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

PURPOSE: To examine the efficacy of laser peripheral iridotomy (LPI) in patients who received a diagnosis of primary angle-closure suspect (PACS). DESIGN: Prospective, randomized controlled trial. PARTICIPANTS: 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). METHODS: 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. MAIN OUTCOME MEASURES: 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. RESULTS: 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). CONCLUSIONS: 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.

Glaucoma drainage implant exposure: A review of aetiology, risks and repair considerations.

In recent years, there has been a paradigm shift in glaucoma surgical procedures. Glaucoma drainage implant (GDI) surgeries are being performed much more commonly. Thus, it is important for surgeons to be cognisant of potential complications and their management. Exposure of a GDI is a well-known complication, and prompt recognition and treatment are required to prevent endophthalmitis, a potentially blinding condition. In this review, we discuss the mechanisms and risk factors for GDI exposure, highlight important considerations for repair, and discuss repair techniques, with the aim of improving patient outcomes and minimising the risk of re-exposure.

Novel Automated Approach to Predict the Outcome of Laser Peripheral Iridotomy for Primary Angle Closure Suspect Eyes Using Anterior Segment Optical Coherence Tomography.

Develop an algorithm to predict the success of laser peripheral iridotomy (LPI) in primary angle closure suspect (PACS), using pre-treatment anterior segment optical coherence tomography (ASOCT) scans. A total of 116 eyes with PACS underwent LPI and time-domain ASOCT scans (temporal and nasal cuts) were performed before and 1 month after LPI. All the post-treatment scans were classified to one of the following categories: (a) both angles open, (b) one of two angles open and (c) both angles closed. After LPI, success is defined as one or more angles changed from close to open. In this proposed method, the pre and post-LPI ASOCT scans were registered at the corresponding angles based on similarities between the respective local descriptor features and random sample consensus technique was used to identify the largest consensus set of correspondences between the pre and post-LPI ASOCT scans. Subsequently, features such as correlation co-efficient (CC) and structural similarity index (SSIM) were extracted and correlated with the success of LPI. We included 116 eyes and 91 (78.44%) eyes fulfilled the criteria for success after LPI. Using the CC and SSIM index scores from this training set of ASOCT images, our algorithm showed that the success of LPI in eyes with narrow angles can be predicted with 89.7% accuracy, specificity of 95.2% and sensitivity of 36.4% based on pre-LPI ASOCT scans only. Using pre-LPI ASOCT scans, our proposed algorithm showed good accuracy in predicting the success of LPI for PACS eyes. This fully-automated algorithm could aid decision making in offering LPI as a prophylactic treatment for PACS.

ABCC5, a gene that influences the anterior chamber depth, is associated with primary angle closure glaucoma.

Anterior chamber depth (ACD) is a key anatomical risk factor for primary angle closure glaucoma (PACG). We conducted a genome-wide association study (GWAS) on ACD to discover novel genes for PACG on a total of 5,308 population-based individuals of Asian descent. Genome-wide significant association was observed at a sequence variant within ABCC5 (rs1401999; per-allele effect size =  -0.045 mm, P = 8.17 × 10(-9)). This locus was associated with an increase in risk of PACG in a separate case-control study of 4,276 PACG cases and 18,801 controls (per-allele OR = 1.13 [95% CI: 1.06-1.22], P = 0.00046). The association was strengthened when a sub-group of controls with open angles were included in the analysis (per-allele OR = 1.30, P = 7.45 × 10(-9); 3,458 cases vs. 3,831 controls). Our findings suggest that the increase in PACG risk could in part be mediated by genetic sequence variants influencing anterior chamber dimensions.

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

PURPOSE: To determine the effectiveness of argon laser peripheral iridoplasty (ALPI) in primary angle closure (PAC) and primary angle-closure glaucoma (PACG). DESIGN: Randomized controlled trial. PARTICIPANTS: 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. METHODS: 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. MAIN OUTCOME MEASURES: 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. RESULTS: 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. CONCLUSIONS: 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.

Determinants of pupil diameters and pupil dynamics in an adult Chinese population.

