Urrets-Zavalia syndrome as a complication of argon laser peripheral iridoplasty

OBJECTIVE: To report on 8 patients who developed prolonged mydriasis after argon laser peripheral iridoplasty (ALPI). DESIGN: Retrospective case series. METHODS: A review of the charts of 8 patients with persistent occludable angles after laser iridotomy who developed mydriasis after undergoing ALPI. RESULTS: 12 eyes of 8 patients (mean age 50.2, standard deviation 6.9, range 40-61 years) developed persistent dilatation. 7 of 8 patients had plateau iris syndrome. Only one patient had a decrease in visual acuity. Intraocular pressure increased only in 1 eye and remained stable or decreased in the others. Of the 8 patients, 7 had blurred vision, 2 had photophobia, 4 had glare and 1 had discomfort. The pupillary response to pilocarpine instillation was minimal or absent. Mydriasis eventually resolved in all eyes without treatment. CONCLUSION: ALPI can be complicated by mydriasis unresponsive to pilocarpine. Mydriasis and accompanying symptoms resolved spontaneously within 1 year in most patients.     

Iridociliary apposition in plateau iris syndrome persists after cataract extraction

PURPOSE: To evaluate the ultrasound biomicroscopic appearance of the anterior segment before and after cataract extraction in eyes with plateau iris syndrome and to determine the effect of postoperative zonular relaxation on ciliary body position. DESIGN: Interventional case series. METHODS: Eyes with plateau iris syndrome scanned before and after cataract extraction between January 1994 and September 2001 were enrolled. The iridociliary relationship and the anterior chamber depth at a distance of 3 mm from the scleral spur were assessed. RESULTS: We examined six eyes of six patients. Mean patient age was 74.2 +/- 6.4 years (standard deviation [SD]) (range, 65-81 years). Mean refractive error was + 1.0 +/- 3.9 diopters [D] (range, -5.75-+5.50), and mean axial length was 21.85 +/- 0.77 mm (range, 20.90-22.95 mm). All eyes had undergone laser iridotomy and argon laser peripheral iridoplasty before cataract extraction. Ultrasound biomicroscopy examination revealed a narrow angle and absence of a ciliary body sulcus in all eyes with focal areas of iridotrabecular apposition in three eyes. Following cataract extraction, the anterior chamber depth increased (P =.0006, paired t test), while the iridociliary contact remained unchanged. CONCLUSIONS: Iridociliary apposition persists after cataract extraction in plateau iris syndrome. Whether the cause is congenital or acquired, or both, remains to be determined.     

激光周边虹膜成形术联合周边虹膜切除术治疗高褶虹膜型青光眼

目的探讨采用联合激光技术治疗高褶虹膜型青光眼的疗效。方法对２０例（３７只眼）早期原发性慢性闭角型高褶虹膜型青光眼，一次性行氩激光周边虹膜成形术联合氩激光加ＮｄＹＡＧ激光周边虹膜切除术（联合激光手术）。结果随访８个月至４年零７个月，平均２．７年。１７例（３２只眼）获得满意疗效，在观察期内无青光眼急性发作，眼压从５．８０±１．０４ｋＰａ（１ｋＰａ＝７．５ｍｍＨｇ）下降到２．７４ｋＰａ以下，周边前房加深，房角增宽，虹膜皱缩，有效地防止了房角的进一步粘连，８６．７％的患者暗室试验转阴性。结论联合激光手术是治疗高褶虹膜型青光眼的有效方法之一。     

Laser peripheral iridoplasty as initial treatment of acute attack of primary angle-closure: a long-term follow-up study

