Dark Room Provocative Test Research Articles

Iris lens distance to predict the risk of intraocular pressure elevation after dark room provocative test.

To investigate if a new ultrasound biomicroscopy (UBM) parameter, iris lens distance (ILD), and its model could predict clinically significant intraocular pressure (IOP) elevation after darkroom provocative test (DRPT). Cases with a peripheral anterior chamber depth less than one-fourth corneal thickness were enrolled. All subjects underwent UBM examination and DRPT if possible. Anterior chamber depth (ACD) and ILD were measured in the central axis at different positions in dark (ACDD, ILDD) and bright (ACDB, ILDB). An IOP elevation over 5mmHg and 8mmHg was set as cutoffs for a positive DRPT result (positive-5 and positive-8). SAS 9.3 statistical software was used to manage and analyze data and calculate the linear probability model (LPM). Another 17 patients (34 eyes) were included to validate the model. Two hundred and ten (210) UBM images qualified for analysis. ILD was significantly less in the dark than in the bright and in patients with a positive DRPT result (p< 0.001). The LPM for positive-5 and positive-8 were P= 1.14 + (- 0.49*ILDD) + (- 0.41*ACDD) (n= 210, R2= 0.1079, AUC = 0.715), and P= 0.87 + (- 0.44*ILDD) + (- 0.35*ACDD) (n= 210, R2= 0.1358, AUC = 0.807), respectively. LPMs based on ILD could predict the risk of an IOP elevation over 5mmHg or 8mmHg. The LPM for positive-8 reached a good level of diagnostic accuracy.

Clinical observation of 3 minutes dark-room provocative test in patients with laser peripheral iridectomy in the fellow eyes of acute angle-closure glaucoma

Clinical observation of 3 minutes dark-room provocative test in patients with laser peripheral iridectomy in the fellow eyes of acute angle-closure glaucoma

Evaluation of the efficacy of laser peripheral iridoplasty in reversing the darkroom provocative test result in Chinese patients with primary angle closure status post laser iridotomy.

To investigate the efficacy and safety of krypton laser peripheral iridoplasty (LPIP) for Chinese patients with primary angle closure (PAC) or primary angle-closure glaucoma (PACG) status post laser iridotomy in reversing the positive results of the dark room provocative test (DRPT). This study was prospective, noncomparative, interventional case series. Thirty-three patients (thirty-eight eyes) with PAC or PACG status post patent laser iridotomy and maintained normal intraocular pressure (IOP) but with positive DRPT results were enrolled. All the subjects were treated with krypton LPIP. DRPT was repeated after krypton LPIP. Results of DRPT were recorded. The visual acuity, IOP and gonioscopy were analyzed before and after krypton LPIP. A minimum time limit for follow-up was 6mo. Thirty-three patients (thirty-eight eyes) were followed for 17.7±8.37mo (range 7-41mo) after LPIP. Positive results of DRPT decreased from 38 eyes to 9 eyes (23.7%) after LPIP. Peripheral anterior synechiae of angle in 34 of 38 eyes (89.5%) remained unchanged at dynamic gonioscopy throughout the follow-up period after LPIP. LPIP decreased positive rates of the DRPT significantly. The mechanism may be that LPIP minimized contact between the peripheral iris and trabecular meshwork, which is a key factor for developing peripheral anterior synechiae.

Influence of pupil on anterior chamber morphology change after darkroom provocative test in healthy subjects

Influence of pupil on anterior chamber morphology change after darkroom provocative test in healthy subjects

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.

Gonioscopic Findings Associated With a Positive Dark-room Provocative Test in Narrow Angles After Laser Iridotomy

To determine clinical factors and ultrasound biomicroscopic (UBM) findings associated with a positive prone dark-room provocative test (DRPT) in patients with narrow angles after laser peripheral iridotomy (LPI). Seventeen eyes with a positive DRPT and 18 eyes with a negative DRPT were included in this comparative case series, based on chart review of patients diagnosed with narrow angles persisting after LPI who had undergone clinical evaluation with a 45-minute DRPT and UBM imaging. Subjects with a positive DRPT [an increase of intraocular pressure (IOP) of 6 mm Hg or more] were compared with a negative DRPT control group. Charts were reviewed for age, refraction and gonioscopic examination. UBM measurements obtained included the anterior chamber depth, angle opening distance at 500 μm, angle recess area, anterior chamber angle, trabecular-ciliary process distance, iris thickness, iris-ciliary process distance, height of plateau, and distance of iris-cornea contact. Mean increase in IOP was 11.1±3.5 mm Hg in the positive DRPT group (group A) and 0.9±0.1 mm Hg in the negative DRPT (group B). On indentation gonioscopy, patients in group A had significantly more synechial angle closure of 180 degrees or more (35% vs. 0%, P=0.008), more frequent double-hump sign (59% vs. 11%, P=0.005), and significantly more patients in this group had at least one of these findings, (13/16 vs. 2/15, P=<0.001). Mean age did not differ between groups (P=0.88). There were significantly more women in group B (58% men in group A and 83% women in group B, P=0.01). Mean refraction was +3.41±2.27 D in group A and +2.60±2.06 D in group B (P=0.32). There were no statistically significant differences in any of the UBM parameters between the 2 groups. A positive DRPT was found in patients presenting a more compromised drainage angle after LPI, due to anterior synechiae and/or an anteriorly positioned ciliary body as shown by the presence of a double-hump sign. DRPT may help identify patients at higher risk of intermittent increases in IOP among those presenting persistent narrow angles after LPI, and indentation gonioscopy remains an important step in evaluating these patients.

