Legal blindness: Nursing

Legal blindness is defined as having a central visual acuity of 20/200 or less in the better-seeing eye, or having a peripheral visual field of 20 degrees or less.

So, many people who are legally blind in some sense can still see, but they have severe visual impairment.First, let’s quickly review the physiology of vision.

Okay, now, the visual pathways begin in the eye. If we zoom into the wall of the eye, there's an outer fibrous layer, which contains the cornea and sclera, and helps control and focus the entry of light.

So the light that passes through the cornea is directed to the lens, which in turn collects light arrays and focuses them into the retina at the back of the eye.

The retina houses photoreceptors that translate light into electrical impulses, which are then carried by the optic nerve into the visual cortex of the brain.

Finally, the visual cortex processes the impulses coming from both eyes, and fuses them into one clear image.Now, common causes of legal blindness include eye conditions like cataracts, age-related macular degeneration, glaucoma, diabetic retinopathy, eye infections like trachoma, or it can be congenital.

Lastly, the cause of legal blindness may also be idiopathic or unknown. Risk factors for legal blindness include being assigned female at birth or over the age of 50, as well as having a systemic disease like diabetes mellitus, or undergoing eye surgery.Okay, so the pathology of legal blindness can have two main origins.

On the one hand, it can originate from abnormalities or damage involving a structure within the eye, such as the lens or retina.

If any of these structures isn’t properly functioning, the eye is not able to perceive light and images, and thus fails to translate it to electrical impulses for the brain.

On the other hand, the eye might be fine, but a part of the central nervous system, such as the optic nerve or the brain, can be affected.

As a result, either the optic nerve is unable to carry the electrical impulses from the eye to the brain; or the brain isn’t able to process the impulses into images.

Ultimately, regardless of the origin, the outcome is the same, meaning vision loss. Additionally, vision loss can also lead to circadian rhythm disorders, such as non-24 hour sleep-wake disorder.

This means that, in the absence of visual cues of light and dark, individuals are unable to maintain a relatively regular sleeping pattern, so they gradually go to sleep and wake up at later times throughout the day, until their sleep times eventually go all the way around the clock.

Typically, the clinical manifestations of legal blindness include blurred or cloudy vision; the inability to see shapes; tunnel vision or seeing only shadows; as well as seeing wavy spots in the center of vision, and even difficulty seeing colors.

In addition, clients may experience poor night vision, and in severe cases, even complete blindness.Diagnosis of legal blindness begins with the client’s history and physical assessment.

This includes visual acuity testing, using the Snellen eye chart. Other tests include perimetry or visual field testing to measure all areas of the client’s eyesight, including peripheral vision; as well as tonometry to check the intraocular pressure; dilated-pupil fundus examination and fundoscopy; and color vision testing.Treatment of legal blindness typically includes addressing the underlying cause, when possible.

In addition, clients are often monitored with routine comprehensive eye exams. Low vision rehabilitation is typically recommended to learn techniques to perform daily tasks with their visual acuity and may include glasses or contacts, magnification devices, and assistive technology.Alright, let’s look at the nursing care you’ll provide for a client with legal blindness.

Your nursing goals are to maintain the safety of your client and provide supportive care. Begin by reviewing their medical record to better understand the extent of their visual loss, and ensure that all members of the healthcare team are notified of their visual impairment.

Before entering your client’s room, knock on the door, address them by name, and ask to enter their room. Introduce yourself and your role on the healthcare team, and be sure to address them directly, make eye contact, speak to them with a normal volume and tone, and stay within their visual field if they have partial vision.

Ask them about how they perform their activities of daily living and ask how you can assist them during their stay. Lastly, during your assessment, always explain what you are going to do first, and let them know before you touch them.

Next, orient them to their environment, including the location of their bedside table, call light, telephone, and water pitcher.

Keep all these items, as well as any personal belongings within your client’s reach. Also explain any sounds such as alarms from IV pumps or monitors.

During mealtimes, use the clock face technique to describe the location of food on their plate, and be sure to provide assistance as needed.

Keep their bed in its lowest position and institute fall precautions. When helping your client ambulate, be sure to use the sighted guide technique, which includes standing slightly in front and to the side of them, offering them an elbow to grasp, walking slightly ahead of them at a comfortable pace, and describing the environment as you go.

When helping them to get seated, be sure to place their hands on the seat of the chair to help them orient to the location of the chair.

Next, assess their psychosocial needs, such as anxiety, depression, and changes in self-perception. Encourage them to discuss their feelings they may have about their vision loss, and be sure to use therapeutic techniques like active listening.

Lastly, after providing care, ask if they have any other needs, assist them into a position of comfort, check that the call light and other needed items are within reach, and let them know when you are leaving the room.

Finally, provide referrals for continued coordination of care, including the collaborating with the unit social worker or case manager, home health care services, and community resources, as well as resources for adaptive equipment such as an audible watch, desktop video magnifier, electronic hand-held magnifier, a text-to-speech scanner, cane, education courses on Braille, and information on obtaining a guide dog, as needed.Okay, moving on to client and family education.

Begin by reviewing the treatment plan with your client, including prescriptions for medications or corrective lenses as well as participation in low vision rehabilitation.

Review some strategies they can implement to promote safety in the home, and ensure they are able to safely self-administer their medications, that they have the referrals and resources they need to manage their chronic conditions, that they are able to accomplish their activities of daily living, and keep their follow-up appointments with their healthcare provider.

Alright as a quick recap…. Legal blindness is a severe visual impairment defined by having a central visual acuity of 20/200 or less in the better-seeing eye, or a peripheral visual field of 20 degrees or less.

Common causes of legal blindness include cataracts, age-related macular degeneration, glaucoma, diabetic retinopathy, eye infections, or it can be congenital.

Legal blindness may manifest as blurred or cloudy vision, difficulty seeing shapes and colors, tunnel vision, seeing only shadows, wavy spots in the center of vision, or complete blindness.

Diagnosis begins with a history and physical, as well as visual acuity testing, perimetry, tonometry, color vision testing, and a dilated-pupil fundus examination with fundoscopy.

Treatment involves addressing the underlying cause, low vision rehabilitation, and using adaptive equipment such as corrective lenses, magnification devices, and the use of assistive technology.

Nursing management goals are to maintain the safety of the client and provide supportive care. Client and family teaching focuses on lifestyle modifications that promote safety within the home.