Appositional Angle Closure Research Articles

Imaging iridotrabecular contact in angle closure.

With ultrasound biomicroscopy (UBM), radial scans are taken by using a typical ciliary process, to show the details of the iridocorneal angle, the anterior surface of the ciliary body, and its relation to the posterior iris. Appositional closure represents potentially reversible contact between the peripheral iris and trabecular meshwork. The appositional closure can further be classified according to the configuration of iridotrabecular contact (ITC). UBM can be performed in dark and light conditions, which has been shown to be useful for detecting changes in iridocorneal angle configuration associated with dark and light. To image ITC configuration in appositional angle closure and also image iridocorneal angle in dark and bright light room illumination. Synopsis: UBM demonstrates two types of ITC configuration in appositional closure which are, B-type and S-type. It can also demonstrate the presence of sinus of Mapstone in S-type of ITC. UBM allows imaging of dynamic changes in the iris and shows that the degree of appositional angle closure is a dynamic process that can change rapidly depending on the lighting conditions. https://youtu.be/tgN4SLyx6wQ.

EFFICACY OF PHACOEMULSIFICATION AND PHACOEMULSIFICATION COMBINED WITH GONIOSYNECHIALYSIS IN SURGICAL TREATMENT OF CHRONIC ANGLE-CLOSURE GLAUCOMA: 2-YEARS STUDY

Aim. To study the degree of angle opening and the decrease of intraocular pressure in primary angle-closure glaucoma (PACG) after cataract phacoemulsification and cataract phacoemulsification with goniosynechialysis (phaco + GLS).
 Materials and Methods. The study involved 28 patients (28 eyes) with primary chronic angle-closure glaucoma. The patients were divided into two groups, group 1 of 15 patients undergoing phaco with posterior chamber IOL implantation, and group 2 of 13 patients undergoing phaco with IOL implantation and GLS. The patients were followed for 24 months. Phaco was indicated in cases with IOP above 22 mmHg, appositional anterior chamber angle closure, and optic neuropathy; Phaco with GSL was indicated in cases of synechial angle closure and IOP above 22 mmHg
 Results. In group 1 after Phaco, postoperative anterior chamber angle opening was >20° in all quadrants. Postoperative IOP after 24 month follow-up it decreased by 32,6 % from the preoperative levels. In group 2 after Phaco+GSL, anterior chamber angle opened at least to 20° in three or more quadrants in all cases. Postoperative IOP after 24 month follow-up it decreased by 33.0% from the preoperative levels.
 Conclusions. Thus, phacoemulsification is an efficient procedure for PACG and appositional angle closure, leading to reopening of the anterior chamber angle with significant IOP reduction. Phacoemulsification alone does not lead to reopening of anterior chamber angle in cases with synechial angle closure, necessitating a combined surgery of phacoemulsification with GSL.

Relationship of degrees of gonioscopy assisted transluminal trabeculotomy and trabecular shelf to success using a marker suture technique.

To evaluate the safety and efficacy of gonioscopy-assisted transluminal trabeculotomy (GATT) using a marker suture which could be a viable low cost alternative to an illuminated micro catheter, by helping the surgeon identify obstruction to suture passage, and estimate the degree of Schlemm's canal cannulated. Thirty four eyes with 360° of open angles with uncontrolled IOP despite maximal medical therapy, non-compliant to medical therapy or failed incisional glaucoma surgery underwent GATT. 5-0 or 6-0 Prolene® suture was used to cannulate Schlemm's canal. An 8-0 Vicryl® suture was tied around the trailing portion of the Prolene® suture and acted as a guide to estimate the length of Schlemm's canal negotiated. The degree of trabecular shelf seen was noted postoperatively. Mean baseline IOP was 24.7 ± 8.8 mm Hg (range 13-54 mmHg). Six patients had appositional angle closure and the rest had open angles. Patients were followed up for a period of 45.0 ± 14.6weeks (range 6 weeks-2 years). The mean IOP 6 weeks after surgery was 13 ± 3.3 mm Hg, and at 1 year was 13.5 ± 2.6 mm Hg. Mean degrees of cannulation achieved was 264.5 ± 84.0˚ (90-360˚). The mean number of medications prior to surgery was 2.1 ± 1.0 and at 6 months review was 0.15 ± 0.3. The absolute success was 92.6% 1 year after surgery. Nine patients lost some of their trabecular shelf in the postoperative period, but this did not seem to affect the short term success rate. Suture GATT is a safe and effective procedure to lower IOP even in patients with partial cannulation. Adding a marker suture is a useful adjunct to help identify the length of Schlemm's canal successfully cannulated and monitor progress of the Prolene® suture.

