The Effect of Yoga on Intraocular Pressure Using the "iCare HOME2" Tonometer.

BACKGROUND: Various yoga positions may have an unfavorable impact on intraocular pressure (IOP) and may therefore be seen as a potential risk factor for the progression of glaucoma. The new "iCare HOME2" is a handheld self-tonometer for IOP measurements outside clinical settings. This is the first study to evaluate the immediate effect of common yoga postures on the IOP of healthy and glaucomatous eyes using the "iCare HOME2" self-tonometer and to compare the time of IOP recovery in both groups. METHODS: This is a single-center, prospective, observational study including 25 healthy and 25 glaucoma patients performing the following yoga positions: "legs up" (Viparita Karani), "bend over" (Uttanasana), "plough pose" (Halasana), and the "down face dog" (Adho Mukha Svanasana) for 90 s each, with a 2-min break in between. IOP was measured with the "iCare HOME2" before, during, and after each position. RESULTS: IOP significantly increased in all eyes in all positions (p < 0.05), showing no statistically significant difference between healthy or glaucomatous eyes (p > 0.05). The mean rise in IOP in healthy subjects was 1.6 mmHg (SD 1.42; p = 0.037), 14.4 mmHg (SD 4.48; p < 0.001), 7.5 mmHg (SD 4.21; p < 0.001), and 16.5 mmHg (SD 3.71; p < 0.001), whereas in glaucoma patients, IOP rose by 2.8 mmHg (SD 2.8; p = 0.017), 11.6 mmHg (SD 3.86; p < 0.001), 6.0 mmHg (SD 2.24; p < 0.001), and 15.1 mmHg (SD 4.44; p < 0.001) during the above listed yoga positions, repsectively. The highest increase in IOP was seen in the down face position, reaching mean IOP values above 31 mmHg in both study groups. IOP elevation was observed immediately after assuming the yoga position, with no significant change during the following 90 s of holding each pose (p > 0.05). All IOP values returned to baseline level in all individuals, with no significant difference between healthy and glaucoma participants. CONCLUSION: Our data show that common yoga positions can lead to an acute IOP elevation of up to 31 mmHg in healthy as well as glaucoma eyes, with higher IOP values during head-down positions. Given that IOP peaks are a major risk factor for glaucomatous optic neuropathy, we generally advise glaucoma patients to carefully choose their yoga exercises. If and to what extent practicing yoga leads to glaucoma progression, however, remains unclear and warrants further research.

Effect of digital ocular massage on intraocular pressure and Schlemm's canal dimensions.

Digital ocular massage has been reported to temporarily lower intraocular pressure (IOP). This could be related to an enhanced aqueous humor outflow; however, the mechanism is not clearly understood. Using anterior segment optical coherence tomography, the Schlemm's canal (SC) and trabecular meshwork (TM) can be imaged and measured. Here, 66 healthy adults underwent digital ocular massage for 10 min in their right eyes. The IOP and dimensions of the SC and TM were measured before and after ocular massage. All subjects demonstrated IOP reduction from 15.7 ± 2.5 mmHg at baseline to 9.6 ± 2.2 mmHg immediately after, and median of 11.6 mmHg 5-min after ocular massage (Friedman's test, p < 0.001). There was significant change in SC area (median 10,063.5 µm2 at baseline to median 10,151.0 µm2 after ocular massage, Wilcoxon test, p = 0.02), and TM thickness (median 149.8 µm at baseline to 144.6 ± 25.3 µm after ocular massage, Wilcoxon test, p = 0.036). One-third of the subjects demonstrated collapse of the SC area (-2 to -52%), while two-thirds showed expansion of the SC area (2 to 168%). There were no significant changes in SC diameter (270.4 ± 84.1 µm vs. 276.5 ± 68.7 µm, paired t-test, p = 0.499), and TM width (733.3 ± 110.1 µm vs. 733.5 ± 111.6 µm, paired t-test, p = 0.988). Eyes with a higher baseline IOP demonstrated a greater IOP reduction (Pearson correlation coefficient r = -0.521, p < 0.001). Eyes with smaller SC area at baseline showed greater SC area expansion (Pearson correlation coefficient = -0.389, p < 0.001). Greater IOP reduction appeared in eyes with greater SC area expansion (Pearson correlation coefficient r = -0.306, p = 0.01). Association between change in IOP and change in TM thickness was not significant (Spearman's ρ = 0.015, p = 0.902). Simple digital ocular massage is an effective method to lower IOP values, and change in the SC area was significantly associated with IOP changes.

