PURPOSE: To evaluate trends in glaucoma procedures in the United States Medicare population and to evaluate which physicians are performing newer procedures. DESIGN: Analysis of publicly available claims and payment data. PARTICIPANTS: Surgeons and beneficiaries enrolled in United States Medicare between 1994 and 2017. METHODS: Data regarding payments to physicians by the Centers for Medicare and Medicaid Services (CMS) were downloaded for the years 2012 through 2017. Data regarding claims to CMS by physicians were requested and processed between 1994 and 2017. Procedure counts from both data sets then were normalized for changes in the Medicare population, with 1995 as the baseline. The normalized volumes of procedures over time were visualized, as were geographic distributions of surgeons and their volume of procedures. MAIN OUTCOME MEASURES: Trends in procedure counts over time, geographic distribution of surgeons, and their volume of procedures. RESULTS: The number of trabeculectomies continues to decline and now is similar to the number of tubes. Use of the relatively new trabecular bypass shunts has increased rapidly. Surgeons performing these procedures are less likely to be performing traditional glaucoma surgeries as well. The number of laser-based cyclodestruction procedures increased after introduction of the endoscopic technique and again with the introduction of so-called micropulse procedures. The procedure counts obtained with physician payment data consistently are lower than those from claims data given the limitations of the payment data. CONCLUSIONS: Glaucoma practice patterns change each time a new device or procedure is introduced. Collectively, the use of new microinvasive glaucoma surgery procedures has increased rapidly such that they now account for a significant majority of glaucoma surgeries. Given the almost complete lack of comparative data to inform surgeon choices regarding these procedures, it will be important that randomized studies are carried out to fill this gap.
PURPOSE OF REVIEW: The strength of the relationship between diabetes, diabetic retinopathy (DR), and glaucoma remains controversial. We review evidence supporting and refuting this association and explore mechanistic pathological and treatment relationships linking these diseases. RECENT FINDINGS: While studies have shown diabetes/DR may increase the risk for glaucoma, this remains inconsistently demonstrated. Diabetes/DR may contribute toward glaucomatous optic neuropathy indirectly (either by increasing intraocular pressure or vasculopathy) or through direct damage to the optic nerve. However, certain elements of diabetes may slow glaucoma progression, and diabetic treatment may concurrently be beneficial in glaucoma management. Diabetes plays a significant role in poor outcomes after glaucoma surgery. While the relationship between diabetes/DR and glaucoma remains controversial, multiple mechanistic links connecting pathophysiology and management of diabetes, DR, and glaucoma have been made. However, a deeper understanding of the causes of disease association is needed.
PURPOSE: To review information pertaining to glaucoma following infant lensectomy surgery and to provide evidence to support the responsible mechanism of this condition. METHODS AND RESULTS: Described risk factors and proposed mechanisms for infantile aphakic glaucoma were assessed. The clinical evidence observed in affected glaucoma patients was analyzed, and evidence of postoperative anterior chamber fibrosis was reviewed and interpreted. CONCLUSION: The review and assessment of laboratory and clinical evidence support the proposal that infantile aphakic glaucoma is caused, in part, by postoperative anterior chamber fibroization related to lens cell dispersion and active epithelial-mesenchymal transition with resultant filtration angle tissue injury and loss of function.
Purpose: Archetypal analysis, a form of unsupervised machine learning, identifies archetypal patterns within a visual field (VF) dataset such that any VF is described as a weighted sum of its archetypes (ATs) and has been used to quantify VF defects in glaucoma. We applied archetypal analysis to VFs affected by nonglaucomatous optic neuropathy caused by idiopathic intracranial hypertension (IIH). Methods: We created an AT model from 2862 VFs prospectively collected from 330 eyes in the IIH Treatment Trial (IIHTT). We compared baseline IIH AT patterns with their descriptive VF classifications from the IIHTT. Results: The optimum IIH AT model yielded 14 ATs resembling VF patterns reported in the IIHTT. Baseline VFs contained four or fewer meaningful ATs in 147 (89%) of study eyes. AT2 (mild general VF depression pattern) demonstrated the greatest number of study eyes with meaningful AT weight at baseline (n = 114), followed by AT1 (n = 91). Other ATs captured patterns of blind spot enlargement, hemianopia, arcuate, nasal defects, and more nonspecific patterns of general VF depression. Of all ATs, AT1 (normal pattern) had the strongest correlation with mean deviation (r = 0.69, P < 0.001). For 65 of the 93 VFs with a dominant AT, this AT matched the expert classification. Conclusions: Archetypal analysis identifies quantifiable, archetypal VF defects that resemble those commonly seen in IIH. Translational Relevance: Archetypal analysis provides a quantitative, objective method of measuring and monitoring disease-specific regional VF defects in IIH.
