Glaucoma

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Shen LQ, Kloek CE, Turalba AV. Assessing the Effect of a Glaucoma Surgical Curriculum in Resident Physicians. JAMA Ophthalmol 2015;133(9):1077-80.Abstract

IMPORTANCE: Subspecialty surgical training is an important part of resident education. We changed the glaucoma rotation in which postgraduate year 4 residents worked with multiple attending physicians with varying teaching styles to a structured surgical curriculum led by 2 dedicated preceptors, and we evaluated the effect on residents' surgical performance prospectively. OBSERVATIONS: A curriculum consisting of preoperative training, intraoperative teaching, postoperative feedback, and repetition was implemented for postgraduate year 4 residents between July 2, 2012, and June 30, 2014. In a class of 8 residents per year, the mean (SD) glaucoma surgical volume increased from 8.9 (0.8) cases in the prior year to 13.6 (2.5) in 2013 (mean difference, 4.8 cases; 95% CI, 2.4-7.1; P = .001) and 14.8 (4.2) in 2014 (mean difference, 5.9 cases; 95% CI, 2.1-9.6; P = .007). A self-assessment survey showed improvement in suturing (scores for each section range from 1 [worst] to 5 [best]; mean rating, 3.9 in the prior year vs 4.4 in 2013 [P = .04] and 4.5 in 2014 [P = .02]). A validated survey assessing overall surgical competency revealed improvement in handling adverse events (mean rating, 4.1 in the prior year vs 5.0 for both 2013 and 2014; both P < .001). CONCLUSIONS AND RELEVANCE: Despite the small sample size and nonrandomized study design, these data suggest that a structured surgical curriculum has advantages in teaching subspecialty surgery and might be considered by other ophthalmology training programs.

Shi Y, Wang H, Yin J, Li M, Zhang X, Xin C, Chen X, Wang N. Microcatheter-assisted trabeculotomy versus rigid probe trabeculotomy in childhood glaucoma. Br J Ophthalmol 2016;100(9):1257-62.Abstract

PURPOSE: To compare microcatheter-assisted trabeculotomy with standard rigid probe trabeculotomy for the treatment of childhood glaucoma. METHODS: The early postoperative (12 months) results of microcatheter-assisted trabeculotomy (group 1) performed by single surgeon were retrospectively compared with those of rigid probe trabeculotomy (group 2) performed by the same surgeon in patients treated for childhood glaucoma. Success was defined as an intraocular pressure (IOP) <21 mm Hg with at least a 30% reduction from preoperative IOP with (qualified success) or without (complete success) the use of anti-glaucoma medication. RESULTS: A total of 43 eyes of 36 patients were included. Mean IOP in group 1 was significantly lower than that in group 2 at 6 months (17.0±5.1 vs 22.5±9.8; p=0.042), 9 months (16.3±5.0 vs 21.6±9.6; p=0.009) and 12 months (14.8±2.5 vs 19.0±7.1; p=0.049) postoperatively. The mean percentage reduction in IOP from preoperative to the last postoperative follow-up was greater in group 1 (47.3±17.7%) than in group 2 (34.2±21.9%) (p=0.036). group 1 demonstrated an 81.0% complete and 86.4% qualified success rate, exceeding the 51.6% complete (p=0.060) and 61.9% qualified (p=0.037) success rate of group 2. There were no long-term complications in either group, but choroidal detachment occurred in one eye in group 2. CONCLUSION: Microcatheter-assisted circumferential trabeculotomy is a more effective treatment and is as safe as traditional trabeculotomy with a rigid probe for primary congenital glaucoma in the early postoperative course. TRIAL REGISTRATION NUMBER: ChiCTR-OCC-15005789, Results.

Shi Y, Wang H, Yin J, Zhang X, Li M, Xin C, Chen X, Wang N. Outcomes of microcatheter-assisted trabeculotomy following failed angle surgeries in primary congenital glaucoma. Eye (Lond) 2017;31(1):132-139.Abstract

PurposeTo report surgical outcomes of microcatheter-assisted trabeculotomy following failed angle surgeries, and compare those with no previous angle surgery, in primary congenital glaucoma (PCG).MethodsThe early postoperative (12 months) results of 42 eyes of 36 patients who underwent microcatheter-assisted trabeculotomy by single surgeon for PCG were retrospectively analyzed. Group 1, 20 eyes of 16 patients, had no previous angle surgery. Group 2, 22 eyes of 20 patients, had one or two previous failed angle surgeries. Success was defined as an intraocular pressure (IOP) <21 mm Hg with at least a 30% reduction from preoperative IOP with (qualified success) or without (complete success) the use of antiglaucoma medication.ResultsMean IOP decreased from 31.5±7.2 mm Hg on 3 (median, range: 1-5) medications in Group 1 and 34.6±7.3 mm Hg on 3 (median, range: 1-4) medications in Group 2 preoperatively to 15.6±3.1 mm Hg on 0 (median, range: 0-4) medications in Group 1 and 16.0±4.6 mm Hg on 0 (median, range: 0-2) medications in Group 2 postoperatively at 12 months (both P<0.001), respectively. The mean percentage of IOP reduction from preoperative to last postoperative visit was 46.0±20.1% in Group 1 and 45.5±25.0% in Group 2, P=0.947. Qualified and complete successes were comparable between Group 1 and Group 2 (qualified success: 90.0% vs 77.3%, P=0.294; complete success: 78.9% vs 77.3%, P=0.853). Complications were minimal.ConclusionsMicrocatheter-assisted trabeculotomy achieved significant pressure-lowering effects with a reduction in medication use in PCG, and it represents a reasonable choice of initial and repeat surgical treatment for PCG.

