Article Text
Abstract
Background/Aims To evaluate the treatment course of patients with primary rhegmatogenous retinal detachment (RRD) that re-detach after initial retinal detachment surgery.
Methods Patients were divided into three groups based on initial surgical treatment: scleral buckle procedure (SBP) (63 eyes), pars plana vitrectomy (PPV) (88 eyes) and combined SBP/PPV (135 eyes). Charts were reviewed for a mean follow-up of 12 months.
Results Average number of secondary procedures to achieve anatomical success was lowest in the SBP group (1.1), compared with the PPV group (1.47) and the SBP/PPV group (1.5) (p<0.05). Patients that re-detached after initial PPV/SBP, PPV or SBP required silicone oil injection in 83%, 60% and 22% of the cases and had final best-corrected visual acuity better than or equal to 20/50 in 21%, 33% and 45% of the cases, respectively. Phakic patients that re-detached after initial treatment with PPV/SBP, PPV and SBP required pars plana lensectomy (PPL) in 42%, 25% and 12.5% of the cases, respectively.
Conclusion Patients with primary RRD that re-detach after initial treatment with SBP require fewer number of secondary operations and silicone oil injections, show a trend for better visual outcomes and are less likely to develop dense cataract or to require PPL compared to patients that re-detach after initial PPV or PPV/SBP.
- Retinal detachment
- pars plana vitrectomy
- scleral buckling surgery
- retina
- treatment surgery
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Despite the advances in vitreoretinal surgery, primary rhegmatogenous retinal detachment (RRD) remains a significant cause of visual morbidity. The prerequisites for the development of primary RRD are liquefaction of the vitreous and tractional forces producing retinal breaks through which fluid gains access into the subretinal space. To achieve successful retinal re-attachment, the goal of treatment is to treat all retinal breaks and relieve vitreous traction. Of the currently available surgical options for treatment of retinal detachment, scleral buckling procedure (SBP) and pars plan vitrectomy (PPV) are commonly used. SBP works through relieving vitreous traction and displacing subretinal fluid away from the breaks. PPV allows for direct relief of vitreous traction and internal drainage of subretinal fluid.
In many vitreoretinal surgical centres, SBP continues to be the treatment of choice for RRD either alone for routine cases or in combination with PPV for more complicated cases.1–3 In recent years, there has been an increase in the use of PPV for repair of primary RRD.4–11 Advantages of PPV include the ability to remove media opacities and capsular remnants and better visualisation of retinal breaks using endoillumination and wide-angle biomicroscopy. Disadvantages include the possibility of iatrogenic retinal breaks and damage to the lens, cataract progression in phakic patients, higher costs, residual peripheral vitreous skirt and vitreous base contraction.12
There are many studies comparing anatomic and functional success rates between SBP and PPV.13–17 Brazitikos et al18 showed a higher single operation success rate (SOSR) for PPV among pseudophakic patients (94% PPV versus 83% SBP). Sharma et al19 found a better visual outcome for PPV but equivalent SOSR. The Scleral Buckling versus Primary Vitrectomy in Rhegmatogenous Retinal Detachment Study (SPR study)20 showed a better visual outcome among phakic patients for SBP but a higher SOSR among pseudophakic patients for PPV.
There are few studies characterising the course and visual outcome of patients who re-detach after primary treatment.21 Currently, even less data exist that compare patients who fail initial repair with SBP versus PPV. This study aims to elucidate the treatment course of, and identify differences among, those patients that re-detach after initial surgical repair for RRD with SBP, PPV or both.
Methods
Institutional review board approval was obtained for the study, and all data were collected in accordance with the Health Insurance Portability and Accountability Act of 1996. Office charts of patients seen at the Barnes Retina Institute for the diagnosis of retinal detachment were retrospectively reviewed, and patients diagnosed as having primary RRD who underwent SBP, PPV or both from January 2007 to November 2008 were identified. Patients with history of prior vitreoretinal surgery or SBP in the affected eye were excluded. Patients with ocular trauma, dense vitreous haemorrhage mandating vitrectomy treatment, combined rhegmatogenous/tractional detachments, documented follow-up less than 1 month, known macular disease significantly affecting visual acuity and proliferative vitreoretinopathy (PVR) grade C or worse were also excluded.
