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Rhegmatogenous Retinal Detachment: Diagnosis and Repair
Pathogenesis
Rhegmatogenous retinal detachment requires a full-thickness retinal break -- the term rhegmatogenous derives from the Greek word rhegma, meaning tear or break. The typical sequence begins with vitreous liquefaction and posterior vitreous detachment, in which the vitreous gel separates from the retinal surface. As the vitreous separates, it exerts traction at sites of firm vitreoretinal adhesion, and if the tractional force exceeds the tensile strength of the retina, a retinal tear forms. Once a break exists, liquefied vitreous gains access to the subretinal space through the tear, progressively separating the neurosensory retina from the underlying retinal pigment epithelium. The RPE pump, which normally maintains the subretinal space in a dehydrated state, cannot reabsorb fluid at the rate it accumulates through the break, and the detachment extends.
Types of Retinal Breaks
Several types of retinal breaks can lead to rhegmatogenous detachment. The horseshoe (flap) tear is caused by vitreous traction and is the most common cause of RRD; the torn retinal flap remains attached at its base. Atrophic round holes are common in young myopic patients and are associated with lattice degeneration; they carry a lower risk of progressing to RRD because they lack the dynamic traction of a horseshoe tear. A dialysis is a circumferential tear at the ora serrata, occurring in an inferotemporal location after trauma or spontaneously in a superonasal location in young patients. A giant retinal tear extends 90 degrees or more (three or more clock hours) and presents a significant surgical challenge due to the large flap of mobile retina.
Risk Factors
Posterior vitreous detachment is the most important risk factor, as it is the precipitating event for most horseshoe tears. High myopia, with axial lengths exceeding 26 mm, predisposes to RRD through retinal thinning and a higher prevalence of peripheral retinal degenerations. Lattice degeneration is present in approximately 30% of eyes with RRD. Prior cataract surgery confers a 1 to 2% lifetime risk of pseudophakic retinal detachment following phacoemulsification. Other risk factors include ocular trauma, family history of retinal detachment, retinal detachment in the fellow eye (carrying a 10 to 15% lifetime risk), and prior YAG laser capsulotomy.
Clinical Presentation
Patients typically report photopsia -- flashing lights caused by vitreous traction stimulating the retina -- followed by a sudden increase in floaters. The floaters may result from vitreous hemorrhage or, critically, from pigmented cells released into the vitreous cavity (Shafer sign, also known as tobacco dust). As the detachment extends, patients describe progressive visual field loss, often as a curtain or shadow advancing from the periphery toward the center. Central vision is lost when the macula becomes involved (macula-off detachment). The intraocular pressure is typically reduced compared with the fellow eye, and a relative afferent pupillary defect may be present in extensive detachments.
Key Examination Findings
The Shafer sign -- pigmented cells visible in the anterior vitreous on slit-lamp examination -- is pathognomonic for a retinal break and should prompt a thorough dilated examination even when no obvious break is initially identified. Indirect ophthalmoscopy reveals an elevated, corrugated, mobile retina. The causative retinal break can be identified in most cases, though scleral depression of the peripheral retina may be required. Subretinal fluid shifts with changes in patient position. A demarcation line, a pigmented line marking the border of a longstanding detachment, indicates chronicity.
<image>Fundus photograph showing a macula-off rhegmatogenous retinal detachment with a horseshoe tear superiorly, elevated bullous detachment, and subretinal fluid extending through the macula</image>
Classification
Macula Status
The most important classification factor is the status of the macula. A macula-on detachment, in which the fovea remains attached, is a true surgical urgency that should be repaired within 24 to 72 hours to preserve central vision. A macula-off detachment, in which the fovea has already detached, is managed semi-urgently, with repair generally within one week, though a recently detached macula still warrants urgent attention. Whether the macula is on or off at the time of surgery is the single strongest predictor of final visual acuity.