Glaucoma is a group of optic neuropathies characterised by the degeneration of retinal ganglion cells, resulting in damage to the optic nerve head (ONH) and loss of vision in one or both eyes. Increased intraocular pressure (IOP) is one of the major aetiological risk factors in glaucoma, and is currently the only modifiable risk factor. However, 30-40% of glaucoma patients do not present with elevated IOP and still proceed to lose vision. The pathophysiology of glaucoma is therefore not completely understood, and there is a need for the development of IOP-independent neuroprotective therapies to preserve vision. Neuroinflammation has been shown to play a key role in glaucoma and, specifically, the NLRP3 inflammasome, a key driver of inflammation, has recently been implicated. The NLRP3 inflammasome is expressed in the eye and its activation is reported in pre-clinical studies of glaucoma. Activation of the NLRP3 inflammasome results in IL-1β processing. This pro inflammatory cytokine is elevated in the blood of glaucoma patients and is believed to drive neurotoxic inflammation, resulting in axon degeneration and the death of retinal ganglion cells (RGCs). This review discusses glaucoma as an inflammatory disease and evaluates targeting the NLRP3 inflammasome as a therapeutic strategy. A hypothetical mechanism for the action of the NLRP3 inflammasome in glaucoma is presented.
Purpose: To describe the ocular phenotype of spontaneous glaucoma in a non-human primate colony. Methods: In total, 722 Rhesus macaque monkeys aged 10 to 25 years underwent optical coherence tomography (OCT), fundus photography (FP), and intraocular pressure (IOP) measurements. Monkeys with baseline cup-to-disc ratio (CDR) <0.5 were used to establish baseline ocular features. A subset was followed longitudinally for three years and compared to glaucoma suspects on the basis of OCT/FP criteria. Results: The average IOP under ketamine sedation and average CDR for the entire colony was 13.0 ± 4.3 mm Hg and 0.38 ± 0.07, respectively. The mean baseline conscious IOP of glaucoma suspects (N = 18) versus controls (N = 108) was 16.2 ± 3.5 mm Hg and 13.9 ± 2.3 mm Hg, respectively (P = 0.001). All glaucoma suspects had unremarkable slit lamp examinations and open angles based on anterior segment OCT. Baseline global circumpapillary retinal nerve fiber layer (RNFL) thickness was 91.5 ± 11.0 µM versus 102.7 ± 8.5 µM in suspects and controls, respectively (P < 0.0001). All sectors on the baseline circumpapillary OCT showed a significant reduction in RNFL thickness versus controls (P ≤ 0.0022) except for the temporal sector (P ≥ 0.07). In three-year longitudinal analysis, neither CDR nor OCT parameters changed in controls (N = 40; P ≥ 0.16), whereas significant increase in CDR (P = 0.018) and nominally significant decreases in two OCT sectors (nasal, P = 0.023 and nasal inferior, P = 0.046) were noted in suspects. Conclusions: Members of a nonhuman primate colony exhibit important ophthalmic features of human primary open-angle glaucoma. Translational Relevance: Identification of a spontaneous model of glaucoma in nonhuman primates represents an unprecedented opportunity to elucidate the natural history, pathogenesis and effective therapeutic strategies for the disease.
PURPOSE: To examine the efficacy of laser peripheral iridotomy (LPI) in subjects diagnosed as primary angle closure suspects (PACS) DESIGN: Prospective, randomized controlled trial PARTICIPANTS: This multi-center, randomized controlled trial (NCT00347178, Clinical trials.gov) enrolled 480 subjects over the age of 50 years from glaucoma clinics in Singapore with bilateral asymptomatic PACS (defined as having ≥2 quadrants of appositional angle closure on gonioscopy). METHODS: Each subject underwent prophylactic LPI in one randomly selected eye, while the fellow eye served as control. Subjects 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, and/or intraocular pressure>21 mmHg or acute angle closure [AAC]) or PACG over 5 years. RESULTS: Of the 480 randomized subjects, the majority were Chinese (92.7%) and female (75.8%) with mean age of 62.8±6.9 years. LPI-treated eyes reached endpoint less frequently after five years (24, 5.0%, incidence rate [IR]=11.65 per 1000 eye-years) compared to control eyes (45, 9.4%, IR=21.84 per 1000 eye-years, p=0.001). The adjusted hazards ratio (HR) for progression to PAC was 0.55 (95%CI: 0.37-0.83, p=0.004) in LPI-treated eyes compared to control eyes. Older subjects (per year, HR=1.06, 95%CI: 1.03-1.10, p<0.001) and eyes with higher baseline IOP (per mm Hg, HR=1.35, 95%CI: 1.22-1.50, p<0.0001) were more likely to reach an endpoint. The number needed to treat in order to prevent an endpoint was 22 (95%CI: 12.8-57.5). CONCLUSIONS: In subjects with bilateral asymptomatic PACS, eyes that underwent prophylactic LPI had significantly fewer endpoints compared to control eyes over 5 years. However, the overall incidence of PAC or PACG was low.