Shieh E, Lee R, Que C, Srinivasan V, Guo R, DeLuna R, Pandit S, Simavli H, Seevaratnam R, Tsikata E, de Boer J, Chen TC. Diagnostic Performance of a Novel Three-Dimensional Neuroretinal Rim Parameter for Glaucoma Using High-Density Volume Scans. Am J Ophthalmol 2016;169:168-78.Abstract

PURPOSE: To evaluate the diagnostic performance of a 3-dimensional (3D) neuroretinal rim parameter, the minimum distance band (MDB), using optical coherence tomography (OCT) high-density volume scans for open-angle glaucoma. DESIGN: Reliability analysis. METHODS: setting: Institutional. STUDY POPULATION: Total of 163 patients (105 glaucoma and 58 healthy subjects). OBSERVATION PROCEDURES: One eye of each patient was included. MDB and retinal nerve fiber layer (RNFL) thickness values were determined for 4 quadrants and 4 sectors using a spectral-domain OCT device. MAIN OUTCOME MEASURES: Area under the receiver operating characteristic curve (AUROC) values, sensitivities, specificities, and positive and negative predictive values. RESULTS: The best AUROC values of 3D MDB thickness for glaucoma and early glaucoma were for the overall globe (0.969, 0.952), followed by the inferior quadrant (0.966, 0.949) and inferior-temporal sector (0.966, 0.944), and then followed by the superior-temporal sector (0.964, 0.932) and superior quadrant (0.962, 0.924). All 3D MDB thickness AUROC values were higher than those of 2D RNFL thickness. Pairwise comparisons showed that the diagnostic performance of the 3D MDB parameter was significantly better than 2D RNFL thickness only for the nasal quadrant and inferior-nasal and superior-nasal sectors (P = .023-.049). Combining 3D MDB with 2D RNFL parameters provided significantly better diagnostic performance (AUROC 0.984) than most single MDB parameters and all single RNFL parameters. CONCLUSIONS: Compared with the 2D RNFL thickness parameter, the 3D MDB neuroretinal rim thickness parameter had uniformly equal or better diagnostic performance for glaucoma in all regions and was significantly better in the nasal region.

