Glaucoma

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.

Weinreb RN, Leung CKS, Crowston JG, Medeiros FA, Friedman DS, Wiggs JL, Martin KR. Primary open-angle glaucoma. Nat Rev Dis Primers 2016;2:16067.Abstract

Glaucoma is an optic neuropathy that is characterized by the progressive degeneration of the optic nerve, leading to visual impairment. Glaucoma is the main cause of irreversible blindness worldwide, but typically remains asymptomatic until very severe. Open-angle glaucoma comprises the majority of cases in the United States and western Europe, of which, primary open-angle glaucoma (POAG) is the most common type. By contrast, in China and other Asian countries, angle-closure glaucoma is highly prevalent. These two types of glaucoma are characterized based on the anatomic configuration of the aqueous humour outflow pathway. The pathophysiology of POAG is not well understood, but it is an optic neuropathy that is thought to be associated with intraocular pressure (IOP)-related damage to the optic nerve head and resultant loss of retinal ganglion cells (RGCs). POAG is generally diagnosed during routine eye examination, which includes fundoscopic evaluation and visual field assessment (using perimetry). An increase in IOP, measured by tonometry, is not essential for diagnosis. Management of POAG includes topical drug therapies and surgery to reduce IOP, although new therapies targeting neuroprotection of RGCs and axonal regeneration are under development.

Khawaja AP, Cooke Bailey JN, Kang JH, Allingham RR, Hauser MA, Brilliant M, Budenz DL, Christen WG, Fingert J, Gaasterland D, Gaasterland T, Kraft P, Lee RK, Lichter PR, Liu Y, Medeiros F, Moroi SE, Richards JE, Realini T, Ritch R, Schuman JS, Scott WK, Singh K, Sit AJ, Vollrath D, Wollstein G, Zack DJ, Zhang K, Pericak-Vance M, Weinreb RN, Haines JL, Pasquale LR, Wiggs JL. Assessing the Association of Mitochondrial Genetic Variation With Primary Open-Angle Glaucoma Using Gene-Set Analyses. Invest Ophthalmol Vis Sci 2016;57(11):5046-5052.Abstract

Purpose: Recent studies indicate that mitochondrial proteins may contribute to the pathogenesis of primary open-angle glaucoma (POAG). In this study, we examined the association between POAG and common variations in gene-encoding mitochondrial proteins. Methods: We examined genetic data from 3430 POAG cases and 3108 controls derived from the combination of the GLAUGEN and NEIGHBOR studies. We constructed biological-system coherent mitochondrial nuclear-encoded protein gene-sets by intersecting the MitoCarta database with the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. We examined the mitochondrial gene-sets for association with POAG and with normal-tension glaucoma (NTG) and high-tension glaucoma (HTG) subsets using Pathway Analysis by Randomization Incorporating Structure. Results: We identified 22 KEGG pathways with significant mitochondrial protein-encoding gene enrichment, belonging to six general biological classes. Among the pathway classes, mitochondrial lipid metabolism was associated with POAG overall (P = 0.013) and with NTG (P = 0.0006), and mitochondrial carbohydrate metabolism was associated with NTG (P = 0.030). Examining the individual KEGG pathway mitochondrial gene-sets, fatty acid elongation and synthesis and degradation of ketone bodies, both lipid metabolism pathways, were significantly associated with POAG (P = 0.005 and P = 0.002, respectively) and NTG (P = 0.0004 and P < 0.0001, respectively). Butanoate metabolism, a carbohydrate metabolism pathway, was significantly associated with POAG (P = 0.004), NTG (P = 0.001), and HTG (P = 0.010). Conclusions: We present an effective approach for assessing the contributions of mitochondrial genetic variation to open-angle glaucoma. Our findings support a role for mitochondria in POAG pathogenesis and specifically point to lipid and carbohydrate metabolism pathways as being important.

