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

Aqueous misdirection syndrome post silicone oil removal in a vitrectomized eye - a case report

PUROPSE

Aqueous misdirection syndrome (AMS) is an aggressive post-operative glaucoma unresponsive to conventional measures with grave outcomes. In this report, we describe a rare case of AMS following silicon oil removal in a vitrectomized eye.

METHODS

A diabetic patient with tractional retinal detachment underwent pars plana vitrectomy with silicon oil injection. Following retinal reattachment, silicon oil removal was performed at three months. Post oil removal she developed increased intraocular pressure with shallowing of both the peripheral and central anterior chamber suggestive of AMS.

RESULTS

Initial medical management with anti-glaucoma medications and cycloplegics was not beneficial. A pars plana lensectomy with complete anterior hyaloidectomy along with a surgical peripheral iridectomy helped relieve the aqueous misdirection.

CONCLUSION

AMS can rarely occur following vitrectomy and is likely secondary to intact anterior hyaloid. Lensectomy along with zonulo-hyaloido-iridectomy is essential. This report highlights the occurrence of this rare complication and its effective management.

Incidence and characteristics of aqueous misdirection after glaucoma surgery in Chinese patients with primary angle-closure glaucoma

BACKGROUND

To report the incidence and clinical characteristics of aqueous misdirection (AM) after glaucoma surgery in Chinese patients with primary angle-closure glaucoma.

METHODS

Medical records of all patients diagnosed with primary angle-closure glaucoma who underwent glaucoma surgery in the Eye Hospital of Wenzhou Medical University between January 2012 and December 2021 were retrospectively reviewed. Cases of AM were identified through a keyword-based search. The incidence of AM was calculated. Demographic and clinical characteristics of the AM patients were also described.

RESULTS

A total of 5044 eyes with primary angle-closure glaucoma were included (mean age 65.81 ± 9.96 years, 68.11% women). Thirty-eight eyes developed AM, presenting an overall incidence of 0.75%. The mean time interval between surgery and first record of AM diagnosis was 2.57 ± 5.24 months (range, 0 day to 24 months). The incidence of AM was significantly higher in patients aged ≤ 40 years (21.28%) and those aged 40-50 years (3.32%), compared to those > 50 years (0.42%) (P < 0.001). AM developed much more frequently among patients with chronic angle-closure glaucoma (1.30%), compared to those with acute angle-closure glaucoma (0.32%, P < 0.001). Eleven eyes (0.37%) developed AM following non-filtering surgery compared to 24 eyes (2.27%) after filtering surgery (P < 0.001).

CONCLUSION

The incidence of AM after glaucoma surgery was 0.75% in Chinese patients with primary angle closure glaucoma. Younger age, chronic angle-closure glaucoma, and undergoing filtering surgery, were identified as associated risk factors for developing AM. Phacoemulsification may have less risk of developing AM compared to filtering surgery.

Associations Between the Choroidal Vascularity Index and Malignant Glaucoma After Trabeculectomy for Primary Angle Closure Glaucoma

Purpose: To compare the choroidal vasculature characteristics by using the choroidal vascularity index (CVI) in eyes with malignant glaucoma (MG), fellow eyes with non-MG, and eyes with uncomplicated primary angle-closure glaucoma (PACG) after trabeculectomy by spectral-domain optical coherence tomography (SD-OCT). Methods: This case-control study included 53 patients diagnosed with MG after trabeculectomy. Eyes with MG (n = 53) and the fellow eyes with non-MG (n = 50) were included. Eyes with PACG without MG after trabeculectomy (n = 60) were also enrolled as controls. The choroidal parameters, including CVI and the subfoveal choroidal thickness (SFCT), were measured by using SD-OCT images. Results: Eyes with MG and the fellow eyes showed a significantly lower CVI than eyes with PACG controls (p < 0.001). After adjusting for age, sex, axial length (AL), and intraocular pressure (IOP), eyes with the greater CVI [odds ratio (OR), 0.44] were significantly related to MG. The area under the receiver operating characteristic curve of the CVI was greater than that of the SFCT in the diagnosis of MG (0.911 vs. 0.840, p = 0.034). Conclusion: Eyes with MG showed a significantly lower macular CVI than eyes with PACG controls. A higher macular CVI was an associated factor of eyes with MG. The CVI serves as a more stable and sensitive indicator for MG than the SFCT in this group of patients with PACG.