Shiga Y, Akiyama M, Nishiguchi KM, Sato K, Shimozawa N, Takahashi A, Momozawa Y, Hirata M, Matsuda K, Yamaji T, Iwasaki M, Tsugane S, Oze I, Mikami H, Naito M, Wakai K, Yoshikawa M, Miyake M, Yamashiro K, Kashiwagi K, Iwata T, Mabuchi F, Takamoto M, Ozaki M, Kawase K, Aihara M, Araie M, Yamamoto T, Kiuchi Y, Nakamura M, Ikeda Y, Sonoda K-H, Ishibashi T, Nitta K, Iwase A, Shirato S, Oka Y, Satoh M, Sasaki M, Fuse N, Suzuki Y, Cheng C-Y, Khor CC, Baskaran M, Perera S, Aung T, Vithana EN, Cooke Bailey JN, Kang JH, Pasquale LR, Haines JL, Wiggs JL, Burdon KP, Gharahkhani P, Hewitt AW, Mackey DA, Macgregor S, Craig JE, Allingham RR, Hauser M, Ashaye A, Budenz DL, Akafo S, Williams SEI, Kamatani Y, Nakazawa T, Kubo M. Genome-wide association study identifies seven novel susceptibility loci for primary open-angle glaucoma. Hum Mol Genet 2018;27(8):1486-1496.Abstract
Primary open-angle glaucoma (POAG) is the leading cause of irreversible blindness worldwide for which 15 disease-associated loci had been discovered. Among them, only 5 loci have been associated with POAG in Asians. We carried out a genome-wide association study and a replication study that included a total of 7378 POAG cases and 36 385 controls from a Japanese population. After combining the genome-wide association study and the two replication sets, we identified 11 POAG-associated loci, including 4 known (CDKN2B-AS1, ABCA1, SIX6 and AFAP1) and 7 novel loci (FNDC3B, ANKRD55-MAP3K1, LMX1B, LHPP, HMGA2, MEIS2 and LOXL1) at a genome-wide significance level (P < 5.0×10-8), bringing the total number of POAG-susceptibility loci to 22. The 7 novel variants were subsequently evaluated in a multiethnic population comprising non-Japanese East Asians (1008 cases, 591 controls), Europeans (5008 cases, 35 472 controls) and Africans (2341 cases, 2037 controls). The candidate genes located within the new loci were related to ocular development (LMX1B, HMGA2 and MAP3K1) and glaucoma-related phenotypes (FNDC3B, LMX1B and LOXL1). Pathway analysis suggested epidermal growth factor receptor signaling might be involved in POAG pathogenesis. Genetic correlation analysis revealed the relationships between POAG and systemic diseases, including type 2 diabetes and cardiovascular diseases. These results improve our understanding of the genetic factors that affect the risk of developing POAG and provide new insight into the genetic architecture of POAG in Asians.
Shoji MK, Cousins CC, Saini C, Silva RNE, Wang M, Brauner SC, Greenstein SH, Pasquale LR, Shen LQ. Paired Optic Nerve Microvasculature and Nailfold Capillary Measurements in Primary Open-Angle Glaucoma. Transl Vis Sci Technol 2021;10(7):13.Abstract
Purpose: To assess microvascular beds in the optic nerve head (ONH), peripapillary tissue, and the nailfold in patients with primary open-angle glaucoma (POAG) versus controls. Methods: Patients with POAG (n = 22) and controls (n = 12) underwent swept-source optical coherence tomography angiography of ophthalmic microvasculature and nailfold video capillaroscopy of the hand. The main outcomes were vessel density (VD) and blood flow of the ONH, the peripapillary and the nailfold microvasculatures. Results: Patients with POAG were younger than controls (63.5 ± 9.4 vs. 69.9 ± 6.5 years, P = 0.03). Deep ONH VD and blood flow were lower in patients with POAG than controls (39.1% ± 3.5% vs. 43.8% ± 5.7%; 37.8% ± 5.3% vs. 46.0% ± 7.8%, respectively, P < 0.02 for both); similar results were observed with peripapillary VD (37.9 ± 2.6%, 43.4 ± 7.6%, respectively, P = 0.03). Nailfold capillary density and blood flow were lower in patients with POAG than controls (8.8 ± 1.0 vs. 9.8 ± 0.9 capillaries/mm; 19.9 ± 9.4 vs. 33.7 ± 9.8 pL/s, respectively; P < 0.009 for both). After adjusting for age and gender, deep ONH VD and blood flow, peripapillary VD, and nailfold capillary blood flow were lower in POAG than controls (β = -0.04, -0.07, -0.05, -13.19, respectively, P ≤ 0.046 for all). Among all participants, there were positive correlations between deep ONH and nailfold capillary blood flow (Pearson's correlation coefficient r = 0.42, P = 0.02), peripapillary and nailfold capillary density (r = 0.43, P = 0.03), and peripapillary and nailfold capillary blood flow (r = 0.49, P = 0.01). Conclusions: Patients with POAG demonstrated morphologic and hemodynamic alterations in both ophthalmic and nailfold microvascular beds compared to controls. Translational Relevance: The concomitant abnormalities in nailfold capillaries and relevant ocular vascular beds in POAG suggest that the microvasculature may be a target for POAG treatment.
Shroff S, Gu SZ, Vardhan S A, Mani I, Aziz K, P N, Datta D, Friedman DS. Screening first-degree relatives of glaucoma patients reveals barriers to participation. Br J Ophthalmol 2021;Abstract
PURPOSE: To report the results of a glaucoma screening campaign targeting first-degree relatives of glaucoma patients in South India. METHODS: 1598 glaucoma patients were contacted via letter or letter and phone call and asked to bring their siblings and children to a glaucoma screening. Participants underwent standardised eye examinations and completed questionnaires that assessed barriers to participation and awareness of glaucoma risk. Two-proportion z-tests were used to compare categorical data. Costs associated with the screening were recorded. RESULTS: 206 probands (12.9%) attended the screening along with 50 siblings and children. Probands were nearly twice as likely to attend if they had been contacted via both letter and phone call rather than letter only. Over half of probands reported that their relatives could not participate because they did not live in the region, and one-fifth reported that their relatives had other commitments. Fifty-eight per cent of the siblings and children who attended did not know that they were at increased risk for glaucoma due to their family history, and 32.0% did not know that the relative who had invited them to the screening had glaucoma. Thirteen siblings and children (26.0% of those who attended) were found to have findings concerning for glaucoma. The average cost per first-degree relative who was screened was INR2422 (£26). CONCLUSION: Participation in this glaucoma screening campaign was poor. The major barrier to participation was distance from the screening site and associated indirect costs. Better strategies for bringing first-degree relatives in for examinations are needed.
Shuldiner SR, Boland MV, Ramulu PY, De Moraes GC, Elze T, Myers J, Pasquale L, Wellik S, Yohannan J. Predicting eyes at risk for rapid glaucoma progression based on an initial visual field test using machine learning. PLoS One 2021;16(4):e0249856.Abstract
OBJECTIVE: To assess whether machine learning algorithms (MLA) can predict eyes that will undergo rapid glaucoma progression based on an initial visual field (VF) test. DESIGN: Retrospective analysis of longitudinal data. SUBJECTS: 175,786 VFs (22,925 initial VFs) from 14,217 patients who completed ≥5 reliable VFs at academic glaucoma centers were included. METHODS: Summary measures and reliability metrics from the initial VF and age were used to train MLA designed to predict the likelihood of rapid progression. Additionally, the neural network model was trained with point-wise threshold data in addition to summary measures, reliability metrics and age. 80% of eyes were used for a training set and 20% were used as a test set. MLA test set performance was assessed using the area under the receiver operating curve (AUC). Performance of models trained on initial VF data alone was compared to performance of models trained on data from the first two VFs. MAIN OUTCOME MEASURES: Accuracy in predicting future rapid progression defined as MD worsening more than 1 dB/year. RESULTS: 1,968 eyes (8.6%) underwent rapid progression. The support vector machine model (AUC 0.72 [95% CI 0.70-0.75]) most accurately predicted rapid progression when trained on initial VF data. Artificial neural network, random forest, logistic regression and naïve Bayes classifiers produced AUC of 0.72, 0.70, 0.69, 0.68 respectively. Models trained on data from the first two VFs performed no better than top models trained on the initial VF alone. Based on the odds ratio (OR) from logistic regression and variable importance plots from the random forest model, older age (OR: 1.41 per 10 year increment [95% CI: 1.34 to 1.08]) and higher pattern standard deviation (OR: 1.31 per 5-dB increment [95% CI: 1.18 to 1.46]) were the variables in the initial VF most strongly associated with rapid progression. CONCLUSIONS: MLA can be used to predict eyes at risk for rapid progression with modest accuracy based on an initial VF test. Incorporating additional clinical data to the current model may offer opportunities to predict patients most likely to rapidly progress with even greater accuracy.
Sii S, Barton K, Pasquale LR, Yamamoto T, King AJ, Azuara-Blanco A. Reporting Harm in Glaucoma Surgical Trials: Systematic Review and a Consensus-Derived New Classification System. Am J Ophthalmol 2018;194:153-162.Abstract
PURPOSE: To evaluate the standards of harm reporting for glaucoma surgical trials and to develop a classification system for reporting surgical complication severity. DESIGN: Systematic review and Delphi consensus method. METHODS: Systematic review of glaucoma surgical trials published from January 2010 until July 2017 with a quality assessment against the CONSORT checklist for harm. A Delphi method was employed to generate consensus grading (interquartile range ≤ 2) among international glaucoma experts (n = 43) on severity of glaucoma surgical complications, and specifically for trabeculectomy and aqueous shunt complications, from 1 (no clinical significance) to 10 (most severe complication). RESULTS: Forty-seven studies were eligible. The items of the CONSORT checklist for harm that were most frequently missing were use of a validated instrument to report severity (0%), withdrawals due to harm, and subgroup analyses, both reported in 3 publications (6.4%). Most glaucoma experts participating in the Delphi process (80%) completed the second round, and consensus was achieved for all but 1 complication. The least severe complications (graded 2) were "transient loss of vision," "early low intraocular pressure," "choroidal detachment anterior to equator," "small layered hyphema < 1 mm," and "increased lens opacity not clinically significant." The most severe complications (graded 10) were "endophthalmitis" and "permanent severe loss of vision (hand movements or worse)." CONCLUSIONS: Glaucoma surgical randomized controlled trials report frequency of complications, but their severity is rarely reported. The quality of harm reporting is poor. We propose the use of a newly developed system of classification for assessing the severity of surgical complications based on consensus.