BACKGROUND: To investigate the determinants of pupil diameter (PD), amplitude of pupil diameter change (PD-change) and speed of pupil constriction (SPC) using video anterior segment optical coherence tomography (AS-OCT) in a population-based sample of Chinese adults. METHODS: Chinese adults aged 40 to 80 years who were free from glaucoma were consecutively recruited from the population-based Singapore Chinese Eye Study. The SPC was measured by AS-OCT videography. Univariate and multivariate analyses were performed to examine the effects of demographic and ocular biometric factors (e.g., axial length [AL], anterior chamber depth [ACD], baseline PD, iris thickness at the area of the dilator muscle [ITDMR], iris area [IA], and iris bowing [IB]) on SPC, PD, and PD-change. RESULTS: A total of 266/302 (89.5 %) AS-OCT videos of eligible eyes were available for analysis. Among these subjects, 64.3 % were women, and the mean age (± standard deviation [SD]) was 56 ± 8.3 years. SPC was not associated with sex. In multiple regression analyses, SPC was independently associated with baseline PD (ß = 0.116, p = 0.006). Baseline PD was independently associated with ACD (ß = 0.341, p < 0.001), TISA 500 (ß = -4.513, p < 0.001), IA (ß = -2.796, p < 0.001), and ITDMR (ß = 6.573, p < 0.001). PD-change was independently associated with ACD (ß = 0.256, p < 0.001), IA (ß = -1.507, p < 0.001), IB (ß = 0.630, p = 0.011), and ITDMR (ß = 3.124, p < 0.001). CONCLUSIONS: Among normal eyes in an adult Chinese population, SPC was associated with larger baseline PD. Larger baseline PD and greater PD change form dark to light were associated with greater ACD, with smaller IA and thicker ITDMR.

Learning ECOC Code Matrix for Multiclass Classification with Application to Glaucoma Diagnosis.

Classification of different mechanisms of angle closure glaucoma (ACG) is important for medical diagnosis. Error-correcting output code (ECOC) is an effective approach for multiclass classification. In this study, we propose a new ensemble learning method based on ECOC with application to classification of four ACG mechanisms. The dichotomizers in ECOC are first optimized individually to increase their accuracy and diversity (or interdependence) which is beneficial to the ECOC framework. Specifically, the best feature set is determined for each possible dichotomizer and a wrapper approach is applied to evaluate the classification accuracy of each dichotomizer on the training dataset using cross-validation. The separability of the ECOC codes is maximized by selecting a set of competitive dichotomizers according to a new criterion, in which a regularization term is introduced in consideration of the binary classification performance of each selected dichotomizer. The proposed method is experimentally applied for classifying four ACG mechanisms. The eye images of 152 glaucoma patients are collected by using anterior segment optical coherence tomography (AS-OCT) and then segmented, from which 84 features are extracted. The weighted average classification accuracy of the proposed method is 87.65 % based on the results of leave-one-out cross-validation (LOOCV), which is much better than that of the other existing ECOC methods. The proposed method achieves accurate classification of four ACG mechanisms which is promising to be applied in diagnosis of glaucoma.

Micropulse versus continuous wave transscleral diode cyclophotocoagulation in refractory glaucoma: a randomized exploratory study.

