Retinal Detachment

Definition

Types

1. Rhegmatogenous RD (RRD) — Most Common

• Caused by a retinal break (tear or hole) that allows liquefied vitreous to seep under the neurosensory retina
• Nearly always requires concurrent vitreous liquefaction and traction — a break alone rarely causes detachment
• Affects ~1 in 10,000 per year; both eyes eventually affected in ~10% of patients
• Over 40% occur in myopic eyes — higher myopia = greater risk
• Also associated with posterior vitreous detachment (PVD), lattice degeneration, snail-track degeneration, prior cataract surgery, and laser capsulotomy

2. Tractional RD

• Caused by fibrocellular bands in the vitreous contracting and pulling the retina off
• Causes: proliferative diabetic retinopathy (most common), sickle cell retinopathy, retinopathy of prematurity, toxocariasis, trauma, proliferative vitreoretinopathy (PVR)
• Retina appears concave with a smooth surface; detachment rarely reaches the ora serrata; retina is immobile

3. Exudative (Serous) RD

• No break or traction — fluid accumulates under the retina due to breakdown of the blood-retinal barrier
• Causes: malignant hypertension, eclampsia of pregnancy, choroidal tumors, posterior scleritis, uveal effusion syndrome
• Generally resolves when the underlying cause is treated — no direct surgical intervention needed

Symptoms (RRD)

• Photopsia (flashing lights) — due to vitreoretinal traction from PVD
• Floaters — due to the causative vitreous detachment
• Curtain-like visual field defect — peripheral, progressing centrally; the quadrant of the field defect is in the opposite quadrant to the primary break
• Some patients note the field defect improves on waking (due to overnight SRF reabsorption) and worsens during the day
• Loss of central vision if the macula (fovea) becomes involved

Break Localization (Lincoff's Rules)

• 60% superotemporal
• 15% superonasal
• 15% inferotemporal
• 10% inferonasal

• Superior break → SRF first spreads inferiorly ipsilateral, then rises on opposite side
• 6 o'clock break → equal inferior fluid levels
• Bullous inferior RD → primary break usually above the horizontal meridian
• Superior nasal break → SRF revolves around the optic disc and rises on temporal side

Fundoscopic Appearance

Workup

1. Dilated fundoscopy with indirect ophthalmoscopy + scleral depression of both eyes — identify all breaks
2. Slit lamp with 90D or widefield lens — assess vitreous, peripheral retina
3. B-scan ultrasound — if media opacity prevents fundus visualization (e.g., dense vitreous hemorrhage)
4. OCT — useful in tractional RD to identify membranes and differentiate from other pathology

Differential Diagnosis

Treatment

Urgency

• Macula-on RRD: Surgical emergency — repair as soon as possible; macula must be protected
• Macula-off RRD: Urgent but not emergent — visual outcomes comparable if surgery done within 7–10 days of onset
• Dense vitreous hemorrhage + RD on B-scan: Operate urgently
• Tractional RD: May observe if not threatening the macula; vitrectomy when indicated
• Exudative RD: Treat the underlying cause — usually no direct surgical intervention

Surgical Options

Follow-Up

• Post-RRD repair: 1 day → 1 week → 1 month → 2–3 months → every 6–12 months
• Fellow eye must always be examined given ~10% bilateral risk

Retinal Detachment — 10 Mark Answer

Definition

Classification

1. Rhegmatogenous RD (RRD) — Most Common

• High myopia (>40% of all RRDs)
• Posterior vitreous detachment (PVD)
• Predisposing lesions: lattice degeneration, snail-track degeneration, atrophic round holes
• Aphakia/pseudophakia, vitreous loss at cataract surgery, laser capsulotomy
• Trauma (dialysis at ora serrata)
• Family history; fellow eye at ~10% risk

2. Tractional RD

3. Exudative (Serous) RD

Symptoms (RRD)

• Photopsia — flashing lights from vitreoretinal traction
• Floaters — pigment cells or vitreous debris (including "tobacco dust" = Shafer's sign)
• Curtain-like visual field defect — appears in the opposite quadrant to the primary break
• Decreased central vision — if the macula (fovea) is involved

The quadrant of the field defect corresponds to the opposite quadrant of the primary break. Photopsia location does not predict break location.

