Silicone oil in the aphakic eye: the influence of a six o'clock peripheral iridectomy

Clinical effect of peripheral capsule preservation in eyes with silicone oil tamponade

BACKGROUND

At present, silicone oil has been widely used in vitrectomy to deal with complex fundus diseases. Usually, cataract extraction is combined with vitrectomy. However, reducing the complications of silicone oil tamponade and facilitating the secondary implantation of intraocular lens (IOL) are still an urgent problem.

AIM

To evaluate the clinical effect of vitrectomy combined with peripheral capsule preservation (PCP) in eyes with silicone oil tamponade.

METHODS

This single-center retrospective analysis included 70 patients (73 eyes) who underwent vitrectomy and silicone oil tamponade combined with cataract surgery (stage I) between January 2015 and July 2019. All patients underwent selective reoperation for silicone oil extraction and IOL implantation (stage II) more than 3 mo after stage I. These patients were divided into three groups according to the different lens capsule preservation methods: 28 patients (31 eyes) in a whole capsule preserved (WCP) group, 17 (17 eyes) in a capsule absent (CA) group, and 25 (25 eyes) in a peripheral capsule preserved (PCP) group. Intraocular pressure (IOP), best-corrected visual acuity, surgery time, and other complications were recorded at each time point (1 d, 1 wk, and 1 mo after stages I and II).

RESULTS

The IOP values were 14.9 ± 8.2 mmHg in the WCP group, 20.3 ± 13.0 mmHg in the CA group, and 14.2 ± 9.7 mmHg in the PCP group (P < 0.05) at 1 mo after stage I operation. Five eyes had IOP higher than 30 mmHg, and one eye in the WCP group appeared to have silicone oil entering the anterior chamber. There was no significant difference in IOP among the three groups at any other time point (P > 0.05). With IOL implantation, visual acuity improved significantly compared to stage I. The incidence rate of posterior capsule opacity was higher in the WCP group than in the other groups (P < 0.001). In the CA group, IOL deviation due to suture relaxation occurred in one case. There was no significant difference in the surgery time among the three groups in stage I (P = 0.618). In stage II, the surgery time of the PCP group and WCP group was significantly shorter than that of the AC group (P = 0.031).

CONCLUSION

Preservation of the peripheral capsule in vitrectomy combined with lens removal is a better option. This method has significant advantages in reducing intraoperative and postoperative complications.

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.

Iridolenticular block in heavy silicone oil tamponade

BACKGROUND

The purpose of this study was to report the adverse effect of iridolenticular block glaucoma after vitreoretinal surgery and endotamponade with heavy silicone oil in cases of complicated retinal detachment.

METHODS

A retrospective analysis of 23 eyes of 23 patients who underwent a pars plana vitrectomy and heavy silicone oil (Densiron 68) endotamponade for repair of complex inferior retinal detachment.

RESULTS

Two patients developed high intraocular pressure postoperatively. The mechanism of secondary glaucoma in both patients was a prolapse of heavy silicone oil into the anterior chamber. When lying in a supine position for a prolonged period, the heavy silicone oil occluded the pupil, causing an iridolenticular block.

CONCLUSION

In the presence of heavy silicone oil in the anterior chamber, lying in a supine position causes the oil drop to sink, blocking the entire diameter of the pupil, and inducing an iridolenticular block with acute angle-closure glaucoma. We conclude that every case of heavy silicone oil migration into the anterior chamber should be regarded as an emergency. The possible treatment could include pupil dilation, anterior chamber irrigation, or an Nd YAG-laser iridotomy.

Incidence and management of elevated intraocular pressure after silicone oil injection

PURPOSE

To determine the incidence and clinical features of chronic elevated intraocular pressure after pars plana vitrectomy and silicone oil injection for complicated retinal detachments, and to evaluate the clinical management of eyes with secondary glaucoma.

METHODS

This was an observational consecutive case series of 450 eyes in 447 patients who were treated with pars plana vitrectomy and silicone oil injection. Patients who developed secondary glaucoma were treated medically with antiglaucoma medications and surgically with glaucoma drainage implants placed in an inferior quadrant. Main outcome measures were intraocular pressure, number of glaucoma medications, surgical success, and complications.

RESULTS

Fifty-one of 450 eyes (11%) developed elevated intraocular pressure after pars plana vitrectomy and silicone oil injection whereas 399 eyes (89%) did not have a rise in intraocular pressure. Of the 51 eyes that developed elevated intraocular pressure, 40 (78%) were treated only with glaucoma medicines. Medical therapy reduced the intraocular pressure from a mean +/- SD of 26 +/- 13.4 mm Hg before treatment to 18 +/- 9.1 mm Hg after medical treatment (P = 0.002). The 11 of 51 eyes (22%) with elevated intraocular pressure that failed medical therapy were treated surgically with Ahmed Glaucoma Valve implantation within 12 months of silicone oil injection. In the surgical group, intraocular pressure was reduced from a mean +/- SD of 44 +/- 11.8 mm Hg before surgery to 14 +/- 4.2 mm Hg at the most recent follow-up after surgery (P < 0.001). The number of antiglaucoma medications was reduced from 3.5 +/- 0.7 before surgery to 1.2 +/- 0.5 at the most recent follow-up after surgery (P < 0.001).

