1,812 research outputs found
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Hypertensive phase and early complications after Ahmed glaucoma valve implantation with intraoperative subtenon triamcinolone acetonide
Objective: To evaluate intraoperative subtenon triamcinolone acetonide (TA) as an adjunct to Ahmed glaucoma valve (AGV) implantation. Design: Retrospective comparative case series. Participants: Forty-two consecutive cases of uncontrolled glaucoma undergoing AGV implantation: 19 eyes receiving intraoperative subtenon TA and 23 eyes that did not receive TA. Methods: A retrospective chart review was performed on consecutive pseudophakic adult patients with uncontrolled glaucoma undergoing AGV with and without intraoperative subtenon TA injection by a single surgeon. Clinical data were collected from 42 eyes and analyzed for the first 6 months after surgery. Main outcome measures Primary outcomes included intraocular pressure (IOP) and number of glaucoma medications prior to and after AGV implantation. The hypertensive phase (HP) was defined as an IOP measurement of greater than 21 mmHg (with or without medications) during the 6-month postoperative period that was not a result of tube obstruction, retraction, or malfunction. Postoperative complications and visual acuity were analyzed as secondary outcome measures. Results: Five out of 19 (26%) TA cases and 12 out of 23 (52%) non-TA cases developed the HP (P=0.027). Mean IOP (14.2±4.6 in TA cases versus [vs] 14.7±5.0 mmHg in non-TA cases; P=0.78), and number of glaucoma medications needed (1.8±1.3 in TA cases vs 1.6±1.1 in the comparison group; P=0.65) were similar between both groups at 6 months. Although rates of serious complications did not differ between the groups (13% in the TA group vs 16% in the non-TA group), early tube erosion (n=1) and bacterial endophthalmitis (n=1) were noted with TA but not in the non-TA group. Conclusions: Subtenon TA injection during AGV implantation may decrease the occurrence of the HP but does not alter the ultimate IOP outcome and may pose increased risk of serious complications within the first 6 months of surgery
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Latanoprost with high precision, piezo-print microdose delivery for IOP lowering: clinical results of the PG21 study of 0.4 µg daily microdose.
Background:Topical high-precision piezo-print delivery of microdoses of latanoprost achieved significant IOP reduction consistent with the eyedropper effect but with a 75% reduced exposure to drugs and preservatives. Prostaglandin analogs are a mainstay glaucoma therapy. However, conventional eyedroppers deliver 30-50 µL drops that greatly exceed the physiologic 7-µL ocular tear film capacity. Eyedropper overdosing floods the eye with excess drug compounds and preservatives, resulting in ocular surface toxicity, periorbitopathy, and other well-characterized ocular side effects. Piezoelectric high-precision microdosing provides targeted delivery that can reduce exposure to both drug and preservatives compared to conventional eyedropper delivery, with the potential to deliver similar biologic effect. Methods:Both eyes (N=60) of 30 healthy volunteers received single 8-µL microdoses of 0.005% latanoprost (0.4 µg; µRx-latanoprost) on the morning of Days 1 and 2 using a high-precision, piezo-print horizontal delivery system. Diurnal IOP was measured before and 2 days after microdosing. Main efficacy outcomes were diurnal IOP change after µRx-latanoprost microdosing and accurate microdosing success rates, and the primary safety outcome was adverse event (AE) incidence. Results:µRx-latanoprost reduced baseline IOP by 26% and 30% at 1 and 2 days postadministration, respectively. Successful topical dosing was achieved in 100% of technician-assisted deliveries. All patients successfully self-administered microdoses after receiving training. Microdose administration was well tolerated and did not result in any AEs. Conclusion:Microdosing of 0.4 µg of µRx-latanoprost achieved significant IOP reduction. Lower ocular exposure with topical prostaglandin analog microdosing can enable new therapeutic opportunities for optimizing glaucoma treatment. Microdosing may also be beneficial in reducing ocular side effects associated with excessive drug product and preservatives often used to treat chronic ocular diseases such as glaucoma
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Regulation of intraocular pressure by soluble and membrane guanylate cyclases and their role in glaucoma
Glaucoma is a progressive optic neuropathy characterized by visual field defects that ultimately lead to irreversible blindness (Alward, 2000; Anderson et al., 2006). By the year 2020, an estimated 80 million people will have glaucoma, 11 million of which will be bilaterally blind. Primary open-angle glaucoma (POAG) is the most common type of glaucoma. Elevated intraocular pressure (IOP) is currently the only risk factor amenable to treatment. How IOP is regulated and can be modulated remains a topic of active investigation. Available therapies, mostly geared toward lowering IOP, offer incomplete protection, and POAG often goes undetected until irreparable damage has been done, highlighting the need for novel therapeutic approaches, drug targets, and biomarkers (Heijl et al., 2002; Quigley, 2011). In this review, the role of soluble (nitric oxide (NO)-activated) and membrane-bound, natriuretic peptide (NP)-activated guanylate cyclases that generate the secondary signaling molecule cyclic guanosine monophosphate (cGMP) in the regulation of IOP and in the pathophysiology of POAG will be discussed