Signs

• Mild iritis (common); severe iritis suggests Schwartz-Matsuo syndrome
• Reduced IOP (~5 mmHg lower than fellow eye); extremely low IOP suggests associated choroidal detachment
• Relative afferent pupillary defect (RAPD) in extensive RD
• Tobacco dust (Shafer's sign) — pigment cells in anterior vitreous; highly specific for RRD

• Fresh RD: Convex, corrugated, opaque appearance (retinal edema); elevated with loss of choroidal pattern
• Longstanding RD: Retinal atrophy, intraretinal cysts (after ~1 year), subretinal demarcation lines/pigment "tide marks" (after ~3 months)
• Breaks: Red discontinuities in the retinal surface (colour contrast with choroid); may be less visible in high myopia

Break Localization — Modified Lincoff's Rules

Investigations

1. Indirect ophthalmoscopy with scleral depression — both eyes; essential to identify all breaks
2. Slit lamp + 90D/widefield lens — vitreous assessment, tobacco dust, posterior breaks
3. B-scan ultrasound — when fundal view is obscured (dense vitreous haemorrhage, media opacity)
4. OCT — useful in tractional membranes, macular status, sub-foveal fluid, and differentiating retinoschisis from RD

Differential Diagnosis

Treatment

Urgency

• Macula-on RRD — surgical emergency; operate as soon as possible
• Macula-off RRD — visual outcome does not significantly change if surgery within 7–10 days of onset
• Dense vitreous haemorrhage + RD on B-scan — urgent surgery
• Exudative RD — treat the underlying cause; direct surgery not usually needed

Surgical Options

• Intravitreal gas bubble (SF₆ or C₃F₈) + cryotherapy or laser
• Office-based, minimally invasive
• Indication: Single small break or cluster <2 clock hours in the upper 2/3 of peripheral retina; uncomplicated RRD
• Limitation: Lower success rate than scleral buckling

• Silicone explant sutured to sclera creates an inward indentation to close the break and reduce vitreoretinal traction
• Configurations: radial, segmental, circumferential, or encircling
• Procedure: Peritomy → break localization → cryotherapy → explant sutured → subretinal fluid drainage if needed
• Indication: Peripheral breaks, post-traumatic dialysis, young phakic patients
• Complications: Diplopia, CME (~25%), epiretinal membrane (~15%), anterior segment ischaemia, buckle extrusion/infection, elevated IOP, choroidal detachment

• 3-port approach (infusion + vitreous cutter + light probe via sclerotomies)
• Steps: Core vitrectomy → posterior hyaloid separation → membrane peeling → fluid-air/gas exchange → laser/cryopexy → tamponade
• Tamponade agents: Expanding gas (SF₆, C₃F₈) or silicone oil (for complex cases, PVR, inferior breaks)
• Indications: Posterior/giant breaks, PVR (Grade B or C), tractional RD, haemorrhage obscuring breaks, pseudophakic RD, failed scleral buckle
• For PVR: Membrane peeling ± ILM peeling ± relaxing retinotomy + long-acting tamponade

Proliferative Vitreoretinopathy (PVR) — Major Complication

Prognosis

• Macula-on RRD repaired promptly: good visual recovery (>6/12 in most)
• Macula-off RRD: Better visual outcomes if surgery within 72 hours; results further decline beyond 7–10 days
• PVR is the leading cause of surgical failure in RRD repair

Rhegmatogenous Retinal Detachment (RRD)

Definition & Etymology

Epidemiology

• Incidence: ~1 in 10,000 per year
• Both eyes eventually affected in ~10%
• Peak age: 50–70 years (PVD-related); younger in high myopes and post-trauma

