Retinal Detachment
Classification, Pathogenesis, Clinical Features & Management
Examination question · ~800 words
Define retinal detachment. Discuss its classification, pathogenesis, clinical features, investigations and management, with special reference to rhegmatogenous retinal detachment.
Try to outline your answer mentally before expanding sections below.
Retinal detachment (RD) is separation of the neurosensory retina from the retinal pigment epithelium (RPE), with accumulation of subretinal fluid in the potential subretinal space. It is a vision-threatening ophthalmic emergency. The three major mechanisms are rhegmatogenous, tractional, and exudative retinal detachment; accurate classification is essential because management differs fundamentally between them.
| Feature | Rhegmatogenous RD | Tractional RD | Exudative RD |
|---|---|---|---|
| Mechanism | Retinal break allows liquefied vitreous to enter the subretinal space | Fibrovascular or contractile membranes pull retina away from RPE | Subretinal fluid accumulates without retinal break or traction |
| Common causes | High myopia, trauma, lattice degeneration, aphakia/pseudophakia, post-cataract surgery | Proliferative diabetic retinopathy, sickle cell retinopathy, ROP, trauma | VKH, sympathetic ophthalmia, posterior scleritis, choroidal tumour, malignant hypertension, eclampsia, CSCR |
| Subretinal fluid | May shift with posture; can extend to ora serrata | Usually non-shifting; concave retinal elevation | Shifting, bullous, convex dome-shaped detachment |
| Shafer's sign | Present: pigment cells in anterior vitreous | Absent unless combined with break | Absent |
| IOP | Often reduced | Variable | Normal or elevated |
| Treatment principle | Find and seal all retinal breaks; relieve vitreoretinal traction | Vitrectomy with membrane segmentation/delamination | Treat the underlying cause |
Step 1: Vitreous Liquefaction
With ageing, high myopia or inflammation, the vitreous gel undergoes synchysis syneresis. Liquefied vitreous collects in lacunae and weakens normal vitreoretinal adhesion.
Step 2: Posterior Vitreous Detachment
Liquefied vitreous enters the retrohyaloid space, producing posterior vitreous detachment (PVD). At sites of abnormal vitreoretinal adhesion such as lattice degeneration, meridional folds or enclosed ora bays, the separating vitreous exerts traction.
Step 3: Retinal Break Formation
- Horseshoe or flap tear: produced by dynamic vitreoretinal traction; the most common pathological tear.
- Atrophic hole: occurs in areas of pre-existing retinal thinning, often in young myopes and may occur without acute PVD.
- Retinal dialysis: circumferential separation at the ora serrata, commonly traumatic.
Step 4: Subretinal Fluid Accumulation
Liquefied vitreous passes through the retinal break into the subretinal space. The RPE pump is overwhelmed, causing progressive separation of neurosensory retina from RPE.
| Risk Factor | Exam-Relevant Point |
|---|---|
| High myopia > 6 D | Approximately 10-fold increased risk; associated with lattice degeneration and thin peripheral retina |
| Ocular surgery | Post-phacoemulsification RD risk approximately 0.6-1.7%; YAG capsulotomy increases risk |
| Lattice degeneration | Present in about 8% of population; lifetime RD risk about 1%; associated with atrophic holes and tractional tears |
| Fellow eye RD | Approximately 10% lifetime risk; fellow eye must be screened and suspicious lesions treated |
| Trauma | Classically causes retinal dialysis and giant retinal tears |
| Hereditary vitreoretinopathies | Stickler syndrome, Wagner syndrome, Marfan syndrome, Ehlers-Danlos syndrome |
| Aphakia or pseudophakia | Disrupted vitreous architecture; superior breaks are common |
Symptoms
- Photopsia: flashing lights due to dynamic vitreoretinal traction.
- New-onset floaters: due to pigment cells, vitreous debris or vitreous haemorrhage.
- Visual field defect: curtain or shadow corresponding to the detached retina.
- Reduced central acuity: indicates macular involvement, i.e. macula-off RD.
- Metamorphopsia: occurs when the posterior pole is affected.
Anterior Segment and Vitreous Signs
- Reduced IOP due to impaired RPE pump function.
- Shafer's sign: tobacco-dust pigment cells in anterior vitreous; highly suggestive of RRD.
- Relative afferent pupillary defect in extensive RD.
Posterior Segment Signs
- Elevated, corrugated, grey-white translucent retina.
- Retinal break visible on indirect ophthalmoscopy with scleral indentation or Goldmann 3-mirror examination.
- Subretinal fluid may shift with posture in RRD.
- Vitreous haemorrhage may obscure the break and implies significant vitreoretinal traction.
- Demarcation lines indicate chronic RD.