PURPOSE: To study the long-term clinical course and complications of patients with acute primary angle-closure treated with immediate laser peripheral iridoplasty followed by laser peripheral iridotomy. PATIENTS AND METHODS: Consecutive patients with acute primary angle closure treated with immediate laser peripheral iridoplasty, followed by laser peripheral iridotomy, at the Prince of Wales Hospital from July 1997 through January 2000 were followed up to document the clinical course of their disease and any complications from the laser treatment. Visual acuity, intraocular pressure, gonioscopic findings, corneal and lens clarity, iris appearance, pupillary reaction, and progression of glaucomatous optic neuropathy were evaluated. RESULTS: Thirty eyes of 29 Chinese patients with acute primary angle closure treated initially with either argon or diode laser peripheral iridoplasty were recruited. The mean follow-up period was 33.0 +/- 9.3 months. Twenty-one eyes (70%) had no further attack and maintained normal intraocular pressure without medications, and 9 eyes (30%) developed chronic angle-closure glaucoma with peripheral anterior synechiae. All eyes had pigmented laser marks on the peripheral iris, but none had peripheral corneal burn. CONCLUSIONS: Long-term follow-up data indicated that 30% of Chinese eyes with acute primary angle closure successfully treated with immediate laser peripheral iridoplasty followed by laser peripheral iridotomy developed peripheral anterior synechiae and an increase in intraocular pressure. There were minimal long-term complications on the cornea and the lens from the laser treatment.     

Argon laser peripheral iridoplasty (ALPI): an update

Argon laser peripheral iridoplasty is a useful procedure to eliminate appositional angle closure resulting from mechanisms other than pupillary block. For those eyes with angle closure originating at an anatomic level posterior to the iris, such as plateau iris, lens-induced angle closure, or posterior segment processes (malignant glaucoma, central retinal vein occlusion, etc.), laser iridotomy by itself may be insufficient to treat the underlying disease mechanism. Argon laser peripheral iridoplasty is often useful in these cases to further open the angle. It can be used to break an acute attack of angle-closure glaucoma and relieve appositional angle closure secondary to plateau iris syndrome, or lens-related angle closure, and to widen the angle prior to argon laser trabeculoplasty. Peripheral location of long-duration, low-power, large spot size laser burns is essential for optimal success.     

Plateau iris syndrome: changes in angle opening associated with dark, light, and pilocarpine administration.

PURPOSE: To report changes in angle configuration associated with dark, light, and pilocarpine administration in plateau iris syndrome. METHOD: In 10 eyes of 10 patients with plateau iris syndrome and persistent narrow angles after patent peripheral Nd:YAG laser iridotomy, ultrasound biomicroscopy was used to image variations in angle opening, iris thickness, and trabecular-ciliary process distance. Measurements were taken in the dark, in full room light, and after administration of pilocarpine 2%. RESULTS: Average angle opening distance increased in the light compared with the dark (113+/-34 microm vs. 22+/-34 microm, P = .0001) and increased further after pilocarpine administration (171+/-52 microm vs. 113+/-34 microm, P = .0034). Average iris thickness decreased in the light compared with the dark (338+/-34 microm vs. 436+/-58 microm, P = .0009) and decreased further after pilocarpine administration (253+/-48 microm vs. 338+/-34 microm, P = .0002). Average trabecular meshwork-ciliary process distance measurements were smaller than normal and did not change significantly in the light compared with the dark (481+/-42 microm vs. 464+/-44 microm, P = .4001) or after pilocarpine administration compared with light (451+/-67 microm vs. 481+/-42 microm, P = .1304). CONCLUSIONS: In plateau iris syndrome, anteriorly located ciliary processes support the peripheral iris. Changes in angle opening in dark and light are solely related to changes in iris thickness. Pilocarpine produces iris thinning and is an effective method of opening the angle. Ultrasound biomicroscopy can be used to perform a darkroom provocative test, which provides information on whether the angle anatomically closes in the dark.     

Angle closure in younger patients

PURPOSE: Angle-closure glaucoma is rare in children and young adults; only scattered cases associated with specific clinical entities have been reported. We evaluated the findings in patients aged 40 or younger with angle closure in our database. DESIGN: Retrospective noncomparative case series. PARTICIPANTS: Our database was searched for patients aged 40 years or younger with angle closure. Data recorded included age at initial consultation, age at the time of diagnosis, gender, slit-lamp examination, gonioscopy, ultrasound biomicroscopy (from 1993 onward), clinical diagnosis, and therapy. Patients with prior incisional surgery were excluded, as were patients with anterior chamber proliferative mechanisms leading to angle closure. RESULTS: Sixty-seven patients (49 females, 18 males) met entry criteria. Mean age at the time of consultation was 34.4 +/- 9.4 (standard deviation) years (range, 3-68 years). Diagnoses included plateau iris syndrome (35 patients); iridociliary cysts (8 patients); retinopathy of prematurity (7 patients); uveitis (5 patients); isolated nanophthalmos (3 patients); relative pupillary block (2 patients); Weill-Marchesani syndrome (3 patients); and 1 patient each with Marfan syndrome, miotic-induced angle closure, persistent hyperplastic primary vitreous, and idiopathic lens subluxation. CONCLUSIONS: The etiology of angle closure in young individuals differs from the older population and is typically associated with structural/developmental ocular anomalies rather than relative pupillary block. After laser iridotomy, these eyes should be monitored for recurrent angle closure and the need for additional laser or incisional surgical intervention.     