Characteristics for Surgical Planning
Surgical planning depends on several factors: the location and number of retinal breaks, the extent of detachment, the presence of proliferative vitreoretinopathy (PVR), lens status (phakic, pseudophakic, or aphakic), and media clarity, including the presence or absence of vitreous hemorrhage.
RRD Surgical Repair Comparison
| Feature | Pneumatic Retinopexy | Scleral Buckle | Pars Plana Vitrectomy |
|---|---|---|---|
| Setting | Office-based | Operating room | Operating room |
| Approach | Intravitreal gas + cryo/laser | External (scleral indentation) | Internal (vitreous removal) |
| Ideal candidate | Single break, superior 8 clock hours, no PVR, phakic | Young, phakic, inferior breaks, dialysis | Complex RD, PVR, posterior breaks, pseudophakic |
| Single-operation success | 70-80% | 85-90% | 90-95% |
| Final success (with reintervention) | >95% | >95% | >95% |
| Positioning required | Yes (strict) | No | Yes (if gas/oil used) |
| Cataract risk | Low | Low | High (if phakic) |
| Key advantage | Less invasive; better VA (PIVOT trial) | No intraocular entry; preserves lens | Handles complex cases; PVR |
| Key disadvantage | Higher reoperation rate; limited indications | Refractive change; diplopia | Cataractogenic; positioning burden |
Surgical Repair Options
Pneumatic Retinopexy (PR)
Pneumatic retinopexy is an office-based procedure suitable for carefully selected cases. It involves intravitreal injection of an expansile gas (SF6 or C3F8) combined with cryopexy or laser retinopexy to seal the retinal break. The ideal candidate has a single break or a group of breaks located within the superior eight clock hours, no significant PVR, and is preferably phakic. The gas bubble rises to tamponade the break while the cryopexy or laser creates a permanent chorioretinal adhesion. The patient must maintain strict head positioning to keep the break at the highest point. The single-operation anatomic success rate is 70 to 80%, with final success rates exceeding 95% when reintervention is permitted.
PIVOT Trial
The PIVOT trial compared pneumatic retinopexy with pars plana vitrectomy for primary uncomplicated RRD. The pneumatic retinopexy group achieved better visual acuity at 12 months and experienced less metamorphopsia. Although the reoperation rate was higher with pneumatic retinopexy, final anatomical success was comparable between the two groups, and patient-reported outcomes favored pneumatic retinopexy. This trial challenged the prevailing vitrectomy-first paradigm for suitable cases.
Scleral Buckle (SB)
Scleral buckling is an external procedure in which a silicone band or sponge is sutured to the sclera, indenting the eye wall to relieve vitreous traction and bring the RPE into contact with the detached neurosensory retina. Cryopexy is applied to the retinal break under indirect ophthalmoscopic visualization. Subretinal fluid may be drained externally through a sclerotomy or left to absorb spontaneously. Scleral buckling is best suited for young phakic patients, inferior breaks, retinal dialyses, and cases without significant PVR. Its advantages include preservation of the natural lens, avoidance of intraocular entry, and no need for gas tamponade, which eliminates positioning requirements and altitude restrictions. Complications include refractive change from induced myopia, diplopia from extraocular muscle involvement, buckle exposure or infection, and scleral perforation during subretinal fluid drainage.
Pars Plana Vitrectomy (PPV)
Pars plana vitrectomy is an internal approach in which the vitreous gel is removed along with the vitreous traction that caused the detachment. All retinal breaks are identified and treated with endolaser. A fluid-air exchange is performed, followed by injection of gas tamponade (SF6, which lasts approximately two weeks, or C3F8, which lasts approximately six to eight weeks) or silicone oil. PPV is best suited for pseudophakic eyes, posterior breaks, multiple breaks, eyes with PVR, vitreous hemorrhage, and giant retinal tears. Its advantages include complete vitreous removal and direct visualization and treatment of all pathology. The main disadvantages are acceleration of cataract formation in phakic eyes and the positioning and altitude restrictions imposed by intraocular gas -- patients must not fly until the gas has fully absorbed. Silicone oil is reserved for complex cases and PVR but requires a second surgical procedure for removal.
