Diode laser trans-scleral cyclophotocoagulation for glaucoma following silicone oil removal

Surgical Treatment in Silicone Oil-Associated Glaucoma

Glaucoma is a vision threatening, not uncommon complication of eyes that have undergone pars plana vitrectomy with silicone oil endotamponade. Although most patients respond well to medical antiglaucoma therapy, there are refractory cases where surgery is required to control the intraocular pressure. This review, following a comprehensive literature search in the Medline database, aims to present the most important surgical techniques currently in use for glaucoma associated with silicone oil endotamponade and their indication depending on the mechanism of glaucoma. In cases of pupillary block, the presence of a patent iridotomy or iridectomy must be ensured, either by laser or surgically. When silicone oil is in excess and whenever the retinal status permits it, partial or complete removal of the silicone oil should be performed. Trabeculectomy has shown higher failure rates and more complications in these cases compared to other indications, so alternate methods are warranted. For very high intraocular pressures, glaucoma drainage devices and transscleral cyclophotocoagulation are the most used options, with good efficacy and safety profiles, although rarely they may have serious complications. The Ex-PRESS mini shunt has shown excellent results and lower rates of complications. For less important IOP elevations, minimally invasive glaucoma surgery and selective laser trabeculoplasty may be used, either alone or in conjunction with other methods.

Slow Coagulation Transscleral Cyclophotocoagulation for Postvitrectomy Patients With Silicone Oil-induced Glaucoma

PRECIS

Slow coagulation transscleral cyclophotocoagulation (TSCPC) is an effective and safe glaucoma surgery in patients with medically uncontrolled silicone oil (SO)-induced glaucoma.

PURPOSE

The purpose of this study was to report the outcomes of slow coagulation continuous wave TSCPC in patients with medically uncontrolled secondary glaucoma following pars plana vitrectomy (PPV) and intravitreal SO injection.

PATIENTS AND METHODS

This retrospective study enrolled patients with medically uncontrolled glaucoma secondary to PPV with SO injection who underwent TSCPC using slow coagulation TSCPC settings (power of 1250 mW and duration of 4 s). The primary outcome measure was surgical success at 12 months. Surgical success was defined as an intraocular pressure 6 to 21 mm Hg and reduced ≥20% from baseline, no reoperation for glaucoma, and no loss of light perception vision. Secondary outcome measures included number of glaucoma medications, visual acuity changes, and surgical complications.

RESULTS

A total of 18 eyes of 18 patients were included in the study. The mean age and follow-up of the patients were 51.94±14.5 years and 16.3±3.5 months, respectively. The mean intraocular pressure decreased from 29.7±9.6 mm Hg preoperatively to 14.6±6.5 mm Hg at 12 months postoperatively (P<0.001). Glaucoma medications were reduced from 4.2±0.9 at baseline to 1.9±1.3 at 12 months after TSCPC (P<0.001). A nonsignificant change of logarithm of the minimum angle of resolution visual acuity was observed at 12 months (P=0.722). The success rate at 12 months was 72.2%. No major complications were reported during the first year of follow-up.

CONCLUSION

Slow coagulation TSCPC had high efficacy and minimal complications when used as an initial glaucoma surgical procedure in patients with SO-induced glaucoma.

An update on continuous-wave cyclophotocoagulation (CW-CPC) and micropulse transscleral laser treatment (MP-TLT) for adult and paediatric refractory glaucoma

PURPOSE

Continuous-wave cyclophotocoagulation (CW-CPC) is often preferred to medical and surgical treatments for managing refractory glaucoma. This review summarizes diode CW-CPC indications, history, histopathology, methods, efficacy and safety. It also provides an overview of the latest data available on micropulse transscleral laser treatment (MP-TLT) that uses repetitive micropulses of diode laser energy in an off-and-on cyclical fashion.

