Key messages
- There is not enough high-quality information to say whether face-down positioning should be recommended to people after surgery for retinal detachments affecting the center of the retina (the macula).
- Overall, evidence from studies suggests that face-down positioning after surgery may lead to fewer complications, with less postoperative retinal displacement, outer retinal folds, and binocular diplopia (double vision with both eyes open). These complications can be very bothersome to those affected, but their impact on quality of life was not studied.
- Face-down positioning may increase intraocular pressure (fluid pressure inside the eye) compared with support-the-break positioning (head positioning dependent on the location of retinal breaks [holes or tears in the retina]); however, intraocular pressure can most often be treated successfully.
What is a macula-involving rhegmatogenous retinal detachment?
The retina is a layer at the back of the eye which provides sight. It is normally attached to the wall of the eye. When it separates from the wall of the eye, then this is called a retinal detachment. When a retinal detachment is caused by a tear or break in the retina, then it is termed a rhegmatogenous retinal detachment. The macula is the center of the retina. If the macula also detaches, then this is called a macula-involving rhegmatogenous retinal detachment.
The visual cells (the cells in the retina that provide sight) get their nourishment through blood vessels in the wall of the eye. If the retina is detached and away from the wall of the eye, then the visual cells do not receive nourishment. As a result, sight is lost.
Retinal detachments are treated with surgery, often with a type of surgery called a vitrectomy. In vitrectomy surgery, the gel that fills the middle of the eye (called vitreous) is removed, and most often gas is put inside the eye to push the retina back in place (gas tamponade). The gas rises, like a balloon. Some surgeons ask their patients to keep their head down (face-down positioning) right after surgery so that the gas pushes the macula flat into its normal position.
What did we want to find out?
We wanted to find out if keeping the face-down position after vitrectomy and gas tamponade for macula-involving rhegmatogenous retinal detachment is better than keeping the head in other positions. Keeping the head face-down may prevent such complications as large or small folds forming in the macula. These folds can affect sight. We also wanted to find out if face-down positioning has any harmful effects, such as neck problems.
What did we do?
We searched for studies that compared keeping the head face-down after surgery with other head positions in people with macula-involving retinal detachments. We compared and summarized the results of the studies and rated our confidence in the evidence, based on factors such as study methods and sizes.
What did we find?
We found three studies with a total of 368 people (369 eyes) with macula-involving retinal detachments. Study follow-up time varied, with the longest being six months. The results showed that some complications may be less frequent with face-down positioning, including retinal displacement (the retina 'landing' in a different position than where it was before it detached), retinal folds, and double vision. These complications may be very troublesome for people. Face-down positioning may increase the chance of high pressure in the eye; however, this can most often be successfully treated with eye drops. Face-down positioning did not seem to make any difference in the quantity of vision (reading letters in the chart) or quality of vision (how clearly people saw), or in quality of life.
What are the limitations of the evidence?
We have very low confidence in the evidence for face-down positioning after vitrectomy and gas tamponade for macula-involving rhegmatogenous retinal detachment because of the relatively small sample sizes and flawed study designs.
How up-to-date is this evidence?
The evidence is current to November 2022.
Very low certainty evidence suggests that immediate face-down positioning after PPV and gas tamponade may result in a reduction in postoperative retinal displacement, outer retinal folds, and binocular diplopia, but may increase the chance of postoperative raised intraocular pressure compared with support-the-break positioning at six months. We identified two ongoing trials that compare face-down positioning with face-up positioning following PPV and gas tamponade in participants with primary macula-involving RRDs, whose results may provide relevant evidence for our stated objectives. Future trials should be rigorously designed, and investigators should analyze outcome data appropriately and report adequate information to provide evidence of high certainty. Quality of life and patient preferences should be examined in addition to clinical and adverse event outcomes.
