Retinal Detachment and PVR: Classification, Surgery and Viva Points

Retinal-detachment questions become manageable when you answer two questions in order: what mechanism has separated the neurosensory retina, and what features will decide the surgical plan? First classify the detachment as rhegmatogenous, tractional or exudative. Then describe its extent, macular relationship, retinal breaks, vitreoretinal traction and proliferative vitreoretinopathy (PVR). That order works in an MCQ, a fundus drawing and a viva.

This is an examination-revision guide for ophthalmologists. It is not a patient-specific diagnostic or treatment protocol; operative decisions require the full clinical picture and local retinal-service practice.

Start with mechanism, not with the word “detachment”

“Retinal detachment” describes separation of neurosensory retina from retinal pigment epithelium (RPE), but it does not explain why fluid has accumulated. Mechanism predicts configuration, associated findings and the language you should use next.

Mixed mechanisms matter. A diabetic eye can develop a tractional detachment that later acquires a break; an RRD can develop secondary traction from PVR. In a stem that supplies a break, do not ignore it just because the retina also looks stiff. State the dominant mechanism and then state the complicating traction.

For RRD, make the causal chain explicit: a retinal break plus liquefied vitreous plus access for fluid to the subretinal space. A symptomatic posterior vitreous detachment is therefore not synonymous with RRD, but it is a reason to look carefully for a break. The AAO’s posterior-vitreous-detachment guidance is a useful source for revising the break/PVD/lattice framework and the importance of examining the other eye where appropriate.¹

The description grid: turn an image into a complete answer

An examiner is usually testing whether you can report, not whether you can recall one dramatic sign. Use this grid before you discuss treatment.

1. Laterality and extent. Name the eye. Give clock hours or quadrants. State whether the detachment is total, subtotal or localised only when the image permits it.
2. Macular relationship. Say whether the macula is attached, detached or cannot be assessed from the information supplied. “Macula-on” and “macula-off” are shorthand; do not invent macular status from a peripheral-only drawing.
3. Break search. Describe the number, type and location of breaks. Horseshoe tear, operculated break, atrophic hole and giant retinal tear are not interchangeable terms. Look for the highest break in a superior RRD and remember that subretinal fluid can extend beyond the causative break.
4. Vitreoretinal context. Is there a PVD, haemorrhage, lattice, trauma history, high myopia, pseudophakia, aphakia or prior detachment surgery in the stem? Include only supplied or observed facts.
5. PVR and retinal mobility. Report fixed folds, star folds, membrane contraction, anterior displacement or retinal shortening. Do not call every wrinkled retina PVR without supporting morphology.
6. Fellow eye. A concise viva answer notes that the fellow eye needs assessment for predisposing lesions and prior pathology. It signals that you think beyond the photographed eye.

A compact answer may sound like this: “This is a right rhegmatogenous retinal detachment extending from approximately 10 to 4 o’clock, with the macular status shown as detached. I would identify and map all retinal breaks, describe associated PVD and lattice if present, and grade any fixed folds or retinal shortening as PVR features. I would also assess the fellow eye for predisposing retinal lesions.” It is a complete framework even when the image changes.

RRD morphology: avoid predictable MCQ traps

The conventional signs are useful but conditional. RRD is often convex towards the pupil, mobile and undulating because subretinal fluid separates retina from RPE. TRD is often concave because membranes pull the retina forward. Exudative detachments can show shifting fluid. “Often” is the operative word: advanced PVR, chronicity, combined traction and limited viewing can make a stock description unreliable.

Use break versus no break as the principal discriminator, then use contour and mobility as corroboration. If an MCQ asks for the best explanation of a bullous, mobile peripheral detachment with a horseshoe tear, RRD is strong. If it describes taut elevated retina with broad fibrovascular attachments in proliferative diabetic retinopathy and no break, TRD is stronger. If it supplies a mass, inflammation or widespread subretinal fluid without a break, build an exudative differential rather than forcing a surgical-break answer.

Why macular status changes the answer

Macular status is a descriptive and prognostic variable, not merely a phrase to recite. In an exam, it directs urgency language and visual-prognosis discussion. It does not let you infer a universal timetable or a universal procedure. Avoid claims such as “all macula-on detachments must receive operation X immediately”; the timing and technique depend on the documented examination, availability and surgeon judgement. Your safer response is: “Macular relationship needs to be documented because it materially affects the clinical discussion and urgency assessment.”

When B-scan earns a mention

B-scan ultrasonography is helpful when media opacity prevents an adequate fundus view, such as dense vitreous haemorrhage or cataract. In a viva, say what question it answers: “It can establish retinal configuration and look for associated posterior-segment pathology when the retina cannot be directly visualised.” Do not offer ultrasound as a substitute for a break search in a clear view, and do not over-interpret an image you have not seen.

PVR: the failure mechanism you must describe accurately

PVR is the formation and contraction of cellular membranes on or around the retina and vitreous after retinal detachment and/or its repair. Contracture can produce fixed folds, traction, retinal shortening and recurrent detachment. It is a major mechanism of failure in RRD repair; it is not simply “scar tissue” and it is not synonymous with a proliferative diabetic membrane.

The Retina Society introduced a classification in 1983, and the 1991 update is the language most candidates mean when they cite grades A, B and C.²³ Local teaching may emphasise different detail, so learn the edition used by your department. For an exam answer, accurate morphology is more valuable than confidently misquoting a letter.

