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Rhegmatogenous retinal detachment and retinal breaks
In rhegmatogenous retinal detachment fluid from the vitreous passes through a retinal break and separates the retina from the RPE; the break usually forms during posterior vitreous detachment (PVD), so any new flashes and floaters require a dilated fundus examination, and a symptomatic break is sealed with laser or cryotherapy before the retina detaches.
Why it matters in the exam
The classic picture: a person aged 50–70, myopic or after cataract surgery, with new flashes of light and floaters, followed by a "curtain" advancing from the periphery. About 14% of acute symptomatic PVDs have a break, and pigment granules in the anterior vitreous ("tobacco dust", Shafer sign) greatly increase the likelihood of a break. Risk factors: myopia, lattice degeneration, cataract surgery, trauma, detachment in the fellow eye and family history (Stickler). When blood clouds the vitreous and the retina cannot be seen, ocular ultrasound replaces direct examination and looks for a break or a detachment.
Urgency is set by the macula. Macula-on — surgery promptly, usually within 24 hours, to save central vision; macula-off — surgery within a few days, and the outcome depends on how long it has been detached. Three methods: pneumatic retinopexy — gas injection and cryotherapy for a single superior break; scleral buckle — in young phakic patients and in dialysis; vitrectomy — in pseudophakic eyes and complex cases. The main cause of failure is proliferative vitreoretinopathy.
Two other types must be distinguished: tractional detachment — in proliferative diabetic retinopathy or ROP, concave, without a break; and exudative detachment — without a break, with fluid that moves with head position (shifting fluid), in tumours, VKH, Coats disease and inflammation. After SF6 or C3F8 gas injection the patient must not fly and must not be anaesthetised with nitrous oxide until the gas is absorbed, because the bubble expands and raises the pressure.
Key points
- Fluid passes through a break and detaches the retina.
- New flashes and floaters → dilated fundus examination.
- Symptomatic break → laser or cryotherapy.
- Macula-on → urgent surgery.
- After gas — no flying and no nitrous oxide.
Summary table
| Type | Mechanism | Finding | Treatment |
|---|---|---|---|
| Rhegmatogenous | Break and fluid from the vitreous | Mobile corrugated retina, vitreous pigment | Pneumatic, buckle or vitrectomy |
| Tractional | Fibrovascular membranes | Concave retina, no break | Vitrectomy when the macula is threatened |
| Exudative | Leakage under the retina | Fluid shifts with position, no break | Treat the cause |
| Symptomatic horseshoe tear | Vitreous traction | Tear with a flap, flashes | Laser or cryotherapy at once |
A free exam question
מה המאפיין של תאי ענק מסוג Touton giant cells ? (the question as examined, in Hebrew)
- א. הגרעינים מסודרים בצורת פרסת סוס( horseshoe )
- ב. הגרעינים מסודרים בצורת טבעת( annulus ) ומסביב להם אזור בהיר מלא ליפידים בעל מראה קצף( foamy )
- ג. הגרעינים מסודרים בצורה אקראית
- ד. הגרעינים ממלאים את כל השטח המרכזי של התא הענק ובהיקף יש אזורים בהירים ללא גרעינים פתולוגיה וגידולים
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Sources
- AAO Preferred Practice Pattern: Posterior Vitreous Detachment, Retinal Breaks, and Lattice Degeneration, 2019 — Evaluation and management
- Royal College of Ophthalmologists: Retinal detachment — commissioning and referral guidance, 2020 — Urgency of referral
- AAO Basic and Clinical Science Course, Section 12: Retina and Vitreous, 2024-2025 — Retinal detachment
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.