Silva RNE, Shen LQ, Chiou CA, Shanbhag SS, Paschalis EI, Pasquale LR, Colby KA, Dohlman CH, Chodosh J, Alves MR. Glaucoma Management in Patients with Aniridia and Boston Type 1 Keratoprosthesis. Am J Ophthalmol 2019;Abstract
PURPOSE: To assess outcomes and glaucoma management in eyes with aniridia following Boston type 1 Keratoprosthesis (KPro) implantation. DESIGN: Retrospective, interventional comparative case series. METHODS: POPULATION: Patients with aniridia and patients with other preoperative diagnoses (excluding Stevens-Johnson syndrome, mucous membrane pemphigoid, and congenital disorders) who underwent KPro implantation at Massachusetts Eye and Ear with at least 2 years of follow-up. One eye per patient was selected based on the longer follow-up time. MAIN OUTCOME: Intermediate and long-term outcomes related to glaucoma. RESULTS: The aniridia (n=22) and comparison (n=61) groups had similar preoperative visual acuity (VA, mean ± standard deviation, 1.86±0.52 LogMAR, p=0.33) and follow-up time (65.6±26.3 months, p=0.25). Prior to KPro implantation, eyes with aniridia had more glaucoma (76.2%) and glaucoma surgery (57.1%) than comparison eyes (51.8%, p=0.053; 23.2%, p=0.005, respectively). More Ahmed valves were co-implanted with KPro in aniridia (47.6%) versus comparison eyes (17.9%, p=0.008). At final follow-up, more aniridia eyes had glaucoma (90.5%) than comparison eyes (64.3%, p=0.02), but the two groups had similar percentages of eyes with cup-to-disc ratio (CDR) >0.8 (23.8% vs. 30.4%, p=0.57) or CDR progression of ≥0.2 (42.9% vs. 44.6%, p=0.89, respectively). None of the eyes with prophylactic tube implantation developed glaucoma. Eyes with and without aniridia did not differ in post-KPro VA improvement (72.7%, 72.1%, p=0.96), and final VA (1.28±0.79 LogMAR, 1.23±0.98 LogMAR, p=0.51). CONCLUSION: Despite a higher glaucoma prevalence, eyes with aniridia achieved similar VA as comparison eyes with more than 5 years of mean follow-up time. Boston KPro offers satisfactory visual rehabilitation in aniridia when glaucoma is managed aggressively.
Silva RNE, Taniguchi EV, Cruzat A, Paschalis EI, Pasquale LR, Colby KA, Dohlman CH, Chodosh J, Shen LQ. Angle Anatomy and Glaucoma in Patients With Boston Keratoprosthesis. Cornea 2020;39(6):713-719.Abstract
PURPOSE: To quantitatively analyze the angle anatomy in eyes with a Boston type 1 keratoprosthesis (KPro) using anterior segment optical coherence tomography (AS-OCT) and to assess the diagnostic ability of AS-OCT in KPro-associated glaucoma. METHODS: AS-OCT (RTVue) images from KPro eyes with and without glaucoma were reviewed. The angle opening distance at 500 μm from the scleral spur (AOD500), trabecular-iris angle at 500 μm from the scleral spur (TIA500), and trabecular-iris surface area at 500 μm from the scleral spur (TISA500) were measured by 2 observers masked to the diagnosis. The measurements for each visible quadrant were compared between KPro eyes with and without glaucoma. RESULTS: Twenty-two eyes with glaucoma and 17 eyes without glaucoma from 39 patients with KPro were included. Of the 4 quadrants imaged, the temporal angle was the most visible (79.5%) and angle measurements of the temporal quadrant were the only ones that differentiated the 2 groups: the mean AOD500, TIA500, and TISA500 were significantly lower in KPro eyes with glaucoma than without glaucoma (388.2 ± 234.4 μm vs. 624.5 ± 310.5 μm, P = 0.02; 26.1 ± 14.0 degrees vs. 39.1 ± 17.1 degrees, P = 0.03; and 0.15 ± 0.09 mm vs. 0.23 ± 0.12 mm, P = 0.03; respectively). The highest area under the receiver operating characteristic curve for detecting glaucoma was 0.75 for temporal TIA500 (95% confidence interval 0.57-0.94, P = 0.02) with 50% specificity at 80% of sensitivity and a cutoff value of 37 degrees. CONCLUSIONS: The temporal angle was the most visible on AS-OCT in eyes with a KPro. Significant narrowing of the temporal angle detected on AS-OCT was associated with glaucoma in these eyes.
Silva RNE, Chiou CA, Wang M, Wang H, Shoji MK, Chou JC, D'Souza EE, Greenstein SH, Brauner SC, Alves MR, Pasquale LR, Shen LQ. Microvasculature of the Optic Nerve Head and Peripapillary Region in Patients With Primary Open-Angle Glaucoma. J Glaucoma 2019;28(4):281-288.Abstract
PURPOSE: To assess optic nerve head (ONH) and peripapillary microvasculature in primary open-angle glaucoma (POAG) of mild to moderate severity using swept-source optical coherence tomography angiography (OCTA). MATERIALS AND METHODS: In a cross-sectional study, swept-source OCTA images were analyzed for 1 eye from each of 30 POAG patients with glaucomatous Humphrey visual field loss and 16 controls. The anatomic boundary of ONH was manually delineated based on Bruch's membrane opening and large vessels were removed from en face angiography images to measure vessel density (VD) and the integrated OCTA by ratio analysis signal (IOS), suggestive of flow, in the ONH and peripapillary region. POAG subgroup analysis was performed based on a history of disc hemorrhage (DH) matched by visual field mean deviation (MD). RESULTS: POAG (mean MD±SD, -3.3±3.0 dB) and control groups had similar demographic characteristics and intraocular pressure on the day of imaging. Groups did not differ in superficial ONH VD or flow indicated by IOS (P≥0.28). POAG eyes showed significantly lower VD (39.4%±4.0%) and flow (38.8%±5.6%) in deep ONH, peripapillary VD (37.9%±2.9%) and flow (43.6%±4.0%) compared with control eyes (44.1%±5.1%, 44.7%±6.9%, 40.7%±1.7%, 47.8%±2.5%, respectively; P≤0.007 for all). In the subgroup analysis, POAG eyes with (n=14) and without DH (n=16) had similar measured OCTA parameters (P>0.99 for all). CONCLUSIONS: The image processing methodology based on the anatomic boundary of ONH demonstrated compromised microvasculature in the deep ONH and peripapillary region in eyes with mild to moderate POAG, regardless of the history of DH.
Silva RNE, Chiou CA, Wang M, Devlin J, Li D, Lovelace S, Wang H, Greenstein SH, Brauner SC, Shen LQ. Quantification of the Peripapillary Microvasculature in Eyes with Glaucomatous Paracentral Visual Field Loss. Ophthalmol Glaucoma 2021;4(3):286-294.Abstract
PURPOSE: To quantify abnormalities in the peripapillary microvasculature in eyes with primary open-angle glaucoma (POAG) and paracentral visual field (VF) loss. DESIGN: Prospective, cross-sectional study. PARTICIPANTS: Thirty-three POAG patients, including 15 with paracentral VF loss and 18 with peripheral VF loss, and 31 control participants underwent swept-source OCT angiography (OCTA) of the peripapillary region. METHODS: The POAG groups were matched by VF mean deviation (MD). The peripapillary microvasculature from the internal limiting membrane to the retinal nerve fiber layer (RNFL) interface was quantified within a 0.70-mm annulus around Bruch's membrane opening after removal of large vessels. Both vessel density (VD) and the integrated OCTA by ratio analysis signal (IOS) suggestive of flow were measured. Regional VD and IOS were measured from the affected hemisphere corresponding to the VF hemifield of more severe loss, which was used to calculate the paracentral total deviation (PaTD), or total deviation within the central 10°. One eye per participant was included. MAIN OUTCOME MEASURES: Difference in peripapillary OCTA measurements between paracentral and peripheral VF loss groups and correlation of peripapillary VD and IOS with PaTD. RESULTS: The POAG groups had matched VF MD (-3.1 ± 2.5 dB paracentral vs. -2.3 ± 2.0 dB peripheral; P = 0.31), did not differ in average RNFL thickness (71.1 ± 14.7 μm vs. 78.1 ± 15.0 μm; P = 0.55), but differed in age (59.2 ± 9.6 years paracentral vs. 67.4 ± 6.6 years peripheral; P = 0.02). Compared with control participants, both paracentral and peripheral VF loss groups showed reduced VD (P < 0.001 and P = 0.009, respectively) and IOS (P < 0.001 and P = 0.01, respectively) in the affected hemisphere. Compared with POAG eyes with peripheral VF loss, the paracentral group showed reduced peripapillary VD (38.0 ± 2.0%, 35.0 ± 2.2%, respectively; P = 0.001) and IOS (44.3 ± 3.1%, 40.4 ± 4.0%, respectively; P = 0.02) in the affected hemisphere. Among all POAG eyes, peripapillary VD and IOS of the affected hemisphere correlated significantly with functional measurement of paracentral loss (PaTD, r = 0.40, P = 0.02; r = 0.45, P = 0.008; respectively). These correlations remained significant after adjusting for age (r = 0.41, P = 0.02; r = 0.47, P = 0.01; respectively). CONCLUSIONS: Regional peripapillary microvasculature showed decreased VD and flow in POAG with paracentral loss, supporting its importance in this glaucoma subtype.
Simavli H, Poon LY-C, Que CJ, Liu Y, Akduman M, Tsikata E, de Boer JF, Chen TC. Diagnostic Capability of Peripapillary Retinal Volume Measurements in Glaucoma. J Glaucoma 2017;26(6):592-601.Abstract
PURPOSE: To determine the diagnostic capability of spectral domain optical coherence tomography peripapillary retinal volume (RV) measurements. MATERIALS AND METHODS: A total of 156 patients, 89 primary open-angle glaucoma and 67 normal subjects, were recruited. Spectral domain optical coherence tomography peripapillary RV was calculated for 4 quadrants using 3 annuli of varying scan circle diameters: outer circumpapillary annuli of circular grids 1, 2, and 3 (OCA1, OCA2, OCA3). Area under the receiver operating characteristic curves and pairwise comparisons of receiver operating characteristic (ROC) curves were performed to determine which quadrants were best for diagnosing primary open-angle glaucoma. The pairwise comparisons of the best ROC curves for RV and retinal nerve fiber layer (RNFL) were performed. The artifact rates were analyzed. RESULTS: Pairwise comparisons showed that the smaller annuli OCA1 and OCA2 had better diagnostic performance than the largest annulus OCA3 (P<0.05 for all quadrants). OCA1 and OCA2 had similar diagnostic performance, except for the inferior quadrant which was better for OCA1 (P=0.0033). The pairwise comparisons of the best ROC curves for RV and RNFL were not statistically significant. RV measurements had lower rates of artifacts at 7.4% while RNFL measurements had higher rates at 42.9%. CONCLUSIONS: Peripapillary RV measurements have excellent ability for diagnosing not only glaucoma patients but also a subset of early glaucoma patients. The inferior quadrant of peripapillary annulus OCA1 demonstrated the best diagnostic capability for both glaucoma and early glaucoma. The diagnostic ability of RV is comparable with that of RNFL parameters in glaucoma but with lower artifact rates.
Simavli H, Que CJ, Akduman M, Rizzo JL, Tsikata E, de Boer JF, Chen TC. Diagnostic capability of peripapillary retinal thickness in glaucoma using 3D volume scans. Am J Ophthalmol 2015;159(3):545-56.e2.Abstract