Glaucoma Screening in the Haitian Afro-Caribbean Population of South Florida
Objective: To evaluate the presence of clinical signs consistent with suspected glaucoma in Haitian Afro-Caribbean individuals residing in South Florida who do not receive regular eye examinations. Design: Retrospective, cross-sectional study. Methods: SETTING: Community health center in the Little Haiti district of Miami, Florida. PATIENT POPULATION: We reviewed medical records and screening forms from five health screenings between October 2011 to October 2013 of 939 Afro-Caribbean individuals older than 18 years, who were never diagnosed with glaucoma or had an eye examination within the last ten years. PROCEDURES: Measurements of distance visual acuity (VA), intraocular eye pressure (IOP), central corneal thickness (CCT), cup-to-disc ratio (CDR), frequency doubling technology (FDT) perimeter visual field (VF). Main Outcome Measures: Proportion of glaucoma suspects, based on IOP greater than or equal to 24 mm Hg or CDR greater than or equal to 0.7 in either eye, and determinants of CDR and IOP. Results: One hundred ninety-one (25.5%) of 750 patients were identified as glaucoma suspects. Glaucoma suspects were common in both the youngest and oldest age groups (70 years, 25.0%; 95% CI, 21.8–28.2) and higher in men than women less than 70 years; the reverse was true after 70 years. Among all patients, mean IOP was 19.2±4.5 mmHg, mean CDR was 0.37±0.17, and mean CCT was 532±37.1 µm. In multiple linear stepwise regression analysis, determinates of increased CDR included increasing age (P = 0.004), lack of insurance (P = 0.019), and higher IOP (P<0.001), while increasing CDR (P<0.001) and thicker CCT (P<0.001) were associated with higher IOP. Conclusions: This first glaucoma survey in a U.S. Haitian Afro-Caribbean population indicates glaucoma suspect status is high across all age groups, and suggests glaucoma monitoring in people less than 40 years of age is indicated in this population
Lessons from The Glaucoma Foundation Think Tank 2023: A Patient-Centric Approach to Glaucoma
PURPOSE: To summarize the main topics discussed during the 28th Annual Glaucoma Foundation Think Tank Meeting "A Patient-Centric Approach to Glaucoma" held in New York on June 9th and 10th 2023. METHODS: The highlights of the sessions on BIG DATA, genetics, modifiable lifestyle risk factors, female sex hormones, and neuroprotection in the field of primary open-angle glaucoma (POAG) were summarized. RESULTS: The researchers discussed the importance of BIG DATA repositories available at national and international levels for POAG research, including the United Kingdom Biobank. Combining genotyped large cohorts worldwide, facilitated by artificial intelligence (AI) and machine learning approaches, led to the milestone discovery of 312 genome-wide significant disease loci for POAG. While these loci could be combined into a polygenic risk score with clinical utility, Think Tank meeting participants also provided analytical epidemiological evidence that behavioral risk factors modify POAG polygenetic risk, citing specific examples related to caffeine and alcohol use. The impact of female sex hormones on POAG pathophysiology was discussed, as was neuroprotection and the potential use of AI to help mitigate specific challenges faced in clinical trials and speed approval of neuroprotective agents. CONCLUSION: The experts agreed on the importance of genetics in defining individual POAG risk and highlighted the additional crucial role of lifestyle, gender, blood pressure, and vascular risk factors. The main takeaways also included that BIG DATA repositories and AI are important combinatory tools to foster novel strategies to prevent and stabilize glaucoma and, in the future, recover vision loss from the disease
Towards modifying the genetic predisposition for glaucoma: An overview of the contribution and interaction of genetic and environmental factors
Glaucoma, the leading cause of irreversible blindness worldwide, is a complex human disease, with both genetic and environmental determinants. The availability of large-scale, population-based cohorts and biobanks, combining genotyping and detailed phenotyping, has greatly accelerated research into the aetiology of glaucoma in recent years. Hypothesis-free genome-wide association studies have furthered our understanding of the complex genetic architecture underpinning the disease, while epidemiological studies have provided advances in the identification and characterisation of environmental risk factors. It is increasingly recognised that the combined effects of genetic and environmental factors may confer a disease risk that reflects a departure from the simple additive effect of the two. These gene-environment interactions have been implicated in a host of complex human diseases, including glaucoma, and have several important diagnostic and therapeutic implications for future clinical practice. Importantly, the ability to modify the risk associated with a particular genetic makeup promises to lead to personalised recommendations for glaucoma prevention, as well as novel treatment approaches in years to come. Here we provide an overview of genetic and environmental risk factors for glaucoma, as well as reviewing the evidence and discussing the implications of gene-environment interactions for the disease