Ciolino JB, Ross AE, Tulsan R, Watts AC, Wang R-F, Zurakowski D, Serle JB, Kohane DS. Latanoprost-Eluting Contact Lenses in Glaucomatous Monkeys. Ophthalmology 2016;123(10):2085-92.Abstract

PURPOSE: To assess the ability of latanoprost-eluting contact lenses to lower the intraocular pressure (IOP) of glaucomatous eyes of cynomolgus monkeys. DESIGN: Preclinical efficacy study of 3 treatment arms in a crossover design. PARTICIPANTS: Female cynomolgus monkeys with glaucoma induced in 1 eye by repeated argon laser trabeculoplasty. METHODS: Latanoprost-eluting low-dose contact lenses (CLLO) and high-dose contact lenses (CLHI) were produced by encapsulating a thin latanoprost-polymer film within the periphery of a methafilcon hydrogel, which was lathed into a contact lens. We assessed the IOP-lowering effect of CLLO, CLHI, or daily latanoprost ophthalmic solution in the same monkeys. Each monkey consecutively received 1 week of continuous-wear CLLO, 3 weeks without treatment, 5 days of latanoprost drops, 3 weeks without treatment, and 1 week of continuous-wear CLHI. On 2 consecutive days before initiation of each study arm, the IOP was measured hourly over 7 consecutive hours to establish the baseline IOP. Two-tailed Student t tests and repeated-measures analysis of variance were used for statistical analysis. MAIN OUTCOME MEASURES: Intraocular pressure. RESULTS: Latanoprost ophthalmic solution resulted in IOP reduction of 5.4±1.0 mmHg on day 3 and peak IOP reduction of 6.6±1.3 mmHg on day 5. The CLLO reduced IOP by 6.3±1.0, 6.7±0.3, and 6.7±0.3 mmHg on days 3, 5, and 8, respectively. The CLHI lowered IOP by 10.5±1.4, 11.1±4.0, and 10.0±2.5 mmHg on days 3, 5, and 8, respectively. For the CLLO and CLHI, the IOP was statistically significantly reduced compared with the untreated baseline at most time points measured. The CLHI demonstrated greater IOP reduction than latanoprost ophthalmic solution on day 3 (P = 0.001) and day 5 (P = 0.015), and at several time points on day 8 (P < 0.05). CONCLUSIONS: Sustained delivery of latanoprost by contact lenses is at least as effective as delivery with daily latanoprost ophthalmic solution. More research is needed to determine the optimal continuous-release dose that would be well tolerated and maximally effective. Contact lens drug delivery may become an option for the treatment of glaucoma and a platform for ocular drug delivery.

Pasquale LR, Hyman L, Wiggs JL, Rosner BA, Joshipura K, McEvoy M, McPherson ZE, Danias J, Kang JH. Prospective Study of Oral Health and Risk of Primary Open-Angle Glaucoma in Men: Data from the Health Professionals Follow-up Study. Ophthalmology 2016;123(11):2318-2327.Abstract

PURPOSE: Tooth loss or periodontal disease is associated with systemic endothelial dysfunction, which has been implicated in primary open-angle glaucoma (POAG). The relationship between oral health and POAG has received limited attention. Thus, we evaluated the association between oral health history and risk of POAG and POAG subtypes. DESIGN: Prospective cohort study. PARTICIPANTS: Health Professionals Follow-up Study participants (40 536 men) followed biennially from 1986 to 2012. At each 2-year risk period, eligible participants were aged 40+ years, were free of POAG, and reported eye examinations. METHODS: By using validated questions, we updated participants' status on number of natural teeth, teeth lost, periodontal disease with bone loss, and root canal treatments. MAIN OUTCOME MEASURES: During follow-up, 485 incident cases of POAG were confirmed with medical records and classified into subtypes defined by intraocular pressure (IOP; ≥ or <22 mmHg) or visual field (VF) loss pattern at diagnosis (peripheral loss only or early paracentral loss). Multivariable relative risks (MVRRs) and 95% confidence intervals (CIs) were estimated. RESULTS: Number of natural teeth, periodontal disease, and root canal treatment were not associated with POAG. However, compared with no report of tooth loss, a report of losing teeth within the past 2 years was associated with a 1.45-fold increased risk of POAG (95% CI, 1.06-1.97); in particular, a report within the past 2 years of both losing teeth and having a prevalent diagnosis of periodontal disease was associated with a 1.85-fold increased risk of POAG (95% CI, 1.07-3.18). The associations with recent tooth loss were not significantly different for the POAG subtypes (P for heterogeneity ≥0.36), although associations were strongest in relation to the POAG subtypes with IOP <22 mmHg (MVRR, 1.93; 95% CI, 1.09-3.43) and early paracentral VF loss (MVRR, 2.27; 95% CI, 1.32-3.88). CONCLUSIONS: Although the number of natural teeth was not associated with risk of POAG, recent tooth loss was associated with an increased risk of POAG. Because these findings may be due to chance, they need confirmation in larger studies.