Intraocular Pressure Lowering Associated With Worsening Optic Pit-Like Retinoschisis.

In this article, we present a case of optic pit-like macular retinoschisis in the absence of advanced glaucomatous cupping. Intraocular pressure (IOP)-lowering therapy, which was started due to an early concern for glaucoma, caused a worsening of the retinoschisis, which subsequently resolved on discontinuation of the IOP-lowering therapy. Lower IOP likely triggered intraretinal fluid accumulation by facilitating a translaminar gradient from the subarachnoid to intraretinal space. [Ophthalmic Surg Lasers Imaging Retina 2024;55:100-102.].

Effect of Glucosamine on Intraocular Pressure and Risk of Developing Glaucoma.

PRCIS: Glucosamine supplementation is common but can be associated with increased intraocular pressure (IOP) and could contribute to the pathogenesis of glaucoma. It may be prudent for ophthalmologists to elicit any history of glucosamine use from their patients and advise them accordingly. Further studies on the role of glucosamine in glaucoma are warranted. BACKGROUND: The most frequently recommended slow-acting medication for osteoarthritis symptoms is glucosamine, although its effectiveness is questionable. Widely used glucosamine sulfate supplements may increase IOP. METHODS: In the current study, we analyzed online databases such as UK Biobank, MedWatch, and FinnGen to evaluate the relationship between glucosamine and IOP and glaucoma. We included budesonide and fluticasone in the analysis for comparison since these drugs are associated with increased IOP. RESULTS: In UK Biobank subjects, glucosamine use was associated with increased corneal compensated IOP ( P =0.002, 2-tailed t test). This was also true in subjects without glaucoma ( P =0.002, 2-tailed t test). However, no significant association between glucosamine and IOP was detected in subjects with a diagnosis of glaucoma. In MedWatch, 0.21% of subjects taking glucosamine reported glaucoma, 0.29% of subjects using budesonide reported glaucoma, and 0.22% of subjects using fluticasone reported glaucoma. In contrast, 0.08% of subjects using any other drug reported glaucoma. This variability is significant ( P <0.001, 2-tailed Fisher exact test). Data from FinnGen on the risk of primary open angle glaucoma or glaucoma in subjects using glucosamine before the diagnosis of the disease revealed a significantly increased risk for both primary open angle glaucoma (hazard ratio: 2.35) and glaucoma (hazard ratio: 1.95). CONCLUSION: Glucosamine supplementation is common but can be associated with increased IOP and could contribute to the pathogenesis of glaucoma. It may be prudent for ophthalmologists to elicit any history of glucosamine use from their patients and advise them accordingly. Further studies on the role of glucosamine in glaucoma are warranted.

Selective Laser Trabeculoplasty as a Substitute for Medications in Patients with Mild-to-moderate Glaucoma in the Brazilian Public Health System.

PRCIS: Selective laser trabeculoplasty can be used as a substitute for medications in patients with mild-to-moderate glaucoma, reducing the cost of eye drop distribution in the Brazilian public health system. PURPOSE: To observe the effectiveness of selective laser trabeculoplasty (SLT) as a substitute for eye drops in patients with open angle glaucoma in the Brazilian Public Health System. MATERIALS AND METHODS: SLT was performed bilaterally after medication washout. This is a prospective interventional study comparing intraocular pressure (IOP) when using eye drops at baseline (post-washout), and at 12-month follow-up after SLT. Medication was added if the target IOP was not achieved, following the Brazilian Public Health System eye drops protocol, based on medication costs. Absolute (without eye drops) and qualified (with eye drops) success were measured with IOP ≤ 21, IOP ≤ 18, IOP ≤ 15 and IOP ≤ 12 mm Hg. Besides IOP evolution, the ability to reduce IOP (in %), and eye drops reduction were evaluated. RESULTS: Ninety-two eyes of 46 patients were included, 70 eyes with mild glaucoma and 22 with moderate glaucoma; the mean number of eye drops was 2.26±1.06 (82.6% were using a prostaglandin analogue), and post-washout IOP of 21.10±5.24 mm Hg. There was relative success at IOP ≤18 mm Hg, where the mild group had greater success than the moderate group (88.1% vs. 71.4%, P =0.824). The average IOP reductions were 23.04% and 25.74% at 6 and 12 months, respectively. The average number of eye drops was 1.02, with 1.1% using a prostaglandin analogue. Furthermore, 68.19% of the patients had a decrease in the quantity of eye drops used. CONCLUSION: SLT is effective in reducing IOP and replacing eye drops in patients in the Brazilian Public Health System. Moreover, there was a significant reduction in the use of prostaglandin analogues.