Pathogenesis

1. A full-thickness retinal break (tear or hole)
2. Vitreous liquefaction (synchysis) + vitreoretinal traction

Types of Retinal Breaks

Risk Factors / Predisposing Lesions

• High myopia — >40% of all RRDs; elongated globe, vitreous degeneration, chorioretinal atrophy
• Posterior vitreous detachment (PVD) — the most common precipitant of horseshoe tears
• Lattice degeneration — present in ~8% of the population; found in ~40% of eyes with RRD. Areas of spindle-shaped retinal thinning with sclerosed vessels (white arborizing lines), exaggerated vitreous adhesions at margins → tractional tears on PVD
• Snailtrack degeneration — frost-like peripheral white areas; round holes common
• Aphakia/pseudophakia — especially with vitreous loss at surgery
• Trauma — dialysis at ora serrata
• Fellow eye — ~10% bilateral lifetime risk

• Marfan syndrome, Stickler syndrome (hereditary vitreoretinopathy)
• Family history

Symptoms

• Photopsia (flashes) — traction on the retina; does not predict break location
• Floaters — vitreous debris or blood; a sudden "shower" of floaters suggests PVD with possible tear
• Curtain/shadow across visual field — field defect in the opposite quadrant to the primary break
  • Lower field defect noticed sooner than upper; upper break → lower field curtain
  • Some patients note relief on waking (overnight SRF absorption) that recurs later in day
• Loss of central vision — fovea involved by SRF, or large bullous RD obscuring visual axis

Signs

Anterior Segment

Fundus — Fresh RRD

• Convex, corrugated, slightly opaque retinal elevation (retinal edema)
• Loss of underlying choroidal pattern
• Retinal blood vessels appear darker and tortuous over detached area
• Retinal break: red discontinuity (colour contrast with choroid); less visible in high myopia

Fundus — Longstanding RRD

• Intraretinal cysts — develop after ~1 year
• Subretinal demarcation lines ("tide marks"/"high-water marks") — RPE cell proliferation at edge of SRF; appear after ~3 months; represent sites of increased adhesion
• Retinal atrophy and thinning
• Fixed folds, subretinal precipitates

Break Localization — Modified Lincoff's Rules

Investigations

1. Binocular indirect ophthalmoscopy (BIO) with scleral depression — both eyes; identify all breaks; note SRF extent and macula status
2. Slit lamp + 90D/widefield lens — vitreous assessment, tobacco dust, posterior breaks
3. B-scan ultrasound — when fundal view obscured (vitreous haemorrhage, dense cataract, corneal opacification); RD on B-scan = bright hyperechoic membrane attached at disc and ora
4. OCT — macula status (on/off/sub-foveal fluid), epiretinal membrane, intraretinal cysts
5. Examination of fellow eye — essential given 10% bilateral risk

Differential Diagnosis

Treatment

Pre-operative

• Patient fasts if urgent surgery planned
• Bed rest with head positioning so break is most dependent (reduces SRF)
• Do not apply patch or pad (prevents visual monitoring)

Urgency

TIP: Even when the macula is already off, visual results are better if surgery is completed within 72 hours. — Kanski's Clinical Ophthalmology

Surgical Options

1. Pneumatic Retinopexy

• Principle: Intravitreal gas bubble (SF₆ or C₃F₈) expands, tamponades the break from inside; cryotherapy or laser applied to create permanent chorioretinal adhesion
• Head positioning: Patient positions so bubble directly covers the break
• Indication: Single break or cluster of breaks <2 clock hours in the upper 2/3 of peripheral retina; uncomplicated RRD; office-based procedure
• Limitation: Lower success rate than scleral buckling

2. Scleral Buckling (External Surgery)

• Principle: Silicone explant sutured to sclera creates inward indentation (buckle) → opposes RPE to sensory retina, reduces vitreoretinal traction, closes break
• Technique: Peritomy → break localization → cryotherapy to break → explant sutured (radial/segmental/circumferential/encircling) → SRF drainage if needed
• Mandatory: For post-traumatic dialysis
• Explant configuration: Radial (single peripheral tear), segmental (cluster), circumferential or encircling (multiple breaks/high PVR risk)
• Complications: Diplopia, CME (~25%), epiretinal membrane (~15%), buckle extrusion/infection, anterior segment ischaemia (encircling), elevated IOP, choroidal detachment