PURPOSE: To determine the diagnostic capability of spectral-domain optical coherence tomography (SD OCT) peripapillary retinal thickness (RT) measurements from 3-dimensional (3D) volume scans for primary open-angle glaucoma (POAG). DESIGN: Cross-sectional study. METHODS: setting: Institutional. study population: 156 patients (89 POAG and 67 normal subjects). observation procedures: One eye of each subject was included. SD OCT peripapillary RT values from 3D volume scans were calculated for 4 quadrants of 3 different sized annuli. Peripapillary retinal nerve fiber layer (RNFL) thickness values were also determined. main outcome measures: Area under the receiver operating characteristic curve (AUROC) values, sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios. RESULTS: The top 5 RT AUROCs for all glaucoma patients and for a subset of early glaucoma patients were for the inferior quadrant of outer circumpapillary annulus of circular grid (OCA) 1 (0.959, 0.939), inferior quadrant of OCA2 (0.945, 0.921), superior quadrant of OCA1 (0.890, 0.811), inferior quadrant of OCA3 (0.887, 0.854), and superior quadrant of OCA2 (0.879, 0.807). Smaller RT annuli OCA1 and OCA2 consistently showed better diagnostic performance than the larger RT annulus OCA3. For both RNFL and RT measurements, best AUROC values were found for inferior RT OCA1 and OCA2, followed by inferior and overall RNFL thickness. CONCLUSION: Peripapillary RT measurements from 3D volume scans showed excellent diagnostic performance for detecting both glaucoma and early glaucoma patients. Peripapillary RT values have the same or better diagnostic capability compared to peripapillary RNFL thickness measurements, while also having fewer algorithm errors.