Do not confuse PVR grade C with “any detachment with three breaks,” and do not use “grade D” as though it were part of every current system. The most defensible answer gives the current observed morphology: “There are fixed full-thickness folds posterior to the equator over __ clock hours, consistent with posterior grade-C PVR.” If the image does not allow grading, say so and describe the folds.

Surgery in an exam: state principles before naming a procedure

The operative objective in RRD is to find and address causative breaks, relieve or neutralise relevant vitreoretinal traction, obtain retinal reapposition and create durable retinopexy around breaks when appropriate. The method is selected from the configuration, not from a memorised “best operation.” Comparative evidence and practice patterns should make you wary of universal claims: trials and systematic reviews compare selected populations, not every detachment in clinic.⁴⁵

Scleral buckling

A buckle indents the scleral wall to support retinal breaks and reduce vitreoretinal traction. In a viva, it is reasonable to say that break configuration, lens status, PVD status, peripheral pathology and surgeon assessment inform whether it is considered. Do not give a single age cut-off or declare that buckling is obsolete. A classic teaching association is a phakic patient with a peripheral break and no advanced PVR, but an association is not an instruction.

Pars plana vitrectomy (PPV)

Vitrectomy permits removal of vitreous traction, treatment of pathology from within the eye and use of internal tamponade where indicated. It may be discussed when PVR, media opacity, posterior breaks, multiple breaks or pseudophakia complicate the picture. Again, “may” is doing important work. The examination question may be testing why PPV offers access to traction, not asking you to prescribe it for an unseen patient.

Pneumatic retinopexy

Pneumatic retinopexy relies on a gas bubble and retinopexy in an appropriately selected break configuration, coupled with postoperative positioning. It is therefore highly configuration- and patient-dependent. In a theory answer, identify the concept: internal tamponade directed at suitable superior break patterns. In a real patient, eligibility and postoperative positioning are clinical decisions.

Tamponade and retinopexy language

Gas or silicone-oil tamponade, laser retinopexy and cryotherapy may appear in stems. Anchor your answer to the intended role: tamponade supports the retina while adhesion develops; retinopexy creates chorioretinal adhesion around a break. Do not reduce this to “laser seals the detachment.” The detachment mechanism and the break/traction problem remain central.

PVR changes the operative conversation

With established PVR, retinal shortening and membranes may prevent simple reapposition. A high-level answer recognises that membrane-related traction and stiffness change surgical complexity; it should not try to teach a step-by-step operation from a blog article. Use phrases such as “the plan would need to address contractile membranes and retinal shortening” and stop there unless the examiner supplies a specific operative scenario.

A 45-second retinal-detachment viva answer

Use this as a rehearsal script, then adapt it to the image:

“This is a [right/left] retinal detachment. I would first classify it as rhegmatogenous, tractional or exudative by looking for a retinal break, tractional membranes and the configuration of subretinal fluid. I would document extent, macular relationship, all breaks, PVD or lattice, and any PVR such as fixed folds or retinal shortening. In an RRD, the operative principles are to identify and treat all causative breaks, manage relevant traction and obtain retinal reapposition with an appropriate support strategy. The choice among buckle, PPV, pneumatic retinopexy and tamponade depends on break pattern, lens status, PVR, media and patient-specific factors. I would assess the fellow eye as well.”

This speech has a useful safety feature: it demonstrates clinical structure without pretending that a photographed retina can receive a complete operative plan.

MCQ traps: test the logic, not the adjective

1. “A retinal detachment with no visible break is exudative.” False as an absolute. A break can be missed, obscured or peripheral. Use the whole pattern.
2. “Tractional detachments are always concave.” Unsafe wording. Concavity is a classic clue, but combined traction-rhegmatogenous disease exists.
3. “PVR means proliferative diabetic retinopathy.” False. PVR is a specific wound-healing/contractile complication in the RD setting.
4. “Grade C PVR means any membrane.” False. The key concept is full-thickness retinal folds; map anterior versus posterior location when asked.
5. “One operation is preferred for all RRD.” False. Procedure choice is configuration- and context-dependent.
6. “Macula-on predicts a particular operation.” False. It affects the clinical discussion; it does not dictate technique by itself.

A revision drill that survives night duty

Make three columns in your notebook: mechanism, morphology, principle. For every past-paper image, force yourself to write one sentence in each column. For example: “RRD because a horseshoe tear permits subretinal fluid; subtotal mobile detachment with macula involved and no visible PVR; identify all breaks, manage traction and use a configuration-appropriate support method.” Then check the marking scheme and correct only the missing observation. This is higher yield than collecting isolated lists of surgical eponyms.

For broader retinal revision, use the verified retina study guide. If you are consolidating retina notes, the site’s Retina Deciphered page is the relevant on-site route. For practical-exam preparation, review the OSCE, Practical & Viva Voce Ready bundle; for a short self-test, use high-yield free MCQs. These resources support study planning; they do not replace supervised clinical training.

Sources

All sources were checked on 18 August 2026. Re-check current society guidance before publication.

Footnotes

1. American Academy of Ophthalmology: Posterior Vitreous Detachment, Retinal Breaks, and Lattice Degeneration Preferred Practice Pattern ↩

2. The Retina Society terminology committee: classification of proliferative vitreoretinopathy (1983) ↩

3. Updated classification of retinal detachment with proliferative vitreoretinopathy (1991) ↩

4. Cochrane review: pneumatic retinopexy versus scleral buckling for primary rhegmatogenous retinal detachment ↩

5. Cochrane review: pars plana vitrectomy versus scleral buckling for rhegmatogenous retinal detachment ↩