PURPOSE: To assess the prevalence of autoimmune diseases (AiD) in patients with primary open angle glaucoma (POAG) undergoing ophthalmic surgery. DESIGN: Retrospective cross-sectional study. PARTICIPANTS: POAG patients undergoing any ophthalmic surgery and control subjects undergoing cataract surgery at the Massachusetts Eye and Ear from March 2019 to April 2020. METHODS: All available medical records with patient demographics, ocular and medical conditions were reviewed. Differences in AiD prevalence were assessed and adjusted for covariates using multiple logistic regression. Additionally, a subgroup analysis comparing the POAG patients with and without AiD was performed. MAIN OUTCOME MEASURES: To assess prevalence of AiD based on the American Autoimmune Related Diseases Association list. RESULTS: 172 POAG patients and 179 controls were included. The overall prevalence of AiD was 17.4% in the POAG group and 10.1% in the controls (p=0.044). 6.4% of POAG patients and 3.4% of controls had more than one AiD (p = 0.18). The most prevalent AiDs in POAG group were rheumatoid arthritis (4.6%) and psoriasis (4.1%), which were also the most common in controls (2.8% each). In a fully adjusted multiple logistic regression analysis accounting for steroid use, having an AiD was associated with 2.62-fold increased odds of POAG relative to controls (95% confidence interval: 1.27-5.36, p = 0.009); other risk factors for POAG derived from the analysis included age (odds ratio [OR] = 1.04, p = 0.006), diabetes mellitus (OR = 2.31, p = 0.008) and non-White ethnicity (OR = 4.75, p < 0.001). In a case-only analysis involving the eye with worse glaucoma, there were no statistical difference in visual field mean deviation or retinal nerve fiber layer thickness (RNFLT) in POAG patients with (n = 30) and without AiD (n = 142, p > 0.13, for both). CONCLUSIONS: A higher prevalence of AiD was found in POAG patients compared to control patients undergoing ophthalmic surgery. The presence of AiD was associated with increased risk for POAG after adjusting for covariates. Additional factors may have prevented a difference in RNFLT in POAG patients with and without AiD. Autoimmunity should be explored further in the pathogenesis of POAG.
Purpose: To examine patterns of standard (trabeculectomy or glaucoma drainage devices, GDDs) vs novel (minimally invasive glaucoma surgery, MIGS) surgical techniques in the US.Methods: We used the American Academy of Ophthalmology (AAO) IRIS® Registry (Intelligent Research in Sight) queried between 2013 and 2018 (inclusive) to calculate the cumulative proportion of stand-alone, concurrent (same day) or sequential (subsequent day) glaucoma surgical techniques performed in each glaucoma diagnosis type. Secondary analyses of adjusted proportions of concurrent and sequential surgeries stratified by glaucoma diagnosis were also performed.Results: Of 203,146 eyes receiving glaucoma surgeries, open angle glaucoma (OAG) was most likely to undergo all types of intervention. The iStent was the most commonly performed MIGS, primarily for those with normal tension glaucoma (NTG) or OAG (p < .001). Conversely, GDD was the most commonly performed procedure in secondary glaucoma or other (specified) glaucoma (p < .001). ECP and iStent were the most common concurrent procedures performed; most often for OAG and NTG (p < .001). After an initial standard surgery, most eyes underwent recurrent standard interventions (90.3%). ECP was the most common MIGS performed after an initial standard surgery; particularly in primary angle-closure (PACG) and secondary glaucoma eyes (p < .001).Conclusion: Glaucoma type may influence the choice of glaucoma procedures and the decision to perform concurrent as well sequential surgical procedures. Given the poorly understood long term safety and effectiveness of MIGS, and with substantially increasing use of MIGS procedures in recent years, future studies comparing their safety and effectiveness vs standard interventions, for a variety of glaucoma types, is needed.
PURPOSE: Interest in micro-invasive glaucoma surgery (MIGS) has exploded over the last 8 years with an increase in MIGS procedures of at least 400% in the United States, according to Medicare data. MIGS is an umbrella term that can cover many different types of surgeries. This review focuses on peer-reviewed evidence for Trabectome®, iStent inject®, Kahook Dual Blade®, XEN® Gel Stent, and Hydrus®. METHODS: We present key recent studies evaluating the efficacy and safety of MIGS in various types of glaucoma patients with different stages of disease. CONCLUSION: We conclude that MIGS is generally safe and efficacious, although only some MIGS have been studied through randomized clinical trials. When comparing and contrasting the different MIGS procedures, large prospective studies are not yet the norm. High-quality large prospective studies involving MIGS will be an important next step as ophthalmologists decide how to incorporate MIGS into their surgical armamentarium.