CONCLUSION

Chronic intraocular pressure elevation occurs in a minority (11%) of patients who are treated with silicone oil. Most of these eyes are effectively treated with antiglaucoma medications. Eyes that do not respond to medical therapy may be effectively managed with glaucoma drainage implant placement in an inferior quadrant.

Unsutured posterior chamber lens implantation in eyes requiring lens extraction at the time of pars plana vitrectomy with silicone oil tamponade

PURPOSE

To describe a technique for the subsequent placement of an unsutured posterior chamber lens intraocular lens (PC IOL) in eyes requiring cataract or clear lens extraction at the time of pars plana vitrectomy (PPV) with silicone oil tamponade.

SETTING

Department of Vitreoretinal Surgery, St. Thomas' Hospital, London, United Kingdom.

METHODS

This retrospective review comprised 25 patients who had phacoemulsification to allow an adequate intraoperative retinal view or adequate access to anterior retinal pathology. Anterior and posterior capsulorhexes were combined with an inferior radial capsulectomy to fashion a keyhole-shaped capsule.

RESULTS

The mean follow-up was 15.9 months +/- 8.0 (SD) (range 3 to 34 months). Silicone oil was removed and IOLs were implanted in 15 eyes (60.0%). Posterior chamber IOLs were implanted in 10 eyes (66.7% of those receiving an IOL), and anterior chamber AC IOLs were implanted in 5 eyes (33.3%). Nine of the 10 eyes receiving a PC IOL (60.0% of all IOLs) had uneventful surgery. In 1 eye, the PC IOL subluxated inferiorly. Two eyes developed pupil block that required further surgery.

CONCLUSIONS

This technique allowed PC IOL implantation in 60% of eyes that received an IOL, showing that in selected patients who require simultaneous lens extraction and silicone oil tamponade, a keyhole-shaped capsulectomy provides for subsequent unsutured PC IOL insertion. The pupil block rate of 8% compares favorably with published rates. Refining the technique may allow it to be used in a greater proportion of eyes that would benefit from safe refractive correction.

Pupil block glaucoma in phakic and pseudophakic patients after vitrectomy with silicone oil injection

PURPOSE

To describe pupil block glaucoma in phakic and pseudophakic patients after vitrectomy with silicone oil injection.

DESIGN

Interventional case series.

METHODS

Cases were collected from January 1997 to July 2000 from three tertiary referral centers.

RESULTS

Seven phakic patients (seven eyes) and one pseudophakic patient (one eye) presented 1 to 90 days after vitrectomy and silicone oil injection with intraocular pressures of 36 to 70 mm Hg. Five patients had an observed or potential weakness of the iris-lens diaphragm. Treatment with Nd:YAG-laser peripheral iridotomy or inferior iridectomy provided a temporary reduction in intraocular pressure for some patients, but all eventually required removal of silicone oil.

CONCLUSION

Pupil block glaucoma after silicone oil injection is well recognized in aphakic patients, but ophthalmologists should be aware that it can occur in phakic and pseudophakic patients, particularly in complicated cases and patients with a weakness of the iris-lens diaphragm.

Surgical management of secondary glaucoma after pars plana vitrectomy and silicone oil injection for complex retinal detachment

OBJECTIVE

To evaluate the outcomes of surgical intervention for secondary glaucoma after pars plana vitrectomy and silicone oil injection for repair of complex retinal detachment.

DESIGN

Retrospective noncomparative interventional case series.

PARTICIPANTS

Forty-three eyes of 43 patients who underwent incisional surgery for secondary glaucoma after pars plana vitrectomy and silicone oil injection for repair of complex retinal detachment over a 9-year period.

MAIN OUTCOME MEASURES

Intraocular pressure (IOP), intraoperative and postoperative complications, visual acuity, and the need for further surgical intervention for glaucoma. Success was defined as IOP < or =21 mmHg and > or =5 mmHg with or without medication but without surgical reoperation for glaucoma.

RESULTS

Findings associated with elevated IOP included emulsified oil in the anterior chamber (n = 14), pupillary block from silicone oil (n = 13), open-angle glaucoma without silicone oil in the anterior chamber (n = 9), and angle-closure glaucoma without pupillary block (n = 7). The mean (+/- standard deviation) IOP was 41.4 +/- 15.1 mmHg before surgery for glaucoma and 17.2 +/- 10.2 mmHg after an average follow-up of 19.6 months (P < 0.001). Cumulative success was 69%, 60%, 56%, and 48% at 6, 12, 24, and 36-months respectively. In patients who underwent silicone oil removal alone for surgical management of glaucoma (n = 32), 11 of 12 IOP failures (92%) were due to uncontrolled IOP, whereas most IOP failures in the group who underwent silicone oil removal plus glaucoma surgery (n = 8) failed because of hypotony (3 of 4, 75%, P = 0.027). Of three patients who underwent glaucoma surgery alone to control IOP, one failed because of hypotony. There was no significant change in visual function at last follow-up (logarithm of the minimum angle of resolution [logMAR] 2.01) compared with preoperative visual function (logMAR 2.07, P = 0.74).