BACKGROUND: The aim of this study was to compare the efficacy and safety of micropulse and continuous wave diode transscleral cyclophotocoagulation in refractory glaucoma. DESIGN: Randomized, comparative, exploratory study in a tertiary hospital setting. PARTICIPANTS: Patients with refractory, end-stage glaucoma. METHODS: Forty-eight patients were randomized to either treatment. The intraocular pressure, visual acuity, number of medicines and repeat treatment were monitored for 18 months. Complications that include visual acuity decline, prolonged anterior chamber inflammation, phthisis bulbi, scleral thinning and ocular pain were noted. MAIN OUTCOME MEASURE: Intraocular pressure between 6 and 21 mmHg and at least a 30% reduction with or without anti-glaucoma medications after 18 months. RESULTS: A successful primary outcome was achieved in 75% of patients who underwent micropulse cyclophotocoagulation and 29% of patients who received continuous wave cyclophotocoagulation after 12 months (P < 0.01). At 18 months, successful outcome was 52% and 30% (P = 0.13), respectively. The mean intraocular pressure was reduced by 45% in both groups (P = 0.70) from a baseline of 36.5 mmHg and 35.0 mmHg (P = 0.50) after 17.5 ± 1.6 months (range 16-19) follow up. No significant difference in retreatment rates or number of intraocular pressure lowering medications was noted. The ocular complication rate was higher in continuous wave treated eyes (P = 0.01). CONCLUSION: Diode transscleral cyclophotocoagulation in both micropulse and continuous modes was effective in lowering intraocular pressure. The micropulse mode provided a more consistent and predictable effect in lowering intraocular pressure with minimal ocular complications.

Pretreatment anterior segment imaging during acute primary angle closure: insights into angle closure mechanisms in the acute phase.

OBJECTIVE: To describe anterior segment optical coherence tomography (ASOCT) parameters during acute primary angle closure (APAC) before therapeutic interventions and comparative analyses of biometric parameters of APAC eyes with fellow eyes. DESIGN: Prospective, comparative case series. PARTICIPANTS: Thirty-one consecutive patients with APAC. METHODS: All patients underwent ASOCT imaging of both eyes during the attack, before therapeutic interventions were administered. Custom software was used to measure anterior chamber depth (ACD), anterior chamber area (ACA), anterior chamber volume (ACV), iris curvature (I-Curv), iris area (I-Area), lens vault (LV), and angle opening distance (AOD750), trabecular iris space area (TISA750), and iris thickness (IT750) at 750 µm from the scleral spur. Multivariate logistic regression modeling using forward selection was used to determine the most important biometric variables associated with APAC compared with the fellow eye during the attack. MAIN OUTCOME MEASURES: Anterior segment biometric parameters associated with APAC. RESULTS: The mean age of the patients was 60.9±7.5 years, and 11 patients (35.5%) were male. The mean intraocular pressure was 3.8±9.2 mmHg in the APAC eye and 4.2±4.3 mmHg in the fellow eye before treatment (P <0.001). After adjustment for pupil diameter, APAC eyes had smaller ACD, ACA, ACV, I-Curv (all P <0.001), AOD750 (P = 0.037), TISA750 (P = 0.043), I-Area (P = 0.027), and IT750 (P = 0.002) and larger LV (P = 0.041) than fellow eyes. An optimal model consisting of 3 variables (pupil diameter, ACD, and I-Curv) explained 36.7% of the variance in APAC occurrence, with ACD accounting for 18.1% and I-Curv accounting for 14.1% of this variance. CONCLUSIONS: Shallower ACD and smaller I-Curv were the 2 main anterior segment biometric parameters associated with APAC during the attack. These findings present new insights into the anterior segment biometric parameters of APAC and fellow eyes before therapeutic interventions. Anatomic changes in the anterior segment explained only about one third of the variance in APAC occurrence, and the role of nonanatomic factors require further investigation.

Comparative efficacy and tolerability of topical prostaglandin analogues for primary open-angle glaucoma and ocular hypertension.