The Singapore Asymptomatic Narrow Angles Laser Iridotomy Study: Five-Year Results of a Randomized Controlled Trial

To examine the efficacy of laser peripheral iridotomy (LPI) in patients who received a diagnosis of primary angle-closure suspect (PACS). Prospective, randomized controlled trial. This multicenter, randomized controlled trial (ClinicalTrials.gov identifier, NCT00347178) enrolled 480 patients older than 50 years from glaucoma clinics in Singapore with bilateral asymptomatic PACS (defined as having ≥2 quadrants of appositional angle closure on gonioscopy). Each participant underwent prophylactic LPI in 1 randomly selected eye, whereas the fellow eye served as a control. Patients were followed up yearly for 5 years. The primary outcome measure was development of primary angle closure (PAC; defined as presence of peripheral anterior synechiae, intraocular pressure [IOP] of >21 mmHg, or both or acute angle closure [AAC]) or primary angle-closure glaucoma (PACG) over 5 years. Of the 480 randomized participants, most were Chinese (92.7%) and were women (75.8%) with mean age of 62.8 ± 6.9 years. Eyes treated with LPI reached the end point less frequently after 5 years (n= 24 [5.0%]; incidence rate [IR], 11.65 per 1000 eye-years) compared with control eyes (n= 45 [9.4%]; IR, 21.84 per 1000 eye-years; P= 0.001). The adjusted hazard ratio (HR) for progression to PAC was 0.55 (95% confidence interval [CI], 0.37-0.83; P= 0.004) in LPI-treated eyes compared with control eyes. Older participants (per year; HR, 1.06; 95% CI, 1.03-1.10; P < 0.001) and eyes with higher baseline IOP (per millimeter of mercury; HR, 1.35; 95% CI, 1.22-1.50; P < 0.0001) were more likely to reach an end point. The number needed to treat to prevent an end point was 22 (95% CI, 12.8-57.5). In patients with bilateral asymptomatic PACS, eyes that underwent prophylactic LPI reached significantly fewer end points compared with control eyes over 5 years. However, the overall incidence of PAC or PACG was low.

Laser peripheral iridoplasty for chronic angle closure.

Laser peripheral iridoplasty for chronic angle closure.

Evaluation of anterior chamber angle by van Herick grading and ultrasound biomicroscopy in light and dark conditions for finding appositional angle closure and plateau iris configuration.

To evaluate association of the van Herick (VH) grades with the ultrasound biomicroscopic (UBM) parameters, appositional irido-trabecular contact (A-ITC) and plateau iris (PI) in a randomly sampled population. A 10% random sample of all residents aged 40 or older of the Kumejima study underwent UBM under dark and light conditions in the four quadrants of right eyes. Of 301 right eyes with eligible UBM images, 101 (33.6%) and 200 (66.4%) were classified as VH≤2 and VH≥3, respectively. The UBM parameters on angle width and ciliary body configuration were significantly different between VH≤2 and VH≥3 eyes (p<0.001). A-ITC was found in at least one quadrant in 54.5% and 75.2% of VH≤2 eyes under light and dark conditions, respectively; and 20.5% and 45.5% of VH≥3 eyes. When 'VH≤2' was used to screen eyes with A-ITC in three or more quadrants, the sensitivity and specificity were 74.1% and 75.3%, respectively. A-ITC was significantly associated with shallower anterior chamber (p=0.018) and higher intraocular pressure (p=0.044) in VH≥3 eyes. Plateau iris (PI) was found in 15.8% and 6.0% of VH≤2 and VH≥3 eyes, respectively. Plateau iris (PI) was significantly associated with the UBM parameters on angle width and ciliary body configuration. When 'VH≤2' was used to screen eyes with PI, the sensitivity and specificity were 57.1% and 68.9%, respectively. The VH grade of ≤2 and ≥3 showed significant association with UBM angle width and ciliary body configuration parameters. The VH≤2 criterion should be useful for screening of A-ITC and PI.