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.

Treatment outcomes and efficacy of pars plana vitrectomy-hyaloidotomy-zonulectomy-iridotomy in malignant glaucoma

AIM

To study the treatment outcomes and efficacy of pars plana vitrectomy-hyaloidotomy-zonulectomy-iridotomy in malignant glaucoma.

METHOD

A retrospective case series study of patients treated for malignant glaucoma between 2005 and 2017. The treatment included medical management as first-line in the form of cycloplegic with anti-glaucoma medications (AGM) or pars plana vitrectomy-hyaloidotomy-zonulectomy-iridotomy as second-line therapy. The resolution was defined as 'deepening of central anterior chamber' with intraocular pressure of ⩽ 21 mm Hg (minimum on two consecutive visits 1 week apart) with or without topical anti-glaucoma medications in the absence (complete success) or presence (qualified success) of systemic medications.

RESULTS

Twenty-three eyes of 22 patients were included. At the time of diagnosis of malignant glaucoma preceding surgeries were cataract surgery (13 eyes) and trabeculectomy (4 eyes). One eye each had phacotrabeculectomy, Yag capsulotomy and optical keratoplasty. Eighteen eyes were pseudophakic and two eyes were phakic. At presentation, mean intraocular pressure was 26.25 ± 14.78 mmHg which was decreased to 15.90 ± 8.12 mmHg (p < 0.0001) at final follow-up (median follow-up was 15.50 months). Fifteen (75%) eyes had complete success, 3 (15%) eyes had qualified success and 2 (10%) eyes had treatment failure. Of 15 eyes that had achieved complete success, 3 eyes had undergone medical management and 12 eyes undergone second-line procedure. There was no significant difference in visual acuity or number of anti-glaucoma medication at presentation and final follow-up (p > 0.05).

CONCLUSIONS

Though malignant glaucoma is highly refractory to treatment, appropriate management in the form of medical or vitrectomy-hyaloidotomy-zonulectomy-iridotomy could achieve 90% success in this series.

Risk Factors of Malignant Glaucoma Occurrence after Glaucoma Surgery

Purpose

The aim of this study was twofold: first, to evaluate the predisposing factors for occurrence of malignant glaucoma and second, to compare frequency of malignant glaucoma depending on the type of primary glaucoma surgery.

Methods

Retrospective analysis was performed in 1689 consecutive patients who underwent glaucoma surgery alone or combined with phacoemulsification. Data collected included the type of surgery, width of the filtration angle, presence or absence of malignant glaucoma in the postoperative period, and time from the primary surgery to malignant glaucoma occurrence.

Results

Malignant glaucoma occurred in 22 eyes that amounted to 1.3% of cases among all surgery performed. Mean time from glaucoma surgery to malignant glaucoma occurrence was 61.4 ± 190.5 days. Among patients with penetrating surgery, malignant glaucoma occurred in 2.3% of patients, whereas after nonpenetrating operations, such complication was not found (p = 0.00004). Malignant glaucoma occurred more often in patients with shallow iridocorneal angle (p = 0.0013).

Conclusions

The risk of malignant glaucoma development is associated with penetrating characteristic of glaucoma surgery, after which this complication appears and its occurrence is higher in eyes with shallow iridocorneal angle. The risk of malignant glaucoma after trabeculectomy compared to iridencleisis as well as after phacotrabeculectomy compared to phacoiridencleisis is equivalent.

Anterior Chamber Angle and Anterior Chamber Volume in a 40- to 64-Year-Old Population

PURPOSE

To determine the distribution of the anterior chamber angle (ACA) and anterior chamber volume (ACV) in an Iranian population of 40- to 64-year-old people using the Pentacam.

METHODS

In this cross-sectional study, multistage sampling was used to select 300 clusters, including 6,311 individuals from the city of Shahroud. All selected participants underwent examinations in one place. Optometric examinations, including measurement of visual acuity and refraction, and ophthalmologic examinations, including slit-lamp examination, were performed for all participants. Moreover, all patients underwent imaging with the Pentacam.