OBJECTIVE: To systematically review the efficacy and tolerability of 4 prostaglandin analogues (PGAs) as first-line monotherapies for intraocular pressure (IOP) lowering in adult patients with primary open-angle glaucoma or ocular hypertension. DATA SOURCES: A literature search was performed in PubMed (1965-June 2013) and the Cochrane Library (1980-June 2013) using the search terms ocular hypertension, open-angle glaucoma, prostaglandin analogues, bimatoprost, latanoprost, tafluprost, and travoprost. Additional studies were searched from the reference lists of identified publications. STUDY SELECTION AND DATA EXTRACTION: In all, 32 randomized controlled trials comparing between PGAs (bimatoprost 0.03%, latanoprost 0.005%, tafluprost 0.0015%, and travoprost 0.004%) or PGA with timolol were selected. DATA SYNTHESIS: A network meta-analysis was conducted. Using timolol as reference, the relative risks (RRs) of achieving treatment success, defined as the proportion of patients achieving at least 30% IOP reduction, with 95% CIs, were as follows: bimatoprost, 1.59 (1.28-1.98); latanoprost, 1.32 (1.00-1.74); travoprost, 1.33 (1.03-1.72); and tafluprost, 1.10 (0.85-1.42). The mean IOP reductions after 1 month were 1.98 (1.50-2.47), 1.01 (0.55-1.46), 1.08 (0.59-1.57), and 0.46 (-0.41 to 1.33) mm Hg, respectively, and the results were sustained at 3 months. Bimatoprost was associated with the highest risk of developing hyperemia, whereas latanoprost had the lowest risk, with RRs (95% CI) of 4.66 (3.49-6.23) and 2.30 (1.76-3.00), respectively. CONCLUSIONS: Bimatoprost achieved the highest efficacy in terms of IOP reduction, whereas latanoprost had the most favorable tolerability profile. This review serves to guide selection of the optimal PGA agent for individual patient care in clinical practice.

Risk of acute angle closure and changes in intraocular pressure after pupillary dilation in Asian subjects with narrow angles.

OBJECTIVE: To evaluate the risk of primary acute angle closure (AAC), changes in intraocular pressure (IOP), and associated risk factors after pupil dilation in Asian subjects with narrow angles (primary angle-closure suspects [PACS]). DESIGN: Prospective clinical study. PARTICIPANTS: A total of 471 subjects aged more than 50 years with narrow angles in Singapore. METHODS: This study was part of a prospective trial of PACS. Subjects underwent a detailed ophthalmic evaluation including gonioscopy, biometry, pachymetry, and ultrasound biomicroscopy. All subjects underwent pupil dilation with 1% tropicamide eye drops at the baseline visit, before any laser or medical intervention. Intraocular pressure was measured using Goldmann applanation tonometry by the same observer before and 1 hour after pupil dilation. A dose of oral acetazolamide was given before the patient left the clinic. MAIN OUTCOME MEASURES: Intraocular pressure before and after dilation, and an AAC event. RESULTS: The mean age of the 471 subjects was 63.0 ± 6.9 years (mean ± standard deviation); 75.4% were women, and 92.8% were Chinese. Of the 471 participants, 3 (0.64%; 95% confidence interval [CI], 0.13-1.85) developed AAC within 6 hours of dilation despite pretreatment with oral acetazolamide. Twenty-two subjects (4.67%; 95% CI, 2.95-6.99) showed a postdilation increase in IOP of ≥ 5 mmHg in either eye, 6 subjects (1.27%; 95% CI, 0.47-2.75) had an IOP increase of ≥ 8 mmHg in either eye, and 4 subjects (0.85%; 95% CI, 0.23-2.16) had a postdilation IOP of >25 mmHg in either eye. Narrower gonioscopic angle width, that is, having a lower mean gonioscopic modified Shaffer grading (coefficient ß -0.51; standard error 0.19; P=0.01), and predilation IOP level (coefficient ß -0.17; standard error 0.04; P < 0.001) were significant risk factors for IOP increase after dilation in multivariate linear regression analysis. CONCLUSIONS: The risk of AAC among Asian subjects with narrow angles was low after pupillary dilation with tropicamide and oral acetazolamide prophylaxis. The presence of narrower angle width by gonioscopy was the only clinical parameter identified for a significant IOP increase after pupil dilation.

Changes in anterior segment morphology after laser peripheral iridotomy: an anterior segment optical coherence tomography study.