Appositional angle closure and conversion of primary angle closure into glaucoma after laser peripheral iridotomy

PurposeTo determine the relationship between appositional angle closure (AppAC) and the conversion of primary angle closure (PAC) into primary angle closure glaucoma (PACG) after laser peripheral iridotomy (LPI).MethodsConsecutive patients with...

A retrospective study on the incidence of post-cataract surgery Descemet’s membrane detachment and outcome of air descemetopexy

PurposeTo study the anatomic and functional outcome of air descemetopexy in postcataract surgery Descemet’s membrane detachment (DMD).DesignRetrospective study.MethodsSetting: Institutional.Study population: Records of 112 patients who underwent air descemetopexy for postcataract...

The role of clear lens extraction in angle closure glaucoma

Clear lens extraction can be considered a therapeutic option in angle closure glaucoma (ACG). Even if it does not represent the first choice of treatment, it can be taken into consideration when the topical treatment does not control the intraocular pressure (IOP) and iridotomy does not have a positive effect on the angle closure, especially in appositional angle closure when biometry or ultrabiomicroscopy (UBM) show lens involvement. In angle closure glaucoma, clear lens extraction represents an etiological treatment that takes into account the role of the lens in the pathogenesis of the disease. If we ignore it and we choose a filtrating surgery as therapeutic option we can end up with complications such as prolonged athalamia, corneal damage and lens opacification that will eventually require cataract surgery, but performed late and with higher risks. Before performing a filtrating surgery in ACG, we should take an UBM. We also need to choose the best moment to perform surgery, after topical treatment and iridotomy have been tested, but before trabecular damage appears.

Endoscopic Cycloplasty (ECPL) and Lens Extraction in the Treatment of Severe Plateau Iris Syndrome.

To describe the anatomic and clinical results of the treatment of severe plateau iris syndrome with lens extraction and endoscopic cycloplasty (ECPL). A secondary aim was to describe 4 novel ultrasound biomicroscopy (UBM) measurements for plateau iris syndrome. Prospective case series with UBM evaluation. Included were 12 eyes of 6 patients with plateau iris refractory to laser iridotomy and iridoplasty, miotic and other glaucoma medical treatment, with appositional angle closure in at least 3 quadrants. Treatment consisted of lens extraction and ECPL, an endoscopic diode laser treatment of the ciliary processes in the superior, nasal, and inferior quadrants. UBM measurements were taken in all quadrants before and after surgery. The untreated temporal quadrants were used as controls. Measurement parameters included: anterior chamber depth (ACD), angle opening distance (AOD 500), trabecular ciliary process distance (TCPD), iris ciliary process distance (ICPD), iris depth (ID), iridocorneal angle (ICA), and sulcus angle (SA). Four novel measurements included: ciliary process thickness (CPT), ciliary process width (CPW), ciliary process area (CPA), and iris ciliary process contact length (ICPCL). Visual acuity, intraocular pressure, glaucoma medications, and complications were also followed. The ACD, AOD 500, and ICA all increased significantly (P<0.001). ICPD, CPT, CPW, CPA, and ICPL all decreased significantly (P<0.01). Parameters remaining unchanged were: TCPD, ID, and SA. The untreated quadrants showed similar measurements to the preoperative measurements. There were no serious complications noted. Treating the ciliary processes with diode laser using an endoscopic approach (ECPL) and lens extraction, results in opening of the anterior chamber angle and shrinkage of the ciliary processes in the treated areas. This effect seems to be primarily a result of the laser treatment in combination rather than the lens extraction alone. This effectively reverses the anatomic cause and angle closure of plateau iris syndrome.