RESULTS

The mean ACA and ACV was 34.3° (95% confidence interval [CI]: 34.1°-34.5°) and 139 μL (95% CI: 137.7-140.3), respectively. In a multiple linear regression model, the ACA was inversely correlated with age (coefficient=-0.08), lens thickness (coefficient=-1.38), corneal diameter (coefficient=-0.36), and corneal curvature (coefficient=-1.43), and directly correlated with the anterior chamber depth (ACD) (coefficient=6.59). In another model, ACV was inversely correlated with age (coefficient=-0.37), central corneal thickness (coefficient=-0.04), and spherical equivalent (coefficient=-1.15), and directly correlated with the ACD (coefficient=85.67), lens thickness (coefficient=14.15), corneal diameter (coefficient=4.80), corneal curvature (coefficient=18.43), ACA (coefficient=0.65), and intraocular pressure (coefficient=0.23).

CONCLUSION

The findings of this study could be used as a reference for diagnosis and treatment in Iran and the Middle East region. Increase in age and decrease in the ACD were important factors associated with decreased ACA and ACV, although the correlation of other biometric components was also evaluated. Some of these components, such as the corneal curvature and lens thickness, had a significant relationship with these two variables.

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.

Two cases of malignant glaucoma unresolved by pars plana vitrectomy

Malignant glaucoma, which is characterized by a shallow or flat anterior chamber with high intraocular pressure, can usually be resolved by pars plana vitrectomy with anterior hyaloidectomy. We describe two cases in which malignant glaucoma was refractory to conventional treatment and complete vitrectomy. Case one an 88-year-old woman with pseudoexfoliation glaucoma underwent trabeculotomy and subsequently developed malignant glaucoma. Four months after transient recovery by pars plana vitrectomy, the malignant glaucoma recurred. She underwent peripheral iridectomy and local zonulectomy with successful control of her intraocular pressure. In case two, an 85-year-old man had a history of pseudoexfoliation glaucoma. Seven months after phacoemulsification and intraocular lens implantation, he developed malignant glaucoma that was refractory to pars plana vitrectomy. He underwent peripheral iridectomy, goniosynechialysis and trabectome surgery resulting in the successful control of his intraocular pressure. In rare cases of malignant glaucoma refractive to vitrectomy, peripheral iridectomy with or without local zonulectomy is a reasonable and minimally invasive surgical procedure.

Elevated expression of H19 and Igf2 in the female mouse eye

The catalogue of genes expressed at different levels in the two sexes is growing, and the mechanisms underlying sex differences in regulation of the mammalian transcriptomes are being explored. Here we report that the expression of the imprinted non-protein-coding maternally expressed gene H19 was female-biased specifically in the female mouse eye (1.9-fold, p = 3.0E−6) while not being sex-biased in other somatic tissues. The female-to-male expression fold-change of H19 fell in the range expected from an effect of biallelic versus monoallelic expression. Recently, the possibility of sex-specific parent-of-origin allelic expression has been debated. This led us to hypothesize that H19 might express biallelically in the female mouse eye, thus escape its silencing imprint on the paternal allele specifically in this tissue. We therefore performed a sex-specific imprinting assay of H19 in female and male eye derived from a cross between Mus musculus and Mus spretus. However, this analysis demonstrated that H19 was exclusively expressed from the maternal gene copy, disproving the escape hypothesis. Instead, this supports that the female-biased expression of H19 is the result of upregulation of the single maternal. Furthermore, if H19 would have been expressed from both gene copies in the female eye, an associated downregulation of Insulin-like growth factor 2 (Igf2) was expected, since H19 and Igf2 compete for a common enhancer element located in the H19/Igf2 imprinted domain. On the contrary we found that also Igf2 was significantly upregulated in its expression in the female eye (1.2-fold, p = 6.1E−3), in further agreement with the conclusion that H19 is monoallelically elevated in females. The female-biased expression of H19 and Igf2 specifically in the eye may contribute to our understanding of sex differences in normal as well as abnormal eye physiology and processes.

Malignant glaucoma: a review of the modern literature

Malignant glaucoma is a rare form of glaucoma that typically follows surgery in patients with primary angle closure and primary angle-closure glaucoma. In this paper, the clinical features, classification, pathogenesis, and principles of management are discussed. Despite a high prevalence of primary angle closure glaucoma in South-East Asia, the vast majority of cases of malignant glaucoma are reported in White populations. This may reflect differing mechanisms of angle closure in White and Asian patients, which somehow reduces the likelihood of an aberrant relationship developing between the lens, ciliary body, anterior hyaloid, and vitreous structures within the eye. Although the exact underlying pathogenic mechanism remains unclear, the prognosis is good with modern medical, laser, and surgical treatment modalities.

