RRD is an alarming diagnosis for any patient. Arguably, it may be of even greater concern to the AMD patient already at risk of losing central vision over time. In addition, managing patient expectations in the preoperative counselling session and going forward over the course of postoperative patient visits is a vital part of patient care. The visual future is admittedly a bit unsure for any patient with RRD, but published literature gives the retina surgeon some guidance as to how to best prepare and inform patients undergoing RRD repair.
Several studies have provided data on macula-off RRD repair in regards to visual acuity outcomes in non-AMD patients. In a study of macula-off RD repair with scleral buckling (SB) by Ross and Kozy, 59% of eyes had visual acuity greater than or equal to 20/50, 35% had visual acuity between 20/60 and 20/200, and 5% had visual acuity less than 20/200 with no significance difference in final visual acuity in regards to timing of repair within first week of detachment(2). Salicone et al reported that out of 457 total macula-off RRDs repaired by SB, 27.8% of eyes had visual acuity greater than or equal to 20/40, 25.2% had visual acuity between 20/50 and 20/100, and 47% had vision less than or equal to 20/200(8). In another study of 164 macula-off RRDs repaired by SB, Ahmadieh et al found 13.4% of eyes with visual acuity better than or equal to 20/40, 17.7% between 20/50 and 20/100, 40.9% between 20/200 and 20/400, and 28% count fingers or worse(9).
A number of other studies have also evaluated visual outcomes in macula-involving RRD repaired by pars plana vitrectomy (PPV). In such a study of 178 eyes, Campo et al found that 65% of eyes with the macula detached fewer than 30 days had visual acuity greater than or equal to 20/50 while 41% of eyes with the macula detached greater than 30 days had visual acuity greater than or 20/50(10). The mean final visual acuity was 20/40. Mendrinos et al reported among 44 eyes, 38.6% saw 20/40 or better and 47.7% saw 20/50 or better(11). Finally, in a study analyzing macula-off RRD repaired by PPV, SB, or PPV combined with SB, Pastor et al reported on 349 patients with macula-off RRDs and found that 28.4% saw 20/40 or better, 44.2% saw between 20/50 to 20/100, and 27.4% had visual acuity worse than 20/100(12). In our study, fewer patients achieved vision better than 20/40 in both the AMD and the control group as compared to the aforementioned studies (5.56% in the control group and 3.45% in the AMD group). However, a higher percentage of patients achieved final vision between 20/40 and 20/200 as compared to prior studies (77.16% in the control group and 55.17% in the AMD group).
Herein, we present to our knowledge the first data on visual acuity outcomes in AMD patients with RRD. There was a statistically significant difference in postoperative visual acuity by AMD status, as those without AMD had a higher frequency of CF, HM, LP, or NLP vision (p = 0.023) and thus worse postoperative visual acuity. This is unlikely a clinically significant finding, but rather a function of the difference in sample size and composition between the two groups. Neither group (control or AMD) was exceptionally large due to the need to exclude many eyes in both groups with confounding variables. The AMD group was significantly smaller than the control group because of the challenge of finding eyes with both AMD and RRD. Accordingly, a larger sample in the control group would likely have found fewer eyes with severe RRD causing CF, HM, LP, or NLP vision. Similarly, a larger AMD group would likely have found more eyes with severe RRD and poor vision. Rather than suggesting that control eyes did worse, this result implies that AMD eyes had comparable visual outcomes to non-AMD eyes. Importantly, this study suggests AMD patients can expect similar outcomes to non-AMD patients after RD repair. This informs patients and clinicians that the double insult to the retina of AMD and RRD involving the macula does not necessarily mean a poor visual prognosis. Based on our data, approximately 58% of patients will maintain functional vision better than 20/200 after RD repair even in the presence of AMD. Moreover, the vast majority of patients in the AMD group (as well as the non-AMD group) had an improvement in visual acuity after surgery (65.5% of AMD eyes, and 75.93% of non-AMD eyes, p = 0.2103).
This information gives surgeons a starting point for the discussion guiding patients’ expectations following surgery. This also gives some hope to these patients, suggesting that there is certainly at least a reasonable chance for visual improvement.
Limitations of our study include its retrospective nature as well as the small number of patients with both AMD and macula-off RRD and the lack of vision tests beyond cone-mediated acuity. The inability to age-match the two samples (due to the older age of AMD patients) is also a limitation. The difference in lens status (more pseudophakia in the AMD group) is also a limitation, though this is expected in the older AMD population. Strengths of the study include the presence of a comparison group without AMD and the fact that this study to our knowledge is the first of its kind. Future studies with larger samples sizes will further clarify the visual prognosis for patients with AMD and RRD. In particular, a study to evaluate the correlation of duration of macular detachment with visual outcomes in AMD patients as compared to controls would be instructive. Studies have demonstrated that duration of detachment is correlated with visual outcomes(13), and one could hypothesize that such an affect may be even greater in AMD eyes.