PURPOSE: Novel anterior segment optical coherence tomography (ASOCT) parameters associated with angle closure include anterior chamber area (ACA), anterior chamber volume (ACV), anterior chamber width (ACW), lens vault (LV), iris thickness (IT), iris area (I-area), and iris curvature (I-curv). We aimed to investigate changes in these parameters after laser peripheral iridotomy (LPI) in a cohort of primary angle-closure suspects (PACS). DESIGN: Prospective observational study. PARTICIPANTS AND CONTROLS: A total of 176 PACS aged ≥ 50 years who underwent LPI in 1 eye. METHODS: We analyzed ASOCT images (Visante, Carl Zeiss Meditec, Dublin, CA) from all subjects using customized software before and 1 week after LPI. Multivariate linear regression analysis was performed for predictors of percentage change in mean angle opening distance (AOD750). MAIN OUTCOME MEASURES: Change in ASOCT parameters after LPI. RESULTS: The mean age of participants was 63 ± 7.3 years. The majority of subjects were Chinese (95.5%) and women (76.7%). Mean angle width (modified Shaffer grade) changed from 0.68 ± 0.54 at baseline to 1.76±0.69 after LPI (P<0.001) with a corresponding increase in mean AOD500 (0.12 vs. 0.19 mm, P<0.001), trabecular iris surface area (TISA500, 0.06 vs. 0.08 mm(2), P<0.001), and angle recess area (ARA, 0.13 vs. 0.17 mm(2), P<0.001). Mean ACA (15.0 vs. 16.0 mm(2), P<0.001) and ACV (91.6 vs. 103.0 mm(3), P<0.001) increased significantly after LPI, but there was no change in ACW, anterior chamber depth (ACD), or LV. Mean I-curv was reduced (0.375 vs. 0.18 mm, P<0.001) after LPI, but there was no significant change in IT or I-area. After multivariate analysis, mean LV (ß = 0.286, P = 0.001), mean IT at 2000 µm (IT2000, ß = 0.172, P = 0.034), and intraocular pressure (ß = 0.159, P = 0.042) at baseline were found to be associated with ΔAOD750. CONCLUSIONS: This study confirms that LPI results in a significant increase in the angle width in PACS. The ACA and ACV increased after LPI, but there was no change in ACD, ACW, LV, IT, or I-area. The increase in ACA/ACV was mainly due to decreased I-curv after LPI.

Pupil dynamics in Chinese subjects with angle closure.

OBJECTIVE: To evaluate the speed of pupil constriction (SPC) in response to a standardized change in illumination from dark to light using anterior segment optical coherence tomography (AS-OCT) in eyes with closed angles, compared to those with open angles. METHODS: This was a prospective, comparative, observational study. Study subjects with primary angle-closure glaucoma (PACG) and/or primary angle-closure (PAC) were recruited along with a group of normal as controls. Videos of iris and anterior segment changes in response to illumination were captured with real-time video recording from AS-OCT and analysed frame by frame, beginning from a dilated to a constricted pupil. Customized software was used to measure speed of iris constriction, anterior chamber depth (ACD), anterior chamber width (ACW), iris thickness, and pupil diameter (PD). SPC was defined as the rate of pupil diameter change in response to illumination. RESULTS: One hundred and sixty three Chinese subjects were recruited in this study. A total of 137 of 163 eligible videos (82.5%) were available for analysis, comprising 87 subjects with closed angles (all had undergone laser peripheral iridotomies before) and 50 with open angles. SPC was less in eyes with closed angles (1.22 mm/sec vs 1.56 mm/sec, p<0.001), after adjusting for age and ACW, and was positively correlated with axial length, ACD, anterior chamber angle status, PD in the dark, and iris thickness in the dark, (all r>0.2, all p<0.05). In multivariate analysis, SPC was independently associated with anterior chamber angle status (closed angle vs open angle) (ß=0.276, p=0.016) and PD in dark (ß= 0.129, p=0.009), after adjusting for age, ACW, ACD, iris thickness and vertical cup-to-disc ratio. CONCLUSIONS: Compared to those with open angles, eyes with closed angles in Chinese subjects have slower speed of pupil constriction in response to dark-light change, even after adjusting for biometric factors associated with angle closure. The results suggest that differences in irido-pupillary dynamics may play a role in the pathogenesis of angle closure.

Quantitative evaluation of anterior chamber parameters using anterior segment optical coherence tomography in primary angle closure mechanisms.

