The effect of a preoperative subconjuntival injection of dexamethasone on blood-retinal barrier breakdown following scleral buckling retinal detachment surgery: a prospective randomized placebo-controlled double blind clinical trial

Background: Blood-retinal barrier breakdown secondary to retinal detachment and retinal detachment repair is a factor in the pathogenesis of proliferative vitreoretinopathy (PVR). We wished to investigate whether an estimated 700 to 1000 ng/ml subretinal dexamethasone concentration at the time of surgery would decrease the blood-retinal barrier breakdown postoperatively. Methods: Prospective, placebo-controlled, double blind clinical trial. In 34 patients with rhegmatogenous retinal detachment scheduled for conventional scleral buckling retinal detachment surgery, a subconjunctival injection of 0.5 ml dexamethasone diphosphate (10 mg) or 0.5 ml placebo was given 5-6 hours before surgery. Differences in laser flare photometry (KOWA) measurements taken 1, 3 and 6 weeks after randomisation between dexamethasone and placebo were analysed using mixed model ANOVA, while correcting for the preoperative flare measurement. Results: Six patients did not complete the study, one because of recurrent detachment within 1 week, and five because they missed their postoperative laser flare visits. The use of dexamethasone resulted in a statistically significant decrease in laser flare measurements at the 1-week postoperative visit. Conclusion: The use of a preoperative subconjunctival injection of dexamethasone decreased 1-week postoperative blood-retina barrier breakdown in patients undergoing conventional scleral buckling retinal detachment surgery. This steroid priming could be useful as a part of a peri-operative regime that would aim at decreasing the incidence of PVR

The effect of a preoperative subconjuntival injection of dexamethasone on blood–retinal barrier breakdown following scleral buckling retinal detachment surgery: a prospective randomized placebo-controlled double blind clinical trial

textabstractBackground: Blood-retinal barrier breakdown secondary to retinal detachment and retinal detachment repair is a factor in the pathogenesis of proliferative vitreoretinopathy (PVR). We wished to investigate whether an estimated 700 to 1000 ng/ml subretinal dexamethasone concentration at the time of surgery would decrease the blood-retinal barrier breakdown postoperatively. Methods: Prospective, placebo-controlled, double blind clinical trial. In 34 patients with rhegmatogenous retinal detachment scheduled for conventional scleral buckling retinal detachment surgery, a subconjunctival injection of 0.5 ml dexamethasone diphosphate (10 mg) or 0.5 ml placebo was given 5-6 hours before surgery. Differences in laser flare photometry (KOWA) measurements taken 1, 3 and 6 weeks after randomisation between dexamethasone and placebo were analysed using mixed model ANOVA, while correcting for the preoperative flare measurement. Results: Six patients did not complete the study, one because of recurrent detachment within 1 week, and five because they missed their postoperative laser flare visits. The use of dexamethasone resulted in a statistically significant decrease in laser flare measurements at the 1-week postoperative visit. Conclusion: The use of a preoperative subconjunctival injection of dexamethasone decreased 1-week postoperative blood-retina barrier breakdown in patients undergoing conventional scleral buckling retinal detachment surgery. This steroid priming could be useful as a part of a peri-operative regime that would aim at decreasing the incidence of PVR

Improving the Outcome of Rhegmatogenous Retinal Detachment Repair by Adding Pieces to the Puzzle