A macula-involving rhegmatogenous retinal detachment (RRD) is one of the most common ophthalmic surgical emergencies and causes significant visual morbidity. Pars plana vitrectomy (PPV) with gas tamponade is often performed to repair primary macula-involving RRDs with a high rate of anatomical retinal reattachment. It has been advocated by some ophthalmologists that face-down positioning after PPV and gas tamponade helps reduce postoperative retinal displacement. Retinal displacement can cause metamorphopsia and binocular diplopia.
The primary objective of this review is to determine whether face-down positioning reduces the risk of retinal displacement following PPV and gas tamponade for primary macula-involving RRDs.
We searched the Cochrane Central Register of Controlled Trials (which contains the Cochrane Eyes and Vision Trials Register) (2022, Issue 11), MEDLINE (January 1946 to 28 November 2022), Embase.com (January 1947 to 28 November 2022), PubMed (1948 to 28 November 2022), Latin American and Caribbean Health Sciences Literature database (1982 to 28 November 2022), ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform. We did not use any date or language restrictions in the electronic search. We last searched the electronic databases on 28 November 2022.
We included randomized controlled trials (RCTs) in which face-down positioning was compared with no positioning or another form of positioning following PPV and gas tamponade for primary macula-involving RRDs.
We used standard Cochrane methodology and assessed the certainty of the body of evidence for the prespecified outcomes using the GRADE approach.
We identified three RCTs (369 eyes of 368 participants) that met the eligibility criteria. Two RCTs provided data on postoperative retinal displacement, one reported on postoperative distortion and quality of life outcomes, two on postoperative best-corrected visual acuity (BCVA) in logMAR, and two on postoperative ocular adverse events such as outer retinal folds.
Study characteristics and risk of bias
All the trials involved predominantly male participants (range: 68% to 72%). Only one trial provided race and ethnicity information, was registered on a trial registry, and reported funding sources. Using the RoB 2 tool, we assessed the risk of bias for proportion of eyes with retinal displacement, mean change in visual acuity, objective distortion scores, quality of life assessments, and ocular adverse events, with most domains judged to be at low risk of bias.
Findings
Immediate face-down positioning may result in a lower proportion of participants with postoperative retinal displacement compared with support-the-break positioning at six months (risk ratio [RR] 0.73, 95% confidence interval [CI] 0.54 to 0.99; 1 RCT; 239 eyes of 239 participants; very low certainty evidence).
One study found no evidence of a difference in BCVA at three months when comparing postoperative face-up with face-down positioning with or without perfluorocarbon liquid (mean difference [MD] −0.03, 95% CI −0.09 to 0.02; I2 = 0; 56 eyes of 56 participants; very low certainty evidence).
Immediate face-down positioning appears to have little to no effect on postoperative distortion scores at week 26 (MD 1.80, 95% CI −1.92 to 5.52; 1 RCT; 219 eyes of 219 participants; very low certainty evidence) and postoperative quality of life assessment scores at week 26 (MD −1.80, 95% CI −5.52 to 1.92; 1 RCT; 217 eyes of 217 participants; very low certainty evidence).
Adverse events
One study that enrolled 262 participants with macula-involving RRDs suggested that immediate face-down positioning after PPV and gas tamponade may reduce the ocular adverse event of postoperative outer retinal folds at six months (RR 0.39, 95% CI 0.17 to 0.90; 1 RCT; 262 eyes of 262 participants; very low certainty evidence) and binocular diplopia (RR 0.20, 95% CI 0.04 to 0.90; 1 RCT; 262 eyes of 262 participants; very low certainty evidence) compared with support-the-break positioning. Immediate face-down positioning may increase the ocular adverse event of elevated intraocular pressure compared with support-the-break positioning (RR 1.74, 95% CI 1.11 to 2.73; 1 RCT; 262 eyes of 262 participants; very low certainty evidence). Another study found no evidence of a difference in postoperative outer retinal folds when comparing face-down versus face-up positioning at one and three months (RR 1.00, 95% CI 0.50 to 2.02; RR 1.00, 95% CI 0.28 to 3.61; 1 RCT; 56 eyes of 56 participants; very low certainty evidence). No studies reported non-ocular adverse events.