METHODS

A literature review was conducted on transscleral CW-CPC (CW-TSCPC), endoscopic CPC (ECP) and MP-TLT. Relevant series of adult and paediatric patients were included for assessing the procedures.

RESULTS

Regarding CW-TCPC, highly variable success rates are reported in the literature, depending on the definition of success, type of underlying glaucoma, energy settings, follow-up duration and retreatment rates. CW-CPC often needs to be repeated, especially in paediatric patients. CW-CPC exposes to risks of inflammation and chronic ocular hypotony or phthisis with irreversible visual loss. CW-TSCPC has mainly been used in very severe forms of glaucoma, in painful eyes with limited visual potential or after filtering surgery failure. Published data on ECP are more limited but overall good success rates have been reported. Through the direct visualization of the targeted ciliary body in anatomically abnormal eyes, ECP is the preferred surgical procedure in paediatric refractory glaucoma. Complication rates are relatively low after ECP; however, large studies with long-term follow-up are needed. ECP may be used in difficult, refractory cases, but it is often used earlier when combined with cataract surgery. Despite limited data on the exact mechanism of action of MP-TLT and a lack of standardization of laser settings, the first data from heterogeneous case series shows that it has a similar efficacy and a better safety profile compared to CW-TSCPC in the medium term.

CONCLUSION

Although they may lead to sight-threatening complications, both CW-TSCPC and ECP seem effective. ECP appears to be superior to CW-TSCPC in paediatric refractory glaucoma. Unlike ECP combined with cataract surgery, evidence supporting a wider use of CW-TSCPC and MP-TLT in earlier stages of neuropathy is lacking. While it now appears that the safety profile of MP-TLT is superior to that of CW-CPC, robust prospective comparative studies including homogeneous and well-defined cohorts of patients are still needed to confirm an at least comparable efficacy in the long term.

Intraocular Pressure Rise Linked to Silicone Oil in Retinal Surgery: A Review

Silicone oil represents the main choice for intraocular tamponade in cases of complicated retinal detachment surgery. The intraocular pressure of an eye filled with silicone oil could increase, driven by a variety of different forces, according to several mechanisms. Two main conditions have been highlighted, depending on the onset: early hypertension or late glaucoma. The different types of silicone oils and their physico-chemical properties are varied and may play a role in the determination of intraocular pressure rise. The current body of literature allows for the illustration and categorization of the incidence and risk factors, as well as the pathogenesis and the management of the early postoperative hypertension subtended by an open- and closed-angle, along with the late onset silicone oil-induced glaucoma. Understanding the leading actors on the stage of ocular pressure elevation concurrently with silicone oil application for retinal surgery could help in guiding the timely and appropriate course of treatment.

DIFFERENT SURGICAL MODALITIES FOR MANAGEMENT OF PERSISTENT GLAUCOMA AFTER SILICONE OIL REMOVAL IN VITRECTOMIZED EYES: One Year Comparative Study

PURPOSE

Aim of this study was to compare outcome of four different surgical modalities for management of persistent glaucoma after silicone oil removal in vitrectomized eyes.

METHODS

This is a prospective comparative study, carried out on a cohort of 41 eyes (41 patients). Patients were randomly allocated to Group A (trabeculectomy), Group B (deep sclerectomy), Group C (Ahmed valve), or Group D (Ex-Press Minishunt). Postoperatively, all patients were followed regularly at 1 day, 1 week, 1, 3, and 6 months, and 1 year for intraocular pressure evaluation.

RESULTS

Postoperatively, there was significant drop in intraocular pressure in each group, and significant difference between the four groups regarding drop and percentage drop in intraocular pressure, with Group C showing the highest mean percentage drop in intraocular pressure, whereas Group B with the least. Success rate was 100% with Ex-Press minishunt, 80% with Ahmed valve, and 50% for each of trabeculectomy and deep sclerectomy. Hypotony occurred in 50% with Ahmed valve and 40% with trabeculectomy, whereas glaucoma occurred in 50% with deep sclerectomy and 30% with trabeculectomy.

