Rhegmatogenous Retinal Detachment (RRD)

Retinal detachment is a condition whereby the neurosensory retina is separated from the retinal pigment epithelium (RPE). There are three types of retinal detachment, categorised according to the underlying mechanism – exudative, tractional and rhegmatogenous. The first two will be explored elsewhere in this atlas and this section will concentrate on rhegmatogenous retinal detachment (RRD).

A RRD occurs when there is a break in the retina (hole or tear) which allows fluid to enter the sub-retinal space and separate the neurosensory retina and the RPE. Patients with RRD typically present with the perception of light flashes, floaters, or a dark "curtain" over their vision however retinal detachments may also be detected during routine examination in asymptomatic patients.

Retinal detachment gives the retina a semi-transparent appearance on funduscopy and this can become more opaque over time. Underlying choroidal detail may be obscured. The detachment of the neurosensory retina also gives it a wrinkled appearance (in contrast to a retinoschisis that has a smooth, translucent appearance). An associated retinal break (hole or tear) is seen in RRD.

Chronic retinal detachments show a pigmented demarcation line at the edge of the detachment. The affected retina may show whitish folds and intraretinal exudates.

Peripheral OCT imaging can be used to confirm the separation of the photoreceptors from the RPE. The associated retinal break may be seen on OCT as a full thickness break. This initial break allows fluid the opportunity to enter the potential space between the neurosensory retina and the RPE, pushing the two layers apart. Chronic retinal detachments may be associated with retinal cyst formation and RPE hyperplasia.

Visual fields show a relative scotoma corresponding to the area of retina that has been detached. This differs from the absolute scotoma associated with a retinoschisis.

The term "Shafer's sign" refers to the presence of pigment cells in the vitreous and may be seen in cases of retinal tear, RRD or a history of intraocular surgery. The presence of pigment is a strong indicator of a retinal break and further investigation is essential.

Established risk factors for retinal detachment include posterior vitreous detachment, high myopia, lattice degeneration, cataract surgery, trauma, family history of retinal detachments in a first-degree relative and RRD in the fellow eye. Other conditions with an increased risk of retinal detachment include retinopathy of prematurity and Stickler syndrome.

An early diagnosis of RRD is vital. The visual prognosis is much improved if a RRD is treated before the macula becomes involved. Once the macula has been detached however, the prognosis is more guarded.

Some studies have shown no difference in visual outcome if a macula-off detachment is repaired anytime within 1 week of occurrence, however a recent study (Greven et al. 2019) showed significant differences in final visual acuity between patients whose macula-off detachments were treated within 1 day when compared with those treated within 3 days. The authors concluded that this type of detachment should be treated as soon as possible after diagnosis.

Frings et al. (2016) also showed that treatment of a macula-off detachment after 10 days produces a clinically comparable outcome to surgery undertaken up to 30 days post-macular-off detachment.

When assessing retinal breaks with regards to urgency of referral, it is helpful to keep the following general guidelines in mind:
- All acute retinal detachments require urgent referral.
- A pigmented demarcation line indicates chronicity of a retinal detachment.
- Symptomatic retinal breaks are more likely to progress to retinal detachment than non-symptomatic breaks.
- A superior retinal detachment is more likely to progress than an inferior one, due to the effects of gravity. Inferior detachments are typically slowly progressive, if at all, and may self-seal over time with no intervention.
- A horseshoe retinal tear and traumatic retinal breaks (e.g. retinal dialysis) are highly likely to progress and require urgent treatment.
- Atrophic and operculated retinal breaks are associated with a low risk of progression to RRD.

Frings A, Markau N, Katz T, et al (2016) Visual recovery after retinal detachment with macula-off: is surgery within the first 72 h better than after? British Journal of Ophthalmology 100:1466-1469.

Greven MA, Leng T, Silva RA, et al (2019) Reductions in final visual acuity occur even within the first 3 days after a macula-off retinal detachment. British Journal of Ophthalmology 103:1503-1506.

H. Dunbar Hoskins Jr., MD Center for Quality Eye Care (2019) Posterior Vitreous Detachment, Retinal Breaks, and Lattice Degeneration Preferred Practice Pattern. American Academy of Ophthalmology.

Wilkinson,C. and Cochrane Eyes and Vision Group Cochrane Database Syst Rev. (2014) Sep; 2014(9): CD003170.