Kang JH, Wu J, Cho E, Ogata S, Jacques P, Taylor A, Chiu C-J, Wiggs JL, Seddon JM, Hankinson SE, Schaumberg DA, Pasquale LR. Contribution of the Nurses' Health Study to the Epidemiology of Cataract, Age-Related Macular Degeneration, and Glaucoma. Am J Public Health 2016;106(9):1684-9.Abstract

OBJECTIVES: To review the contribution of the Nurses' Health Study (NHS) to understanding the genetic and lifestyle factors that influence the risk of cataract, age-related macular degeneration, and glaucoma. METHODS: We performed a narrative review of the publications of the NHS between 1976 and 2016. RESULTS: The NHS has helped to elucidate the roles of genetics, lifestyle factors (e.g., cigarette smoking associated with cataract extraction and age-related macular degeneration), medical conditions (e.g., diabetes associated with cataract extraction and glaucoma), and dietary factors (e.g., greater carotenoid intake and lower glycemic diet associated with lower risk of age-related macular degeneration) in the etiology of degree and progression of lens opacities, cataract extraction, age-related macular degeneration, primary open-angle glaucoma, and exfoliation glaucoma. CONCLUSIONS: The findings from the NHS, combined with those of other studies, have provided compelling evidence to support public health recommendations for helping to prevent age-related eye diseases: abstinence from cigarette smoking, maintenance of healthy weight and diabetes prevention, and a healthy diet rich in fruits and vegetables.

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.

Lowry EA, Hou J, Hennein L, Chang RT, Lin S, Keenan J, Wang SK, Ianchulev S, Pasquale LR, Han Y. Comparison of Peristat Online Perimetry with the Humphrey Perimetry in a Clinic-Based Setting. Transl Vis Sci Technol 2016;5(4):4.Abstract

PURPOSE: We determined the receiver operating characteristic (ROC) curves for Peristat online perimetry at detecting varying degrees of glaucoma and the correlation between Peristat online perimetry and Humphrey visual field. METHODS: A prospective, comparative study of Peristat online perimetry (an achromatic static computer threshold testing program) and Humphrey visual field (HVF) 24-2 SITA standard testing was performed by 63 glaucoma patients and 30 healthy controls in random order. The number of total adjacent abnormal test points were identified for each test, and compared with Spearman correlation. Receive operating characteristic curves were generated for Peristat online perimetry detection of mild and moderate-severe glaucoma patients using contrast sensitivity thresholds of -16.7, -21.7, and -26.7 dB. RESULTS: The area under the ROC curve for glaucoma detection ranged from 0.77 to 0.81 for mild disease (mean deviation [MD], >-6 dB on HVF) and 0.85 to 0.87 for moderate to severe disease (MD, <-6 dB on HVF) depending on contrast threshold. Peristat online perimetry and Humphrey visual field abnormal points were highly correlated with Spearman rank correlations ranging from 0.55 to 0.77 (all P < 0.001). CONCLUSIONS: Peristat online perimetry exhibits a reasonable ROC curve without specialized equipment and exhibited significant correlation with the conventional 24° Humphrey visual field test. TRANSLATIONAL RELEVANCE: Low cost widely available internet-based visual fields may complement traditional office-based visual field testing.

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.

Chen X, Chen Y, Wiggs JL, Pasquale LR, Sun X, Fan BJ. Association of Matrix Metalloproteinase-9 (MMP9) Variants with Primary Angle Closure and Primary Angle Closure Glaucoma. PLoS One 2016;11(6):e0157093.Abstract

