INSTRUCTION

At a distance from the patient, the examiner will say that this patient has HIV, examine

his fundus.

SALIENT FEATURES

History

· Floaters.

· Red eye.

· Impaired vision.

Examination

Patient 1: Cottonwool spots Cottonwool spots (Fig. 86).

Proceed as follows:

Tell the examiner that you would like to exclude diabetes and retinal vascular disease.

Patient 2: Cytomegalovtrus (CMV) retinitis.

· An area of retinitis with nerve fibre layer infarcts, haemorrhages, retinal

opacifi-cation and perivascular sheathing - 'pizza-pie fundus'.

· Tell the examiner that you would like to do a CD4 count (<50 in acute infection).

QUESTIONS

How would you treat cottonwool spots?

In a patient with known HIV infection, such infarcts require no specific therapy.

ADVANCED-LEVEL QUESTIONS

How would you treat the lesions of CMV retinitis?

· Therapy with intravenous ganciclovir or foscarnet is given lifelong to protect

unaffected areas but does not restore functional areas already affected. The optimal

treatment for patients with AIDS, normal renal function and CMV retinitis is foscarnet

plus an antiretroviral nucleoside such as zidovudine. For similar patients with impaired

renal function, ganciclovir would be the drug of choice, perhaps with an antiretroviral

agent such as didanosine that has few over-lapping side-effects. Late retinal

detachment occurs despite therapy in one fifth of these patients.

· Sustained release ganciclovir implant in the pars plana of the eye. Oral

ganciclovir in conjunction with an implant reduces the incidence of new cytomegalovirus

disease and delays the progression of retinitis (N Engl J Med 1999; 340: 1063-70).

· Intravitreal injections of ganciclovir or foscarnet.

What do you know about ganciclovir?

It is a derivative of aciclovir. It can cause bone marrow depression and hence should not

be administered simultaneously with zidovudine.

What do you know about foscarnet?

It is an organic analogue of inorganic pyrophosphate. Its side-effects include renal

impairment, electrolyte imbalance and seizures. It can be safely administered with

zidovudine.

What are the other retinal manifestations in patients with AIDS?

· Toxoplasmosis retinochoroiditis - usually nasal to the disc, characterized by

extensive whitish infarction and inflammation, with minimal associated intra-retinal

haemorrhage (outer retinal involvement may show 'brush-fire' advancement of

infection).

· Pneumocystis carinii choroiditis - characterized by scattered nodular

yellowish-orange lesions deep in the retina, usually throughout the posterior pole.

· Acute retinal necrosis syndrome - with severe peripheral retinal infarction and

retinal vasculitis. Atrophic retinal holes appear later in these areas.

· Progressive outer retinal necrosis syndrome - characterized by diffuse whitish

opacification of the retina beneath the retinal vessels and a cherry-red spot in the fovea.

It is associated with herpes zoster and the prognosis for visual acuity is dismal.

· Ocular presentations of syphilis include anterior and posterior uveitis, retinitis,

retinal vasculitis and papillitis.

· Acute syphilitic posterior placoid chorioretinitis - large placoid yellowish lesions

at the level of the retinal pigment epithelium in the posterior retina with inflam-mation of

the vitreous and loss of vision.

What diagnostic tests would you perform to detect retinal manifestations of AIDS?

· Careful clinical observations.

· Serology: CD4 count (usually <50 in untreated cases of CMV retinitis). · Culture.

· Retinal biopsy by pars plana vitrectomy.

· Fluorescein angiography: helpful in differentiating retinal lesions.

· Sequential fundus photographs: for diagnosis and monitoring of lesions. · Testing of

ocular fluid by polymerase chain reaction.

Mention some ocular non-retinal manifestations of AIDS.

· Optic neuropathy.

· Kaposi's sarcoma of the conjunctiva.

· Orbital lymphoma.

· Cranial nerve palsies.

· Nystagmus.