The Effect of Laser Iridotomy on the Anterior Segment Anatomy of Patients With Plateau Iris Configuration

Argon Laser Iridoplasty For Plateau Iris Syndrome: Long-Term Outcomes of 48 Eyes

PRECIS

Argon laser peripheral iridoplasty (ALPI) was performed on 48 eyes with plateau iris syndrome (PIS). Indentation gonioscopy was used to monitor the opening of the iridocorneal angle. Mean intraocular pressure (IOP) at 5 years decreased from 15.9 to 14.4 mm Hg. None of the eyes required trabeculectomy.

PURPOSE

The purpose of this article was to report the long-term outcomes of ALPI for PIS.

MATERIALS AND METHODS

A retrospective chart review was performed on all patients with PIS treated with ALPI from 2001 to 2012. The study included 48 eyes from 28 patients with PIS after peripheral iridotomy, with a follow-up of at least 5 years. Patients with advanced glaucoma requiring initial surgical treatment (pathologic discs and IOP above the target IOP despite medical treatment) were excluded. The primary outcomes were the effect on the number of IOP medications, and the need for complementary selective laser trabeculoplasty (SLT) or surgery (trabeculectomy and/or phacoemulsification). Secondary outcomes were optic nerve head changes and adverse events.

RESULTS

The mean IOP statistically decreased after ALPI (15.91±2.62 vs. 14.35±2.18 mm Hg, P>0.001). The mean number of IOP-lowering medications statistically increased after ALPI (0.81±0.94 vs. 1.2±1.04, P>0.001). Mean follow-up was 92.4±26.5 months. At the end of the follow-up, 12 (25%) eyes had no medications, 20 (42%) had 1 medication, 11 (23%) had 2 medications, 3 (6%) had 3 medications, and 2 (4%) had 4. Ten (21%) eyes underwent SLT, 6 (10%) underwent phacoemulsification, and no trabeculectomy was necessary during follow-up. The change in cup to disc ratio from pre-ALPI to latest follow-up was not statistically significant, and no adverse events were reported.

CONCLUSIONS

ALPI is relatively effective and safe to prevent angle-closure glaucoma and avoid trabeculectomy in patients with PIS. This procedure often helps to control IOP, although SLT and additional medical treatments are frequently necessary to maintain the target IOP.

Comparison of Anterior Chamber Parameters in Patients With Plateau Iris Configuration and Pupillary Block Using ASOCT

PURPOSE

To quantitatively analyze the anterior chamber parameters in patients with pupillary block (PB) and plateau iris configuration (PIC) using anterior segment optical coherence tomography (ASOCT).

PATIENTS AND METHODS

In this cross-sectional study, nonglaucomatous subjects consecutively recruited and a total of 212 eyes divided into 3 groups of PIC (31 eyes), PB (60 eyes), and open angles (121 eyes) based on gonioscopic and ultrasound biomicroscopy findings. All patients underwent ASOCT imaging and A-scan biometry of both eyes. Anterior chamber depth (ACD), anterior chamber area (ACA), iris thickness (IT), iris curvature, lens vault (LV), anterior vault, and angle parameters including angle opening distance, and trabecular iris space area were measured in qualified images using the Zhongshan Angle Assessment Program, and compared using linear mixed model. The data from 1 eye of each subject were used for final analysis.

RESULTS

Mean age was 64.5±12.1, 64.8±10.5, and 62.3±9.2 years for PB, PIC, and open angle eyes, respectively (P=0.26). There was no significant difference in angle parameters (angle opening distance and trabecular iris space area at 250, 500, and 750 µm from sclera spur), anterior segment parameters (ACD and ACA), iris area, iris curvature, and LV between PB and PIC groups. PIC eyes had greater IT at 750 µm from sclera spur than the PB group (P=0.05). Normal eyes had greater ACD, ACA, and anterior chamber width, and angle parameters and lesser LV and iris curvature than the other 2 groups.

CONCLUSIONS

ASOCT parameters are not significantly different between PB and PIC eyes. PIC eyes may have greater IT at its base.

