A 35-year-old man with HIV infection (CD4 count 45 cells/μL) presents with progressive visual loss, floaters, and photopsia in the right eye. Fundoscopic examination shows hemorrhagic retinal infiltrates with granular appearance and minimal inflammation. What is the most appropriate next step in management?

Explanation

## Diagnosis: Cytomegalovirus (CMV) Retinitis **Key Point:** Hemorrhagic retinal infiltrates with granular appearance ("cottage cheese and ketchup" pattern) in an immunocompromised patient (CD4 <50) is diagnostic of CMV retinitis, specifically the hemorrhagic form. ## CMV Retinitis: Clinical Features & Epidemiology | Feature | Details | | --- | --- | | **CD4 threshold** | <50 cells/μL (highest risk) | | **Presentation** | Floaters, photopsia, visual field defects | | **Fundoscopic finding** | Hemorrhagic infiltrates ("cottage cheese and ketchup") or granular pattern | | **Inflammation** | Minimal to absent (unlike ARN) | | **Progression** | Centripetal (center-to-periphery) | ## Management Algorithm ```mermaid flowchart TD A[CMV Retinitis diagnosed]:::outcome --> B{CD4 count & severity?}:::decision B -->|CD4 <50, active disease| C[IV Ganciclovir 5 mg/kg BD]:::action B -->|CD4 50-100, mild| D[Oral Valganciclovir 900 mg BD]:::action C --> E[Optimize ART immediately]:::action D --> E E --> F[Monitor CD4 recovery]:::action F --> G{CD4 >100-150 sustained?}:::decision G -->|Yes| H[Continue maintenance therapy]:::action G -->|No| I[Intensify ART, continue IV therapy]:::action ``` **High-Yield:** With CD4 <50, IV ganciclovir is MANDATORY for induction therapy. Oral valganciclovir is insufficient for active disease at this CD4 level. **Clinical Pearl:** CMV retinitis is a **vision-threatening emergency**. Delay in IV therapy results in rapid progression and irreversible blindness. Concurrent ART optimization is critical — immune reconstitution (CD4 >100–150) is the only definitive cure. **Mnemonic: IV ganciclovir for CMV retinitis when CD4 <50** — **I**mmediately start IV therapy, **V**ision-threatening emergency, **G**anciclovir is first-line induction, **C**D4 <50 = highest risk, **M**aintenance after induction. ## Why IV Ganciclovir? 1. **Superior intraocular penetration** — IV achieves therapeutic levels in vitreous 2. **Rapid viral suppression** — Essential when CD4 <50 and disease is active 3. **Prevention of blindness** — Delays progression and preserves remaining vision 4. **Standard of care** — Endorsed by CDC, WHO, and ophthalmology guidelines for induction [cite:Harrison 21e Ch 172]