Bilateral, Simultaneous, Acute Angle Closure Glaucoma in Pseudophakia Induced by Chlorthalidone.

Purpose. To report two persons with acute, bilateral, and simultaneous angle closure glaucoma in pseudophakia secondary to uveal effusions induced by administration of chlorthalidone. Methods. Case reports. Results. Bilateral shallow anterior chambers and high intraocular pressure with decline in visual acuity were reported in two patients within days of intake of chlorthalidone for systemic hypertension. Gonioscopy confirmed appositional angle closure while choroidal detachment and ciliochoroidal detachment were revealed on ultrasonographic studies. Discontinuing chlorthalidone and institution of aqueous suppressants to reduce IOP and cycloplegics reversed angle closure and glaucoma. Conclusions. Reports of angle closure glaucoma in pseudophakic eyes induced by idiosyncratic reaction to chlorthalidone confirms that osmotic changes in the crystalline lens has no role in the pathogenesis of drug induced glaucoma and reaffirms that glaucoma is secondary to ciliochoroidal detachment and ciliary body rotation and edema.

Argon Laser Peripheral Iridoplasty for Primary Angle-Closure Glaucoma: A Randomized Controlled Trial

To determine the effectiveness of argon laser peripheral iridoplasty (ALPI) in primary angle closure (PAC) and primary angle-closure glaucoma (PACG). Randomized controlled trial. Eighty PAC or PACG subjects who underwent laser iridotomy (LI) and had at least 180° of persistent appositional angle closure and intraocular pressure (IOP) of more than 21 mmHg were enrolled. Subjects were randomized to receive either 360° ALPI (Visulas 532s; Carl Zeiss Meditec, Jena, Germany) or medical therapy (Travoprost 0.004%; Alcon-Couvreur, Puurs, Antwerp, Belgium). Repeat ALPI was performed if the IOP reduction was less than 20% from baseline along with inadequate angle widening at the month 1 or month 3 visit. Intraocular pressure was controlled with systematic addition of medications when required. The primary outcome measure was success rates after ALPI at 1 year. Complete success was defined as an IOP of 21 mmHg or less without medication, and qualified success was defined as an IOP of 21 mmHg or less with medication. Failure was defined as an IOP more than 21 mmHg despite additional medications or requiring glaucoma surgery. Forty subjects (51 eyes) were randomized to ALPI and 40 subjects (55 eyes) were randomized to medical therapy. Complete success (IOP ≤21 mmHg without medication) was achieved in 35.0% eyes of the ALPI group compared with 85.0% of eyes in the prostaglandin analog (PGA) group (P < 0.001), and qualified success (IOP ≤21 mmHg with medication) was achieved in 35.0% and 7.5%, respectively (P = 0.003). The IOP decreased by 4.9 mmHg (95% confidence interval [CI], 3.5-6.3 mmHg) in the ALPI group (P < 0.001) and by 6.1 mmHg (95% CI, 5.1-7.1 mmHg) in the medication group (P < 0.001). A failure rate of 30.0% was noted in the ALPI group compared with 7.5% in the medication group (P = 0.01). No treatment-related complications were recorded in either group. After 1 year, ALPI was associated with higher failure rates and lower IOP reduction compared with PGA therapy in eyes with persistent appositional angle closure and raised IOP after LI.