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.

Modified Dark Room Provocative Test for Primary Angle Closure

To examine the diagnostic value of a modified dark room provocative test (DRPT) in detecting primary closure of the anterior chamber angle. The cross-sectional observational prospective clinical study included suspects of primary angle closure. Using anterior segment optical coherence tomography (AS-OCT), we measured the anterior chamber angle configuration at room light and after 3 minutes of dark adaptation. Gonioscopy and Perkin's applanation tonometry were performed in room light conditions at baseline and after 1.5 hours of dark adaptation. The number of closed angle quadrants assessed on AS-OCT images and upon gonioscopy were recorded. The DRPT was positive, if intraocular pressure increased by ≥8 mm Hg after 1.5 hours of dark adaptation. The study included 76 subjects (76 eyes). Among 32 (42%) eyes with a positive DRPT, the number of eyes with an increased number of closed angle quadrants was significantly higher for the OCT examination at 3 minutes of dark adaptation than for gonioscopy at 1.5 hours of dark adaptation [29 (91%) eyes vs 21 (66%) eyes; P=0.01]. Kappa statistics showed a moderate agreement between increased closed angle quadrants obtained both after 3 minutes of dark adaptation (κ=0.44; P<0.001; sensitivity: 90.6%; specificity: 56.8%) and after 1.5 hours of dark room test (κ=0.45; P<0.001; sensitivity: 65.6%; specificity: 79.5%) compared with the final intraocular pressure elevation. Correspondingly, the area under the receiver operator characteristics curve was significantly larger for AS-OCT than for gonioscopy (0.86 vs 0.73; P<0.001) in predicting a positive dark room test. A modified DRPT with an anterior chamber angle assessment by OCT at 3 minutes of dark adaptation as compared with a gonioscopic angle assessment after 1.5 hours of dark adaptation had a higher diagnostic precision in predicting primary angle closure.

Dark Room Provocative Test and Extent of Angle Closure

To clarify the risk parameters measured by anterior segment optical coherence tomography (AS-OCT) for elevated intraocular pressures (IOP) provoked by the darkroom test and to provide recommendations for its clinical usage. Subjects aged >40 years and whose peripheral anterior chambers were ≤1/4 corneal thickness were recruited. The anterior segment of the eye was imaged in sitting position and under both light and dark conditions and biometry was performed using anterior segment optical coherence tomography. The analyzed parameters were: (1) central anterior chamber depth (ACD); (2) anterior chamber width; (3) pupil diameter; (4) iris curvature; (5) lens thickness; and (6) number of meridians with closed angles (NCA). Then the darkroom test was performed and a positive provocative test result was defined as a rise in IOP ≥8 mm Hg after the test. Statistical analyses included: (1) the difference in parameters between positive and negative eyes; (2) the association between posttest IOP and the parameters; and (3) the difference in parameters between the 2 eyes in subjects with the asymmetric results. A total of 70 subjects were recruited. ACD (P=0.022), NCA in light (P<0.001), and NCA in dark (P<0.001) were different significantly between eyes with positive and negative results. There was a strong association between NCA in dark (r=0.755, P<0.001) and the posttest IOP. Among subjects with asymmetric results between the 2 eyes, the ACD was shallower and the lens thickness was larger in the positive eye. The posttest IOP is determined by the extent of functionally closed angles in the dark. The test may be useful in the early diagnosis of primary angle closure. At the same time, angle configuration should be evaluated to remove false positive result.

Peripheral iridoplasty with doubled-frequency Nd:YAG laser as treatment for angle-closure glaucoma

OBJECTIVE: To examine the effects and safety of doubled-frequency Nd:YAG laser peripheral iridoplasty(LPI) for angle-closure glaucoma (ACG) with relieving the pupillary block. METHODS: Thirty-seven eyes of 29 patients of ACG with mean intraocular pressure (IOP) of (33.5+/-9.3)mmHg, were treated by LPI. In the follow-up of 5 approximate, equals 35 months, the IOP, angle and complications from LPI were examined. RESULTS: The mean IOP of the patients was reduced to (17.2+/-5.3)mmHg (P<0.0001). Thirty-three eyes of 25 patients, who had negative of dark room provocative test, maintained the angle opened without adjunctive antiglaucoma treatment. Four eyes of 4 patients continued to developed angle closure and had a high IOP. CONCLUSION: Peripheral iridoplasty doubled frequency Nd:YAG laser is a safe and effective method for treatment of ACG.

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 μm vs 22 ± 34 μm, P = .0001) and increased further after pilocarpine administration (171 ± 52 μm vs 113 ± 34 μm, P = .0034). Average iris thickness decreased in the light compared with the dark (338 ± 34 μm vs 436 ± 58 μm, P = .0009) and decreased further after pilocarpine administration (253 ± 48 μm vs 338 ± 34 μm, 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 μm vs 464 ± 44 μm, P = .4001) or after pilocarpine administration compared with light (451 ± 67 μm vs 481 ± 42 μm, 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.

Exercise-Induced Increase of Intraocular Pressure in the Pigmentary Dispersion Syndrome

A 32-year-old man with pigmentary dispersion syndrome had blurred vision and halos after strenuous exercise, associated with a release of pigment into the anterior chamber and increased intraocular pressure (IOP). Additionally, he had typical symptoms after emotional stress or exposure to dim illumination, and had a high IOP without angle closure during a darkroom provocative test. The exercise-induced symptoms and the increase of IOP were prevented by the use of pilocarpine 0.5% drops immediately before exercise.