氩激光周边虹膜成形术治疗急性闭角型青光眼随访研究

目的:观察氩激光周边虹膜成形术在原发性闭角型青光眼急性发作期的作用,评价该治疗方法随访1a疗效的稳定性。方法:原发性闭角型青光眼第1次急性发作患者23例(23眼),局部予以10g/L毛果芸香碱滴眼液及5g/L噻吗心安滴眼液各1滴后,行氩激光周边虹膜成形术,眼压控制稳定后5~7d行激光周边虹膜切开术。观察氩激光周边虹膜成形术治疗前及治疗后2h;1,3,6,9,12mo眼压变化;观察相应时间点房角变化;术后1,3,6,9,12mo行暗室加俯卧激发试验。结果:氩激光周边虹膜成形术前平均眼压为69.43±8.22mmHg,术后2h眼压为15.74±3.09mmHg,随访期间患者未发生高眼压;术前所有23眼前房角镜检查可见前房角关闭,术后2h所有23眼静态前房角镜检查前房角增宽,小梁网可见范围增宽,随访期间各方房角无明显变化;所有患者术后1,3,6,9,12mo行暗室加俯卧激发试验均为阴性。结论:氩激光周边虹膜成形术治疗原发性闭角型青光眼急性发作期(不联合使用全身降眼压药物治疗)可迅速、有效、安全降低眼压,重新开放房角,随访1a疗效稳定。     

Argon laser peripheral iridoplasty in the management of phacomorphic glaucoma.

BACKGROUND AND OBJECTIVE: To document the efficacy and safety of argon laser peripheral iridoplasty (ALPI) as a temporizing measure in the treatment of phacomorphic glaucoma and to evaluate the mid-term visual outcomes. PATIENTS AND METHODS: The clinical records of all patients with phacomorphic glaucoma treated with ALPI from December 1999 to December 2002 were retrospectively reviewed. The primary outcome measure was the rate of successful control of intraocular pressure. Successful cases with at least 12 months of follow-up were further analyzed regarding their outcomes after cataract surgery, including visual acuity, intraocular pressure (IOP), and angle status. RESULTS: ALPI was performed as an initial step in the management of phacomorphic glaucoma in 21 eyes of 21 patients. IOP was successfully controlled in 17 eyes (80.75%), with a statistically significant decrease at 2 and 24 hours postoperatively (P < .0001). Elective cataract surgery was performed in 16 of the 17 successful cases and 12 of these patients completed at least 12 months of follow-up. After a mean follow-up period of 25.58 months, IOP was normal without medications in 11 eyes and only 1 patient required antiglaucoma eye drops to control IOP. All patients achieved a visual acuity of at least 1/60 and 8 (66.67%) of them achieved a visual acuity of 6/21 or better. All patients maintained an open angle without further surgical intervention. No complication was noted directly attributable to ALPI. CONCLUSION: ALPI is a safe and efficacious measure for the initial management of phacomorphic glaucoma, simultaneously obviating the need to operate in highly inflamed eyes in an emergency setting and achieving satisfactory mid-term visual outcome.     

Diode laser transscleral cyclophotocoagulation as primary surgical treatment for medically uncontrolled chronic angle closure glaucoma: long-term clinical outcomes

