CONTROVERSIES IN CARE

Foveal-sparing Rhegmatogenous RD Repair Timing: Is It an Emergency?

EDITED BY MICHAEL COLUCCIELLO, MD

The annual incidence of rhegmatogenous retinal detachment (RRD) is approximately 12 per 100,000 people (a lifetime risk of 0.6%).¹ Historically, functional outcomes following retinal detachment surgery were associated with successful surgical reattachment of the retina (of course) and the status of the macula at presentation.^2-8

Studies have noted no difference in anatomic or visual outcomes in eyes repaired anytime within seven to 10 days of macular detachment. Subsequently, a progressive decline in visual acuity is noted as the duration of macular detachment increased.^2,9

However, we are frequently confronted with a foveal-sparing (“macula-on”) retinal detachment. The “traditional” thinking was that these patients represented surgical emergencies. Those of us who trained in an earlier era often found ourselves performing surgical repair of these patients in the middle of the night, often with the “skeleton crew” of nurses and support staff that had little experience with retina surgical procedures. Was this necessary? Are foveal-sparing retinal detachments still viewed as an emergency? Is “after-hours” surgical repair cost-effective?

Although most retinal surgeons attempt to repair macula-on RRDs at the earliest surgical opportunity, many clinical and nonclinical factors can sometimes result in delay of the repair of macula-on RRDs. Also, not every retinal detachment progresses at the same rate; Ho et al¹⁰ reported that only 13% of retinal detachments extended toward the fovea while the patient awaited surgery.

Despite animal models having shown initiation of outer and inner retinal layer degeneration and glial cell activation occurring within minutes of experimental retinal detachment, multiple retrospective studies have shown no difference in vision outcomes among patients who underwent retinal detachment repair within the first week of onset.

A retrospective analysis by Wykoff et al¹¹ found no relationship between the timing of scleral buckle surgery and outcomes for 199 eyes with macula-on retinal detachments operated on within 24 hours (n=104) vs 1-3 days (n=55), 3-7 days (n=20), and longer than one week (n=8).

The authors did not find a relationship between the timing of surgery and postoperative acuity or the single-procedure success rate at any time interval. Furthermore, there was no correlation of postoperative VA with the duration of symptoms, location of retinal detachment, or need for reoperation.

Lai et al¹² performed a retrospective review of 66 eyes undergoing retinal detachment surgical repair with scleral buckle, vitrectomy, or combination. They reported similar outcomes in eyes having early (0.8+0.4 days) or later (3.7+2.2 days) surgery: there was no statistical difference in single surgery anatomic success, logMAR VA, postoperative glaucoma, or hemorrhage at a mean follow-up of 13.1 months.

Ehrlich et al¹³ performed a retrospective review of 114 patients presenting with acute macula-on RRDs treated with small-gauge vitrectomy operated on between one hour and five days of presentation. Time to surgery was not found to affect final anatomical outcome (P=.56). No statistically significant association was observed between changes in VA and time to surgery (P=.99).

So should our perspective on urgency of repair of foveal-sparing RRD change? This month, we are fortunate to have the comments of Charles Wykoff, MD, clinical assistant professor of ophthalmology at Weill Cornell Medical College in New York, NY, and Jay Stewart, MD, associate professor of ophthalmology at the University of California–San Francisco regarding this important topic.

REFERENCES

Surgical Repair of Foveal-sparing Rhegmatogenous RD: A Clinical Perspective

CHARLES C. WYKOFF, MD, PHD

In my clinical setting of a large retina-only practice, I, and we as a 10-doctor group, typically pursue surgical repair at the earliest opportunity for fovea-sparing RRD. When pneumatic retinopexy is the indicated procedure, it is typically performed immediately on site.

When an operating room is required for scleral buckling and/or pars plana vitrectomy, the assignment of an operating surgeon five days per week minimizes surgical delay in most circumstances. When indicated, we also perform after-hours surgery.

Regardless of foveal status, when presenting with an RRD, patients and their significant others typically expect, their referring doctor anticipates, and we as surgeons desire both anatomic and visual success. Because foveal involvement is the strongest established risk factor for worse outcomes, intervention is often pursued more urgently in fovea-threatening cases to preclude foveal detachment.

Fortunately, accumulating evidence has suggested that the rate of RRD progression is probably slower than might be intuitively feared. One prospective analysis of 82 macula-on RRDs reported no progression from presentation to surgery in 87% of patients. In the remaining 13%, the average rate of subretinal fluid progression was 1.8 disc diameters (DD) daily (range 0.125-4.5 DD/day).¹

Similarly, in a prospective series of 50 acute, fovea-sparing RRDs with posterior involvement, serial spectral-domain OCT revealed progression of subretinal fluid toward the fovea in only 18% of cases, although the majority underwent surgery within 24 hours.²

One patient did progress from fovea-on to fovea-off within a 9.5-hour period, with subretinal fluid progressing 1,806 µm. Importantly, all of the patients in this Danish series were admitted for bed rest, which is an uncommon practice in the United States, and this may have contributed to the remarkable finding of 68% of eyes showing regression of subretinal fluid away from the fovea while the patient awaited surgery.

