Cytomegalovirus (CMV) retinitis is usually an opportunistic viral infection, found in individuals with low immunity. This condition results in the inflammation of the retina, and can eventually lead to blindness.
Cytomegalovirus infection commonly occurs in adults during their fourth decade of life. The retina can be affected when the virus spreads via the bloodstream . People infected with the human immunodeficiency virus (HIV) are at a higher risk of acquiring cytomegalovirus retinitis, as the former organism compromises the endothelial integrity of vasculature, and blood flow, in the retina . Retinitis may involve inflammation as well as bleeding of the retina, often in the ocular fundus. Lesions such as cotton wool spots can be visualized on the retina.
HIV further predisposes individuals to cytomegalovirus retinitis due to its immunosuppressive effects. This results in activation of latent infection after the host immunity decreases . Various conditions, such as diabetes mellitus, malignancy, and organ transplantation, impart the same effect  . Although cytomegalovirus retinitis in immunocompetent individuals is rare, cases have been reported. It has also been described in patients with systemic lupus erythematosus and other autoimmune diseases, with concomitant use of immunosuppressive drugs .
Cytomegalovirus retinitis can be asymptomatic. In symptomatic infection, patients may experience various visual disturbances, including floaters, photopsia, narrowed visual fields, blurred vision, and scotoma . They do not usually complain of red or painful eyes. Blindness can ensue within months of symptom onset. Furthermore, cytomegalovirus retinitis is often initially unilateral before becoming bilateral.
Notably, immunocompromised children do not seem to have increased susceptibility to this disease . Cytomegalovirus retinitis can also be congenital, occurring in 25% of babies already exhibiting other features of CMV infection, and does not usually worsen after birth.
- Retinal Hemorrhage
Retinal examination uncovered classical appearance of retinal whitening and retinal hemorrhages with extensive macular involvement. CMV retinitis can occur as a late complication following liver transplantation. [ncbi.nlm.nih.gov]
White, fluffy retinal necrosis with overlying retinal hemorrhages. [eyerounds.org]
A, Retinal hemorrhages and areas of opaque retina are present. Note the vascular sheathing in the superotemporal arcade and hard exudates in the macular region. B, Histologically, full-thickness retinal necrosis is present. [aao.org]
- Retinal Pigmentation
(n 3 eyes) characterized by inner retinal hyperreflectivity, large empty spaces in outer nuclear layer, and bridges of retinal tissue but retinal pigment epithelium and choriocapillaris sparing. [ncbi.nlm.nih.gov]
- Retinal Scar
Fibrovascular changes occurred in the CMV retinitis scar, were misdiagnosed as CMV retinitis reactivation, and were treated with anti-CMV medication. [ncbi.nlm.nih.gov]
Two patients were not treated (patients 1 and 8), one of whom (patient 8) had received an autologous transplant and was diagnosed with atrophic retinal scarring compatible with previous CMV active retinitis after spontaneous resolution of the acute retinitis [academic.oup.com]
In recovered patients, hemorrhage and exudation were disappeared completely and yellow-white retinal scars were formed in 10 eyes. [bmcinfectdis.biomedcentral.com]
- Unilateral Blindness
However, there is a risk of unilateral blindness in severe cases. [patient.info]
The ophthalmologic examination is the diagnostic procedure employed. This involves dilating the pupils to visualize internal ocular structures through ophthalmoscopy.
It is good practice to screen all patients at risk of cytomegalovirus retinitis, including those that lack symptoms, because early stage diagnosis and treatment are uncomplicated, and in addition, a significant proportion of individuals are asymptomatic at the time of diagnosis. Furthermore, intervention prevents blindness, which is a highly debilitating sequela of cytomegalovirus retinitis. Screening via testing visual acuity of patients using a Snellen chart is insufficient, as only a small portion of the retina, the fovea, is assessed in this way. The use of questionnaires specifically tailored to detect or elicit signs and symptoms of cytomegalovirus retinitis can be a more effective screening tool.
HIV patients have a higher risk of cytomegalovirus retinitis, and it is reported that the latter is the most frequently encountered opportunistic viral infection in the above group, especially when CD4 (cluster of differentiation 4) cell count is extremely low, that is, less than 50 per cubic millimeter . Immunocompetent individuals, especially those who have received steroid injections, make up the minority of cytomegalovirus retinitis patients  .
- Lymphocytic Infiltrate
Here we present a CVID patient who has developed a clinical polyclonal lymphocytic infiltration phenotype associated with severe and irreversible pancytopenia with unknown etiology. [ncbi.nlm.nih.gov]
Viral infection also induces CXCL9 and CXCL10, which are known T-cell chemoattractants that precede lymphocyte infiltration. [doi.org]
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