The prevalence of appositional angle closure among adults aged 50 years or above in Funing county Jiangsu Province

The purpose of the study is to determine the prevalence of appositional angle closure in persons aged 50 or above in Funing County. Cluster sampling randomly selected residents in Funing County aged 50 years or above. From March to May 2010, 484 eyes of 243 patients with the shallow peripheral anterior chamber and the anatomic narrow chamber angle, which was determined by Van Herick technique and gonioscopy, were collected from 5202 individuals. The presence of appositional angle closure and the angle-opening distance (AOD) was determined with photopic and scotopic ultrasound biomicroscopy (UBM) in eight positions. Paired χ² test and paired t test (SPSS 17.0) were used to determine any significant differences at P < 0.05. The prevalence of appositional angle closure was found at least one position in 337 eyes (69.6%) by scotopic UBM and in 116 eyes (24.0%) by photopic UBM. The prevalence of appositional angle closure was significantly higher by scotopic UBM than by photopic UBM (χ² = 204.36, P < 0.001 respectively), and was the highest in superior quadrant. The AOD varied significantly among the eight positions and was significantly narrower by scotopic UBM than by photopic UBM (t = 6.039, 6.883, 11.612, 11.157, 4.732, 6.798, 5.156, 4.071; P < 0.001). Since 197 persons (81.07%) were found anterior angle closure by scotopic UBM, we estimated the prevalence of appositional angle closure was 5.40% (95% CI: 4.80%-6.05%) among adults aged 50 or above in Funing County. The prevalence of appositional angle closure was higher than previous surveys, the possible reason is that scotopic UBM could find early appositional angle closure more preferably.

Uveal Effusion as a Mechanism of Bilateral Angle-Closure Glaucoma Induced by Chlorthalidone

To report a novel case of acute bilateral uveal effusions, angle closure, and acute myopia induced by administration of chlorthalidone. Case report. Bilateral shallow anterior chambers, high intraocular pressure, and a myopic shift were encountered in a patient 1 week after initiation of chlorthalidone. Ultrasound evaluation revealed bilateral ciliochoroidal effusions, appositional angle closure, and suspected ciliary body edema. Cessation of chlorthalidone, in addition to administration of cycloplegics and ocular antihypertensives, resulted in prompt resolution of this idiosyncratic reaction. The antihypertensive medication chlorthalidone may cause bilateral uveal effusions inducing acute angle-closure glaucoma and acute myopia.

Appositional angle closure in Chinese with primary angle closure and primary angle closure glaucoma after laser peripheral iridotomy.

To determine the prevalence of appositional angle closure (AAC) after laser peripheral iridotomy (LPI) in the eyes of Chinese patients with primary angle closure (PAC) and primary angle closure glaucoma (PACG) and to evaluate its pathogenesis by investigating anatomic characteristics. This was a cross-sectional observational study. PAC and PACG subjects were consecutively enrolled after LPI. Ultrasound biomicroscopy (UBM) images, obtained in darkness, of each quadrant without peripheral anterior synechia (PAS) under gonioscopy were qualitatively assessed. Darkroom provocative test (DRPT) was also performed. A total of 134 eyes of 134 patients were enrolled. AAC was observed in ≥ 1 quadrant of UBM image in 85 subjects (63.4%). There were 116 randomly selected quadrants without PAS for 134 patients (86.6%). AAC existed in 38 quadrants (32.8%). Among these, plateau iris accounted for 44.7%, anteriorly inserted iris for 13.2%, thick iris for 13.2%, and anteriorly inserted iris combined with thick iris for 18.4% of the total. One hundred fifteen patients underwent DRPT and its positive rate of eyes with AAC ≥ 2 quadrants (37.5% [12 of 32 patients]) was significantly higher than those ≤ 1 quadrant (16.9% [14 of 83 patients]; P = 0.018). However, no significant differences were found between eyes with nonsynechia plateau iris ≥ 2 quadrants (36.4% [4 of 11 patients]) and those ≤ 1 quadrant (21.2% [22 of 104 patients]; P = 0.266). Approximately two-thirds of PAC and PACG eyes of Chinese patients after LPI had AAC. Plateau iris accounted for less than 50% of AAC. Other factors such as a thick peripheral iris and an anteriorly inserted iris also contributed to AAC. DRPT results suggested AAC might have more functional meaning than plateau iris.

