Introduction:
Infectious eye diseases commonly lead to unilateral or asymmetrical vision loss in children and persons of working age. These disorders include bacterial, fungal, viral, and parasite illnesses in both common and uncommon forms. They may be responsible for much of the world's visual burden. Diagnosis is usually challenging globally.
What Are the Ocular Manifestations of Infectious Diseases?
Some of the common ocular manifestations of infectious disease are,
Leprosy:
Leprosy, commonly known as Hansen's disease, is a chronic granulomatous infectious disease caused by Mycobacterium leprae, an acid-fast bacillus. The bacteria are spread from person to person through contact with droplets.
Ophthalmic Manifestations:
Patients with leprosy affecting the eyes will have diminished visual acuity or even blindness. Leprosy can infect the eye directly through the skin of the eyelids, lacrimal glands, ophthalmic division of the trigeminal nerve or facial nerve, and tear ducts. It can also spread by invading the anterior segment.
The adnexal signs include decreased lacrimal secretion, ectropion, entropion, trichiasis, lagophthalmos (caused by infiltration of the facial nerve), and madarosis of the eyebrows and eyelashes. Anterior segment findings include iris nodules, iris atrophy, corneal opacities, exposure keratitis, conjunctivitis, diminished corneal sensation (because of trigeminal nerve involvement), episcleritis, anterior uveitis, and scleritis.
A common and distinguishing finding in early leprosy is the thickening and beading of corneal nerves, which can be seen during a slit lamp examination. The extremely uncommon posterior segment involvement in leprosy presents as tiny, white, "pearl-like" choroidal nodules that resemble those in the iris.
Tuberculosis:
Mycobacterium tuberculosis, an acid-fast bacillus, is the cause of tuberculosis (TB), a persistent granulomatous infection. Aerosolized droplets are the most typical mode of transmission for the bacterium.
Ophthalmic Manifestations:
Tb ocular symptoms may be an effect of an ongoing infection or an immune response to the organism. Tuberculosis can damage the anterior and posterior sections of the eye and the orbit. Tb can manifest in several ways, including macular edema, vitreous, retinal vasculitis, multifocal choroiditis, neuroretinitis, subretinal abscess, panophthalmitis, endophthalmitis, acute anterior uveitis, and chronic granulomatous anterior uveitis with mutton fat keratic precipitates. TB has also been linked to peripheral ulcerative keratitis, epscleritis, and non-necrotizing and necrotizing diffuse or nodular scleritis.
Tb-associated inflammation can occasionally manifest as interstitial keratitis, iris or ciliary body granulomas, phylyctenulosis, or dacroadenitis. The most frequent clinical finding among these presentations is posterior uveitis. Eales disease is a form of hypersensitivity to tuberculous antigens. It is usually observed in young males in areas where tuberculosis is widespread. It is characterized by peripheral ischemia vasculitis with neovascularization and recurrent vitreous bleeding without other symptoms of inflammation.
Group B Streptococcal Infections:
Streptococcus agalactiae, commonly called Group B streptococcus, is a gram-positive cocci that is a major pathogenic cause of neonatal morbidity and mortality.
Ophthalmic Manifestations:
Most ocular tuberculosis patients do not exhibit any signs of pulmonary or systemic illness. The range of ocular symptoms varies according to the affected area of the eye. Patients may exhibit pain, photophobia, tearing, and visual abnormalities. Endogenous endophthalmitis is the clinical presentation of a GBS eye infection.
What Are the Viral Disorders Causing Eye Problems?
Herpes Simplex Virus:
Herpes simplex virus (HSV) is a type of DNA virus with double strands. The two varieties are HSV-1 and HSV-2. HSV-1 infections usually occur above the waist, while HSV-2 infections usually occur below the waist in highly sexually active people. However, this is only sometimes the case, as viruses may be present anywhere.
Ophthalmic Manifestations:
The most prevalent reason for patients to appear is a recurrent unilateral red eye that is accompanied by pain and photophobia. Many patients have a confirmed diagnosis of HSV, and many may have previous episodes of fever blisters or cold sores. Primary eye infections are frequently characterized by unilateral blepharoconjunctivitis with vesicles on the eyelids. Follicular conjunctivitis affects a lot of kids. Many individuals with a primary HSV-1 infection and a primary ocular infection suffer from epithelial keratitis. This can be geographic keratitis or superficial punctate keratitis.
Patients with recurrent ocular herpes may present with endotheliitis, disciform keratitis, elevated intraocular pressure, or iridiocyclitis in addition to epithelial keratitis. Acute retinal necrosis is another possible outcome of retinal inflammation and only occurs in immunocompromised people. Herpetic corneal lesions often have piled edges with inflated epithelial cells stained by Lissamine Green or Rose Bengal. Fluorescein staining the centrally ulcerated area of the HSV lesion.
Examining for diminished corneal sensitivity is important because it can put the patient at risk for neurotrophic ulcers and secondary bacterial infections. Interstitial keratitis is a rare condition that can arise with iritis or glaucoma.
These patients may not have an underlying epithelial defect or diffuse or numerous stromal infiltrates. HSV-associated uveitis is generally accompanied by iris atrophy, increased intraocular pressure, and granulomatous keratic precipitates.
What Are the Fungal Infections Causing Eye Problem?
Toxoplasmosis:
Toxoplasmosis is caused by Toxoplasma gondii. T. gondii primarily infects felines as hosts. Humans can contract the organism by drinking water, eating contaminated food that contains parasite oocysts, or touching or consuming raw meat that has tissue cysts.
Ophthalmic Manifestations:
Retinochoroiditis is the most typical clinical manifestation of toxoplasmosis. The characteristic ocular finding is a fluffy, white patch of necrotizing retinitis or retinochoroiditis around a chorioretinal scar. Patients may also have vitritis, which looks like a "headlight in the fog." Atypical presentations may present as retinal vasculitis, papillitis, non granulomatous or granulomatous anterior uveitis. Young children may not exhibit any symptoms of ocular illness. Verbal children may report diminished vision or eye pain, whereas parents might suspect leukocoria or strabismus.
Conclusion:
The ophthalmic manifestations of infectious diseases present a wide range of clinical presentations, ranging from mild irritation to severe vision-threatening conditions. Early detection, appropriate diagnosis, and proper management can help reduce the severity of ocular involvement and prevent long-term complications. Moreover, understanding the epidemiology and geographic distribution of infectious diseases aids in clinical suspicion, and accurate diagnosis are aided by the knowledge of the epidemiology and geographic distribution.