3. Pars Plana Vitrectomy (PPV — Internal Surgery)

• Principle: Remove vitreous + posterior hyaloid (relieving traction) → drain SRF internally → laser/cryopexy to break → intraocular tamponade to hold retina in place
• 3-port technique: Infusion cannula (4 mm from limbus in phakic; 3.5 mm in pseudophakic) + vitreous cutter + light probe at 10 and 2 o'clock
• Tamponade options: Air, SF₆, C₃F₈ gas (short-to-long acting); silicone oil (for PVR, inferior breaks, giant tears, unable to posture)
• PPV preferred over SB when:
  • Breaks not visualizable (haemorrhage, media opacity)
  • Giant tears, large posterior breaks
  • Proliferative vitreoretinopathy (PVR)
  • Pseudophakic RD
  • Failed prior scleral buckle

Complications of RRD

1. Proliferative Vitreoretinopathy (PVR) — Leading Cause of Surgical Failure

2. Macular complications (macula-off RD)

• Reduced final visual acuity even after successful reattachment
• Epiretinal membrane, CME, persistent subfoveal fluid, photoreceptor loss

Prognosis

• Macula-on, prompt repair: >6/12 visual acuity achievable in most cases
• Macula-off <72 hours: Good recovery likely
• Macula-off >1 week: Significant photoreceptor atrophy; poorer prognosis
• Primary anatomical success rate: ~80–90% with a single procedure; >95% with re-operations
• PVR is the principal cause of failure

Central Serous Chorioretinopathy (CSCR)

Definition

Epidemiology & Demography

• Predominantly affects young to middle-aged males (3rd–5th decade)
• Male : Female ratio = 3:1; females with CSCR tend to be older
• Usually unilateral, but fellow eye shows signs of pachychoroid pigment epitheliopathy in ~2/3 of cases
• Incidence: ~10 per 100,000 per year in males
• Associated with Type A personality (stress-prone, perfectionistic individuals)

Pathogenesis

Choroidal hyperpermeability / pachychoroid
         ↓
Dilated outer choroidal vessels (Haller's layer)
         ↓
Compression of choriocapillaris → ischaemia
         ↓
RPE dysfunction / decompensation
         ↓
Breakdown of outer blood-retinal barrier
         ↓
Leakage of fluid through RPE defect
         ↓
Accumulation of subretinal fluid → neurosensory detachment

• Both endogenous (stress, Cushing syndrome) and exogenous corticosteroids upregulate mineralocorticoid receptors in the choroid → choroidal vasodilation and hyperpermeability
• This explains the strong association with steroid use and stress

Risk Factors / Associations

Classification

Symptoms

• Unilateral blurring of central vision
• Metamorphopsia (distortion of straight lines)
• Micropsia (objects appear smaller — due to photoreceptor displacement by SRF)
• Acquired hypermetropia (visual acuity may improve with a low + power lens)
• Mild dyschromatopsia (colour desaturation)
• Central relative scotoma (detected on Amsler grid)
• Symptoms may fluctuate in morning (overnight reabsorption of SRF)

Signs

• Round or oval serous detachment at the macula — convex, dome-shaped, well-demarcated, with a sloping margin that merges gradually into attached retina
• Subretinal fluid is usually clear (early) or turbid (chronic); precipitates on posterior retinal surface may be present
• One or more small RPE detachments (PEDs) within the neurosensory detachment
• Focal RPE atrophy or hyperplasia at posterior pole — sites of previous episodes
• Gravitational tract — fluid tracks inferiorly from posterior pole in chronic cases (best seen on FAF)
• Bullous CSCR — extensive serous detachment, resembling exudative RD

Multimodal Imaging

1. Optical Coherence Tomography (OCT) — Primary Investigation

• Neurosensory detachment: Optically empty (black) space under the retina with dome-shaped elevation of the sensory retina
• RPE detachment (PED): Small focal elevation of RPE
• Pachychoroid: Choroidal thickening with dilated outer choroidal vessels (Haller's layer)
• Enhanced-depth imaging OCT (EDI-OCT): Demonstrates choroidal thickening — hallmark of pachychoroid