Factors Related to Future Peripheral Anterior Synechiae Formation on Ultrasound Biomicroscopy

To study factors associated with future peripheral anterior synechiae (PAS) formation on ultrasound biomicroscopy (UBM) in eyes with a shallow peripheral anterior chamber. Fifteen subjects with a shallow peripheral anterior chamber but no PAS in both eyes, in 2001, that had no medical or surgical intervention until 2008 were included in this study. The same examiners performed gonioscopy and UBM at the 3, 6, 9, and 12 o'clock limbal positions under dark and light conditions in 2001 and 2008. A masked examiner performed a quantitative evaluation of the angle configurations in the UBM images. The presence or absence of PAS was determined by compression gonioscopy. The UBM parameters and the number of appositional closures per eye were compared between PAS-positive eyes and PAS-negative eyes. One eye from 15 subjects were randomly selected and included in the analyses. The gonioscopic gradings and UBM parameters did not change significantly (P>0.1) between 2001 and 2008. Seven (47%; 95% confidence interval, 25-70) of 15 eyes developed PAS. In 2001, under dark conditions, the appositional angle closure in 3 to 4 quadrants was found more often (P=0.026) in 7 eyes where PAS developed during the following 7 years than in other 8 eyes. In eyes with a shallow peripheral anterior chamber but no PAS, PAS developed in 47% of eyes followed without intervention for 7 years. PAS was significantly more likely to develop in eyes with the appositional angle closure found in 3 to 4 quadrants under dark conditions.

Anterior Chamber Morphology Before and After Laser Peripheral Iridotomy Determined by Scheimpflug Technology in White Patients With Narrow Angles

To investigate the changes of anterior segment morphology in patients with narrow angles using a rotating Scheimpflug camera before and after laser peripheral iridotomy (LPI). Forty-six eyes of 46 patients classified as primary angle closure suspect, primary angle closure, primary angle closure glaucoma, acute angle closure glaucoma, fellow eyes of acute angle closure glaucoma, and iris plateau configuration were enrolled in this prospective interventional case series. Anterior chamber volume (ACV), anterior chamber depth (ACD), and anterior chamber angle (ACA) were evaluated with an Scheimpflug camera, before and after LPI. After LPI, the average anterior chamber depth increased from 1.88 ± 0.36 to 1.93 ± 0.32 mm (P=0.49). The mean ACV increased from 74.6 ± 25 to 89.4 ± 21.1 mm (P=0.003). The average ACA increased from 21.1 ± 4.8 to 23.4 ± 3.8 degrees (P=0.01). Eyes with synechial angle closure (primary angle closure and primary angle closure glaucoma) demonstrated a significantly smaller change in ACV compared with eyes with appositional angle closure (primary angle closure suspect). ACV and ACA determined by Scheimpflug technology increase to a statistically significant degree and this change appears to be more pronounced in cases of appositional angle closure.

Angle Closure Associated With a Cobblestone Iris Configuration

The purpose of the study was to report a patient with primary angle closure associated with a different nonpupillary block mechanism in which an abnormally thick peripheral iris assumes a cross-sectional shape resembling a cobblestone. This is a case report focussing on clinical and imaging description. Slit-lamp biomicroscopy revealed patent laser peripheral iridotomies OU. The anterior chamber was relatively deep in the center but 360 degrees narrow at the periphery, associated with an abnormally elevated iris contour OU. On dark-room gonioscopy, the angles were occludable with few areas of peripheral anterior synechiae. Anterior segment-adapted spectral domain-optical coherence tomography revealed an unusual iris profile. Despite a flat contour and normal thickness until the mid-periphery, the iris assumed a rectangular cross-sectional shape (resembling a cobblestone) with an abnormal increase in its thickness in the periphery (360 degrees OU). Ultrasound biomicroscopy imaging showed a normal ciliary sulcus and ciliary body configuration, revealing no cysts at 360 degrees. Definitive relief of appositional angle closure was achieved with laser peripheral iridoplasty OU. This unusual anatomic condition of the peripheral iris, which has different characteristics when compared with ordinary cases of thick peripheral iris roll, may lead to angle closure and intraocular pressure elevation despite a patent iridotomy. Clinicians should be aware of this anatomic condition whenever dealing with cases of angle closure.