Singh RB, Ichhpujani P, Thakur S, Jindal S. Promising therapeutic drug delivery systems for glaucoma: a comprehensive review. Ther Adv Ophthalmol 2020;12:2515841420905740.Abstract
The delivery of ophthalmic drugs is challenging despite easy accessibility via the ocular surface. Topical instillation of eye drops is a relatively easy and most commonly used as a conduit for drug delivery for treating a myriad of ocular morbidities, particularly involving the anterior segment, and has an additional benefit of avoiding the first-pass metabolism while passing through the systemic circulation. The primary challenges of drug administration through traditional methods include-inadequate patient education for proper drug instillation technique, compliance, adherence, and persistence. Various dynamic (choroidal and conjunctival blood flow, lymphatic clearance, and tear dilution) and static (namely, different layers of cornea, sclera, and retina including blood aqueous and blood-retinal barriers) ocular barriers limit drug delivery to the target ocular tissues. The maintenance of the therapeutic drug levels on the ocular surface for a prolonged duration is an added challenge, thus preventing persistent delivery for longer durations. These factors result in inadequate management, leading to poor prognosis in vision loss in as many as 27% of the patients diagnosed with glaucoma. We have reviewed the research and advancements in the development of novel and well-tolerated drug delivery systems with the common goal of overcoming the factors limiting adequate drug delivery to the target tissues in glaucomatous patients with traditional techniques. In the recent past, multiple research groups have successfully designed noninvasive, sustained drug delivery systems, promoting the efficacy as well as the feasibility of delivering topical drugs to the anterior segment.
Smits DJ, Elze T, Wang H, Pasquale LR. Machine Learning in the Detection of the Glaucomatous Disc and Visual Field. Semin Ophthalmol 2019;:1-11.Abstract
Glaucoma is the leading cause of irreversible blindness worldwide. Early detection is of utmost importance as there is abundant evidence that early treatment prevents disease progression, preserves vision, and improves patients' long-term quality of life. The structure and function thresholds that alert to the diagnosis of glaucoma can be obtained entirely via digital means, and as such, screening is well suited to benefit from artificial intelligence and specifically machine learning. This paper reviews the concepts and current literature on the use of machine learning for detection of the glaucomatous disc and visual field.
Soh ZD, Yu M, Betzler BK, Majithia S, Thakur S, Tham YC, Wong TY, Aung T, Friedman DS, Cheng C-Y. The global extent of undetected glaucoma in adults: a systematic review and meta-analysis. Ophthalmology 2021;Abstract
TOPIC: Glaucoma is the leading cause of irreversible blindness despite having good prognosis with early treatment. We evaluated the global extent of undetected glaucoma and the factors associated with it in this systematic review and meta-analysis of population-based epidemiological studies. CLINICAL RELEVANCE: Undetected glaucoma increases the risk of vision impairment, which leads to detrimental effects on the quality-of-life and socio-economic well-being of those affected. Detailed information on the extent and factors associated with undetected glaucoma aid in the development of public health interventions. METHODS: We conducted a systematic review and meta-analysis of population-based studies published between January 1, 1990 to June 1, 2020. Article search was conducted in online databases (PubMED, Web-of-Science), grey literatures (opengrey) and non-government organization (NGOs) reports. Our outcome measure was the proportion of glaucoma cases that were undetected previously. Manifest glaucoma included any form of glaucoma reported in the respective study and may include primary-open-angle-glaucoma (POAG), primary-angle-closure-glaucoma (PACG), and/or secondary glaucoma. Undetected glaucoma was defined as glaucoma cases that were undetected prior to diagnosis in the respective study. Random-effect meta-analysis was used to estimate the pooled proportion and factors associated with undetected glaucoma. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines in our study. RESULTS: We identified 61 articles from 55 population-based studies (N= 189,359 participants; N= 6,949 manifest glaucoma; N= 5,558 undetected glaucoma). Globally, more than half of all glaucoma cases were previously undetected in each geographical region. Regionally, Africa (OR 12.70, 95% CI 4.91, 32.86) and Asia (OR 3.41, 95% CI 1.63, 7.16) had higher odds of undetected glaucoma as compared to Europe. Countries with low human development index (HDI, <0.55) had higher proportion of undetected manifest glaucoma as compared to countries of medium to very high HDI (≥0.55, all P <0.001). In 2020, 43.78 million POAG cases were undetected, of which 76.7% reside in Africa and Asia. CONCLUSION: Undetected glaucoma is highly prevalent across diverse communities worldwide, and more common in Africa and Asia. Strategies to improve detection are needed to prevent excess visual disability and blindness due to glaucoma.
Song BJ, Aiello LP, Pasquale LR. Presence and Risk Factors for Glaucoma in Patients with Diabetes. Curr Diab Rep 2016;16(12):124.Abstract