CONCLUSION

Surgical management of secondary glaucoma after silicone oil injection for complex retinal detachment may achieve good IOP control and stabilization of visual function in most patients. Patients who undergo silicone oil removal alone to control IOP are more likely to have persistent elevation of IOP and possibly undergo reoperation for glaucoma, whereas patients who undergo concurrent silicone oil removal and glaucoma surgery are more likely to have hypotony.

Silicone oil and fluorosilicone

Silicone oil has been used to fill the vitreous cavity for long-term or permanent internal tamponade in eyes with proliferative vitreoretinopathy or complicated retinal detachment due to ocular trauma, giant retinal tears, proliferative diabetic retinopathy, and cytomegalovirus retinitis. Reports from the Silicone Study confirmed its efficacy in the treatment of proliferative vitreoretinopathy and addressed outcome differences in vitrectomized and nonvitrectomized eyes, combined retinotomy, silicone oil removal, and complications associated with silicone oil tamponade, such as intraocular pressure abnormalities and corneal abnormalities. Because silicone oil is lighter than water and not adequate in supporting the inferior quadrants, several heavier-than-water materials have been introduced for intraocular tamponade. Silicone oil can be a potential vehicle for delivering antiproliferative agents to treat proliferative vitreoretinopathy.

Tissue plasminogen activator for preserving inferior peripheral iridectomy patency in eyes with silicone oil

PURPOSE

An inferior peripheral iridectomy (IPI) was used to prevent forward migration of silicone oil in vitrectomized eyes; however, in approximately one third of eyes, the IPI closed spontaneously. Occlusion of the IPI by fibrin is believed to be an early event in permanent IPI closure by scar tissue. The authors determined whether intraocular tissue plasminogen activator (tPA) would restore and maintain IPI patency in eyes that had early occlusion of the IPI by fibrin.

METHODS

Between November 1993 and January 1995, 12 patients who underwent vitrectomy with silicone tamponade and IPI for complicated retinal detachment received an anterior chamber injection of tPA (6.25 or 12.5 microgram) for occlusion of the IPI by fibrin.

RESULTS

All 12 patients had lysis of fibrin and maintained a patent IPI at the last follow-up (124+/-95 days). One patient required multiple tPA injections for recurrent fibrin formation. In another patient, a small hyphema developed after the tPA injection, which did not occlude the IPI. When compared with the natural course in a very similar group of patients previously reported, tPA had a statistically significant beneficial effect in the maintenance of IPI patency (P = 0.040).

CONCLUSIONS

Intraocular tPA can be safely used to lyse postoperative fibrin occluding the IPI in eyes with silicone oil tamponade. Early lysis of this fibrin maintains IPI patency.

The efficacy of neodymium: YAG laser iridotomy in the treatment of closed peripheral iridotomies in silicone-oil-filled aphakic eyes

Eighteen patients had a surgical inferior peripheral iridotomy performed to prevent pupil block and silicone oil anterior chamber prolapse. The occlusion of an iridotomy was treated by neodymium: YAG laser therapy and this form of treatment was successful only in 4 cases (22%). The reopening of occluded iridotomies is best performed by surgery as opposed to laser treatment.

Removal of silicone oil--rewards and penalties

Silicone oil is a useful tool in retinal reattachment surgery in selected cases, but complications, particularly cataract, glaucoma and keratopathy, have led to worries about its use for prolonged internal tamponade. Removal of silicone oil has been recommended to preempt or reverse these complications. A retrospective review of 120 eyes in which temporary silicone oil tamponade had been employed is presented. One hundred and twelve eyes were examined six months and two years after removal of silicone oil. Retinal redetachment occurred in 21 eyes (19%). Cataract formation was delayed by early removal of silicone oil, but after two years the majority of eyes had undergone surgery for cataract or had developed lens opacities. Removal of silicone oil was ineffective in reversing an established pressure rise in nearly all cases. Three phakic eyes developed glaucoma after removal of silicone oil but no new cases occurred in phakic eyes in the two years following silicone oil removal. Keratopathy was uncommon and was arrested and occasionally reversed by silicone oil removal. Visual acuities improved in the majority of eyes after removal of silicone oil.

The superior peripheral iridectomy: prevention of pupil block due to silicone oil

Superior peripheral iridectomy has been performed in 40 patients who have undergone silicone oil surgery for retinal detachment and who are aphakic. Only two developed raised intraocular pressure due to pupil block by liquid silicone and in each case the iridectomies seemed to be closed by proliferative membrane rather than the silicone meniscus. This type of iridectomy is particularly suitable in patients requiring intracapsular cataract extraction after previous vitrectomy and silicone oil surgery.