his daily visual requirements would be essential. As a retired dentist, he may no longer perform fine near tasks professionally, but his desire for improved near vision warrants clarification of his reading habits, hobbies, and difficulties under low-light conditions. Evaluating whether magnifying aids or optimized illumination currently improve his visual function would be important because simple low vision rehabilitation strategies might provide an incremental benefit.
From a surgical standpoint, the endothelial cell count is reassuring and not a contraindication for modern cataract surgery. Mild nuclear sclerosis may be contributing modestly to his visual complaints but is unlikely to be the sole limiting factor. Considering the patient’s advanced dry AMD, the implantation of a standard monofocal IOL would not significantly enhance his central vision.
One option would be to place a SING IMT, which is designed to provide a magnified retinal image for patients with geographic atrophy. The implant can improve functional near vision in carefully selected individuals. Preoperative suitability testing is mandatory, particularly regarding the dimensions of the capsular bag and macular fixation stability. Because of the large size of the device (4-mm optical diameter and 12-mm overall diameter), anatomic feasibility must be verified preoperatively, and intensive postoperative rehabilitation is essential to optimize visual adaptation.
Alternatively, a secondary IOL could be implanted. The AddOn SML (Scharioth macula lens; 1st Q) offers approximately +10.00 D of near addition and may be considered in individuals with advanced dry AMD who have already undergone cataract surgery. Sequential IOL implantation would allow individualized adjustment based on the patient’s postoperative outcome and satisfaction level.
WHAT I DID: SUPHI TANERI, MD, PHD, FEBOS-CR
Such early cataracts affect a patient’s vision only slightly. Like most of the panelists, I ruled out the patient’s candidacy for a multifocal or EDOF IOL because of his retinal pathology. I thoroughly discussed this decision with him as well as his limited visual potential after cataract surgery due to severe AMD. Because he was unhappy with the low vision aids he had tried before our consultation and because he demonstrated a solid understanding of his retinal disease, we discussed the risks and benefits of the SING IMT in detail. The device is designed to enhance recipients’ visual acuity by magnifying the retinal image 2.7 times. Unilateral implantation is recommended because magnification decreases the visual field. The patient’s visual acuity was 0.4 OD when tested with a demonstration device (external telescope). He was happy with the simulation and eager to proceed with implantation of the SING IMT.
Surgery was uneventful. Phacoemulsification was performed through a 2.5-mm incision, which was subsequently enlarged to 7.5 mm to allow implantation of the telescopic device in the capsular bag. An iridectomy was performed, and the incision was sutured.
One day after surgery, the patient noticed a brighter environment and a magnified image, but his vision was blurry and without contrast due to central corneal edema. He was instructed to administer topical atropine drops for 2 weeks postoperatively to prevent the formation of synechiae between the iris and telescopic device, which protrudes through the pupil (Figure 2).
Figure 2. OCT scan obtained 2 weeks after the implantation of a SING IMT, which features two lenses—one within the capsular bag and one that protrudes into the anterior chamber.
Over time, the patient learned to use one eye or the other depending on his visual requirements, but he found the change in image size between eyes bothersome. Then, he noticed a decrease in the visual acuity in his left eye.
Three months after SING IMT implantation, the patient underwent cataract surgery with a monofocal IOL in his left eye. The refractive target was -1.00 D to provide a degree of blended vision.
Now, 3 years after receiving the telescopic device—and after many follow-up visits and much chair time—the patient finds the implant beneficial when watching television or looking at faces but not when reading (Figure 3). He is less than satisfied with his outcome and unsure whether he would elect to receive the implant if given the choice again. Of note, as one of the first patients in Germany to receive this device in 2021, he did not have to pay for it.
Figure 3. Slit-lamp photograph of the telescopic device 2.5 years after implantation.