Recurrent acute angle-closure attack due to plateau iris syndrome after cataract extraction with or without argon laser peripheral iridoplasty: a case report

Background

We describe two cases of recurrent acute angle-closure attack in patients with plateau iris syndrome after cataract extraction. Argon laser peripheral iridoplasty and cataract extraction have been used to reduce the occurrence of acute angle-closure attack in plateau iris syndrome although the risk cannot be completely eliminated. There is no consensus on the long term management of plateau iris syndrome. This is, as far as we know, the first case report of recurrent acute angle-closure attack in plateau iris syndrome after cataract extraction.

Case presentation

We report two cases of recurrent acute angle-closure attack in 2 Chinese patients with plateau iris syndrome. The first patient was a 69 year-old woman who received bilateral argon laser peripheral iridoplasty and cataract extraction 2 years prior to the latest acute angle-closure with right eye intraocular pressure 48 mmHg. The attack was aborted medically. Peripheral iridotomy was patent and argon laser peripheral iridoplasty marks were mostly at peripheral 2/3 of the iris. Anterior segment optical coherence tomography confirmed bilateral plateau iris configuration. Use of long term pilocarpine or repeated argon laser peripheral iridoplasty to prevent recurrent angle-closure attack was discussed but she opted for observation. The second patient was a 64 year-old man presented with acute angle-closure after cataract extraction despite placement of laser peripheral iridotomy. Plateau iris syndrome was confirmed by anterior segment optical coherence tomography and he received argon laser peripheral iridoplasty.

Conclusions

Acute angle-closure due to plateau iris syndrome can still occur despite previous cataract extraction and argon laser peripheral iridoplasty. These are the first reported cases of recurrent acute angle-closure attack due to plateau iris syndrome following cataract extraction, with or without previous argon laser peripheral iridoplasty. Repeated treatment with argon laser peripheral iridoplasty or pilocarpine could be considered although the long term efficacy is questionable. Argon laser peripheral iridoplasty should be applied as peripheral as possible so as to open up the drainage angle effectively.

Cystoid macular edema after cataract surgery in a patient with previous severe iritis following argon laser peripheral iridoplasty

This report describes a patient who had exaggerated responses to different inflammatory stimuli represented by laser and incisional surgery, respectively. These separate episodes should have a common link represented by a genetic predisposition to abnormal release of proinflammatory mediators within the eye. This 51-year old Hispanic woman showed a narrow iridocorneal angle with plateau iris configuration. Nd-YAG laser peripheral iridotomy was successfully performed to both eyes. No substantial changes in the iridotrabecular angle occurred despite patent iridotomies, thus confirming the diagnosis of plateau iris configuration. Argon laser iridoplasty was then performed to the right eye, while the left eye was scheduled for a later session. A severe inflammatory reaction within the anterior chamber developed after tapering of a one-week course of steroid therapy. Phacoemulsification of the lens was performed some months later when no signs of inflammation were detectable; no intraoperative complications occurred during surgery and an intraocular lens was placed. Cystoid macular edema developed four weeks after surgery despite no apparent risk factors, and resolved completely after anti-inflammatory medical therapy. Based on this case report, the unusual occurrence of severe iritis after laser treatment should be regarded as a risk factor for any other incisional or nonincisional procedures because it might indicate that the patient’s ocular tissues are prone to release of abnormally elevated proinflammatory mediators. Although further studies are needed to confirm this predisposition, prophylactic adjunctive topical nonsteroidal anti-inflammatory drug administration after cataract surgery should be considered in such cases in order to prevent potentially sight-threatening conditions.

Argon laser peripheral iridoplasty for plateau iris associated with iridociliary cysts: a case report

Introduction

Plateau iris is recognised as an important cause of primary angle closure glaucoma. The management of this condition generally comprises laser peripheral iridotomy and iridoplasty, to remove any component of relative pupillary block and to widen the iridotrabecular drainage angle respectively. However, plateau iris may be associated with multiple iris cysts at the iridociliary junction, which then presents diagnostic and management problems.

Case presentation

We present a fifty-three year old Caucasian gentleman with plateau iris associated with peripheral iris cysts, in which the iridotrabecular angle did not widen despite having had both laser peripheral iridotomy and iridoplasty. The patient has remained asymptomatic over 12 months, and is under close follow-up to monitor for signs of glaucoma.