BACKGROUND: To evaluate different mechanisms of primary angle closure and to quantify anterior chamber parameters in these mechanisms using anterior segment optical coherence tomography in an Asian population. DESIGN: Hospital-based cross-sectional observational study. PARTICIPANTS: Forty-eight consecutive patients with primary angle closure glaucoma. METHODS: Patients underwent complete ophthalmic examination and imaging of nasal-temporal angles with anterior segment optical coherence tomography. Images were categorized into four primary angle closure mechanisms: pupil block, plateau iris configuration, Thick peripheral iris roll and exaggerated lens vault. Parameters computed: anterior chamber depth central, anterior chamber depth at 1000 µm and 2000 µm anterior to scleral spur, lens vault, anterior chamber area, angle opening distance, trabecular iris space area and iris thickness. MAIN OUTCOME MEASURE: Anterior chamber parameters and primary angle closure mechanisms. RESULTS: Mean values of anterior chamber depths: central (P < 0.001), at 2000 µm (P < 0.001), 1000 µm (P < 0.001), lens vault (P < 0.001), anterior chamber area (P < 0.001), were significantly different among the four groups. Multivariate analysis showed anterior chamber depths: central, and anterior chamber depth at 2000 µm and anterior chamber area were higher in plateau iris and Thick peripheral iris roll and lower in exaggerated lens vault (P < 0.001) as compared to pupil block mechanism, lens vault was greater in exaggerated lens vault (P < 0.001) and lesser in plateau iris and Thick peripheral iris roll as compared to pupil block mechanism. CONCLUSION: Anterior segment optical coherence tomography may be used for evaluation of underlying primary angle closure mechanism(s) in a patient and tailor the treatment accordingly.

Efficacy and Safety of Repeated Micropulse Transscleral Diode Cyclophotocoagulation in Advanced Glaucoma.

PRECIS: Repeat micropulse transscleral cyclophotocoagulation (MPTCP) has some benefit in lowering intraocular pressure (IOP). There was a small risk of loss of vision, prolonged hypotony, and phthisis bulbi. AIM: This study aimed to determine the efficacy and safety of repeated MPTCP for an Asian population with refractory glaucoma. METHODS: This is a retrospective case series of 43 eyes (43 patients) with severe glaucoma which underwent repeated MPTCP. Baseline parameters were taken from the visit just before the second MPTCP session. Success was defined as IOP of 6 to 21 mm Hg or ≥20% reduction in IOP without an increase in glaucoma medication from baseline, without further glaucoma reoperation, and ≤3 total MPTCP episodes. The IOP, number of IOP-lowering medications, and best-corrected visual acuity were documented preoperatively and postoperatively. Postoperative complications were also analyzed. RESULTS: The mean age±SD was 57.4±18.2 years with a mean follow-up duration of 28.9±27.5 months. Neovascular glaucoma was the most common type of glaucoma [18 eyes (41.9%)]. The success rates at postoperative years 1, 2, and 3, and the latest follow-up were 36.4%, 42.9%, 32.0%, and 39.5%, respectively. The median survival time of repeat MPTCP was 4.6 months. Compared with the preoperative mean IOP (35.2±11.0 mm Hg), the mean IOP at postoperative years 1, 2, and 3, and latest follow-up, was 27.8±13.7 mm Hg (P=0.004), 27.4±12.4 (P=0.003), 31.8±13.2 (P=0.35), and 27.1±13.8 mm Hg (P=0.002), respectively. The mean number of IOP-lowering medications was reduced from 3.3±0.9 preoperatively to 2.8±1.3 at the final follow-up (P=0.007). Postoperative complications included prolonged hypotony [3 eyes (7.0%)] and phthisis bulbi [2 eyes (4.7%)]. CONCLUSION: Repeated MPTCP is at best moderately effective in lowering IOP for eyes with advanced glaucoma.

Clinical Efficacy and Safety Outcomes of Micropulse Transscleral Diode Cyclophotocoagulation in Patients With Advanced Glaucoma.

