The role of the vitreous in retinal detachment surgery with external buckling

Mini vitrectomy as an alternative technique for intraocular pressure adjustment in non-drainage scleral buckling

Purpose In non-drainage scleral buckling, anterior chamber paracentesis is usually carried out to decrease intraocular pressure. When the buckling is extensive however, this technique may be inefficient and time consuming. In this study, we tried to determine if a mini 25-gauge pars plana vitrectomy could be used as an efficient and safe alternative procedure to anterior chamber paracentesis for adjusting intraocular pressure during a non-drainage scleral buckling. Methods In this case series, 44 patients with rhegmatogenous retinal detachment (proliferative vitreoretinopathy stage < C) were included. In all cases, a mini 25-gauge pars plana vitrectomy was performed before buckle fixation and repeated if necessary. Complete retinal attachment was defined as the anatomical success. Results Forty-four eyes of 44 patients with mean age of 48.1 ± 18.2 years were included. Silicon buckle nº 276, sponge 505, and sponge 507 were utilized for 7, 34, and 3 eyes, respectively. Intravitreal injection of SF6 gas was performed for 54.5% of the eyes. Mean total time of the operation was 61 ± 16 min and the mean time for vitrectomy was 87 ± 31 s. Complete retinal attachment in 37 and incomplete attachment in 4 eyes were achieved after single operation that was a success rate of 93.2%. One had more than usual vitreous leak at the site of scleretomy and one developed a tiny vitreous hemorrhage at the sclerotomy site. Three sclerotomy sites needed suturing. Conclusion The anatomical outcome and the safety observed in this study were comparable to the current methods reported in the literature. Therefore, if anterior chamber paracentesis fails to adjust intraocular pressure during a non-drainage scleral buckling, performing a small gauge mini vitrectomy is safe and helpful.

Transscleral Removal of Subretinal Strand without Vitrectomy: A Case Report

Recurrence of inferior retinal detachment, after vitreoretinal surgery and silicone oil tamponade, along with a subretinal strand, presents a challenge for surgeons. Vitrectomy and retinotomy are the usual treatment in such cases. Here, we present a new transscleral method for addressing this problem. A 13-year-old boy with recurrent retinal detachment after silicone oil tamponade underwent scleral buckling surgery and had a transscleral subretinal strand removed without retinotomy. The retina reattached, and silicone oil was removed 3 months later. The best-corrected visual acuity was 0.4 in decimal vision at 1 year after silicone oil removal. Scleral buckling surgery combined with subretinal strand removal may be used as an alternative to retinotomy, especially for patients with an inferior retinal detachment and local subretinal strand formation.

Supplemental scleral buckling for inferior retinal detachment in silicone oil-filled eyes

PURPOSE

To evaluate the efficiency of treating selected cases of inferior retinal detachment in silicone oil-filled eyes using a supplemental scleral buckling with external drainage of subretinal fluid, versus performing a second vitreoretinal surgery and silicone oil endotamponade.

METHODS

A prospective interventional pilot study that was performed on silicone oil-filled eyes with inferior retinal detachment. Twenty-three eyes of 23 consecutive patients were alternatively distributed between 2 groups: Group A included 12 eyes treated with supplemental scleral buckling with drainage of subretinal fluid and without the removal of silicone oil, and Group B included 11 eyes treated with silicone oil removal, vitreoretinal surgery, and reinjection of silicone oil. The preoperative data included indications and details of primary vitreoretinal surgery, cause of retinal redetachment, subretinal fluid, grade of proliferative vitreoretinopathy, lens status, and the duration between primary vitreoretinal surgery and reoperation. The postoperative examination included the best-corrected visual acuity, retina status, proliferative vitreoretinopathy, silicone oil, and any reported complication. Follow-up examinations were scheduled at Day 1, weekly for 1 month, and monthly thereafter till the end of the follow-up period which extended for at least 2 months after silicone oil removal.

RESULTS

The average number of detached clock hours per eye was 2.7 in Group A and 2.4 in Group B, caused by a mean of 1.58 ± 0.80 break per eye in Group A and 1.48 ± 0.66 break per eye in Group B. The mean interval between the primary vitreoretinal surgery and the scleral buckling procedure in Group A patients was 2.83 ± 1.22 months (range, 1-5 months), while in Group B, the mean interval between the primary and the secondary vitreoretinal surgeries was 3.00 ± 1.61 months (range, 1-6 months). The mean operative time was statistically significantly (P < 0.05) shorter in Group A (38.7 ± 11.2 minutes) than in Group B (65.3 ± 15.1 minutes). The mean follow-up duration was 15.00 ± 3.22 months in Group A and 14.18 ± 2.99 months in Group B. After silicone oil removal, the retina was attached in 10 of the 12 eyes (83.3%) and redetached in 2 eyes (16.7%) in Group A, while in Group B, the retina was attached in 9 of the 11 eyes (81.8%) and redetached in 2 eyes (18.2%) after silicone oil removal. The mean logarithm of the minimum angle of resolution best-corrected visual acuity has improved from 1.82 ± 0.72 to 1.36 ± 0.52 in Group A patients (P > 0.05) and from 1.93 ± 0.74 to 1.55 ± 0.63 in Group B patients (P > 0.05) at the end of the follow-up duration.

CONCLUSION

For selected cases of inferior retinal detachment in silicone oil-filled eyes, supplemental scleral buckling could be as effective as a second vitreoretinal surgery. Scleral buckling could offer a faster, less invasive, and better economic alternative to repeated vitreoretinal surgery for treatment of such cases.

Conventional surgery for complicated retinal detachment in silicone oil-filled eyes

PURPOSE

To evaluate the anatomic and functional outcomes of conventional surgery in silicone oil (SO)-filled eyes with complicated retinal detachment (RD).