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Reliable intraocular pressure measurement using automated radio-wave telemetry
Purpose To present an autonomous intraocular pressure (IOP) measurement technique using a wireless implantable transducer (WIT) and a motion sensor. Methods: The WIT optical aid was implanted within the ciliary sulcus of a normotensive rabbit eye after extracapsular clear lens extraction. An autonomous wireless data system (AWDS) comprising of a WIT and an external antenna aided by a motion sensor provided continuous IOP readings. The sensitivity of the technique was determined by the ability to detect IOP changes resulting from the administration of latanoprost 0.005% or dorzolamide 2%, while the reliability was determined by the agreement between baseline and vehicle (saline) IOP. Results: On average, 12 diurnal and 205 nocturnal IOP measurements were performed with latanoprost, and 26 diurnal and 205 nocturnal measurements with dorzolamide. No difference was found between mean baseline IOP (13.08±2.2 mmHg) and mean vehicle IOP (13.27±2.1 mmHg) (P=0.45), suggesting good measurement reliability. Both antiglaucoma medications caused significant IOP reduction compared to baseline; latanoprost reduced mean IOP by 10% (1.3±3.54 mmHg; P<0.001), and dorzolamide by 5% (0.62±2.22 mmHg; P<0.001). Use of latanoprost resulted in an overall twofold higher IOP reduction compared to dorzolamide (P<0.001). Repeatability was ±1.8 mmHg, assessed by the variability of consecutive IOP measurements performed in a short period of time (≤1 minute), during which the IOP is not expected to change. Conclusion: IOP measurements in conscious rabbits obtained without the need for human interactions using the AWDS are feasible and provide reproducible results
Reliable intraocular pressure measurement using automated radio-wave telemetry
Purpose To present an autonomous intraocular pressure (IOP) measurement technique using a wireless implantable transducer (WIT) and a motion sensor. Methods: The WIT optical aid was implanted within the ciliary sulcus of a normotensive rabbit eye after extracapsular clear lens extraction. An autonomous wireless data system (AWDS) comprising of a WIT and an external antenna aided by a motion sensor provided continuous IOP readings. The sensitivity of the technique was determined by the ability to detect IOP changes resulting from the administration of latanoprost 0.005% or dorzolamide 2%, while the reliability was determined by the agreement between baseline and vehicle (saline) IOP. Results: On average, 12 diurnal and 205 nocturnal IOP measurements were performed with latanoprost, and 26 diurnal and 205 nocturnal measurements with dorzolamide. No difference was found between mean baseline IOP (13.08±2.2 mmHg) and mean vehicle IOP (13.27±2.1 mmHg) (P=0.45), suggesting good measurement reliability. Both antiglaucoma medications caused significant IOP reduction compared to baseline; latanoprost reduced mean IOP by 10% (1.3±3.54 mmHg; P<0.001), and dorzolamide by 5% (0.62±2.22 mmHg; P<0.001). Use of latanoprost resulted in an overall twofold higher IOP reduction compared to dorzolamide (P<0.001). Repeatability was ±1.8 mmHg, assessed by the variability of consecutive IOP measurements performed in a short period of time (≤1 minute), during which the IOP is not expected to change. Conclusion: IOP measurements in conscious rabbits obtained without the need for human interactions using the AWDS are feasible and provide reproducible results
Harvard Glaucoma Fairness: A Retinal Nerve Disease Dataset for Fairness Learning and Fair Identity Normalization
Fairness (also known as equity interchangeably) in machine learning is
important for societal well-being, but limited public datasets hinder its
progress. Currently, no dedicated public medical datasets with imaging data for
fairness learning are available, though minority groups suffer from more health
issues. To address this gap, we introduce Harvard Glaucoma Fairness
(Harvard-GF), a retinal nerve disease dataset with both 2D and 3D imaging data
and balanced racial groups for glaucoma detection. Glaucoma is the leading
cause of irreversible blindness globally with Blacks having doubled glaucoma
prevalence than other races. We also propose a fair identity normalization
(FIN) approach to equalize the feature importance between different identity
groups. Our FIN approach is compared with various the-state-of-the-art fairness
learning methods with superior performance in the racial, gender, and ethnicity
fairness tasks with 2D and 3D imaging data, which demonstrate the utilities of
our dataset Harvard-GF for fairness learning. To facilitate fairness
comparisons between different models, we propose an equity-scaled performance
measure, which can be flexibly used to compare all kinds of performance metrics
in the context of fairness. The dataset and code are publicly accessible via
\url{https://ophai.hms.harvard.edu/datasets/harvard-glaucoma-fairness-3300-samples/}
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