Cytomegalovirus retinitis
 

In the early stages, CMV retinitis may resemble cotton wool spots as seen in HIV retinopathy. However, unlike the cotton wool spots in  HIV retinopathy which tend to be multiple and  transient, the lesions seen in CMV retinitis tend to be solitary and show enlargement over time. The retinitis spread along the retinal vessels with white lesions and scattered haemorrhages. The involved vessels show sheathing. The retina behind the advancing edge may be atrophy. The vitreous is quiet and contains little cells. Other signs: Hickman's line in the upper chest for intravenous drug administration. However, in some centres, the patient may have intraocular implant instead. (Note: the use of intravenous line is becoming less common with the use of HAART) Look for AIDS defining lesions such as molluscum contagiosum and Kaposi's sarcoma

Questions:

1. What is the most important factor in predicting the development of CMV retinitis in AIDS patient?

Answer

The CD4+ counts. The chance is increased with falling CD4+ counts. It is estimated that patients with count of less than 50 cells/ml runs a 20% risk of developing CMV retinitis per year.

 

2. How does CMV retinitis affect the vision?

Answer
Blindness is due to sequential optic neuropathy, direct optic nerve involvement, retinitis at the macula and retinal detachment.

 

3. What drugs are useful in CMV retinitis and how often do they need to be administer?

Answer
Three drugs are currently available:
ganciclovir (side effect: bone marrow suppression)
foscarnet (side effect: nephrotoxicity)
cidofovir (side effect: nephrotoxicity)
The patient needs to be on the treatment life-long.
 

4. What is HAART?

Answer
HAART (Highly active antiviral therapy) uses a combination of antiviral therapy in the treatment of CMV retinitis. The regime also increases the CD4+ counts and prevent the recurrence of CMV retinitis. However, during the treatment, the patient may develop severe intraocular inflammation.

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