Introduction:
Systemic diseases, which affect various body parts, can often affect the eyes and cause ocular symptoms and signs. Usually, individuals with systemic disease may first present with ocular manifestations. If the systemic illness has already been identified, regular eye examinations must be performed to avoid ocular complications. Understanding these ocular manifestations is crucial for early identification, diagnosis, and treatment of underlying systemic conditions.
What Does Ocular Manifestations of Systemic Diseases Mean?
An ocular manifestation of a systemic disease refers to any eye condition that directly or indirectly results from a disease originating from various other parts of the body. Multiple systemic conditions are known to cause eye problems or visual disturbances due to the disease. These manifestations can occur in any part of the eye, such as the cornea, lens, retina, optic nerve, or other structures.
Ocular manifestations occurring due to systemic disease are due to the complex interconnectedness of the body's systems. The most common eye manifestations due to systemic conditions include diabetic retinopathy and macular edema occurring because of diabetes. The ocular manifestations of systemic diseases often require early and prompt diagnosis and treatment by eye specialists and physicians specializing in the particular systemic condition.
What Are the Ocular Manifestations of Systemic Diseases?
1) Diabetes:
Diabetes is a chronic metabolic disorder causing elevated blood sugar levels. It is notorious for its intense impact on eye health. Diabetic retinopathy is one of the most common causes of blindness caused by diabetes. It is estimated that mostly all individuals with type 1 diabetes and about 60 percent of individuals with type 2 diabetes can develop retinopathy within 20 years of disease onset. This condition occurs due to blood vessel damage to the retina, the innermost, light-sensitive part of the eye.
In the early stages of diabetic retinopathy, do not present with any symptoms. Some individuals may notice changes in their vision. In advanced stages, the blood vessels in the retina begin to bleed into the vitreous, causing dark, floating spots that look like cobwebs. Without prompt treatment, scar formation can occur and lead to vision loss. The risk factors for the development of diabetic retinopathy include poor control of diabetes, the duration of diabetes, pregnancy, nephropathy, and hypertension.
The treatment of diabetic retinopathy involves a multidisciplinary approach. The blood sugar level of the individual should be at a normal level. Laser photocoagulation is applied to ischaemic areas (deficient blood supply) and oedematous areas (fluid accumulated area) to decrease hypoxic retina. New adjunctive therapies for diabetic retinopathy management include steroid and anti-vascular endothelial growth factor (VEGF) agents injected into the vitreous cavity to reduce inflammation and edema.
2) Hypertension:
Hypertension, which means increased blood pressure, is another common systemic disease causing ocular complications. Hypertension is a major risk factor for retinal vascular disease development, including hypertensive retinopathy (an eye condition occurring due to retina damage) and eye stroke (blockage of the blood vessels feeding the retina). If the blood pressure is high, it can also increase the risk for diabetic retinopathy development and progression.
High blood pressure affects various body parts, such as the heart, brain, kidney, large arteries, and eyes. When the eyes are affected, the retinal, choroidal, and optic nerve blood vessels undergo pathophysiological changes, leading to clinical signs of hypertensive retinopathy.
The symptoms of hypertensive retinopathy include reduced vision, double vision, eye swelling, and the bursting of a blood vessel. The treatment for hypertensive retinopathy involves keeping blood pressure levels under control through antihypertensive medications and lifestyle modifications. Regular eye examinations to monitor retinal changes are also necessary.
3) Thyroid Disorders:
Ocular manifestations are common in individuals who suffer from thyroid dysfunction. Graves' disease, causing hyperthyroidism, is commonly associated with a thyroid eye disease called thyroid ophthalmopathy. It can cause inflammation and swelling of the extraocular muscles, orbital fat, and connective tissue accumulation, leading to double vision and restriction of eye movements.
The muscle commonly affected is the inferior rectus muscle, which leads to restriction on attempted upgaze. In severe cases, vision loss can occur due to optic nerve compression. Bulging eyes and lid retraction can lead to corneal damage.
Treating thyroid eye disease involves controlling thyroid hormone levels and treating ocular surface inflammation, orbital congestion, and muscle imbalance. Treatment options include corticosteroids, orbital decompression surgery, orbital radiotherapy, and rehabilitative measures, including prisms and strabismus surgery.
4) Autoimmune Disorders:
Certain autoimmune disorders present with ocular manifestations, which include:
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Rheumatoid Arthritis - Rheumatoid arthritis causes inflammation of the synovial joints. It can lead to secondary ocular complications such as episcleritis (an inflammatory condition affecting the tissue between the sclera and the conjunctiva), severe ocular inflammation, dry eyes, and scleromalacia perforans (thinning of the sclera).
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Systemic Lupus Erythematosus (SLE) - It is an autoimmune disorder that can affect the eyes through multiple mechanisms, including vasculitis, immune complex deposition, and antiphospholipid antibody-mediated thrombosis. The ocular symptoms of SLE may include inflammation of the cornea and retinal blood vessels, as well as secondary. For the management of SLE and rheumatoid arthritis, Hydroxychloroquine and Aminoquinolones chloroquine, antimalarial drugs, are used.
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Sjogren's Syndrome - Sjogren's syndrome mainly causes dry eyes (keratoconjunctivitis sicca) and dry mouth as the condition targets the exocrine glands. Inflammation and damage to the eye in Sjögren's syndrome can result in conjunctival scarring, corneal epithelial defects, and vision impairment. Management of this condition may include immunosuppressive medications, punctal plugs, artificial tears, and ocular surface lubricants to reduce the symptoms and prevent complications.
5) Human Immunodeficiency Virus (HIV):
HIV is a viral infection that targets the immune system of the affected individual and causes various symptoms. HIV also has significant implications for ocular health. The ocular conditions caused by HIV can vary widely, ranging from mild conditions to sight-threatening diseases. Common ocular manifestations of HIV include conjunctival microvasculopathy, dry eyes, HIV-associated retinal microvasculopathy, inflammation of the eyes, and conjunctival squamous cell carcinoma. The treatment of HIV-associated ocular manifestations requires a multidisciplinary approach. Antiretroviral therapy (ART) plays a crucial role in preventing disease progression.
Conclusion:
Ocular manifestations of systemic diseases are eye conditions that directly or indirectly result from a disease originating from various other parts of the body. Various conditions present with various ocular manifestations. It is important to address the underlying systemic conditions in order to optimize patient outcomes. Also, early detection and management are necessary to provide the best treatment and avoid complications.