Shorter axial length observed in patients with primary angle closure glaucoma (PACG) might be due to altered matrix metalloproteinase-9 (MMP9) activity resulting in ECM remodeling during eye growth and development. This study aimed to evaluate common variants in MMP9 for association with PACG. Six tag SNPs of MMP9 were genotyped in a Chinese sample of 1,030 cases, including 572 PACG and 458 primary angle closure (PAC), and 499 controls. None of 6 SNPs were significantly associated with overall PAC/PACG (P > 0.07) or with PAC/PACG subgroups (Pc > 0.18). Meta-analysis of two non-Chinese studies revealed significant association between rs17576 and PACG (ORs = 0.56, P < 0.0001); however, meta-analysis of our dataset with 4 Chinese datasets did not replicate this association (ORs = 1.23, P = 0.29). Prior significant association for rs3918249 in one Caucasian study (OR = 0.63, P = 0.006) was not replicated in meta-analysis of 3 Chinese studies including this study (ORs = 0.91, P = 0.13). Significant heterogeneity between non-Chinese and Chinese datasets precluded overall meta-analysis for rs17576 and rs3918249 (Q = 0.001 and 0.04 respectively). rs17577 was nominally associated with PACG in one Caucasian study (OR = 1.71, P = 0.02), but not in 3 Chinese studies including our study (ORs = 1.20, P = 0.07). Overall meta-analysis revealed nominal association for rs17577 and PAC/PACG (ORs = 1.26, Pc = 0.05). Meta-analysis did not show significant association between the other SNPs and PAC/PACG (P > 0.47). The largest association study to date did not find significant association between MMP9 and PAC/PACG in Chinese; meta-analysis with other Chinese datasets did not produce significant association. In most instances combination with non-Chinese datasets was not possible except for one variant showing nominally significant association. More work is needed to define the role of MMP9 variants in PACG.

Yang L, Li S, Miao L, Huang H, Liang F, Teng X, Xu L, Wang Q, Xiao W, Ridder WH, Ferguson TA, Chen DF, Kaufman RJ, Hu Y. Rescue of Glaucomatous Neurodegeneration by Differentially Modulating Neuronal Endoplasmic Reticulum Stress Molecules. J Neurosci 2016;36(21):5891-903.Abstract

UNLABELLED: Axon injury is an early event in neurodegenerative diseases that often leads to retrograde neuronal cell death and progressive permanent loss of vital neuronal functions. The connection of these two obviously sequential degenerative events, however, is elusive. Deciphering the upstream signals that trigger the neurodegeneration cascades in both neuronal soma and axon would be a key step toward developing the effective neuroprotectants that are greatly needed in the clinic. We showed previously that optic nerve injury-induced neuronal endoplasmic reticulum (ER) stress plays an important role in retinal ganglion cell (RGC) death. Using two in vivo mouse models of optic neuropathies (traumatic optic nerve injury and glaucoma) and adeno-associated virus-mediated RGC-specific gene targeting, we now show that differential manipulation of unfolded protein response pathways in opposite directions-inhibition of eukaryotic translation initiation factor 2α-C/EBP homologous protein and activation of X-box binding protein 1-promotes both RGC axons and somata survival and preserves visual function. Our results indicate that axon injury-induced neuronal ER stress plays an important role in both axon degeneration and neuron soma death. Neuronal ER stress is therefore a promising therapeutic target for glaucoma and potentially other types of neurodegeneration. SIGNIFICANCE STATEMENT: Neuron soma and axon degeneration have distinct molecular mechanisms although they are clearly connected after axon injury. We previously demonstrated that axon injury induces neuronal endoplasmic reticulum (ER) stress and that manipulation of ER stress molecules synergistically promotes neuron cell body survival. Here we investigated the possibility that ER stress also plays a role in axon degeneration and whether ER stress modulation preserves neuronal function in neurodegenerative diseases. Our results suggest that neuronal ER stress is a general mechanism of degeneration for both neuronal cell body and axon, and that therapeutic targeting of ER stress produces significant functional recovery.

Dordea AC, Bray M-A, Allen K, Logan DJ, Fei F, Malhotra R, Gregory MS, Carpenter AE, Buys ES. An open-source computational tool to automatically quantify immunolabeled retinal ganglion cells. Exp Eye Res 2016;147:50-6.Abstract

A fully automated and robust method was developed to quantify β-III-tubulin-stained retinal ganglion cells, combining computational recognition of individual cells by CellProfiler and a machine-learning tool to teach phenotypic classification of the retinal ganglion cells by CellProfiler Analyst. In animal models of glaucoma, quantification of immunolabeled retinal ganglion cells is currently performed manually and remains time-consuming. Using this automated method, quantifications of retinal ganglion cell images were accelerated tenfold: 1800 images were counted in 3 h using our automated method, while manual counting of the same images took 72 h. This new method was validated in an established murine model of microbead-induced optic neuropathy. The use of the publicly available software and the method's user-friendly design allows this technique to be easily implemented in any laboratory.