PURPOSE: To evaluate the long-term efficacy and safety of diode laser transscleral cyclophotocoagulation as primary surgical treatment of medically uncontrolled chronic angle closure glaucoma. PATIENTS AND METHODS: Thirteen eyes of 13 Chinese patients with medically uncontrolled chronic angle closure glaucoma were treated with diode laser transscleral cyclophotocoagulation between February 2000 and May 2001, and followed up for over 18 months. Post-treatment anti-glaucoma medications were adjusted according to intraocular pressure. If intraocular pressure remained above 21 mm Hg despite medications for more than 4 weeks after cyclophotocoagulation, the procedure was repeated. RESULTS: Mean follow-up +/- SD was 26.5 +/- 4.2 months. Two eyes required repeat cyclophotocoagulation at 6 weeks. Rate of relative success, defined as maintaining an intraocular pressure of 21 mm Hg or below with or without medications, was 92.3% (12 of 13 eyes). Rate of absolute success, defined as maintaining an intraocular pressure of 21 mm Hg or below without medications, was 0% (0 of 13 eyes). Mean +/- SD intraocular pressure was reduced from 36.4 +/- 12.6 mm Hg pre-operatively, to 18.7 +/- 12.2 mm Hg at final follow-up (P = 0.003, paired t test). The mean +/- SD number of intraocular pressure-lowering eye drops was reduced from 2.0 +/- 0.8 pre-operatively, to the lowest point of 0.5 +/- 0.8 at 12 months, and then gradually increased to 2.1 +/- 0.9 at final follow-up. The visual acuity improved after treatment in 2 of 13 eyes (15.4%), remained unchanged in 6 of 13 eyes (46.2%) and deteriorated in 5 of 13 eyes (38.5%). No major complications were encountered. CONCLUSION: Diode laser cyclophotocoagulation appeared to be an effective and safe primary surgical treatment of medically uncontrolled chronic angle closure glaucoma, with intraocular pressure-lowering effect persisting for up to two years.     

To compare argon laser peripheral iridoplasty (ALPI) against systemic medications in treatment of acute primary angle-closure: mid-term results

PURPOSE: To compare the clinical outcome of argon laser peripheral iridoplasty (ALPI) against systemic medications in treatment of acute primary angle-closure (APAC). METHODS: Consecutive patients with APAC were recruited and randomized to receive one of two treatment options: immediate ALPI or systemic acetazolamide +/- mannitol. All eyes were followed up for at least 6 months after laser iridotomy. Main outcome measures were intraocular pressure (IOP) and requirement for glaucoma medications. RESULTS: A total of 41 eyes (39 patients) were randomized into the ALPI group, and 38 eyes (32 patients) into the medical treatment group. There were no significant differences between the two groups in sex, age, presenting IOP, and duration of attack. Mean follow-up duration +/- SD was 15.7 +/- 5.8 months. There were no significant differences between the two groups in mean final IOP and requirement for glaucoma medications. CONCLUSIONS: There were no statistically significant differences in mean IOP and requirement for glaucoma drugs between APAC eyes treated with ALPI and systemic medications.     

Laser surgery for angle closure glaucoma

The angle closure glaucomas are defined by iridotrabecular contact, trabecular dysfunction, and elevated intraocular pressure (IOP). Laser iridotomy successfully eliminates the relative pupillary block component of the angle closure process, regardless of whether the underlying angle closure is related primarily to pupillary block or another mechanism. For those eyes with angle closure originating at an anatomic level posterior to the iris, such as plateau iris, lens-induced angle closure, or posterior segment processes, argon laser peripheral iridoplasty is often useful to further open the angle. The purpose of this article is to review the indications and techniques for laser iridotomy and laser iridoplasty in clinical practice.     

Laser surgery for angle closure glaucoma

The angle closure glaucomas are defined by iridotrabecular contact, trabecular dysfunction, and elevated intraocular pressure (IOP). Laser iridotomy successfully eliminates the relative pupillary block component of the angle closure process, regardless of whether the underlying angle closure is related primarily to pupillary block or another mechanism. For those eyes with angle closure originating at an anatomic level posterior to the iris, such as plateau iris, lens-induced angle closure, or posterior segment processes, argon laser peripheral iridoplasty is often useful to further open the angle. The purpose of this article is to review the indications and techniques for laser iridotomy and laser iridoplasty in clinical practice.     

