A 62-year-old woman with poorly controlled diabetes mellitus presents with progressive visual loss over 3 months. She denies floaters or photopsia. Examination reveals visual acuity of 6/60 in both eyes. Fundoscopy shows extensive retinal neovascularization, vitreous haemorrhage, and a smooth, funnel-shaped retinal detachment with the apex at the optic disc and the base at the equator. There are no visible retinal breaks. What is the most appropriate next step in management?

Explanation

## Diagnosis & Management: Tractional Retinal Detachment in Proliferative Diabetic Retinopathy ### Clinical Diagnosis This patient has **tractional retinal detachment (TRD)** secondary to proliferative diabetic retinopathy (PDR). ### Key Diagnostic Features **Key Point:** The **funnel-shaped detachment with the apex at the optic disc and base at the equator** is pathognomonic for tractional detachment. The absence of retinal breaks and the smooth detachment edge distinguish it from rhegmatogenous detachment. | Feature | Tractional RD | Rhegmatogenous RD | | --- | --- | --- | | **Retinal breaks** | Absent | Present | | **Detachment shape** | Smooth, funnel-like | Irregular, mobile | | **Onset** | Gradual (weeks–months) | Acute (hours–days) | | **Floaters/photopsia** | Absent or minimal | Prominent | | **Vitreous inflammation** | None | Mild | | **Cause** | Vitreous contraction | Retinal break + PVD | ### Pathophysiology of Tractional Detachment ```mermaid flowchart TD A[Proliferative Diabetic Retinopathy]:::outcome --> B[Neovascularization]:::action B --> C[Epiretinal and subretinal fibrovascular membranes]:::action C --> D[Vitreous contraction]:::action D --> E[Mechanical traction on retina]:::urgent E --> F[Smooth funnel-shaped detachment]:::outcome F --> G[No retinal breaks]:::outcome ``` ### Why Pars Plana Vitrectomy Is Indicated **High-Yield:** Tractional RD with **vision-threatening extent** (macula involved, progressive visual loss) requires **surgical intervention**. Vitrectomy is the gold standard because it: 1. **Removes the vitreous scaffold** that supports the epiretinal membranes 2. **Allows membrane peeling** to relieve traction 3. **Restores retinal anatomy** and reattachment 4. **Permits silicone oil tamponade** for long-term support in complex cases ### Why Silicone Oil Tamponade? - Provides **long-term internal support** against re-detachment - Allows **complete membrane dissection** without fear of re-detachment during surgery - Indicated in **macula-off TRD** with extensive vitreous involvement ### Management Algorithm ```mermaid flowchart TD A[Tractional RD in PDR]:::outcome --> B{Macula involved?}:::decision B -->|Yes| C{Extensive?}:::decision B -->|No| D[Observation + PRP]:::action C -->|Yes| E[PPV + membrane peeling + silicone oil]:::action C -->|No| F[PPV + membrane peeling]:::action E --> G[Reattachment achieved]:::outcome F --> G ``` **Clinical Pearl:** Anti-VEGF agents (bevacizumab, aflibercept) may stabilize neovascularization but do NOT reverse established traction — they cannot substitute for vitrectomy in vision-threatening TRD.