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Scleral Buckling versus Primary Vitrectomy
Letters to the Editor Scleral Buckling versus Primary Vitrectomy
Author reply
Dear Editor: Ahmadieh et al1 presented the anatomic and visual outcomes of scleral buckling versus primary vitrectomy (pars plana vitrectomy [PPV]) in patients with pseudophakic and aphakic retinal detachment. This study raises questions in terms of study design and interpretation of results. The surgeons were either attending vitreoretinal surgeons or vitreoretinal fellows. The authors report an extremely low success rate in both groups relative to other studies (68.2% in the scleral buckling group and 62.6% in the PPV group).2– 4 How many were attending surgeons, and what percentage were fellows for each patient group? The percentage of reoperations was very high in both groups. Who did the reoperations, an attending or a vitreoretinal fellow? The authors try to identify any possible factors that might have influenced the results such as myopia, intraocular lens dislocation, vitreous incarceration, and inflammation; they do not, however, comment on the surgeons’ experience. If the cases operated by trainees were excluded, would the results have been totally different? We conducted a very similar study starting 6 years ago, and have published our results.5 The severity of our cases was the same as Ahmadieh et al’s (staged B or less). I was the only surgeon involved, and reported a higher attachment rate with a single surgery in both groups (83% for the scleral buckling group and 94% for the PPV group). One other important issue is that the authors do not give complete information on the follow-up of the patients who redetached. How many operations were necessary for each group? The follow-up of 6 months is too short, especially for the patients who had a second surgery, and therefore, all the available results (reattachment rate, visual acuity) must be interpreted with caution.
Dear Editor: Dr Brazitikos has commented on the results of our multicenter study. The comments do not raise questions about the study design. We agree with Dr Brazitikos that surgeon effect (attending surgeon vs. fellow) on the main outcomes should have been evaluated. We did not consider this in our statistical analysis because in most cases both fellows and attending surgeons were present during the surgical procedures, and it was not possible to record precisely which surgeon did which aspect of each case. We are continuing studies on the issue of surgical management of pseudophakic and aphakic retinal detachment (RD) and have decided to limit the role of fellows in our active clinical trials. One of the most significant findings of our study was the high incidence of proliferative vitreoretinopathy (PVR) in cases of pseudophakic and aphakic RD regardless of the surgical technique used.1 The retinal reattachment rates 1 month after surgery were 82.5% and 75.7% in the buckle and vitrectomy groups, respectively. However, the retinal reattachment rates declined to 68.2% in the scleral buckling group and 62.6% in the vitrectomy group after 6 months. Proliferative vitreoretinopathy was the main cause of anatomic failure in both groups. Most cases of retinal redetachment occurred within 4 to 8 weeks after surgery. The high rate of PVR after scleral buckling has been reported.2 Based on our data, we concluded that primary vitrectomy does not reduce the rate of PVR in these high-risk cases. Dr Brazitikos compares the results of our study with those of a similar study he is conducting with his colleagues.3 Our study is a multicenter study with multiple surgeons, whereas Brazitikos et al’s is a single-center and single-surgeon study. A multicenter study differs from a single-center study in many aspects.4 One of the benefits of a multicenter study is its higher external validity— the findings more likely can be generalized to surgeons not in the study. On the other hand, the overall effects size is smaller in multicenter clinical trials than in single-center ones. We are not comfortable accepting Dr Brazitikos’s statement about the similarity of his cases with ours in terms of severity. Although the number of eyes with PVR grade B and the extent of RD were not mentioned in Brazitikos et al’s study, most RDs in our study were total or nearly total, with signs of PVR grade B in all cases. We did report final reattachment rates, 85% in the buckle group and 92% in the vitrectomy group after further operations. The 12-month follow-up results of a single operation and the details of the reoperations will be reported in the future.
PERIKLIS BRAZITIKOS, MD Thessaloniki, Greece References 1. Ahmadieh H, Moradian S, Faghihi H, et al. Anatomic and visual outcomes of scleral buckling versus primary vitrectomy in pseudophakic and aphakic retinal detachment. Six-month follow-up results of a single operation—report no. 1. Ophthalmology 2005;112:1421–9. 2. Bovey EH, Gonvers M, Sahli O. Surgical treatment of retinal detachment in pseudophakia: comparison between vitrectomy and scleral buckling [in French]. Klin Monatsbl Augenheilkd 1998;212:314 –7. 3. Brazitikos PD, Androudi S, D’Amico DJ, et al. Perfluorocarbon liquid utilization in primary vitrectomy repair of retinal detachment with multiple breaks. Retina 2003;23:615–21. 4. Campo RV, Sipperley JO, Sneed SR, et al. Pars plana vitrectomy without scleral buckle for pseudophakic retinal detachments. Ophthalmology 1999;106:1811–5. 5. Brazitikos P, Androudi S, Christen WG, Stangos NT. Primary pars-plana vitrectomy versus scleral buckle surgery for the treatment of pseudophakic retinal detachment: a randomized clinical trial. Retina 2005;25:957– 64.
HAMID AHMADIEH, MD SIAMAK MORADIAN, MD Tehran, Iran References 1. Ahmadieh H, Moradian S, Faghihi H, et al. Anatomic and visual outcomes of scleral buckling versus primary vitrectomy in pseudophakic and aphakic retinal detachment. Six-month follow-up results of a single operation—report no. 1. Ophthalmology 2005;112:1421–9.
