Malignant glaucoma following laser iridotomy

Pars plana vitrectomy combined with hyaloido-zonula-iridectomy in treatment of patients with chronic aqueous misdirection: A systematic literature review and case series

PURPOSE

To evaluate the efficacy of vitrectomy combined with hyaloido-zonula-iridectomy from an anterior or a posterior approach in patients with treatment-resistant aqueous misdirection (chronic aqueous misdirection) by systematically reviewing existing literature in combination with presentation of a case series.

METHODS

A systematic literature review was performed in PubMed, EMBASE and Cochrane Library databases using search terms: malignant glaucoma, ciliary block, ciliolenticular block and aqueous misdirection. A consecutive series of three pseudophakic patients (5 eyes) diagnosed with chronic aqueous misdirection after cataract surgery is presented.

RESULTS

A literature search identified 31 articles describing treatment of chronic aqueous misdirection with vitrectomy and a hyaloido-zonula-iridectomy. Studies, where patients were treated with a complete vitrectomy from pars plana in combination with a hyaloido-zonula-iridectomy, reported low relapse rates. Studies describing a surgical approach with vitrectomy performed from the anterior chamber, followed by a hyaloido-zonula-iridectomy, also reported low relapse rates except for one reporting relapse in nearly half of the patients. In our case series, a complete vitrectomy combined with a hyaloido-zonula-iridectomy resolved the chronic aqueous misdirection in all five eyes after one procedure except one eye where the hyaloido-zonula-iridectomy was repeated due to an insufficient opening. Some of the eyes still needed antiglaucomatous treatment due to chronic angle closure.

CONCLUSION

In treatment-resistant malignant glaucoma, vitrectomy combined with a hyaloido-zonula-iridectomy should be considered performed to ensure communication between the anterior chamber and the vitreous cavity. If the condition has been unresolved for a long time, extensive synechiae of the angle may decrease the success rate due to chronic angle closure.

Long-term follow-up of zonulo-hyaloido-vitrectomy for pseudophakic malignant glaucoma

Purpose:

To report long-term follow-up of zonulo-hyaloido-vitrectomy (ZHV) via anterior approach for pseudophakic malignant glaucoma refractory to medical treatment.

Design:

Noncomparative case-series.

Materials and Methods:

Medical records of 9 patients who sought treatment for aqueous humor misdirection refractory to medical treatment were reviewed. All patients underwent anterior vitrectomy, hyaloido-zonulectomy, and peripheral iridectomy (PI) via an anterior approach. Main outcome measures were preoperative and postoperative visual acuity, intraocular pressure, medications, slit-lamp examination, and fundus findings.

Results:

10 eyes of 9 patients (7 female, 2 male) who underwent ZHV for refractory pseudophakic malignant glaucoma between 2003 and 2010 were included in this case-series. The mean age of patients was 77.4 ± 9.0 years, mean follow-up duration 50.2 ± 27.2 months. Recurrence of malignant glaucoma was noted in 40% (four cases) after a successful ZHV on long-term follow-up.

Conclusions:

An anterior segment surgeon can treat malignant glaucoma refractory to medical treatment successfully by vitrectomy, hyaloido-zonulectomy, and PI. This can be done via an anterior approach and patients require long follow-up to rule out a relapse despite a successful outcome in the short term.

Current concepts in the treatment of vitreous block, also known as aqueous misdirection

Vitreous block (VB), a rare secondary angle-closure caused by anterior rotation of the ciliary body, occurs in a variety of settings, but most frequently after glaucoma filtering surgery. The etiology remains unclear, but choroidal expansion and anterior vitreous abnormalities have been proposed. In the past, treatment of VB has yielded high rates of failure and recurrence. Advancements in surgical techniques, however, have led to improved visual outcomes. We review the history of this condition and present a stepwise approach to its diagnosis and treatment using modern imaging modalities and surgical techniques.