Diabetes mellitus represents a growing international public health issue with a near quadrupling in its worldwide prevalence since 1980. Though it has many known microvascular complications, vision loss from diabetic retinopathy is one of the most devastating for affected individuals. In addition, there is increasing evidence to suggest that diabetic patients have a greater risk for glaucoma as well. Though the pathophysiology of glaucoma is not completely understood, both diabetes and glaucoma appear to share some common risk factors and pathophysiologic similarities with studies also reporting that the presence of diabetes and elevated fasting glucose levels are associated with elevated intraocular pressure-the primary risk factor for glaucomatous optic neuropathy. While no study has completely addressed the possibility of detection bias, most recent epidemiologic evidence suggests that diabetic populations are likely enriched with glaucoma patients. As the association between diabetes and glaucoma becomes better defined, routine evaluation for glaucoma in diabetic patients, particularly in the telemedicine setting, may become a reasonable consideration to reduce the risk of vision loss in these patients.

Song BJ, Ramanathan M, Morales E, Law SK, Giaconi JAA, Coleman AL, Caprioli J. Trabeculectomy and Combined Phacoemulsification-Trabeculectomy: Outcomes and Risk Factors for Failure in Primary Angle Closure Glaucoma. J Glaucoma 2016;25(9):763-9.Abstract