急性原发性房角关闭对侧眼激光周边虹膜切除术后接触性房角关闭的研究

目的了解急性原发性房角关闭（APAC）对侧眼激光周边虹膜切除术（LPI）后接触性房角关闭的发生率和眼部解剖特征。方法前瞻性研究。选择54例APAC对侧眼没有虹膜前黏连（PAS）的患者作为研究对象,平均年龄（67．1±7．2）岁（54—83岁）。采用超声生物显微镜（UBM）在暗环境下观察LPI后是否发生接触性房角关闭．并比较发生接触性房角关闭与不发生接触性房角关闭患眼的眼压、房角及各项UBM参数,包括房角开放距离。（AOD跏）、房角隐窝面积,。（ARA750）、小梁虹膜夹角（T—I角）、小梁睫状体距离（TCPD）、周边虹膜厚度（IT1）、虹膜悬韧带距离（IZD）、虹膜根部附着位置、中央前房深度（ACD）。对两组数据采用独立样本t检验及两样本秩和检验进行分析。结果LPI后暗环境下UBM检查至少一个象限发生接触性房角关闭的有20例,占37％。反映房角开放程度的指标（AOD500、ARA750、T-I角）和反映睫状体位置的指标（TCPD）：接触性房角关闭（＋）组小于（-）组（t=11．741、11．089、12．175、4．349,P均〈0．01）;反映虹膜形态和位置的指标IT1：接触性房角关闭（＋）组大于（-）组（t=-3．300,P=0．002）;IZD、虹膜根部附着位置及ACD比较,两组差异无统计学意义（t=-1．880,P=0．066;Z=-1．423,P=0．155;t=0．072,P=0．942）。结论APAC对侧眼LPI后在暗环境下仍有一定比例发生接触性房角关闭,房角窄、睫状体前位、周边虹膜厚是LPI后发生接触性房角关闭的解剖学特点,提示LPI后具有这些解剖特点的APAC患者有可能进展为慢性房角关闭。     

An ultrasound biomicroscopic study of the anterior segment in Indian eyes with primary angle-closure glaucoma

PURPOSE: To evaluate the presence of plateau iris in eyes with primary angle-closure glaucoma (PACG) after laser peripheral iridotomy by gonioscopy and ultrasound biomicroscopy and to evaluate the pathogenesis of this condition by comparing the UBM parameters of these eyes with those in normal subjects. PATIENTS AND METHODS: This prospective study was carried out in the Glaucoma clinic of a tertiary eye care center. A detailed clinical examination including applanation tonometry, indentation gonioscopy with a Sussman four-mirror gonioscope, and ultrasound biomicroscopic examination in one randomly selected eye of 55 patients (55 eyes) with PACG who had undergone laser peripheral iridotomy and 22 normal subjects (22 eyes). RESULTS: Among the PACG eyes, 40% (22/55) had an open angle (angle opening distance > 130 microns) and 60% (33/55) eyes had a narrow angle (angle opening distance 相似文献   

Prevalence of plateau iris configuration in primary angle closure glaucoma using ultrasound biomicroscopy in the Indian population

Purpose:

To report the prevalence of plateau iris in patients with primary angle closure glaucoma (PACG), in North India.

Materials and Methods:

The patients with PACG, attending the glaucoma services at a tertiary care center in North India were included in the study. All patients had undergone Nd-YAG laser peripheral iridotomy at least four weeks prior to inclusion in the study. Four weeks prior to inclusion in the study, none of the patients had used pilocarpine. Ultrasound Biomicroscopy (UBM) images were qualitatively evaluated and plateau iris configuration was defined in an eye if the following criteria were fulfilled in two or more quadrants: anteriorly directed ciliary process supporting the peripheral iris, steep rise of iris root from its point of insertion followed by a downward angulation from the corneoscleral wall, absent ciliary sulcus, and iridotrabecular contact in the same quadrant.

Results:

One hundred and one eyes were included in the study. There were 63 (62.4%) females and 38 (37.6%) males. The mean age of the patients was 57.8 ± 9.5 years (range: 42 to 78 years). The mean axial length in the study population was 22.2 ± 1.1 mm. The mean spherical equivalent refraction was 0.06 ± 1.12 D. The mean intraocular pressure was 18.5 ± 4.7 mmHg (range: 12 – 24 mmHg). Twenty-nine (28.7%) subjects were diagnosed with plateau iris on the basis of above-defined criteria. Of the 29 eyes, 18 (62.1%) subjects had plateau iris in two quadrants, nine (31.03%) in three quadrants, and two (6.8%) had this configuration in all the four quadrants.

Conclusions:

Approximately 30% of the eyes with PACG had plateau iris on UBM. Plateau iris was very often the cause for residual angle closure following laser peripheral iridotomy in Indian eyes with PACG.     