2. Fundus Fluorescein Angiography (FFA/IVFA)

• Underlying PEDs may be demonstrated
• Multiple foci of leakage in chronic CSCR

3. Indocyanine Green Angiography (ICGA)

• Early phase: Delayed choroidal artery filling, dilated outer choroidal vessels
• Mid-phase: Multifocal areas of choroidal hyperfluorescence (choroidal hyperpermeability) — often more extensive than clinically evident
• Late phase: Persistent hyperfluorescence
• ICGA is essential for identifying active leakage site(s) before PDT

4. Fundus Autofluorescence (FAF)

• Hypoautofluorescence at leakage site (RPE loss)
• Hyperautofluorescence — excessive RPE lipofuscin accumulation at adjacent areas
• Gravitational tract: Hyperfluorescent linear streak inferiorly in chronic/recurrent disease

5. Amsler Grid

• Confirms metamorphopsia; documents the area of field involvement

Multimodal Imaging Summary

Differential Diagnosis

Natural History / Course

• Acute CSCR: Spontaneous resolution within 3–6 months in ~80% of cases with return to near-normal vision
• Recurrence: Up to 50% of cases recur
• Chronic CSCR: ~15% follow a chronic course (>4 months); prolonged SRF leads to gradual photoreceptor and RPE degeneration → permanent visual loss
• Complications: Cystoid macular oedema (CMO), macular neovascularisation (MNV), RPE tears (in a small minority)

Management

Step 1 — Identify and Withdraw Precipitating Cause

• Stop all corticosteroids (systemic, topical, inhaled, intranasal) wherever possible — this alone may lead to resolution
• Avoid NSAIDs, excessive stress, and sleep deprivation

Step 2 — Observation (Acute CSCR)

• Most acute cases resolve spontaneously within 3–6 months
• Follow up every 6–8 weeks with OCT and VA monitoring
• All treatment modalities carry risk of RPE tear — do not over-treat early cases

Step 3 — Indications for Active Treatment

• SRF persists for >3–4 months without sign of resolution
• Recurrence in an eye with previous permanent visual deficit
• Visual deterioration affecting occupational or daily function
• Fellow eye previously suffered permanent visual loss
• Chronic CSCR with ongoing RPE damage

Treatment Options

A. Photodynamic Therapy (PDT) with Verteporfin — Gold Standard for Chronic CSCR

• Half-dose / reduced-fluence PDT: Verteporfin at 30–50% of standard MNV dose + 50% light intensity
• Mechanism: Selectively obliterates hyperpermeable choriocapillaris → reduces choroidal blood flow → resolves SRF
• Leakage site identified on ICGA before treatment
• Results: Complete resolution in the majority of cases, including severe chronic cases
• Lower risk of significant choroidal ischaemia compared to full-dose PDT
• Anti-VEGF agents commonly used in conjunction with PDT; bevacizumab alone is not effective unless coexisting MNV is present

B. Subthreshold (Micropulse) Diode Laser

• Delivers energy only to RPE cells at the leakage site without visible retinal damage
• Uses 810 nm diode laser in a micropulse mode (on/off cycling)
• Advantage: No scotoma, no chorioretinal scar, can treat juxtafoveal leaks
• Shows good results in several studies; significantly less OCT-detectable retinal damage than conventional laser
• Used when leakage site is away from the fovea and identifiable on FFA

C. Conventional Laser Photocoagulation

• Direct treatment of FFA-identified leakage site
• May accelerate visual recovery but no long-term benefit shown
• Risk: CNV formation at laser scar; use low intensity settings
• Indications: Leakage site is >300 µm from the foveal centre; occupational urgency; recurrent disease with prior visual loss
• Contraindicated if leakage is subfoveal or juxtafoveal

D. Mineralocorticoid Receptor Antagonists (MRAs)

• Spironolactone (40 mg twice daily) and Eplerenone (25–50 mg daily)
• Mechanism: Block mineralocorticoid receptors in choroidal endothelium → reduce choroidal hyperpermeability
• Evidence (2025 Cochrane network meta-analysis [PMID 40522203]; 2025 meta-analysis of eplerenone/spironolactone [PMID 40513762]): Associated with improved anatomic and visual outcomes in chronic CSCR
• Oral spironolactone may accelerate SRF resorption even in acute CSCR
• Side effects: Hyperkalaemia, gynaecomastia (spironolactone); eplerenone has better tolerability