Combined Scleral Buckle + PPV
Combined scleral buckling with vitrectomy is used for complex detachments, including those with PVR, inferior breaks requiring vitrectomy, and giant retinal tears. The buckle provides support at the vitreous base while the vitrectomy addresses internal pathology.
<image>Surgical approaches for rhegmatogenous retinal detachment showing pneumatic retinopexy with intravitreal gas bubble and cryopexy, scleral buckle indenting the eye wall, and pars plana vitrectomy with endolaser and gas tamponade</image>
Proliferative Vitreoretinopathy (PVR)
Pathophysiology
Proliferative vitreoretinopathy is the proliferation of RPE cells, glial cells, and fibroblasts on the surfaces of the retina. These cells form contractile membranes that create fixed retinal folds and cause re-detachment. PVR is the most common cause of surgical failure in rhegmatogenous retinal detachment repair.
Classification (Updated Retina Society)
PVR is graded into three stages. Grade A is characterized by vitreous haze and pigment clumps. Grade B shows wrinkling of the inner retinal surface, rolled edges of retinal breaks, and retinal stiffness. Grade C represents full-thickness retinal folds, specified by their location (anterior or posterior) and extent in clock hours.
Management
PVR is managed with pars plana vitrectomy including membrane peeling, relaxing retinotomies to allow the stiffened retina to flatten, perfluorocarbon liquid to stabilize the retina during surgery, and silicone oil tamponade for long-term support. Anti-inflammatory adjuncts including intravitreal steroids, 5-fluorouracil, and low-molecular-weight heparin are under investigation. The prognosis for PVR is guarded: anatomical success rates of 60 to 80% can be achieved, but visual outcomes are often limited by the retinal damage that has already occurred.
Clinical Pearls
The Shafer sign -- tobacco dust in the anterior vitreous -- means a retinal break is present until proven otherwise, and the eye must be examined thoroughly even if no obvious break is initially found. A macula-on RRD is a true surgical emergency in which every hour of delay risks foveal detachment and permanent central vision loss. In a young phakic patient with a single superior break, pneumatic retinopexy should be strongly considered as the initial approach, supported by the PIVOT trial evidence. The fellow eye must always be examined, as the lifetime risk of RRD in the fellow eye is 10 to 15%. Prophylactic laser barricade around symptomatic retinal tears -- those associated with photopsia and floaters from an acute PVD -- reduces the risk of progression to retinal detachment from approximately 50% to approximately 5%. In contrast, asymptomatic retinal holes found incidentally within lattice degeneration do not routinely require prophylactic treatment. Pseudophakic retinal detachment is most common in the first year after cataract surgery, particularly in myopic eyes and after complicated surgical cases. Silicone oil must eventually be removed in most patients due to the risks of band keratopathy, secondary glaucoma, and oil emulsification.
<image>Intraoperative view during pars plana vitrectomy for retinal detachment repair showing endolaser application around a retinal tear after fluid-air exchange</image>
References
- Hillier RJ, et al. The Pneumatic Retinopexy versus Vitrectomy for the Management of Primary Rhegmatogenous Retinal Detachment Outcomes Randomized Trial (PIVOT). Ophthalmology. 2019;126(4):531-539.
- Schwartz SG, et al. Primary retinal detachment: scleral buckle or pars plana vitrectomy? Curr Opin Ophthalmol. 2014;25(3):179-184.
- Machemer R, et al. An updated classification of retinal detachment with proliferative vitreoretinopathy. Am J Ophthalmol. 1991;112(2):159-165.
- American Academy of Ophthalmology. Basic and Clinical Science Course, Section 12: Retina and Vitreous.
- Retina Society Terminology Committee. The classification of retinal detachment with proliferative vitreoretinopathy. Ophthalmology. 1983;90(2):121-125.
