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cytomegalovirus (CMV) retinitis

A sight-threatening disorder secondary to cytomegalovirus infection of the retina, generally in immunocompromised individuals. Epidemiology: 1) most common ocular opportunistic infection 2) occurs in 25-30% of patients with advanced HIV disease Pathology: - untreated a) inflammatory destruction of retina b) retinal detachment Clinical manifestations: 1) peripheral retinal lesions generally do not cause visual symptoms 2) generally far advanced before recognition of symptoms 3) lesions impinging on the macula or optic nerve head a) floaters b) scotomas c) visual field defects 4) blurred vision, painless vision loss [4] 5) yellow-white exudates, hemorrhages & vascular sheathing on ophthalmoscopic examination 6) retinitis is generally unilateral, but may be bilateral in 20% of patients 7) untreated, leads to visual loss Laboratory: - dilated ophthalmoscopy required for diagnosis Differential diagnosis: - Toxoplasma gondii chorioretinitis - fluffy white necrotizing retinitis adjacent to pigmented chorioretinal scar - vitreous inflammation Management: 1) ganciclovir a) induction therapy - 5 mg/kg every 12-24 hours IV for 14-21 days infused over 1 hour b) maintenance therapy 1] intravenous infusion a] 6 mg/kg/day for 5 days per week b] 5 mg/kg/day 2] 1000 mg PO TID or 500 mg 6 times/day c) intravitreous implant 1] may substantially increase disease-free interval 2] may be associated with post-operative visual changes 3] increased incidence of retinal detachment 4] no coverage for contralateral eye or systemic disease 2) foscarnet a) indications 1] patients with ganciclovir-resistant CMV 2] patients who cannot tolerate ganciclovir b) induction therapy: 60 mg/kg every 8 hours for 2-3 weeks c) maintenance therapy: 90-120 mg/kg/day d) foscarnet is given IV as a 1-2 hour infusion 3) cidofovir 4) indefinite maintenance therapy is generally required to suppress CMV disease in patients with AIDS [1] 5) in some AIDS patients, CMV maintenance therapy can be discontinued when immune parameters improve [2] 6) median time to progression of disease is 2 months with IV treatment but may be longer with intravitreous implants

Related

cytomegalovirus (CMV, human herpesvirus 5, HHV5)

General

retinitis viral infection

References

  1. Manual of Medical Therapeutics, 28th ed, Ewald & McKenzie (eds), Little, Brown & Co, Boston, 1995, pg 293-294
  2. Journal Watch, Mass Med Soc 19(23):182-83 (Dec) 1999
  3. Medical Knowledge Self Assessment Program (MKSAP) 11, American College of Physicians, Philadelphia 1998
  4. NEJM Knowedge+