Abstract Thanks to the consecutive introduction of penetrating thermocautery, buckling surgery and pars plana vitrectomy, the anatomical success rate of rhegmatogenous retinal detachment (RRD) repair improved dramatically, from 1/1000 about a hundred years ago, to about 90% by the late 20th century. In the past 30 years, the basic approach is shifting towards vitrectomy and (in phakic eyes) primary lens extraction, as standard care for all cases of RRD. This more aggressive surgical approach has many potential complications and does not yield better results. We have therefore attempted to modify our surgical approach to better address the critical causes of failure, while eliminating certain elements that can adversely affect the outcome. Blood-ocular barrier (B-O B) breakdown is an important event in RRD and extensive surgical manipulation seems to increase the B-O B breakdown. We have demonstrated that both pre-treatment with subconjunctival dexamethasone and omitting intra-operative retinopexy, can reduce B-O B breakdown. Functional recovery can be effected by post-operative persistence of subretinal fluid under the fovea. A modified surgical drainage technique (“subretinal fluid lavage”) was designed to prevent fluid persistence. To improve the efficacy and reproducibility of membrane peeling during PVR surgery, we reported the use of trypan blue dye to enhance the visibility of membranes on the retinal surface. To limit the surgical trauma of a retinotomy to treat recurrent PVR related detachments, we have eliminated intra-operative retinopexy. This modification may allow the ongoing contraction to shorten the retina without promoting re-detachment as long as the oil tamponade is in place. Laser retinopexy to secure the central retinotomy edge can be applied before oil removal. The treatment of RRD has come a long way in the past century. In order to tackle the remaining obstacles we should aim to re-define minimally invasive surgery and target the key aspects of the disease without creating additional iatrogenic pathology. The future of RRD therapy looks bright, let’s keep our eye on the target

Microplasmin intravitreal administration in patients with vitreomacular traction scheduled for vitrectomy: the MIVI I trial

PURPOSE: To evaluate the safety and preliminary efficacy of 4 doses and several exposure times of intravitreal microplasmin given before pars plana vitrectomy for vitreomacular traction maculopathy. DESIGN: A multicenter, prospective, uncontrolled, dose-escalation, phase I/II clinical trial. PARTICIPANTS: Sixty patients enrolled into 6 successive cohorts. INTERVENTION: A single intravitreal injection of microplasmin at 1 of 4 doses (25, 50, 75, or 125 microg in 100 microl) administered either 1 to 2 hours, 24 hours, or 7 days before planned pars plana vitrectomy. MAIN OUTCOME MEASURES: For safety, a complete ophthalmologic examination, fundus photography, fluorescein angiography, Humphrey visual fields, and electrophysiology; for efficacy, posterior vitreous detachment (PVD) induction as assessed by B-scan ultrasound and ease of PVD induction at the time of vitrectomy. RESULTS: The use of microplasmin led to a progressively higher incidence of PVD induction on ultrasonography with increasing time exposure. A PVD before surgery was observed with 25 microg microplasmin in 0, 2, and 5 patients with increasing exposures (2 hours, 24 hours, 7 days). With increasing dose, a PVD before surgery was observed by ultrasound as follows: 25 microg, 0; 50 microg, 1; 75 microg, 2; 125 microg, 3. However, at surgery, with a 125-microg dose, these patients had a discontinuous layer of vitreous present on the retinal surface resulting from the induction of an anomalous PVD in the form of vitreoschisis. One retinal detachment developed shortly after administration of microplasmin. Two developed after surgery. There were no other safety concerns. CONCLUSIONS: Results from this initial clinical trial evaluating intravitreal microplasmin show the drug to be well tolerated and capable of inducing a pharmacologic PVD in some patients. These results warrant evaluation of microplasmin in larger, controlled trial

Persistent subretinal fluid after surgery for rhegmatogenous retinal detachment: hypothesis and review

Persistent subretinal fluid after rhegmatogenous retinal detachment (RRD) surgery is responsible for delayed recovery, and may affect the final visual outcome. Cause, consequences, and treatment remain elusive. Literature review and case series. We reviewed the pathophysiological principles and therapeutic options from the literature, and we report the results from a subretinal fluid cytology study. Nine eyes from nine patients with macula-involving RRD underwent surgical repair. The cellular content of subretinal fluid (SRF) was studied by electron microscopy and anti-rhodopsin immunostaining. All eyes were assessed postoperatively with optical coherence tomography for the detection of persistent submacular fluid (PSF) (Ethics Committee Ghent University Hospital, registration number B6702006169). Certain patient characteristics as well as surgical methods were implicated. PSF appears to occur more frequently in patients with longstanding detachments treated with buckling surgery. Several therapeutic options have been suggested but safety and efficacy remain unclear. We found PSF in three eyes on postoperative OCT scans, which corresponded to the three cell-rich subretinal samples. PSF after successful RRD repair seems to be related to fluid composition. We hypothesize, in the absence of an effective treatment, that a modified surgical drainage, including a washout of the subretinal space, could evacuate the subretinal fluid more completely, and may prevent this complication