The correlative factors of darkroom provocative test in anterior segment parameters

To investigate the correlative anterior segment parameters of positive darkroom provocative test in patients with narrow anterior chamber angles. It was a retrospective case series study. Two hundred and sixty patients [36 males and 224 females, mean age (59.6 ± 9.3) years] with narrow anterior chamber angles underwent darkroom provocative test and UBM scan were analyzed retrospectively. Anterior segment parameters including anterior chamber depth (ACD), pupil diameter (PD), lens vault (LV), peripheral iris thickness (IT), iris convex (IC), anterior chamber angle open distance (AOD), trabecular-meshwork ciliary process angle (TCPA) and the number of appositional angle closure (NPAC) were quantitatively analyzed. Correlative factors of positive results were analysis by both single factor and multiple-factor analysis. Seventy-one (27.3%) of the 260 patients had positive results in the darkroom provocative test. Males (15 out of 36) had statistically higher positive result rate than females (56 out of 224) (M: 41.7% vs. F:25.0%, χ(2) = 4.340, P = 0.037). In single factor analysis, male (OR = 2.14), AOD (OR = 0.98), IT (OR = 1.68) and NPAC (OR = 2.24) were correlative factors for positive results. In multiple-factor analysis, only IT (OR = 1.47) and NPAC (OR = 1.70) were independent risk factors of positive results. Positive darkroom provocative test is correlated to parameters of anterior chamber angle and iris, while IT and NPAC are independent correlative factors in patients with narrow anterior chamber angle.

Evaluation of the Anterior Chamber Angle in Glaucoma: A Report by the American Academy of Ophthalmology

To assess the published literature pertaining to the association between anterior segment imaging and gonioscopy and to determine whether such imaging aids in the diagnosis of primary angle closure (PAC). Literature searches of the PubMed and Cochrane Library databases were last conducted on July 6, 2011. The searches yielded 371 unique citations. Members of the Ophthalmic Technology Assessment Committee Glaucoma Panel reviewed the titles and abstracts of these articles and selected 134 of possible clinical significance for further review. The panel reviewed the full text of these articles and identified 79 studies meeting the inclusion criteria, for which the panel methodologist assigned a level of evidence based on a standardized grading scheme adopted by the American Academy of Ophthalmology. Three, 70, and 6 studies were rated as providing level I, II, and III evidence, respectively. Quantitative and qualitative parameters defined from ultrasound biomicroscopy (UBM), anterior segment optical coherence tomography (OCT), Scheimpflug photography, and the scanning peripheral anterior chamber depth analyzer (SPAC) demonstrate a strong association with the results of gonioscopy. There is substantial variability in the type of information obtained from each imaging method. Imaging of structures posterior to the iris is possible only with UBM. Direct imaging of the anterior chamber angle (ACA) is possible using UBM and OCT. The ability to acquire OCT images in a completely dark environment allows greater sensitivity in detecting eyes with appositional angle closure. Noncontact imaging using OCT, Scheimpflug photography, or SPAC makes these methods more attractive for large-scale PAC screening than contact imaging using UBM. Although there is evidence suggesting that anterior segment imaging provides useful information in the evaluation of PAC, none of these imaging methods provides sufficient information about the ACA anatomy to be considered a substitute for gonioscopy. Longitudinal studies are needed to validate the diagnostic significance of the parameters measured by these instruments for prospectively identifying individuals at risk for PAC. Proprietary or commercial disclosure may be found after the references.