Plateau iris syndrome and angle-closure glaucoma in a patient with nail-patella syndrome

Plateau Iris: A Review

Purpose

To review the concept of plateau iris and summarize the recent evidence on its diagnosis and management.

Methods

This is a narrative review on the plateau iris. A literature review was conducted in PubMed, Google Scholar, and Scopus databases using keywords: angle-closure glaucoma, glaucoma, nonpupillary block glaucoma, plateau iris, and plateau iris management.

Results

This review defined the current knowledge about plateau iris. First of all, the anatomy and epidemiology were discussed. Then, we outlined the available evidence on the diagnosis of plateau iris and its differential diagnosis. Conclusively, the treatment options were mentioned.

Conclusions

Plateau iris is a condition in which nonpupillary block mechanisms are responsible for intraocular pressure elevation and angle closure attack when a patent peripheral iridotomy has removed the relative pupillary block. An anteriorly positioned ciliary body causes mechanical obstruction of trabecular meshwork in these patients. It is usually seen in younger patients with angle closure and is diagnosed by gonioscopic examination and imaging modalities such as Ultrasound biomicroscopy. Despite the known mechanism of plateau iris, there is no consensus over treatment. Low-dose pilocarpine and Argon laser peripheral iridoplasty are nonsurgical treatments for these patients, but their effects are short-term. Cataract extraction with/without endocyclophotocoagulation (ECP), endocycloplasty, excisional goniotomy, and transscleral cyclophotocoagulation are alternative treatments. Patients should be examined periodically for further progression or recurrence of plateau iris. In cases of glaucoma unresponsive to conventional medical treatments, surgical treatments such as trabeculectomy and drainage devices should be considered.

Nail-Patella Syndrome and Glaucoma: A Case Report and Review of the Literature

Nail-patella syndrome (NPS) is a rare autosomal dominant disease characterized by nail dysplasia, aplastic or hypoplastic patellae, elbow dysplasia, and presence of iliac horns. Renal or ocular abnormalities are also associated with the disease. We report the case of a 57-year-old woman affected by NPS and having haploinsufficiency of the LMX1B gene who experienced severe bilateral chronic angle-closure glaucoma in both eyes and that was successfully managed with a flap-express procedure in the right eye. The left eye had no light perception, and medical treatment was considered. Glaucoma is the most frequent ocular abnormalities observed in association with NPS and usually presents with an open angle. Glaucoma associated with NPS typically has an early onset open-angle phenotype. In fewer cases, it may present with an angle-closure phenotype. Therefore, we emphasize the need for glaucoma case-finding protocols comprehensive of gonioscopy in NPS patients and their relatives.

Association analysis of variants rs35934224 in TXNRD2 and rs6478746 in LMX1B in primary angle-closure and pseudoexfoliation glaucoma

OBJECTIVE

Previous genome-wide studies have demonstrated significant pathogenic association between variants rs35934224 within TXNRD2 and rs6478746 near LMX1B in primary open-angle glaucoma. We investigated the association between these variants in primary angle-closure glaucoma (PACG) and pseudoexfoliation glaucoma (PXG) patients of Saudi origin.

METHODS

In a case-control study, DNA samples from 249 controls (135 men and 114 women), 100 PACG cases (44 men and 56 women), and 95 PXG cases (61 men and 34 women) were genotyped by TaqMan^® based real-time PCR. Statistical tests were performed to evaluate genetic association with glaucoma types and related clinical indices.

RESULTS

The allele frequencies of rs35934224 and rs6478746 did not show significant variation in PACG and PXG than controls, except that the rs35934224[T] allele was found to be significantly low among PXG women (0.10) as compared to controls (0.21) (odds ratio = 0.38, 95% confidence interval = 0.16-0.94, p = 0.024). Rs35934224 genotypes showed a nominal-to-borderline protective association with PACG and PXG among women in different genetic models. However, except for the over-dominant model in PACG (p = 0.0095), none of the effects survived Bonferroni's correction (p < 0.01). Rs6478746 showed no significant genotype or allelic association with PACG and PXG. Regression analysis showed no influence on disease outcome, and neither showed any correlation with intraocular pressure and cup/disk ratio in both PACG and PXG.

CONCLUSIONS

Variants rs35934224 in TXNRD2 and rs6478746 near LMX1B are not associated with PACG and PXG in the Saudi cohort, but rs35934224 may confer modest protection among women. Further population-based studies are needed to validate these results.