Overall, 286 consecutive eyes from 284 patients who met our inclusion/exclusion criteria were included in the study. Patients were divided into three groups based on their initial surgical procedure (SBP, PPV and SBP/PPV). Each group was further divided into phakic and pseudophakic subgroups. Overall, patients had a mean follow-up of 12.1 months with a range of 1–23 months. Data collected from all patients included demographics, lens status, extension of detachment to macula, size (in clock hours) and location of detachment, and final best-corrected visual acuity (BCVA). Data collected from patients who re-detached also included number of re-detachments, average time to first re-detachment, number of secondary procedures performed, type of secondary procedures and whether or not silicone oil was used. Student t test and χ2 test were used to compare age, extent of retinal detachment, mean number of secondary procedures, final BCVA, and percentage of phakic patients developing dense cataract and requiring pars plana lensectomy (PPL).
Results
Of the 286 eyes studied, 135 had initial treatment with a combination of SBP and PPV; 88 eyes had initial treatment with PPV alone and 63 with SBP alone. Table 1 summarises patient characteristics in each group. Patients who had SBP as their primary treatment were younger and more likely to be phakic compared to the PPV and PPV/SBP groups. However, the extent of retinal detachment measured in clock hours and proportion involving the macula were statistically similar. The average size of retinal detachment (in clock hours) for patients in the PPV/SBP, PPV and SBP groups was 5.8, 4.9 and 4.4, respectively.
Characteristics of retinal detachments
In the PPV/SBP group, 74 patients were phakic, of which 12 re-detached, and 61 were pseudophakic, of which 12 re-detached. In the PPV group, 36 patients were phakic and 52 were pseudophakic, of which 8 and 7 patients re-detached, respectively. In the SBP group, 58 patients were phakic and 5 were pseudophakic, of which 8 and 1 re-detached, respectively. Table 2 shows the SOSR for each subcategory. The final re-attachment success rate was 100% for all patients at study's final follow-up evaluation.
Single operation success rates in phakic and pseudophakic eyes
The mean duration at which the first re-detachment occurred was 45, 35 and 17 days in the PPV/SBP, PPV and SBP groups, respectively. The average number of re-detachments, which equalled the number of secondary surgical procedures (for each re-detachment event, one secondary surgical procedure was performed), was 1.5, 1.47 and 1.1 for the PPV/SBP, PPV and SBP groups, respectively (table 3).
Recurrence of retinal detachments
Table 4 shows the final BCVA for patients in each treatment group and also for the re-detached patients in each group. The frequency of patients with final visual acuities better than or equal to 20/50 among patients that re-detached after initial treatment with PPV/SBP, PPV or SBP was 21%, 33% and 45%, respectively.
Final visual acuity
Of the patients who re-detached after initial treatment with PPV/SBP, PPV or SBP, 20/24 (83%), 9/15 (60%) and 2/9 (22%) were treated with silicone oil, respectively (p=0.01, χ2). Of the phakic patients who re-detached after PPV/SBP, PPV or SBP, 42%, 25% and 12.5% required PPL. All phakic patients who re-detached after PPV/SBP or PPV developed dense cataract compared to 50% for the SBP group (table 5).
Long-term complications in phakic eyes
Discussion
Surgical treatment of RRD is influenced by many preoperative factors such as patient characteristics, available instrumentation and visualisation, presence of PVR, and surgeon experience and preference for a particular surgical treatment. One important factor that influences the surgical outcome is the choice of operating method. There are many studies that attempt to compare the main operating methods, namely SBP and PPV, in terms of efficacy; however, only few studies elucidate the treatment course and visual outcome of patients who re-detach. We report the results of 286 consecutive eyes with primary RRD that underwent surgical treatment with PPV, SBP or a combination of SBP/PPV.
In this study, we found a combined phakic/pseudophakic SOSR of 82.2%, 82.9% and 85.7% for patients in the PPV/SBP, PPV and SBP, respectively. Our results corroborate other studies. Most reports on SOSR for SBP, PPV and SBP/PPV, regardless of lens status, fall in the 70–90% range.5 9 10 14 15 18–23 Ahmadieh et al13 showed a SOSR of 68.2% and 62.6% for pseudophakic patients with primary RRD who had SBP and PPV, respectively. The SPR study20 showed lower SOSR (53.4% for pseudophakic SBP, and 63.6% and 63.8% for phakic SBP and PPV, respectively), which was attributed to a stricter definition of primary anatomical success and longer follow-up (12 months). Our average follow-up was 12.1 months with a range of 1–23 months. It is quite plausible that some re-detachments were missed, hence contributing to a higher SOSR in our study.