- PVR membranes cause fixed folds and star-fold configuration in advanced cases.
| Investigation | Role |
|---|---|
| Indirect ophthalmoscopy with scleral indentation | Mandatory before surgery; localises all breaks, maps RD extent and assesses PVR |
| B-scan ultrasonography | Most useful when media are opaque due to vitreous haemorrhage or cataract; detects RD extent, PVR, choroidal detachment and intraocular foreign body |
| OCT macula | Assesses foveal attachment, subretinal fluid height and post-repair ELM/ellipsoid zone integrity |
| Fundus fluorescein angiography | Rarely needed in RRD; useful in exudative RD to identify leakage source |
| Full-field ERG | May be depressed in extensive chronic RD; rarely routine but may help prognostication |
Proliferative vitreoretinopathy (PVR) is formation of epiretinal and subretinal membranes from dedifferentiated RPE cells, glial cells and macrophages. It is the leading cause of primary retinal detachment repair failure.
| Grade | Features | Clinical Significance |
|---|---|---|
| A | Vitreous haze and pigment clumps | Risk marker; monitor closely |
| B | Wrinkling of inner retinal surface, rolled break edges, vessel tortuosity and reduced vitreous mobility | Early PVR; vitrectomy may be required |
| C | Full-thickness retinal folds, subretinal strands, star folds and anterior displacement; recorded by clock hours | Significant membrane contraction; usually needs PPV with membrane peel, possible relaxing retinotomy and often silicone oil tamponade |
1. Prophylaxis
- Treat high-risk lesions such as symptomatic horseshoe tears, giant retinal tears and dialysis.
- Options are laser photocoagulation with three rows around the break or cryotherapy.
2. Macular Status
| Scenario | Timing and Priority |
|---|---|
| Macula-on RD | Emergency surgery, same day if possible |
| Macula-off RD < 1 week | Urgent surgery; best prognosis when repaired early, especially within the first few days |
| Macula-off RD > 1 week | Semi-elective scheduling may be reasonable, but visual prognosis is guarded |
3. Surgical Choice
Choice between pneumatic retinopexy, scleral buckling and pars plana vitrectomy (PPV) depends on break location, number of breaks, PVR, lens status, media clarity, patient compliance and surgeon expertise.
| Feature | Pneumatic Retinopexy | Scleral Buckling | Primary PPV |
|---|---|---|---|
| Best indication | Single superior break, phakic eye, clear media, no significant PVR | Young phakic patient, inferior breaks, no PVR, multiple breaks in one quadrant | PVR, media opacity, giant retinal tear, aphakia/pseudophakia or complex RD |
| Principle | Gas bubble tamponades the break; laser or cryotherapy seals it | External indentation relieves traction and supports the break | Vitreous removal, traction relief, SRF drainage, retinopexy and internal tamponade |
| Primary success | About 80% in selected cases | About 85-90% | About 85-95% |
| Advantages | Office procedure, no incision, quick recovery | Preserves lens; avoids intraocular surgery; supports breaks effectively | Excellent visualisation; handles PVR and complex pathology |
| Disadvantages | New break risk 10-15%; strict positioning required | Diplopia, strabismus, myopic shift, anterior segment ischaemia | Cataract progression, endophthalmitis risk, tamponade dependence |
| Tamponade | SF6 or C3F8 | Not routine; may be combined with intravitreal tamponade if needed | SF6, C3F8, standard silicone oil or heavy silicone oil depending on case |
After pneumatic retinopexy or PPV with gas, the gas bubble must tamponade the retinal break. The patient is positioned so that the break is uppermost, often for at least 50 minutes in every hour depending on the surgeon's protocol.
- Failure of positioning is a major cause of failed pneumatic retinopexy.
- Patients with intraocular gas must avoid air travel.
- Nitrous oxide anaesthesia is contraindicated because it rapidly diffuses into the gas-filled eye and can cause dangerous gas expansion, acute IOP rise and visual loss.
| Point | Exam-Ready Detail |
|---|---|
| Indications | PVR Grade C, need for prolonged tamponade, poor positioning compliance, single-eyed patient, complex RD |
| 1000 cSt | Easier to inject and remove; more prone to emulsification than higher-viscosity oil |
| 5000 cSt | Less emulsification and preferred when prolonged tamponade is required; it has similar specific gravity to 1000 cSt and floats superiorly |
| Inferior breaks | Require scleral buckling or heavy silicone oil with specific gravity > 1.0, such as Oxane HD; standard 1000/5000 cSt silicone oil is not a primary inferior tamponade |
| Heavy silicone oil | Specific gravity > 1.0; sinks and can tamponade inferior retina in inferior breaks or inferior PVR |
| Complications | Emulsification, glaucoma, cataract, band keratopathy and hypotony after removal |
| Removal | Usually after 3-6 months once retina is stable, earlier if complications occur |
Giant Retinal Tear
- Defined as a circumferential retinal break of 90 degrees or more.