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.     

Changes in Caucasian eyes after laser peripheral iridotomy: an anterior segment optical coherence tomography study

Background: To evaluate by anterior segment optical coherence tomography (AS‐OCT) the changes in the anterior chamber structures in Caucasian eyes after laser peripheral iridotomy (PI). Methods: Retrospective study of consecutive Caucasian primary angle closure suspect (PACS), primary angle closure (PAC) or primary angle closure glaucoma (PACG) patients who underwent laser PI over a 25‐month period at a specialist glaucoma practice. The AS‐OCT images of the temporal and nasal angles (in light and dark) before and after laser PI were analysed. The parameters studied were trabecular‐iris angle (TIA), angle opening distance (AOD), trabecular‐iris space area (TISA), trabecular‐iris contact length (TICL), iris thickness (IT) and maximum iris bow height (MIBH). Results: Images of 71 eyes of 71 patients were assessed. The mean age at laser PI was 60.3 ± 10.0 years. Forty (56.3%) were women, and 14 (19.7%) had PACG. The mean time from laser PI to the follow‐up AS‐OCT scan was 5.92 ± 3.22 weeks. The IT did not alter significantly after laser PI, but there were significant increases in the TIA, AOD and TISA, as well as a significant decrease in MIBH, in both light and dark. There was no difference in the magnitude of change seen between the temporal and nasal angles, or between PACS/PAC and PACG eyes. Conclusion: In Caucasian eyes, laser PI resulted in significant angle widening (increased TIA, AOD and TISA) and iris profile flattening (decreased MIBH) at the temporal and nasal angles based on AS‐OCT imaging in both light and dark.     

周边虹膜切除术后前房角粘连进展的危险因素

目的探讨原发性前房角关闭（PAC）者行周边虹膜切除术（PI）后，前房角粘连继续发展的危险因素。方法采用病例对照研究方法，对就诊我院的116例（116眼）50岁以上诊断为PAC并行PI者进行回顾研究，按照前房角粘连进展与否分为观察组和对照组，对患者术前术后的指标进行比较分析。结果本研究中PAC术后平均3年前房角粘连进展率为23．3％（27／116），研究发现PAC者高褶虹膜构型（比值比，5．312；95％置信区间，1．56—24．42，P=0．037）、急性前房角关闭（比值比，3．217；95％置信区间，1．13—19．87，P=0．023）以及初诊高眼压（比值比，1．312；95％置信区间，0．067—3．142，P=0．043）为前房角粘连（PAS）进展的危险因素。结论PAC行PI手术后仍有相当比例的患者前房角粘连继续发展，仍需密切随访，尤其对术前存在有高褶虹膜构型、急性前房角关闭和初诊高眼压的患者，更需要告知患者随访的重要性。     

Anterior chamber depth in plateau iris syndrome and pupillary block as measured by ultrasound biomicroscopy

PURPOSE: To quantitatively analyze the anterior chamber depth (ACD) in patients with pupillary block and plateau iris syndrome. DESIGN: Retrospective, consecutive, observational case series. METHODS: We measured the ACD in 318 eyes of 318 patients who had been diagnosed by ultrasound biomicroscopy as having either pupillary block or plateau iris syndrome. Pupillary block patients were all preiridotomy and plateau iris patients were all postiridotomy. Anterior chamber depth was measured axially from the internal corneal surface to the lens surface using the ultrasound instrument's internal measuring capability. RESULTS: The mean ACD in patients with plateau iris syndrome (n = 181) was significantly smaller than the hypothesized normal ACD (2.04 +/- 0.30 mm vs 3.0 mm, P =.0001). The mean ACD in patients with pupillary block (n = 137) was also significantly smaller than the hypothesized normal ACD (2.17 +/- 0.30 mm vs 3.0 mm, P =.0001). The mean ACD in patients with plateau iris syndrome was significantly smaller than the ACD in patients with pupillary block (2.04 +/- 0.30 mm vs 2.17 +/- 0.30 mm, P =.001). CONCLUSIONS: Review of the literature suggests that patients with plateau iris have a normal or deeper axial ACD compared with pupillary block. This study found that the ACD associated with plateau iris syndrome is shallower than normal and also shallower than in pupillary block.