We found that the number of secondary surgical procedures performed on patients that re-detached after initial PPV/SBP, PPV or SBP was 1.5, 1.47 and 1.1, respectively. This difference was statistically significant (p<0.05). Weichel et al22 reported 20 secondary surgical operations per 10 re-detachments from a total of 152 patients divided into either the PPV or PPV/SBP group. This implies an average of two secondary procedures per each re-detachment post PPV or SBP/PPV. Mendrinos et al9 reported an average of 1.75 secondary operations performed on re-detached patients post primary PPV. The SPR study20 reported significantly fewer secondary operations in their pseudophakic PPV group compared to SBP (0.77 vs 0.43, respectively). It is important, however, to point out that in the SPR study, secondary operations were averaged per the whole group regardless of patients' attachment status. We computed the average number of secondary procedures in the re-detached groups only. It is also noteworthy to point out that the SBP group in the SPR study had much lower SOSR (hence more secondary operations) compared to ours (53.4% vs 85.7%).
The average time to first re-detachment in this study was 45 and 35 days for PPV/SBP and PPV groups, respectively. This corroborates well with Richardson et al's21 report of 5.3 weeks post PPV. We found that re-detachment post SBP showed a trend for sooner occurrence (17 days); however, it did not reach statistical significance. Ahmadieh et al13 showed that the majority of re-detachments post SBP and PPV occur within 2 months; however, they did not report on the average time to re-detachment for each group. One could speculate why re-detachments post SBP occur sooner. Different re-detachment mechanisms could be in play. Sharma et al19 found in their series that the most frequent causes of re-detachment post SBP and PPV were PVR and missed breaks, respectively. Ahmadieh et al13 found that in their series, PVR was the most common cause for re-detachment post PPV and post SBP. Further studies are indeed needed to further elucidate different re-detachment mechanisms.
The average size of retinal detachment obtained from patients' preoperative office exams in the PPV/SBP, PPV and SBP groups was 5.8, 4.9 and 4.4 clock hours, respectively, in our series. Patients that re-detached had similar extent of retinal detachment compared to their corresponding treatment groups. Our finding corroborates Ahmadieh et al,13 who did not find any correlation between the extent of retinal detachment and likelihood of re-detachment.
In our series, the frequency of patients with final BCVA better than or equal to 20/50 among all the patients in the PPV/SBP, PPV and SBP groups was 44%, 64% and 73%, respectively. This corroborates well with Brazitikos et al,18 who reported the frequency of visual acuity better than or equal to 20/40 in the SBP and PPV groups to be 65.3% and 72.0%, respectively. Patients that re-detached showed a trend for worse final visual acuities. The frequency of final BCVA better than or equal to 20/50 in patients that re-detached after initial treatment with PPV/SBP, PPV or SBP was 21%, 33% and 45%, respectively, which also showed a trend, although it did not reach statistical significance, for better visual outcome in patients that were initially treated with SBP.
In this study, patients that re-detached after initial treatment with SBP were less likely (22%) to require silicone oil injection compared to PPV/SBP (83%) or PPV (60%). The SPR study20 showed a 10–20% frequency of silicone oil injection varying among the study's subgroups; however, the frequency of silicone oil among re-detached patients was not reported.
We found that all phakic patients who re-detached post initial PPV/SBP or PPV developed significant (3+ or more) cataract. However, only 50% of patients re-detaching post SBP developed significant cataract. Of the phakic patients who re-detached after initial treatment with PPV/SBP, PPV or SBP, 42%, 25% and 12.5% required PPL, respectively.
In summary, we studied 286 eyes with primary RRD that underwent primary repair with PPV/SB, PPV or SBP. Our SOSR was above 77% for all the subgroups, which fits with the majority of previously published results. We found that compared to primary repair with PPV or PPV/SBP, patients that re-detached post primary SBP required fewer secondary operations and silicone oil injections, showed a trend for better visual outcomes and were less likely to develop dense cataract or require PPL. It is important to point out that due to the retrospective nature of our study, it was impossible to completely eradicate selection bias. We excluded patients with severe PVR, vitreous haemorrhage, and traumatic or tractional detachments. In addition, all three groups had similar size detachments and statistically similar proportion of macular involvement. However, patients that were initially treated with SBP were younger and more likely to be phakic compared to the PPV and PPV/SBP groups. Further randomised control trials are needed to ensure complete lack of selection bias.
References
Footnotes
Competing interests None.
Ethics approval This study was conducted with the approval of the institutional review board of Barnes Jewish Hospital and Washington University, St Louis, Missouri, USA.
Provenance and peer review Not commissioned; externally peer reviewed.