PRECIS: Micropulse transscleral cyclophotocoagulation (MPTCP) is only moderately effective in lowering intraocular pressure (IOP) and is useful as an adjunct procedure to other glaucoma surgeries. There was a small risk of loss of vision, prolonged hypotony, and phthisis bulbi. AIM: The aim of this study was to determine the efficacy and safety of a single MPTCP treatment for an Asian population with advanced glaucoma. METHODS: This is a retrospective single-center study of 207 eyes (207 patients) with advanced glaucoma which underwent first-time MPTCP between January 1, 2008, and March 31, 2018. Success was defined as IOP of 6 to 21 mm Hg or ≥20% reduction in IOP without an increase in glaucoma medication from baseline, and without glaucoma reoperation. The IOP, best-corrected visual acuity, and number of glaucoma medications were also analyzed. RESULTS: The mean (SD) age was 64.9±16.9 years. The mean follow-up duration was 18.7±16.2 months. The rate of success at postoperative years 1 and 2 follow-up was 44.1% and 32.6%, respectively. The median survival time of MPTCP was 9.0 months and 85 (40.9%) eyes received reoperation. The mean IOP decreased from 31.5±12.0 mm Hg preoperatively to 22.1±10.3 and 23.8±11.8 mm Hg at postoperative years 1 and 2, respectively (P<0.0001). The mean number of glaucoma medications was reduced from 3.3±1.0 preoperatively to 2.6±1.1 and 2.4±1.1 at postoperative years 1 and 2, respectively (P<0.0001). Significant complications included prolonged hypotony [1 eye (0.5%)], phthisis bulbi [7 eyes (3.4%)], and best-corrected visual acuity reduction [29 eyes (13.9%)]. CONCLUSION: Single first-time MPTCP for advanced glaucoma eyes was moderately effective in lowering IOP but >50% failed by 1 year.

Anticoagulation for Radiation-Induced Optic Neuropathy.

Radiation-induced optic neuropathy (RION) is a severely disabling complication of radiotherapy, without any known effective treatment. Three patients, one female and two males, aged 60, 34, and 45 years, respectively, developed progressive deterioration in visual acuity over 1 month, 8 years, and 2 months, starting 3, 12, and 9 years after radiotherapy for nasopharyngeal carcinoma. They received 70.15, 60.89, and 56.11 Gy over a period of 6-7 weeks, with fractionated doses of 2, 1.79, and 1.81 Gy, respectively. Ophthalmological examination revealed a relative afferent pupillary defect in the latter 2 patients, best-corrected visual acuity was 6/12 or better in all. Visual field charting showed a superior altitudinal field defect in the first two, and generalised visual loss in the third patient in the symptomatic eyes. Anticoagulation with heparin bridging and oral warfarin with an INR target of 2.0-3.0 was commenced within 2 months of symptom onset. All showed improvement in visual fields within 2 weeks, and remained stable for at least 2 years while on warfarin. Our encouraging findings will need to be confirmed in a randomised controlled clinical trial.

The singapore 5-Fluorouracil trabeculectomy study: effects on intraocular pressure control and disease progression at 3 years.

PURPOSE: To report 3-year results of a randomized, controlled trial comparing the use of a single application of 5-fluorouracil (5-FU) with placebo in trabeculectomy surgery. DESIGN: Prospective, randomized, double-blinded treatment trial. PARTICIPANTS: Two hundred forty-three Asian patients with primary open-angle or primary angle-closure glaucoma undergoing primary trabeculectomy. METHODS: One eye of each patient was randomized to receive either intraoperative 5-FU or normal saline (placebo) during trabeculectomy. MAIN OUTCOME MEASURES: Primary outcome measure was the level of intraocular pressure (IOP). Secondary outcomes were progression of visual field loss, rates of adverse events, and interventions after surgery. RESULTS: Of the 288 eligible patients, 243 were enrolled and 228 completed 3 years follow-up; 120 patients received 5-FU and 123 received placebo. Trial failure, according to predefined IOP criteria, was lower in the 5-FU group compared with the placebo group, although the difference was only significant with a failure criterion of IOP >17 mmHg (P = 0.0154). There was no significant difference in progression of optic disc and/or visual field loss over 36 months between 5-FU and placebo (relative risk [RR], 0.67; 95% confidence interval [CI], 0.34-1.31; P = 0.239). Uveitis occurred more often in the 5-FU-treated group (14/115 [12%] vs 5/120 [4%]; P = 0.032). CONCLUSIONS: This is the first masked, prospective, randomized trial reporting the effect of adjunctive 5-FU in trabeculectomy surgery in an East Asian population. The trial shows that an increased success rate can be achieved for several years after a single intraoperative treatment with 5-FU. We conclude that 5-FU is relatively safe and can be routinely used in low-risk East Asian patients. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any materials discussed in this article.