- Associated with Stickler syndrome, Marfan syndrome, trauma and high myopia.
- Posterior flap may fold over, producing the fish-mouth phenomenon.
- Management: PPV, PFCL to unfold and stabilise the posterior flap, laser retinopexy and silicone oil tamponade.
Paediatric RD
- Common causes include ROP, Stickler syndrome and trauma; non-accidental injury must be considered.
- Often presents late because symptoms are poorly communicated.
- Usually extensive and chronic; PPV is often required and amblyopia management after repair is essential.
Tractional RD
- Most common cause is proliferative diabetic retinopathy.
- Classically concave, non-shifting, does not extend to ora serrata and has no retinal break.
- Combined TRD-RRD has poor prognosis and needs urgent surgery.
- Treatment: PPV with membrane segmentation/delamination, endolaser and tamponade.
Exudative RD
- No break and no traction.
- Subretinal fluid is exudative, bullous and shifting.
- Causes include VKH, sympathetic ophthalmia, posterior scleritis, choroidal tumour, malignant hypertension, eclampsia and CSCR.
- Treatment is directed at the cause: systemic steroids for inflammatory causes, tumour-directed treatment, anti-VEGF/PDT where appropriate and antihypertensives for malignant hypertension.
Macular status at presentation is the single most important determinant of final visual outcome.
| Scenario | Expected Visual Outcome |
|---|---|
| Macula-on RD | Best prognosis; emergency repair is strongly recommended |
| Macula-off < 3 days | Better chance of useful central visual recovery if repaired promptly |
| Macula-off 3-7 days | Recovery declines with increasing duration |
| Macula-off > 1 week | Poorer central visual recovery due to photoreceptor/RPE changes |
| PVR Grade C | Guarded prognosis; multiple surgeries and silicone oil may be required |
On OCT, disruption of the external limiting membrane (ELM) and ellipsoid zone correlates with poorer visual recovery. Restoration of ELM integrity generally precedes ellipsoid zone recovery.
| Study | Year | Key Finding |
|---|---|---|
| SPR Study: Scleral Buckling vs Primary Vitrectomy | 2007 | In phakic eyes, scleral buckling had superior anatomical success; in pseudophakic eyes, PPV was comparable. SB caused myopic shift; PPV was associated with cataract progression. |
| PIVOT Trial | 2019 | In selected primary RRD with superior breaks, pneumatic retinopexy achieved better visual acuity outcomes than PPV but required careful case selection. |
| PVR prevention adjuvant studies | Ongoing / mixed evidence | Agents such as 5-FU/low molecular weight heparin, daunorubicin and bevacizumab have shown mixed results; no adjuvant is universally proven to prevent PVR recurrence. |
- OCT angiography after RD repair may quantify choriocapillaris and deep retinal plexus recovery as functional outcome markers.
- Intraoperative OCT can help visualise subretinal fluid drainage, membrane peeling completeness and macular configuration during PPV.
- Suprachoroidal drug delivery of anti-VEGF or steroids is being explored as adjunctive therapy in PVR.
- Bioresorbable scleral buckles are experimental and aim to reduce long-term explant-related complications.
- PFCL-silicone oil direct exchange may reduce steps in selected giant retinal tear surgery.
- Artificial intelligence systems using fundus photographs are being developed for early RD detection and triage.
Retinal detachment is a true ophthalmic emergency. Prognosis is primarily determined by macular status and duration of macular detachment. Accurate classification into rhegmatogenous, tractional or exudative RD directs therapy. Modern management uses pneumatic retinopexy for selected superior breaks, scleral buckling especially in suitable young phakic eyes and inferior breaks, and PPV for pseudophakic or complex detachments. PVR remains the major cause of surgical failure.
Trap 1 — TRUE
“Shafer's sign is seen in rhegmatogenous retinal detachment and represents pigment cells in the anterior vitreous.”
Tobacco-dust pigment cells arise from torn RPE and are highly suggestive of RRD; they are not expected in pure TRD or ERD.
Trap 2 — FALSE
“Inferior retinal breaks can be adequately treated with C3F8 gas tamponade alone because it is long acting.”
C3F8 is a gas and rises superiorly, so it cannot tamponade inferior breaks effectively. Inferior breaks require scleral buckling or heavy silicone oil with specific gravity > 1.0, such as Oxane HD.
Trap 3 — FALSE
“Standard 1000 cSt and 5000 cSt silicone oils are primary tamponades for inferior breaks.”
Both are lighter-than-water oils with specific gravity around 0.97 and float superiorly. 5000 cSt has less emulsification and is useful for prolonged tamponade, but inferior breaks need buckle support or heavy silicone oil.
Trap 4 — TRUE
“Low IOP in a white quiet eye should raise suspicion of rhegmatogenous retinal detachment.”
RRD can reduce IOP due to impaired RPE pump function and altered ocular fluid dynamics.