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Author reply
Dear Editor: Ahmadieh et al1 presented the anatomic and visual outcomes of scleral buckling versus primary vitrectomy (pars plana vitrectomy [PPV]) in patients with pseudophakic and aphakic retinal detachment. This study raises questions in terms of study design and interpretation of results. The surgeons were either attending vitreoretinal surgeons or vitreoretinal fellows. The authors report an extremely low success rate in both groups relative to other studies (68.2% in the scleral buckling group and 62.6% in the PPV group).2– 4 How many were attending surgeons, and what percentage were fellows for each patient group? The percentage of reoperations was very high in both groups. Who did the reoperations, an attending or a vitreoretinal fellow? The authors try to identify any possible factors that might have influenced the results such as myopia, intraocular lens dislocation, vitreous incarceration, and inflammation; they do not, however, comment on the surgeons’ experience. If the cases operated by trainees were excluded, would the results have been totally different? We conducted a very similar study starting 6 years ago, and have published our results.5 The severity of our cases was the same as Ahmadieh et al’s (staged B or less). I was the only surgeon involved, and reported a higher attachment rate with a single surgery in both groups (83% for the scleral buckling group and 94% for the PPV group). One other important issue is that the authors do not give complete information on the follow-up of the patients who redetached. How many operations were necessary for each group? The follow-up of 6 months is too short, especially for the patients who had a second surgery, and therefore, all the available results (reattachment rate, visual acuity) must be interpreted with caution.
Dear Editor: Dr Brazitikos has commented on the results of our multicenter study. The comments do not raise questions about the study design. We agree with Dr Brazitikos that surgeon effect (attending surgeon vs. fellow) on the main outcomes should have been evaluated. We did not consider this in our statistical analysis because in most cases both fellows and attending surgeons were present during the surgical procedures, and it was not possible to record precisely which surgeon did which aspect of each case. We are continuing studies on the issue of surgical management of pseudophakic and aphakic retinal detachment (RD) and have decided to limit the role of fellows in our active clinical trials. One of the most significant findings of our study was the high incidence of proliferative vitreoretinopathy (PVR) in cases of pseudophakic and aphakic RD regardless of the surgical technique used.1 The retinal reattachment rates 1 month after surgery were 82.5% and 75.7% in the buckle and vitrectomy groups, respectively. However, the retinal reattachment rates declined to 68.2% in the scleral buckling group and 62.6% in the vitrectomy group after 6 months. Proliferative vitreoretinopathy was the main cause of anatomic failure in both groups. Most cases of retinal redetachment occurred within 4 to 8 weeks after surgery. The high rate of PVR after scleral buckling has been reported.2 Based on our data, we concluded that primary vitrectomy does not reduce the rate of PVR in these high-risk cases. Dr Brazitikos compares the results of our study with those of a similar study he is conducting with his colleagues.3 Our study is a multicenter study with multiple surgeons, whereas Brazitikos et al’s is a single-center and single-surgeon study. A multicenter study differs from a single-center study in many aspects.4 One of the benefits of a multicenter study is its higher external validity— the findings more likely can be generalized to surgeons not in the study. On the other hand, the overall effects size is smaller in multicenter clinical trials than in single-center ones. We are not comfortable accepting Dr Brazitikos’s statement about the similarity of his cases with ours in terms of severity. Although the number of eyes with PVR grade B and the extent of RD were not mentioned in Brazitikos et al’s study, most RDs in our study were total or nearly total, with signs of PVR grade B in all cases. We did report final reattachment rates, 85% in the buckle group and 92% in the vitrectomy group after further operations. The 12-month follow-up results of a single operation and the details of the reoperations will be reported in the future.
PERIKLIS BRAZITIKOS, MD Thessaloniki, Greece References 1. Ahmadieh H, Moradian S, Faghihi H, et al. Anatomic and visual outcomes of scleral buckling versus primary vitrectomy in pseudophakic and aphakic retinal detachment. Six-month follow-up results of a single operation—report no. 1. Ophthalmology 2005;112:1421–9. 2. Bovey EH, Gonvers M, Sahli O. Surgical treatment of retinal detachment in pseudophakia: comparison between vitrectomy and scleral buckling [in French]. Klin Monatsbl Augenheilkd 1998;212:314 –7. 3. Brazitikos PD, Androudi S, D’Amico DJ, et al. Perfluorocarbon liquid utilization in primary vitrectomy repair of retinal detachment with multiple breaks. Retina 2003;23:615–21. 4. Campo RV, Sipperley JO, Sneed SR, et al. Pars plana vitrectomy without scleral buckle for pseudophakic retinal detachments. Ophthalmology 1999;106:1811–5. 5. Brazitikos P, Androudi S, Christen WG, Stangos NT. Primary pars-plana vitrectomy versus scleral buckle surgery for the treatment of pseudophakic retinal detachment: a randomized clinical trial. Retina 2005;25:957– 64.
HAMID AHMADIEH, MD SIAMAK MORADIAN, MD Tehran, Iran References 1. Ahmadieh H, Moradian S, Faghihi H, et al. Anatomic and visual outcomes of scleral buckling versus primary vitrectomy in pseudophakic and aphakic retinal detachment. Six-month follow-up results of a single operation—report no. 1. Ophthalmology 2005;112:1421–9.
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