METHODS

The records of patients who underwent scleral buckling surgery for complex RD in SO-filled eyes were retrospectively reviewed. Conventional RD surgery involved a 2.5-mm encircling band, 6-mm silicone strip for the inferior quadrants or local sponge implant, subretinal fluid (SRF) drainage, and/or SO aspiration with a 27-G needle. Cryotherapy and/or laser photocoagulation was applied around the tears and 360° of the peripheral retina.

RESULTS

In all, 4 of the cases had retinal breaks in the lower quadrants, 1 of which had a macular hole; recurrence was due to proliferative vitreoretinopathy (PVR) in the 3 other cases. Three cases were treated with external SRF drainage, 3 cases with SO aspiration, and 1 case with both external drainage and SO aspiration. The retina was attached at the last follow-up visit in 6 (85.7%) of the 7 eyes. One of the cases required secondary vitreoretinal surgery for recurrent RD due to PVR and still had SO tamponade at last follow-up visit. Mean follow-up period was 17.28 ± 8.64 months. Mean logMAR visual acuity was 1.47 ± 0.47 preoperatively and 1.4 ± 0.97 postoperatively.

CONCLUSIONS

Inferior RD in eyes treated with silicone oil tamponade, with or without a retinal break, can be treated with scleral buckling surgery, external SRF drainage, and/or pars plana SO aspiration with satisfactory functional and anatomic outcomes in selected complicated RD cases.

The fluid mechanics of scleral buckling surgery for the repair of retinal detachment

BACKGROUND

Scleral buckling is a common surgical technique used to treat retinal detachments that involves suturing a radial or circumferential silicone element on the sclera. Although this procedure has been performed since the 1960s, and there is a reasonable experimental model of retinal detachment, there is still debate as to how this surgery facilitates the re-attachment of the retina.

METHODS

Finite element calculations using the COMSOL Multiphysics system are utilized to explain the influence of the scleral buckle on the flow of sub-retinal fluid in a physical model of retinal detachment.

RESULTS

We found that, by coupling fluid mechanics with structural mechanics, laminar fluid flow and the Bernoulli effect are necessary for a physically consistent explanation of retinal reattachment. Improved fluid outflow and retinal reattachment are found with low fluid viscosity and rapid eye movements. A simulation of saccadic eye movements was more effective in removing sub-retinal fluid than slower, reading speed, eye movements in removing subretinal fluid.

CONCLUSIONS

The results of our simulations allow us to explain the physical principles behind scleral buckling surgery and provide insight that can be utilized clinically. In particular, we find that rapid eye movements facilitate more rapid retinal reattachment. This is contradictory to the conventional wisdom of attempting to minimize eye movements.

[Incidence and prophylaxis of retinal detachment following pars plana vitrectomy]

PURPOSE

The aim of this study was to investigate the incidence of retinal detachment (RD) following pars plana vitrectomy and the efficacy of prophylactic means by cryoapplication central to the superior sclerotomies.

PATIENTS AND METHODS

From February 2002 to January 2005 a total of 2,298 eyes received a pars plana vitrectomy in our department. Excluding eyes with previous peripheral coagulation therapy, preexisting retinal detachment, and endophthalmitis 1,640 eyes could be reexamined at least 6 months after surgery (mean: 17+/-12 months). The incidence of RD was compared between two groups: one with intraoperative cryoapplication central to the superior sclerotomies (n=533) and one without any prophylactic treatment (n=1,107).

RESULTS

A total of 66 rhegmatogenous RD occurred during the follow-up, 23 with prophylactic cryotherapy and 43 without. This difference does not reach the level of significance. Only a subgroup of eyes operated on for macular pucker and venous occlusions showed a strong trend to prove the efficacy of prophylactic cryotherapy (p=0.07). Comparing the first 934 surgeries performed with the last 706 the incidence of RD decreased from 5.25 to 2.41%.

CONCLUSIONS

The incidence of RD could be decreased significantly during the period investigated. Cryoapplication at the superior sclerotomies failed to reach statistical significance in the total group, though the results in eyes in two special subgroups showed a strong trend towards a protective effect of cryoapplication (p=0.07). Other factors may have contributed to the reduction of RD after pars plana vitrectomy.

Vitrectomy and gas for inferior break retinal detachments: are the results comparable to vitrectomy, gas, and scleral buckle?

AIMS

To compare the success rates of vitrectomy and gas with vitrectomy, gas, and buckle in the treatment of inferior break retinal detachments.

METHODS

A retrospective case note review of 86 patients who presented with inferior break retinal detachments was carried out. An inferior break was defined as a horseshoe tear present between 4 and 8 o'clock. Patients were analysed in two groups; group A consisted of 41 patients who underwent a vitrectomy and gas, group B consisted of 45 patients who underwent a vitrectomy, gas, and scleral buckle. The features of the retinal detachment, peroperative and postoperative complications, and outcomes of treatment were recorded for each patient.

RESULTS

The primary anatomical success rate at 3 months was 89% in group A versus 73% in group B (p = 0.11). There was no statistical difference in the complication rate between the two groups (p = 0.819). The most common cause of treatment failure was proliferative vitreoretinopathy, 20% (n = 9) in group B compared with 5% (n = 2) in group A and this reached statistical significance (p = 0.0159). There was a higher rate of epiretinal membrane development in group B (p = 0.0004). The final attachment rate was not statistically different between the two groups, 95% (39) in group A and 93% (42) in group B (p = 1.0).

CONCLUSION

Vitrectomy and gas without the application of a scleral buckle may be used to safely treat inferior break retinal detachments. It may be used as an alternative to vitrectomy, gas, and buckle which has an increased risk of choroidal haemorrhage, requires a longer operating time, and has all the associated complications of a scleral buckle.