Effect of yoga on intra-ocular pressure in patients with glaucoma: A systematic review and meta-analysis.

Glaucoma is the second leading cause of blindness in the world, with an estimated 57.5 million people suffering from glaucoma globally. Treatment of glaucoma focuses on lowering intra-ocular pressure to prevent progression of visual field defects, which is the only proven method for treating this disease. Yoga practices are believed to lower intra-ocular pressure in the eyes and prevent further damage in patients with glaucoma. Therefore, this systematic review was planned to explore the available scientific studies on yoga and intra-ocular pressure in glaucoma patients. PubMed, Cochrane Library, and Google Scholar were the basis for the investigation of the literature. The Jadad Scale was used to assess the quality of included clinical trials, and the JBI Critical Appraisal Checklist was used to assess the quality of included case studies. Based on the quality assessment and eligibility, six studies on yoga and intra-ocular pressure in glaucoma patients carried out between 2007 and 2021 were included in the final review. The results showed a reduction in intra-ocular pressure in patients with glaucoma through Jyoti-trataka (gazing steadily on a point or candle flame) and some other slow yogic breathing techniques, whereas studies on inversion Asanas (yoga postures) showed a rapid increase in intra-ocular pressure soon after starting. The three high-quality RCTs included in the meta-analysis showed a greater improvement in intra-ocular pressure in the yoga groups in both eyes than in the control groups; however, there were some limitations related to a small sample size, study quality, a long-term follow-up period, and variations in the yoga practices. Therefore, further studies with larger sample sizes and long-term follow-up are needed to overcome the limitations for a better understanding.

The short-term effects of intranasal steroids on intraocular pressure in pediatric population.

PURPOSE: To evaluate the effect of intranasal mometasone furoate (INMF) on short-term intraocular pressure (IOP) alterations in children with allergic rhinitis (AR). METHODS: Children diagnosed with AR and to whom INMF nasal spray had been firstly prescribed were enrolled. Cases with any ocular diseases except for refractive errors were excluded. Complete ophthalmologic examinations including IOP measurements using Tonopen XL were performed before the treatment as well as at the first and sixth weeks of follow-up. Demographics and ophthalmologic findings were noted and statistically analyzed. RESULTS: Study population consisted of 62 right eyes of 62 children with a mean age of 8.55 ± 3.14 years. Of them, 29 were female (46.8%) and 33 were male (53.2%). Dilated fundoscopy revealed an enlarged Cup/Disc ratio in 12 eyes (19.4%). Family history of glaucoma was positive in 13 cases (21.0%). Mean best corrected visual acuity was found as 0.05 ± 0.08 logMAR. Initial IOP was 17.1 ± 2.3 mmHg; whereas it was measured as 18.2 ± 2.0 mmHg and 17.3 ± 2.1 mmHg at the first and sixth weeks of follow-up, respectively (p < 0.001). Both at the first and sixth weeks of follow-up, significant IOP rise was present in children with a positive family history of glaucoma (p < 0.001 and p = 0.003, respectively). Besides, increased IOP was found in participants with cupping revealed on fundoscopy at the first week of follow-up (p = 0.044). CONCLUSION: Since children have greater risk for steroid-induced ocular hypertensive response than adults, ophthalmologic evaluation must be recommended in children receiving intranasal steroids.

Spontaneously Arrested Bilateral Primary Congenital Glaucoma: A Case Report From Ethiopia.

Background: Primary congenital glaucoma is potentially blinding condition characterized by elevated intraocular pressure and optic disc cupping. It is typically bilateral and usually manifest in the first year of life. Spontaneously arrested primary congenital glaucoma can occur, but it is very rare. Case Report: A 32-year-old male patient from North Shewa presented to the department of ophthalmology, Menelik II Hospital with deterioration of vision. On examination he had large corneas with horizontal diameter of 14 mm, increased axial length, faint corneal stromal opacity and Haab's striae of both eyes. Anterior chamber angles were wide open. His intraocular pressure, optic nerve head appearance and visual field in both eyes were normal. He had subluxated dense cataract of the right eye. Conclusion: Late presentation with sequelae of primary congenital glaucoma without optic neuropathy is possible. Regular follow-up of spontaneously arrested congenital glaucoma and scleral fixation of intraocular lens is recommended.

