Retina specialists might rely on a certain level of visual acuity to determine when to stop giving injections to a patient. It can be difficult to justify the need to continue giving injections in an eye that demonstrates only hand-motion vision. However, it could be that the generally accepted understanding of hand-motion vision is based on limited methods of measuring acuity. The aim of this article is to explain what we may be missing and why a comprehensive low-vision evaluation is far more important to the patient, to the retinal surgeon, and to the overall outcomes that eye-care providers’ services are truly capable of providing. Low-vision evaluation may be a vitally important intervention before a decision is made to extend the interval between injections or to cease injections entirely.

Retina specialists can often hesitate to refer patients for low-vision services, yet David W. Parke, MD, immediate past CEO of the American Academy of Ophthalmology, has stated that “vision rehabilitation is now the standard of care for patients who are losing their vision.”¹ The lag in incorporating low-vision services in the continuum of care today may be due to the perception of low vision in that it relates to the older models of how low vision examinations and services were previously managed.

AN ANTIQUATED UNDERSTANDING OF LOW-VISION SERVICES

Previously, the connotation of low vision services was probably construed as referring a patient to a practitioner who would utilize a series of magnifiers to enlarge the images patients were viewing. These tools might have been in the form of hand-held magnifiers or stand magnifiers for reading, to monocular telescopes for sighting distant objects. They would simply increase the power of magnification until the patient could read at near or see in the distance. They were quite limited in scope and their outcomes were marginal as manifested both by the less than satisfactory patient outcomes as well as the feedback given to referring ophthalmologists.

More recently, the idea of low vision services may be expanded with the advent of electronic forms of magnification, such as closed-circuit televisions and hand-held and headborne self-contained video magnification. If the patient was thought to be beyond the level of help from these aids, then a referral for orientation and mobility training or adaptive/compensatory forms of therapy or intervention were considered. These often left the patient with low vision survival skills, but no enhanced visual skills. It is these visual skills that are critically important to improving quality of life beyond the adaptive/compensatory procedures. As such, there was, and still seems to be, a certain reluctance to refer a patient for low-vision services.

Why does a patient have a cataract removed? Simply to “see better.” Why does a patient subject themselves to ocular injections? It’s the same simple answer. Patients are not interested in how much tissue you are saving or “anatomic success” or how much central retinal fluid has been reduced by measuring serial OCT scans. They simply want to know how much their vision has improved and how long will they retain their sight. Simply stated, they only want to see and hopefully see better.

When patients ask if there is anything else that can be done, it is no longer appropriate to remain silent or state that the intent of anti-VEGF therapy in most patients is to stabilize the vision and prevent it from getting worse. With the evolution of low-vision services, the paradigm has shifted whereby the standard of care must incorporate a referral to a low-vision specialist to potentiate and enhance their visual function.

NEW OPTIONS FOR PATIENTS

In our practice, we continue to receive patients who have been told that they were “legally blind” in one or both eyes. They come with reported visual acuities of less than 20/400 or worse. Retina specialists will say that it is relatively simple to determine when to commence anti-VEGF injections, but the real quandary is in determining when to stop. When there is a large cicatricial change in the posterior pole or when the vision is less than useable, continuing injections and interventions can be fruitless.

Let’s consider a patient who was referred with hand motion in one eye and 20/400 visual acuity in the other. The ophthalmologist might determine that this patient has no reason to continue receiving injections or treatment. However, when evaluated in our low-vision service, the patient achieved 20/200 vision in the hand-motion eye and 20/80 in the 20/400 eye when viewing 10 degrees off center. With a 1.7x full-diameter telemicroscopic system, she read 1.0M standard text and was seeing 20/40 at distance. It is not very hard to explain to that patient or to justify the importance of continued care to preserve that level of sight. This dynamic interplay between the retinal surgeon and the low-vision service is critical in not only guiding continued treatments but to give hope to the frustrated patients. While the acuity shift in this example might seem extreme, it is not uncommon. However it is important to remember that there are times where we are not able to identify any reasonable presence of eccentric vision, or shifts that may not be quite as dramatic. On the other hand, it would be a shame to fail to find and recognize any level of functional vision that may remain.

LOW-VISION EVALUATION

Modern low-vision practice is very different from what might be conceptualized. The first step is to go through a very comprehensive questionnaire to determine the level of functional vision the patient has under many different tasks and conditions. Next, establishing a list of goals is critical. The average patient with AMD is older, and their top priorities inevitably include reading, seeing the TV, and seeing the faces of loved ones. They also want to remain independent, doing their own cooking, cleaning, and paying their own bills. They would like to remain social, play cards, bowl, or play a round of golf. A great deal of emphasis should be placed on finding these eccentric islands of vision, determining their size, position, and sensitivity. Once done, then selecting or designing the proper low-vision instrumentation to meet their goals becomes the next level of concern.

In a comprehensive low-vision program, rehabilitation and therapy is the cornerstone of learning to use the eccentric island effectively and efficiently and integrating this with the appropriate devices (see sidebar). This all goes back to proper assessment. As long as this was done accurately, then the chances for overall success and a very positive outcome are greatly enhanced.

CONCLUSION

A comprehensive low-vision service goes far beyond simple magnification. It is truly an assessment of the remaining functional vision the patient has. The program should include a through explanation of the patient’s condition, strengths, and limitations, and it should realistically predict and demonstrate outcomes and goals. Once the patient understands what they are dealing with, their life changes. The incorporation of low-vision services as part of the retina specialist’s continuum of care elevates the level of patient care. It may yield very functional vision that was unrealized and undiscovered. The responsibilities of the retinal surgeon are complex, and the pressure to diagnose and manage the condition of the patient, decrease progression, and stabilize the retina are only increasing with our aging population. Low vision, aside from giving the patients back a significant improvement in their quality of life and an impetus to continue their treatments, can also serve as a true litmus test to monitor both subjectively and objectively our patients’ ability to “see better.” RP

REFERENCES

1. American Academy of Ophthalmology. Recommendations on assistive technology for patients with low vision. 2020. https://www.aao.org/clinical-statement/recommendations-on-assistive-technology-patients-w