Outcomes of different management options for malignant glaucoma: a retrospective study

BACKGROUND

To assess the outcomes of the various medical and surgical treatment options for malignant glaucoma.

METHODS

Design Retrospective, comparative case series. Participants Twenty-four eyes of 21 patients with malignant glaucoma. Intervention Nine eyes were treated medically. Twenty-one eyes underwent surgery, 15 of which had the full vitrectomy-(phaco)-iridectomy-zonulectomy procedure. Main outcome measures Intraocular pressure (IOP), best-corrected visual acuity (BCVA) and number of glaucoma medications were measured.

RESULTS

The relapse rate was 100% after medical therapy, 75% after a Yag laser capsulotomy and a hyaloidotomy, 75% after a conventional vitrectomy and 66% after an anterior vitrectomy in combination with an iridectomy-zonulectomy. All patients who underwent a full vitrectomy combined with an iridectomy and a zonulectomy (and phacoemulsification if phakic) had postoperative relief of malignant glaucoma without relapse within the follow-up period. After this vitrectomy-tunnel technique, the IOP ranged from 10 to 22 mmHg (mean 16 mmHg) after a mean follow-up of 61 days. Mean BCVA improved by 5 Early Treatment Diabetic Retinopathy Study (ETDRS) lines, and mean number of glaucoma medications decreased from two to one.

CONCLUSION

Complete vitrectomy combined with iridectomy and zonulectomy (and phacoemulsification, if applicable) most successfully managed aqueous misdirection syndrome in our retrospective case series.

Sex- and gender-based differences in healthy and diseased eyes

PURPOSE

The aim of this study was to identify sex- and gender-based differences in ocular anatomy, physiology, and disease susceptibility or manifestation.

METHODS

Review of current indexed literature was conducted.

RESULTS

Sex and sex hormones influence the lacrimal system, eyelids and blinking, corneal anatomy and disease, aqueous humor dynamics and glaucoma, crystalline lens and cataract, uveitis and retinal disease, ocular circulation, and optic nerve anatomy and disease. Systemic conditions, particularly autoimmune disease, and conditions that are unique to women, such as pregnancy and menopause, further illustrate the effects of sex hormones on the eye. Gender-based differences in ocular conditions and disease should be considered within the context of the underlying physical and social environment.

CONCLUSIONS

Many sex- and gender-based differences exist in healthy and diseased eyes.

[Diode laser in "Malignant Glaucoma" treatment]

Malignant glaucoma remains one of the most dramatic complications of ocular surgery. It can occur after glaucoma surgery but also after iridotomy, capsulotomy, or cataract extraction. However, the mechanisms remain unclear.

PURPOSE

to evaluate diode laser cyclodestruction as a complementary treatment in refractory malignant glaucoma.

PATIENTS

Seven women with malignant glaucoma with onset several months before (mean, 43 months; range, 12-96 months), in whom shallow anterior chamber and high IOP (25 mmHg +/- 5.5 treated with 2.86 +/- 0.9 topical and systemic medications) persisted despite prior surgical treatment (mean, 2; range, 1-5). Controlateral eyes had hyperopia (mean, +3.7 D, range, +1 to +6), five had shallow anterior chamber and high IOP. UBM detected plateau iris in four women.

METHODS

Seven eyes with malignant glaucoma and three controlateral eyes underwent cyclodestruction with diode laser (Viridis Twin Quantel Medical, laser, 810 nm), 22 burns around 270 degrees , 2 mm from the limbus for glaucomatous eyes and 15 inferior burns for controlateral eyes.

RESULTS

Resolution of malignant glaucoma, with lower pressure (mean, 35%; range, 10%-70%), lower levels of medications (64%), final IOP at 13.2 mmHg (+/- 4.7), and deepening anterior chamber was achieved in all cases (mean follow-up, 18 months; range, 12-22). Cycloplegic topical treatment was stopped in 70% of cases.

CONCLUSION

Diode laser cyclodestruction can help to resolve refractory malignant glaucoma. Larger UBM studies could help us to better understand the mechanisms of malignant glaucoma.