E. Anti-VEGF Therapy

• Not first-line for uncomplicated CSCR
• Indicated when macular neovascularisation (MNV) develops as a complication
• Bevacizumab alone: no benefit in CSCR without MNV

F. Others (limited evidence)

• Aspirin, beta-blockers, mifepristone (anti-progesterone): case reports only; not routine practice

Treatment Decision Algorithm

Acute CSCR (<3–4 months)
      ↓
Withdraw steroids + Observe
      ↓
No resolution at 3–4 months / occupational urgency
      ↓
Leakage site identifiable?
   ├─ Away from fovea → Micropulse diode laser OR conventional laser (low intensity)
   └─ Subfoveal/diffuse → Half-dose PDT (preferred) + consider MRA
      
Chronic CSCR (>4 months)
      ↓
Half-dose verteporfin PDT (first line) ± MRA (spironolactone/eplerenone)
      ↓
MNV develops → Add anti-VEGF

Prognosis

Recent Evidence

• A 2025 Cochrane network meta-analysis (PMID 40522203) comparing all interventions for CSCR confirmed PDT and mineralocorticoid antagonists as the treatments with the strongest evidence base for chronic CSCR.
• A 2025 systematic review and meta-analysis (PMID 40513762) specifically on eplerenone and spironolactone confirmed improved anatomic and visual outcomes in chronic CSCR with both agents.

Eales Disease

Definition & Historical Note

Epidemiology

• Predominantly affects young males in the 2nd–4th decade of life
• Male : Female ratio ≈ 3:1
• Rare in White people; important cause of visual morbidity in young South Asian males (Indian subcontinent, Middle East)
• Typically bilateral, though presentation is often asymmetrical
• Incidence higher in regions with high prevalence of tuberculosis

Aetiology & Pathogenesis

Proposed Mechanisms:

• It is hypothesized that Eales disease represents a delayed-type hypersensitivity reaction to Mycobacterium tuberculosis antigens (tuberculoprotein)
• Evidence: High prevalence in TB-endemic regions; positive Mantoux test in many patients; PCR detection of mycobacterial DNA in vitreous; some cases classified as frank tuberculous vasculitis
• However, evidence is conflicting and TB is not isolated in all cases

• Cell-mediated immune response targeting retinal vascular endothelium
• Activated T lymphocytes infiltrate perivascular spaces → perivenous inflammation

• Impaired free radical scavenging; increased lipid peroxidation demonstrated in patients with Eales disease

Perivenous inflammation (periphlebitis)
         ↓
Endothelial cell damage → vascular wall thickening
         ↓
Venous occlusion → peripheral capillary non-perfusion
         ↓
Retinal ischaemia → VEGF upregulation
         ↓
Peripheral retinal neovascularization
         ↓
Vitreous haemorrhage / tractional retinal detachment

Staging (Three Overlapping Stages)

Symptoms

• Floaters — early symptom; black dots or cobwebs
• Sudden painless visual reduction — due to vitreous haemorrhage (most common presentation)
• Symptoms may be recurrent (vitreous haemorrhage recurs in about 1/3 of eyes)
• Bilateral visual symptoms — though not always simultaneous
• Neurological features (headache, cerebrovascular events) — rarely reported; Eales disease is also listed as a rare cause of brain infarction

Signs

Anterior Segment

• Mild anterior uveitis — common
• Vitreous haemorrhage — fresh or resolving (orange-red or yellowish opacity)
• Posterior vitreous detachment with fibrovascular membranes in advanced cases

Fundus (in order of stage)

• Perivenous sheathing — white cuffing around peripheral retinal veins (periphlebitis)
• Superficial retinal haemorrhages (flame-shaped) around affected veins
• Cotton-wool spots (nerve fibre layer infarcts) in area of ischaemia
• Pigmented chorioretinal scars (evidence of old lesions)

• Branch retinal vein occlusion (BRVO) in periphery
• Peripheral capillary non-perfusion — detected best on FFA; avascular zones
• Microaneurysms, arteriovenous shunts, telangiectatic vessels at junction of perfused and non-perfused retina