Hoguet A, Grajewski A, Hodapp E, Chang TCP. A retrospective survey of childhood glaucoma prevalence according to Childhood Glaucoma Research Network classification. Indian J Ophthalmol 2016;64(2):118-23.Abstract

PURPOSE: To evaluate the Childhood Glaucoma Research Network (CGRN) classification system and describe the prevalence of each subtype according to this classification. MATERIALS AND METHODS: Retrospectively, the medical records of 205 consecutive childhood glaucoma and glaucoma suspect patients at an urban tertiary care center were reviewed. The initial diagnosis and new diagnosis according to CGRN classification were recorded. RESULTS: All patients fit one of the seven categories of the new classification. Seventy-one percent of diagnoses were changed upon reclassification. Twenty-three percent of patients had primary glaucoma (juvenile open-angle glaucoma and primary congenital glaucoma [PCG]); 36% had secondary glaucoma (glaucoma associated with nonacquired ocular anomalies; glaucoma associated with nonacquired systemic disease or syndrome; glaucoma associated with acquired condition; and glaucoma following cataract surgery); and 39% were glaucoma suspect. Of the patients diagnosed with glaucoma, PCG was the most common diagnosis, seen in 32% of patients. CONCLUSION: The CGRN classification provides a useful method of classifying childhood glaucoma.

Haleem MS, Han L, van Hemert J, Fleming A, Pasquale LR, Silva PS, Song BJ, Aiello LP. Regional Image Features Model for Automatic Classification between Normal and Glaucoma in Fundus and Scanning Laser Ophthalmoscopy (SLO) Images. J Med Syst 2016;40(6):132.Abstract

Glaucoma is one of the leading causes of blindness worldwide. There is no cure for glaucoma but detection at its earliest stage and subsequent treatment can aid patients to prevent blindness. Currently, optic disc and retinal imaging facilitates glaucoma detection but this method requires manual post-imaging modifications that are time-consuming and subjective to image assessment by human observers. Therefore, it is necessary to automate this process. In this work, we have first proposed a novel computer aided approach for automatic glaucoma detection based on Regional Image Features Model (RIFM) which can automatically perform classification between normal and glaucoma images on the basis of regional information. Different from all the existing methods, our approach can extract both geometric (e.g. morphometric properties) and non-geometric based properties (e.g. pixel appearance/intensity values, texture) from images and significantly increase the classification performance. Our proposed approach consists of three new major contributions including automatic localisation of optic disc, automatic segmentation of disc, and classification between normal and glaucoma based on geometric and non-geometric properties of different regions of an image. We have compared our method with existing approaches and tested it on both fundus and Scanning laser ophthalmoscopy (SLO) images. The experimental results show that our proposed approach outperforms the state-of-the-art approaches using either geometric or non-geometric properties. The overall glaucoma classification accuracy for fundus images is 94.4 % and accuracy of detection of suspicion of glaucoma in SLO images is 93.9 %.

Saboo US, Amparo F, Shikari H, Dana R. Prevalence of ocular hypertension and glaucoma in patients with chronic ocular graft-versus-host disease. Graefes Arch Clin Exp Ophthalmol 2016;254(5):923-8.Abstract

PURPOSE: To evaluate the prevalence of ocular hypertension (OHT) and glaucoma in patients with chronic ocular graft-versus-host disease (GVHD). METHODS: We performed a retrospective chart review of 218 patients diagnosed with chronic ocular GVHD. Ocular hypertension was defined as intraocular pressure (IOP) ≥ 24 mmHg in either eye without any glaucomatous optic disc changes. Glaucoma suspect was defined as optic disc changes with a cup-to-disc ratio ≥ 0.7 in either eye or asymmetry of ≥ 0.3 between the two eyes. Glaucoma was defined by glaucomatous optic disc changes plus glaucomatous visual field defects in two consecutive reliable visual field tests. The number of cases of ocular hypertension, glaucoma, and glaucoma suspects was evaluated. RESULTS: Thirty-three patients (15 %) were diagnosed with OHT, eight patients (3.6 %) with suspicion of glaucoma, and one patient (0.4 %) with glaucoma. OHT occurred within 6 months of developing ocular GVHD in 60 % of the cases and within the first year in 76 %. High IOP normalized in 67 % of patients when the dosage of topical or systemic corticosteroids was lowered, and 27 % of patients required anti-glaucoma therapy. CONCLUSIONS: Ocular hypertension is a common complication in patients with ocular GVHD, with a prevalence of 15 %. The rise in intraocular pressure is often transient and resolves with management of corticosteroids in most cases. However, clinicians should be aware that nearly one-third of the patients with OHT might require anti-glaucoma treatment. The prevalences of glaucoma and suspicion of glaucoma were not higher than in the general population.

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