Dark-room prone-position test for intermittent angle closure

Purpose

To determine the efficacy and safety of the dark-room prone-position test (DRPT) for intermittent angle closure (IAC) and to investigate the correlation between A-scan ultrasound biometric measurements and the results of DRPT.

Methods

Medical records were reviewed of 37 eyes in 24 patients who were diagnosed with IAC and received DRPT. The increase of intraocular pressure (IOP) induced by DRPT and the results from A-scan ultrasound biometric measurements were obtained. An increase in IOP of at least 8 mmHg from baseline was considered a positive result for DRPT. Associations between the increase of IOP induced by DRPT and the parameters of A-scan biometry were tested by linear regression analysis.

Results

The DRPT results were positive in 28 eyes of 19 patients. After DRPT, the IOP returned to near-baseline levels within 2 hours in all patients; some patients were treated with anti-glaucoma eye drops. Lens thickness was significantly correlated with the amount of IOP elevation induced by DRPT (r=0.338, p=0.041).

Conclusions

DRPT is a safe and effective test in patients with IAC. DRPT can be used effectively to make a concrete diagnosis of IAC. Lens thickness appears to be associated with a positive response to DRPT.

Malignant glaucoma after phacoemulsification: Treatment with diode laser cyclophotocoagulation

Phacoemulsification was performed in an 84-year-old woman with ocular hypertension and narrow drainage angles, previously treated by neodymium:YAG (Nd:YAG) laser peripheral iridotomy. Despite temporal zonular weakness, the surgery was uneventful. An intraocular lens (IOL) was placed and centered in the capsular bag. Two months later, the patient presented with malignant glaucoma. The IOL optic was anteriorly displaced in the capsular bag, and the IOL shift correlated with a -4.0 diopter myopic refractive error. There was no response after medical treatment or Nd:YAG hyaloidotomy. One week later, a single treatment with transscleral diode laser cyclophotocoagulation was performed. The intraocular pressure normalized and the anterior chamber deepened within 48 hours. The patient's condition has remained stable for 3 months with no further treatment; the Snellen visual acuity is 6/9. If medical therapy fails to control malignant glaucoma, cyclodiode laser treatment may be more effective and have fewer risks than current laser and surgical interventions.

Lesser anterior chamber dimensions in women may be a predisposing factor for malignant glaucoma

Malignant glaucoma is a potentially devastating complication of intraocular surgery that may also occur spontaneously. In this condition the aqueous is diverted into the vitreous, so the Iris lens diaphragm is moved forward. This causes shall owing of the anterior chamber and increasing of intraocular pressure. By reviewing 103 patients with malignant glaucoma, the disease was more prevalent in women that men (70% vs 30%). Anterior chamber dimensions in the women is 4% lesser than the men. Therefore, it is hypothesized that these may be due to more anterior position of the lens which not only causes lesser dimension of the anterior chamber but also more cilio-lenticular block and further aqueous diversion into the vitreous cavity, in the women.

Prevalence of ciliochoroidal effusion after prophylactic laser iridotomy

PURPOSE

To study the prevalence of ciliochoroidal effusion (CE) after prophylactic laser iridotomy (LI).

METHODS

An ultrasound biomicroscope (UBM) examination was performed before, 2, and 24 hours after LI to investigate the changes in supraciliary-choroidal space after LI in circumference of 38 eyes in 23 chronic primary angle-closure patients. Subjects were divided randomly into two groups based on LI settings: 21 eyes by argon laser (Ar-LI group) and argon combined with yttrium-aluminum-garnet (YAG) laser in 17 eyes (Ar-YAG-LI group). Ciliochoroidal effusion was observed predominantly in the inferior sector (12 of 12 eyes, 100%) and rare in nasal part of the eyes (4 of 12 eyes, 33%). Ciliochoroidal effusion appeared more often in the Ar-LI group (10 eyes, 52%) than in the Ar-YAG-LI group (2 eyes, 12%). All CE disappeared 7 days after by UBM observation.

CONCLUSIONS

Subclinical CE observed by UBM frequently occurs after LI.