Trap 5 — TRUE
“Demarcation lines in RD indicate chronicity and are associated with guarded visual prognosis.”
Demarcation lines are high-water marks of chronic RD; surgery may still be indicated but visual recovery is limited by duration and retinal changes.
Trap 6 — FALSE
“Fresh rhegmatogenous RD commonly has advanced PVR at presentation.”
PVR develops after RPE cell dispersion and cellular proliferation; it is more typical of chronic or complicated RD.
Trap 7 — FALSE
“Nitrous oxide anaesthesia is safe in an eye with intraocular gas.”
Nitrous oxide rapidly diffuses into intraocular gas, expands the bubble and can cause acute IOP rise, angle closure and visual loss.
Trap 8 — TRUE
“Pneumatic retinopexy is contraindicated in inferior breaks, multiple breaks in different quadrants, significant PVR, media opacity or inability to posture.”
Pneumatic retinopexy requires a suitable superior break, clear media, minimal PVR and reliable positioning.
Trap 9 — FALSE
“In giant retinal tear surgery, subretinal fluid should be drained before unfolding the posterior flap.”
PFCL is used first to unfold and stabilise the posterior flap; premature SRF drainage risks retinal incarceration.
Trap 10 — TRUE
“Duration of macular detachment is more important than presenting visual acuity for prognosis.”
Macular detachment time predicts postoperative central visual recovery; early macula-off RD may still have relatively good presenting acuity.
Q: Define retinal detachment.
A: Separation of neurosensory retina from RPE with accumulation of fluid in the subretinal space.
Q: What are the three main types of RD?
A: Rhegmatogenous, tractional and exudative retinal detachment.
Q: What is the most important determinant of final vision after RD repair?
A: Macular status and duration of macular detachment.
Q: What is Shafer's sign?
A: Pigment cells in the anterior vitreous, seen as tobacco dust, indicating a retinal break/RRD.
Q: What is the most common pathological retinal tear in RRD?
A: A horseshoe or flap tear due to dynamic vitreoretinal traction.
Q: What is the leading cause of primary RD repair failure?
A: Proliferative vitreoretinopathy.
Q: How is a giant retinal tear defined?
A: A circumferential retinal break of 90 degrees or more.
Q: What is the usual surgery for TRD due to PDR?
A: Pars plana vitrectomy with membrane segmentation/delamination, endolaser and tamponade.
Q: How do you treat exudative RD?
A: Treat the underlying cause rather than sealing a break, because there is no retinal break.
Q: Which tamponade is preferred for inferior retinal tamponade when internal tamponade is needed?
A: Heavy silicone oil with specific gravity greater than 1.0, such as Oxane HD; otherwise scleral buckle support is important.
A 45-year-old high myope presents 10 days after pneumatic retinopexy with SF6 for a single superior horseshoe tear. The superior retina is reattached, but there is a new 6 o'clock break with inferior RD extending to the macula. PVR Grade B is present. Discuss surgical decision-making.
Answer
This is failed pneumatic retinopexy with a new inferior break, macula-off RD, early PVR and residual intraocular SF6. Repeat pneumatic retinopexy is inappropriate because inferior breaks cannot be reliably tamponaded by a rising gas bubble. The preferred approach is PPV: remove residual SF6, perform core and peripheral vitrectomy with meticulous vitreous base shaving, stabilise the retina with PFCL if required, drain SRF through the break or a drainage retinotomy, peel early PVR/ERM membranes as needed, and apply endolaser in three rows around all breaks including the original superior tear and the new inferior break. Because of the inferior break and early PVR, long-term support is required: combine inferior scleral buckle support and/or use heavy silicone oil when inferior internal tamponade is needed. Standard light silicone oil may be chosen for prolonged tamponade in complex cases but does not itself tamponade inferior retina. Counsel regarding guarded visual prognosis due to macula-off status and PVR, possible need for further surgery, cataract, glaucoma, keratopathy, hypotony and later oil removal once stable.
References
- Basic optics/fluid physics (SG < 1.0 agents float); internally consistent with rd-030 which correctly identifies heavy SiO as the inferior break agent; Kanski Clinical Ophthalmology; Ryan Retina
- Fluid physics (SG-based buoyancy); rd-030 (heavy SiO for inferior breaks); Kanski; Ryan Retina
- Machemer R, Aaberg TM, Freeman HM, et al. Am J Ophthalmol 1991;112(2):159-165
- Heimann H et al. Ophthalmology 2007;114(12):2142-2154
- Hillier RJ et al. Ophthalmology 2019;126(4):531-539
- Multiple searches across PubMed, EyeWiki Clinical Trials in Surgical Retina,
- AAO, AJO, and Ophthalmology Retina (2022–2023 literature); MIRA-1 on PubMed (rheopheresis/AMD trial only).