So how does one identify the proverbial “needle in a haystack” — that case deserving Saturday night surgery? While the mechanisms of RRD extension are incompletely understood, they likely involve factors such as the location and size of retinal breaks, the extent of retinal traction, and the degree of vitreous liquefaction.

Vitreous has a higher specific gravity than aqueous, and gravity-enhanced vitreous traction may open a superior retinal tear more; conversely, vitreous may provide some tamponade effect on inferior breaks. Therefore, in general, I tend to be particularly respectful of a superior, bullous RRD associated with a large, gaping retinal break with subretinal fluid extending inside of the macula.

Correspondingly, published clinical series have indicated that, for many cases of fovea-sparing RRD, intervention may be safely pursued less emergently, a day or two later, without compromising outcomes.^3-5

Such flexibility of even a short deferral period from diagnosis to surgery can offer potential benefits to patients and the healthcare system. The timing of RRD repair may also be influenced by perioperative considerations, including operating room and caregiver availability and anesthesia or comprehensive medical clearance for comorbid medical conditions when indicated. While awaiting surgery, steps can be taken to theoretically limit RRD progression.

I typically recommend minimizing patient activity, especially those that may cause saccadic ocular movements. If the patient will sleep between diagnosis and surgery, when relevant, I often consider positioning him or her so that the causative retinal break(s) are inferior more than superior from a gravitational perspective. More extreme measures, including bed rest and immobilization of both eyes, can also be considered.

REFERENCES

Another Perspective on Surgical Repair of Foveal-sparing Rhegmatogenous RD

JAY STEWART, MD

In medicine, we are very much attuned to the need for urgency in addressing and managing patient conditions that can get worse without prompt management. Rushing a patient to surgery seems like the right thing to do when there is a possibility that the patient would suffer harm were treatment delayed.

When it comes to RD, who could argue with doing things as quickly as possible to help a patient recover or maintain his/her vision? Historically, fovea-sparing RDs have fallen into this category of conditions in which physicians and patients would drop everything and head to the operating room, even in the middle of the night. This month’s Controversies in Care topic asks us to think critically about the assumptions underlying this decision-making process.

At the University of California–San Francisco (UCSF), we sit down on a weekly basis to conduct a quality improvement review of all ophthalmic surgeries performed during the prior week. This allows the members of the department to assess the indications, operative techniques, and outcomes (including complications) of procedures for both elective and urgent cases.

Over the years, this process has provided insight into the good and the bad of performing emergent surgery for RDs. One of the most striking aspects has become apparent as treatment has evolved more toward vitrectomy and away from scleral buckle: as at many other institutions, we have found that the flawless execution of this surgery depends heavily upon staff support, because vitrectomy is much more dependent upon complex equipment than scleral buckling is. Anecdotally we have observed instances in which after-hours staff’s lack of familiarity with vitrectomy equipment and protocols has resulted in intraoperative delays.

Recently we decided to perform a retrospective review of surgeries done at UCSF for fovea-sparing RDs over a six-year period. We compared procedures performed on the same day as diagnosis vs those performed on the following day and examined the outcomes and complications.¹

There were no statistically significant differences in anatomic or visual outcomes at six months between the two groups. This finding suggests that it is reasonable to consider deferring surgical repair of an RD to the following day.

Notably, one patient in the study did progress to fovea-off status within four hours of presentation. This patient had a superior, bullous detachment with multiple breaks in areas of lattice degeneration. We reviewed other recent published studies that also examined the timing of RD repair,^2-5 and we found that three of these four studies also reported a few patients who progressed to fovea-off. All of the patients who progressed had detachments involving the superior retina. Adding all the patients from these studies together, eight patients of 237 progressed before surgery was performed.

According to these data, a number-needed-to-treat analysis indicated that 29.6 patients would need to be repaired at the time of diagnosis to prevent foveal RD in a single patient. Surgeons may consider this finding when deciding upon the timing of repair. The consistent observation that superior detachments were the only ones to progress also suggests that it may be appropriate to prioritize the repair of detachments in that quadrant.

The potential benefits of intervening emergently to prevent foveal detachment in a patient suspected to be at risk of progressing can be weighed against other considerations that could subject the patient to possible harm. These include physician fatigue, as well as complications or delay resulting from inadequate or insufficiently trained staff. Both of these issues could conceivably be of greater significance in the vitrectomy era.

In our study, we did find a significant increase in time in the operating room for same-day cases, compared to the next day. Finally, cost considerations are secondary to patient safety but also may be increasingly considered at a hospital or healthcare-system level in this context, because after-hours surgery generally consumes greater resources.⁶

Overall, our study suggests, as others recently have, that performing operative repair of a foveal-threatening RD the following day, rather than emergently following diagnosis, may be a reasonable option, particularly if the surgeon has concerns about logistical factors that could impact patient safety and success were the procedure performed after-hours or at night.

This decision depends, of course, upon the surgeon having access to a better set of operative circumstances the following day. Many surgery centers offer flexibility to surgeons in scheduling cases on short notice for the following day. This is a welcome option in the management of patients with fovea-threatening RDs. RP

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