CONCLUSION

For controlling persistent glaucoma after silicone oil removal in our work, Ex-Press minishunt had the highest complete success rate with no postoperative complications.

Update on results and complications of cyclophotocoagulation

PURPOSE OF REVIEW

This review highlights recently published studies on transscleral and endoscopic diode cyclophotocoagulation (TCP, ECP) and summarizes the treatment results and complications.

RECENT FINDINGS

Although both TCP and ECP are efficacious procedures for the treatment of refractory glaucoma, no consensus exists for optimum treatment protocol. TCP has mainly been used as a last-resort treatment for intractable glaucoma with very limited visual potential. Repeated treatment is often required. Serious complications include vision loss, hypotony, and phthisis. High treatment energy per session and underlying abnormality seem risk factors for these complications. Recent growing numbers of investigations are giving promising results for TCP as a primary surgery in eyes with good vision. Although ECP came later into clinical use for glaucoma treatment, it is becoming more accepted and no longer reserved for end-stage cases. ECP is most commonly performed in conjunction with cataract surgery and shows overall good success with relatively low complication rates. Serious complications include hypotony, phthisis, cystoid macular edema, and retinal detachment.

SUMMARY

Recent literatures suggest that both TCP and ECP are performed increasingly as the primary surgery for various types and stages of glaucoma. Both treatments are effective procedures, although potential for serious complications exists.

Glaucoma associated with the management of rhegmatogenous retinal detachment

Transient or permanent elevation of intraocular pressure (IOP) is a common complication following vitreoretinal surgery. Usually secondary glaucoma, which develops after scleral buckling procedures, or pars plana vitrectomy for repair of rhegmatogenous retinal detachment, is of multifactorial origin. It is essential, for appropriate management, to detect the cause of outflow obstruction. An exacerbation of preexisting open-angle glaucoma or a steroid-induced elevation of IOP should also be considered. Scleral buckling may be complicated by congestion and anterior rotation of the ciliary body resulting in secondary angle closure, which can usually resolve with medical therapy. The use of intravitreal gases may also induce secondary angle-closure with or without pupillary block. Aspiration of a quantity of the intraocular gas may be indicated. Secondary glaucoma can also develop after intravitreal injection of silicone oil due to pupillary block, inflammation, synechial angle closure, or migration of emulsified silicone oil in the anterior chamber and obstruction of the aqueous outflow pathway. In most eyes medical therapy is successful in controlling IOP; however, silicone oil removal with or without concurrent glaucoma surgery may also be required. Diode laser transscleral cyclophotocoagulation and glaucoma drainage devices constitute useful treatment modalities for long-term IOP control. Cooperation between vitreoretinal and glaucoma specialists is necessary to achieve successful management.

Effectiveness of diode laser trans-scleral cyclophotocoagulation in patients following silicone oil-induced ocular hypertension in Chinese eyes

We evaluated the effectiveness of diode laser trans-scleral cyclophotocoagulation (TSCPC) on intraocular pressure (IOP) in nine patients having raised IOP following use of silicone oil (SO) for retinal detachment (RD) surgery in a retrospective observational case series. Diode laser TSCPC was applied at a power setting of 1.75 to 2.5 watts, for two sec with a maximum of 30 applications. The patients were followed up for 40 to 312 weeks. The mean pre-laser IOP was 32.06 mm Hg (SD 7.32). The mean post-laser IOP at one month, three months and six months was 17.89 mm Hg (SD 8.23), 21.89 mm Hg (SD 8.16) and 21.67 mm Hg (SD 7.55) respectively. The final IOP (at the last follow-up) was 19.56 mm Hg (SD 7.85) (P=0.021). Seven of them had undergone SO removal. In our observation, effectiveness of TSCPC in long-term control of SO-induced ocular hypertension was limited as compared to short-term control of IOP.