Importance: Gait dysfunction is common in older people with visual impairment and is a major cause of falls. Objective: To compare 3-year longitudinal changes in gait measures across the spectrum of baseline visual field (VF) damage in glaucoma. Design, Setting, and Participants: A post hoc analysis was designed on September 1, 2018, following a prospective cohort study, which enrolled older adults with glaucoma or suspected glaucoma from September 2013 to March 2015 and followed up for up to 3 years. Baseline VF damage was defined by integrated VF (IVF) sensitivity and categorized as normal/mild (IVF >28 dB), moderate (IVF, 23-28 dB), and severe (IVF, <23 dB). Each participant walked on an electronic walkway back and forth twice at normal pace each study year. Linear mixed-effects models evaluated longitudinal change in gait outcomes (1) stratified within each VF severity category and (2) across the range of IVF sensitivity. Analysis took place from October 2019 to October 2020. Main Outcomes and Measures: Three-year changes in 7 gait assessments under usual-pace walking, including base support and its coefficient of variation, stride length and its coefficient of variation, stride velocity and its coefficient of variation, and cadence. Results: Of 241 participants, the mean (SD) age was 70.8 (7.7) years, 116 (48.2%) were women, and 70 (29.0%) were African American. When comparing longitudinal gait changes over 3 years across the spectrum of IVF sensitivity, each 5-unit (dB) decrement was associated with more rapid declines in stride velocity (-0.05 z score unit/y; 95% CI, -0.09 to -0.01; P = .01) and cadence (-0.07 z score unit/y; 95% CI, -0.10 to -0.03; P < .001). When evaluating gait changes within each glaucoma severity group, shorter stride length was associated with persons with normal/mild (-0.06 z score unit/y; 95% CI, -0.10 to -0.03; P = .001), moderate (-0.08 z score unit/y; 95% CI, -0.12 to -0.04; P < .001), and severe VF damage (-0.16 z score unit/y; 95% CI, -0.24 to -0.07; P < .001), while stride velocity (-0.18 z score unit; 95% CI, -0.28 to -0.07; P = .002) and slower cadence (-0.15 z score unit; 95% CI, -0.25 to -0.04; P = .006) were associated with those with severe VF damage. Conclusions and Relevance: At worse levels of baseline VF damage, patients with glaucoma in this study demonstrated an exacerbated decline in walking speeds (ie, stride velocity and cadence), indicating that mobility speeds decrease faster over time in older adults with glaucoma.
PURPOSE: Metabolomic and preclinical studies suggest that branched-chain amino acids (BCAA) may be inversely associated with neurodegenerative diseases including glaucoma. We therefore assessed the long-term association between dietary intake of BCAA and incident primary open-angle glaucoma (POAG) and POAG subtypes. METHODS: We followed biennially participants of the Nurses' Health Study (NHS; 65 531 women: 1984-2016), Health Professionals Follow-up Study (42 254 men: 1986-2016) and NHSII (66 904 women; 1991-2017). Eligible participants were 40+ years old and reported eye examinations. Repeated validated food frequency questionnaires were used to assess dietary intake of BCAA. Incident cases of POAG and POAG subtypes defined by visual field (VF) loss and untreated intraocular pressure (IOP) were confirmed by medical record review. Multivariable-adjusted relative risks (MVRRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models. RESULTS: We identified 1946 incident POAG cases. The pooled MVRRs of POAG for the highest quintile (Q5 = 17.1 g/day) versus lowest quintile (Q1 = 11.2 g/day) of total BCAA intake was 0.93 (95% CI, 0.73-1.19; ptrend = 0.45; pheterogeneity by sex = 0.24). For subtypes of POAG defined by IOP level or POAG with only peripheral VF loss, no associations were observed for men or women (ptrend ≥ 0.20); however, for the POAG subtype with early paracentral VF loss, there was a suggestion of an inverse association in women (MVRRQ5versusQ1 = 0.80 [95% CI, 0.57-1.12; ptrend = 0.12]) but not in men (MVRRQ5versusQ1 = 1.38 [95% CI, 0.81-2.34; ptrend = 0.28; pheterogeneity by sex = 0.06]). CONCLUSION: Higher dietary intake of BCAA was not associated with POAG risk.
Reversal of optic nerve head (ONH) cupping has been considered an important clinical observation that signals surgical success and control of intraocular pressure (IOP) in childhood glaucoma. Many theories based on elasticity of pediatric eyes have been proposed, including anterior movement of the elastic lamina cribrosa or shrinkage of the scleral canal. The relationship between these factors and axonal loss is unclear when reversal of cupping has been observed. Retinal nerve fiber layer (RNFL) optical coherence tomography (OCT) can help to clarify this. We present a case series of 4 pediatric patients with secondary glaucoma that demonstrated ONH cupping reversal with pre- and postoperative clinical images and RNFL OCT.
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.