Rhegmatogenous Retinal Detachment

Separation of the neurosensory retina from the retinal pigment epithelium caused by a full-thickness retinal break through which liquefied vitreous passes into the subretinal space. Incidence is about 1 in 10,000 people per year.

• Requirements: a retinal break, vitreous liquefaction (syneresis) and traction at the break site.
• Risk factors: myopia (above 3 dioptres raises risk several-fold), posterior vitreous detachment, lattice degeneration, previous cataract surgery (0.5 to 3 percent of pseudophakic eyes, higher after posterior capsule rupture), ocular trauma, previous detachment in the fellow eye, family history, Stickler syndrome, Marfan syndrome, and age 50 to 70 years.
• Break types: horseshoe (flap) tear from vitreous traction, round atrophic hole (lattice, young myopes), giant tear (more than 90 degrees), retinal dialysis (disinsertion at the ora serrata, often traumatic, inferotemporal).

• Photopsia (flashes, particularly in the temporal field), a sudden shower of floaters, and a shadow or curtain starting in the periphery and advancing toward the centre; loss of central vision when the macula detaches (macula-off), with distortion before that.
• Visual acuity normal while the macula is attached; relative afferent pupillary defect in extensive detachment; reduced intraocular pressure of the affected eye by 2 to 5 mmHg.
• Anterior vitreous pigment cells ("tobacco dust") are a strong sign of a break.
• Fundus: grey corrugated elevated retina that moves with eye movement, a retinal break (red, horseshoe-shaped), undulating folds, and a bullous configuration superiorly with shifting fluid; inferior detachments progress slowly, and a demarcation line at the edge indicates chronicity.
• Late changes: proliferative vitreoretinopathy with fixed star folds, retinal shortening, and subretinal bands.

• Dilated indirect ophthalmoscopy with scleral depression of the whole periphery (360 degrees) in both eyes, supplemented by slit lamp biomicroscopy with a contact or high-plus lens; draw the detachment and all breaks.
• Rules for locating the primary break from the pattern of detachment: superior temporal and nasal detachments have a break near the highest edge, inferior detachments with an inferotemporal break, and a superior bullous detachment crossing the midline suggests a break at 12 o'clock.
• B-scan ultrasound when the view is obscured by vitreous haemorrhage or cataract.
• Optical coherence tomography of the macula to determine whether the fovea is attached; widefield imaging for documentation.
• Check visual acuity, pupils, and intraocular pressure; examine the fellow eye for treatable breaks and lattice.

• Urgency: macula-on detachments need surgery within 24 hours (bed rest with head positioned so the break lies lowest in the meantime); macula-off detachments within 3 to 7 days for best functional recovery.
• Treat symptomatic horseshoe tears without detachment immediately with laser retinopexy (three rows of confluent burns around the tear, spot size 200 to 500 micrometres, 0.1 to 0.2 seconds, 200 to 400 mW) or cryopexy, which gives a firm scar within 10 to 14 days.
• Surgical options:
  • Pneumatic retinopexy: for a single break or a group of breaks within one clock hour, in the upper eight clock hours, in a phakic or pseudophakic eye without proliferative vitreoretinopathy. Inject 0.3 to 0.5 mL of 100 percent sulphur hexafluoride or 0.3 mL of 100 percent perfluoropropane into the vitreous, apply cryopexy before or after the gas, and position the head so the gas bubble covers the break for 5 to 7 days. Single procedure success is about 65 to 80 percent.
  • Scleral buckle (segmental or encircling silicone band) with cryopexy and drainage of subretinal fluid when needed: best for young phakic patients with anterior breaks and no posterior vitreous detachment, and for inferior breaks. Complications are diplopia, myopic shift, extrusion, and anterior segment ischaemia.
  • Pars plana vitrectomy with removal of vitreous traction, drainage of subretinal fluid (perfluorocarbon liquid), endolaser around breaks, and tamponade with 20 percent sulphur hexafluoride (lasts 2 weeks), 14 percent perfluoropropane (lasts 6 to 8 weeks), or silicone oil (1000 or 5000 centistokes, removed after 3 to 6 months). Preferred for pseudophakic eyes, posterior breaks, giant tears, vitreous haemorrhage, and proliferative vitreoretinopathy.
• Postoperative care: topical antibiotic for 1 week, prednisolone acetate 1 percent four times daily tapered over 4 to 6 weeks, cycloplegic (atropine 1 percent twice daily or cyclopentolate 1 percent three times daily), intraocular pressure monitoring, positioning as instructed, no air travel, high altitude or nitrous oxide anaesthesia until gas has gone, and a medic-alert wristband while the gas is present.
• Outcomes: anatomical success after one operation is 80 to 90 percent and above 95 percent after repeat surgery. Failure is usually caused by proliferative vitreoretinopathy (5 to 10 percent), which needs further vitrectomy, membrane peeling, and silicone oil.
• Complications: cataract (after vitrectomy, almost universal in phakic patients over 50), raised intraocular pressure, macular pucker, redetachment, cystoid macular oedema, and endophthalmitis.
• Counselling: urgency of new symptoms in either eye, posture, driving restrictions, fellow-eye risk (about 10 percent lifetime).