PURPOSE: To evaluate tonometric outcomes of patients with primary angle closure glaucoma (PACG) who have undergone trabeculectomy with mitomycin C (MMC) with and without concurrent phacoemulsification and to identify risk factors for postoperative failure. PATIENTS AND METHODS: Retrospective cohort study of 44 eyes of 33 phakic patients who underwent trabeculectomy with MMC with or without combined phacoemulsification for PACG. The primary endpoint was qualified tonometric success at 12 months according to predefined criteria. LogMAR visual acuity, number of glaucoma medications, and postoperative complications were also evaluated. Cox proportional hazard regression analysis was performed to identify potential risk factors for trabeculectomy failure. RESULTS: Mean intraocular pressure (IOP) decreased from 21.3±7.9 to 12.2±3.9 mm Hg at 12 months (P<0.001) in all patients. A significant reduction in mean number of glaucoma medications (P<0.001) was also seen. There was no change in logMAR visual acuity (P=0.39) after 12 months. There were no significant intergroup differences in mean IOP (P=0.42), number of glaucoma medications (P=0.85), or logMAR visual acuity (P=0.42) between the trabeculectomy versus combined surgery groups after 12 months. Increased age, greater baseline IOP, limbus-based conjunctival flaps, and MMC duration >1 minute were associated with decreased risk of surgical failure. Concurrent phacoemulsification at the time of trabeculectomy did not alter tonometric success or rate of complications. CONCLUSIONS: In phakic patients with PACG, trabeculectomy with MMC significantly reduces IOP and number of glaucoma medications at 12 months without change in visual acuity. However, success rates are modest when based on more demanding tonometric criteria.

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