Outcomes following acute primary angle closure in an Asian population.

BACKGROUND: Data regarding development of primary angle closure glaucoma (PACG) following acute primary angle closure (APAC) is conflicting. This study looks at outcomes after an APAC episode with a secondary aim to identify any risk factors that could predict progression to PACG. METHODS: This is a retrospective review of the charts of consecutive patients who were diagnosed with APAC from December 2003 to June 2006. All were treated in a standard manner with initial intensive medical therapy or laser iridoplasty followed by early laser peripheral iridotomy within 24 h of presentation. RESULTS: Forty-two eyes of 41 patients were analysed. The mean follow-up period was 27.3 +/- 16.2 months. Nine eyes (21.4%) developed an increase in intraocular pressure (IOP) within a mean of 11.9 months (median 5 months) after resolution of APAC. Eight eyes went on to have trabeculectomy or glaucoma drainage device. At final follow up, the mean IOP of attack eye was 13.3 +/- 2.92 mmHg. None of the eyes, including those that underwent surgery, required topical medication to control IOP. Thirty-eight eyes (90.5%) have BCVA of 6/6 to 6/12. The duration of symptoms before presentation (P = 0.00) and duration taken to abort the acute attack (P = 0.01) were found to be significantly associated with development of PACG. CONCLUSION: The results of this study suggest that outcomes following successful treatment of APAC may not be as poor as described previously. Early aggressive management of the acute episode may have a role to play in preventing development of PACG after APAC.

High-definition imaging of trabeculectomy blebs using spectral domain optical coherence tomography adapted for the anterior segment.

BACKGROUND: The aim of this work was to image trabeculectomy blebs using spectral domain optical coherence tomography (SDOCT). METHODS: In this prospective cross-sectional study, patients who had undergone trabeculectomy with at least 3 months of follow up were included. Blebs were imaged using an adapted SDOCT system (Cirrus HD-OCT, Carl Zeiss Meditec Inc., Dublin, CA, USA) and time domain anterior segment optical coherence tomography (ASOCT) (Visante OCT, Carl Zeiss Meditec Inc.). An observer masked to clinical data assessed the utility of SDOCT and ASOCT in visualizing structures in successful and failed blebs. RESULTS: Fifty-one eyes were imaged, of which 43 (84.3%) were successful. SDOCT showed wall thickening (93.0% vs. 67.4%, P = 0.006) and discrete hyporeflective spaces in the wall (88.4% vs. 14.0%, P < 0.0001) in a greater proportion of successful blebs than ASOCT. SDOCT showed the bleb cavity (23.3% vs. 48.8%, P = 0.02), scleral flap (34.9% vs. 90.7%, P < 0.0001), subflap space (20.9% vs. 72.1%, P < 0.0001) and ostium (9.3% vs. 88.4%, P < 0.0001) in fewer successful blebs than ASOCT. The internal ostium was not visualized in any failed bleb using SDOCT, whereas ASOCT showed the ostium in 87.5% of failed blebs (P = 0.001). SDOCT showed cystic spaces in the bleb wall in a greater proportion of successful blebs than failed blebs (88.4% vs. 37.5%, P = 0.005). CONCLUSIONS: SDOCT imaging was able to show fine superficial features in the bleb wall. However, SDOCT had limited clinical utility in that it did not provide useful information about deep features such as flap position, bleb cavity formation or patency of the subflap space and internal ostium.