• Peripheral NVE — frond-like new vessel networks at ischaemia margin
• NVD (disc new vessels) — occasionally
• Vitreous haemorrhage — recurrent; usually limited in amount; absorbs over weeks (may persist)
• Macular involvement — uncommon but can occur with CMO or ERM

• Tractional retinal detachment (TRD)
• Macular epiretinal membrane
• Neovascular glaucoma (rubeosis iridis)
• Complicated cataract
• Vitreous fibrosis

Fundus and FFA Images

Investigations

Ocular

1. Fundus fluorescein angiography (FFA) / Wide-field FFA — essential
   • Active vasculitis: perivenous hyperfluorescence (staining of vessel walls), leakage
   • Areas of capillary non-perfusion (dark avascular zones)
   • Neovascularization: bright hyperfluorescent fronds with late leakage
   • Wide-field imaging is particularly helpful for peripheral disease mapping
2. B-scan ultrasonography — if vitreous haemorrhage obscures the fundus; rules out TRD
3. OCT — macular assessment; CMO, ERM, sub-foveal fluid
4. Indirect ophthalmoscopy with scleral depression — assess peripheral retina

Systemic (to exclude other causes)

1. Mantoux (tuberculin skin test) / IGRA (QuantiFERON-TB Gold) — for TB exposure
2. Chest X-ray / CT chest — hilar lymphadenopathy, TB, sarcoidosis
3. ACE (angiotensin-converting enzyme) levels — sarcoidosis
4. Haemoglobin electrophoresis — sickle cell disease
5. VDRL / FTA-ABS — syphilis
6. FBC, ESR, CRP — systemic inflammation
7. ANA, ANCA — collagen vascular disease
8. Serum glucose, HbA1c — diabetes
9. PCR of vitreous — for Mycobacterium tuberculosis DNA (in selected cases)

Differential Diagnosis

Eales disease is a diagnosis of exclusion — all the above must be ruled out before the diagnosis is made. — The Wills Eye Manual

Treatment

Stage 1 — Inflammatory (Periphlebitis)

• Periocular, systemic, topical and intravitreal steroids are helpful in the inflammatory stage
• Systemic prednisolone (1 mg/kg/day tapered over weeks) for active periphlebitis
• Topical steroids for associated anterior uveitis

• Strongly advocated by some authorities but controversial
• Recommended in combination with steroids when:
  • Strongly positive tuberculin test (Mantoux) or QuantiFERON positive
  • Severe ocular inflammatory signs
  • To avoid reactivation of latent TB during steroid therapy
• Standard 4-drug ATT: RHEZ (Rifampicin, Isoniazid, Ethambutol, Pyrazinamide) × 2 months → RH × 4 months
• Monitor for ethambutol-related optic neuropathy

Stage 2 — Occlusive (Ischaemic)

• Applied to all areas of capillary non-perfusion (identified on FFA)
• Mechanism: Destroys hypoxic outer retinal cells → reduces VEGF → prevents/treats neovascularization
• Performed in sessions; wide-field FFA guides treatment
• Cryotherapy of non-perfused retina — an alternative if laser is not feasible (anterior lesions, media opacity)

Stage 3 — Proliferative (Neovascular)

• Commonly used for active neovascularization
• Causes rapid regression of NVE/NVD
• Used as adjunct to laser (pre-operatively before vitrectomy to reduce bleeding risk)
• Multiple injections may be needed

• Indicated for:
  • Persistent/dense vitreous haemorrhage (non-clearing despite 3–4 months)
  • Tractional retinal detachment (TRD)
  • Macular epiretinal membrane causing significant visual loss
  • Combined TRD-RRD
• Combined with intraoperative laser (endolaser photocoagulation) and anti-VEGF

Treatment Summary Table

Prognosis

• Good in the majority — most cases resolve with treatment
• Spontaneous resolution of vitreous haemorrhage within weeks in many patients
• Poor prognosis factors: TRD involving the macula, neovascular glaucoma, delayed presentation, bilateral severe disease
• Recurrences are common — long-term follow-up essential
• Visual prognosis depends largely on macular sparing — macular involvement is uncommon but significantly worsens outcome