Conclusion

Plateau iris with iridociliary cysts can be difficult to diagnose and manage. Ultrasound biomicroscopy should be performed on patients with appositional iridotrabecular angle closure on gonioscopy, especially if the angle closure is not relieved with either laser peripheral iridotomy or iridoplasty. Question marks can be raised as to the benefit of laser iridotomy when plateau iris without pupillary block has already been conclusively diagnosed on ultrasound biomicroscopy.

The long-term effect of Nd:YAG laser iridotomy on intraocular pressure in Taiwanese eyes with primary angle-closure glaucoma

BACKGROUND

To investigate the long-term effect of Nd:YAG laser iridotomy on intraocular pressure (IOP) in Taiwanese eyes with primary angle-closure glaucoma (PACG).

METHODS

The medical records of 81 patients (130 eyes) who were diagnosed with PACG and who had undergone Nd:YAG laser iridotomy between 1998 and 2002 were reviewed. According to the presence of symptomatic glaucoma attack, eyes were divided into an acute angle-closure glaucoma (AACG) group and chronic angle-closure glaucoma (CACG) group. In the AACG group, the acute episode was treated and resolved after Nd:YAG laser iridotomy. These eyes were diagnosed to have or developed glaucoma during the follow-up period. All patients were followed-up for at least 24 months. The presenting features, treatment and IOP during the follow-up period were analyzed.

RESULTS

The mean follow-up period was 44.1 +/- 17.8 months (median, 36 months). There were 27 eyes (from 25 patients) in the AACG group. Only 2 eyes (7.4%) did not require any treatment after Nd:YAG laser iridotomy. Eleven eyes (40.7%) eventually underwent filtering surgery at a mean of 3.2 months (median, 3 months) after Nd:YAG laser iridotomy. There were 103 eyes (from 56 patients) in the CACG group. Eighty-five eyes (82.5%) required further medical treatment, of which 21 eyes (20.4%) eventually received filtering surgery at a mean of 9.8 months (median, 5 months) after Nd:YAG laser iridotomy.

CONCLUSION

For most Taiwanese eyes with PACG after Nd:YAG laser iridotomy, additional medicine and surgery are required in the long term. Eyes in the AACG group needed more surgical intervention than those in the CACG group.

Prevalence of plateau iris syndrome in young patients with recurrent angle closure

BACKGROUND

To assess and describe the prevalence and clinical features associated with plateau iris syndrome (PIS) in young individuals with recurrent angle closure despite initial therapy.

METHODS

Chart review of 137 relatively young individuals (aged < 60 years) with symptoms of angle closure between 1995 and 2005. A follow-up period of 36 months after initial presentation was retrospectively analysed. Seventy-six patients with recurrent angle closure symptoms were clinically reviewed using gonioscopy and ultrasound biomicroscopy.

RESULTS

Based on chart analysis, 30 of 137 individuals were diagnosed with PIS (22%). After clinical review, 34 additional patients suffered from PIS as the underlying cause for persistent angle closure symptoms. The prevalence of PIS in our patient population with recurrent angle closure symptoms in spite of initial iridotomy or iridectomy was 54%.

CONCLUSION

Among angle closure in young individuals, PIS is not uncommon. The causative mechanism of PIS in young individuals is peripheral iris block, rather than pupillary block which is more often prevalent in older patients. For proper diagnosis and therapy, ultrasound biomicroscopy and gonioscopy should be performed on every young individual with angle closure symptoms.

High prevalence of plateau iris configuration in family members of patients with plateau iris syndrome

PURPOSE

The purpose of the study was to ascertain the prevalence of plateau iris syndrome in the first-degree relatives of those patients affected with plateau iris syndrome.

METHODS

All patients seen with plateau iris syndrome over a 5-year period were identified. These patients were approached for participation and first-degree family members above 18 years of age were screened. All people identified with plateau iris configuration underwent ultrasound biomicroscopy to document and confirm the angle configuration and subsequent gonioscopy after laser iridotomies.

RESULTS

Sixteen patients were identified; 3 refused to participate, 2 were unable to be contacted, and 1 withdrew after initially consenting to participate. In this case, the patient agreed to participate, but all her living first-degree family members refused to be screened. Among the 10 patients whose living first-degree relatives were screened, we found 5 families with at least 1 additional first-degree family member having plateau iris syndrome.

CONCLUSIONS

Some families have more than 1 member with plateau iris syndrome. The pattern of inheritance resembles an autosomal dominant pattern with incomplete penetrance.