Correlation between choroidal thickness and intraocular pressure control in primary angle-closure glaucoma.

PURPOSE: To study the correlation between choroidal thickness (CT) and IOP control in primary angle-closure glaucoma (PACG). METHODS: In total, 61 patients (102 eyes) with PACG underwent subfoveal CT (SFCT) scanning using enhanced depth imaging-optical coherence tomography. The subjects with PACG were further grouped as controlled IOP (≤21 mm Hg on maximal medical therapy) and uncontrolled IOP (>21 mm Hg on maximal medical therapy). The average CT of the PACG eyes was calculated and compared between both groups. A correlation analysis was done between CT and intereye difference in CT with the disease parameters. RESULTS: The mean CT was 274.38 ± 42.10 µm in 102 PACG eyes. SFCT was significantly increased in the uncontrolled IOP group as compared with the controlled IOP group. The mean SFCT was 245.57 ± 62.10 µm in the controlled group and 294.46 ± 51.05 µm in the uncontrolled group (P < 0.01). Factors associated with a thicker choroid were younger age, high IOP, and higher optic nerve head cupping (P < 0.001). Neither the visual field-mean deviation (VF-MD) nor pattern standard deviation (PSD) was found to be associated with overall CT. The intereye asymmetry between CT was significantly associated with poor VF-MD and PSD. CONCLUSION: PACG eyes with thicker choroid may be a risk factor for poor IOP control on medical anti-glaucoma therapy. Thicker choroid as compared to the fellow eye is a poor prognostic sign and these eyes should be monitored closely.

Acupuncture treatment of glaucoma based on radar plots: A protocol for an overview of systematic reviews.

BACKGROUND: Glaucoma is the second most blinding eye disease in the world. Currently, lowering the intraocular pressure through various methods is the main treatment of glaucoma. Acupuncture has been effectively and safely used in the treatment of glaucoma. However, the evidence for the efficacy of acupuncture in the treatment of glaucoma is controversial, leading to inconsistent findings from systematic evaluations at abroad and home. Therefore, this protocol aims to provide a multivariate evaluation on the quality of evidences from current systematic reviews (SRs) and/or meta-analyzes (MAs) of acupuncture in the treatment of glaucoma, and literature quality, thus providing an intuitive and reliable evidence synthesis and basis for clinical decision making. METHODS: MAs/SRs about the acupuncture treatment of glaucoma will be searched online, including Chinese Biomedical Literature Database (CBM), China Science and Technology Journal Database (VIP), China National Knowledge Infrastructure (CNKI), WanFang Database (WF), Web of Science, Embase, PubMed, and Cochrane Library. Two investigators will independently screen literatures according to inclusion and exclusion criteria and extract data. A multivariate evaluation of the included literature will be performed by depicting radar plots in 6 aspects as follows: Year of publication, study type, SRs assessment through the Assessment of Multiple Systematic Reviews 2 (AMSTAR 2), literature quality assessment through the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA), homogeneity, and publication bias. The Grading of Recommendations Assessment, Development, and Evaluation evidence quality assessment tool will be used to grade and evaluate the quality of outcome indicators of the included literatures. RESULTS: This study will be submitted for publication in a peer-reviewed journal. CONCLUSION: We would like to provide a visual and scientific approach for clinical decision making of acupuncture treatment of glaucoma through a accessible and useful assessment of systematic reviews.

Severe Optic Disc Cupping Following the Methanol Toxicity in a 20-Year-old Man: A Case Report.

In April 2018, a 20-year-old man with a history of methanol intoxication from an alcoholic drink two years ago, when he was 18 years old, was referred to Nikookari Eye Hospital in Tabriz, Iran. He was admitted to emergency service and underwent eight hours of hemodialysis at the time of poisoning. His past medical history was negative, and he did not take any medication after discharge. The patient had a driving license and never experienced any visual problems before. At presentation, his visual acuity was 160/200 in both eyes with the main complaint of visual field deterioration. Other neurologic exams and brain magnetic resonance imaging (MRI) were reported normal by a neurologist. Optic disc cupping was near total in both eyes with a very narrow remaining rim. Optic disc cupping was very similar to glaucomatous cupping. Intraocular pressure was checked several times via Goldmann tonometry and was 13 mmHg. There was no history of refractive surgery leading to thin cornea. Based on this case, methanol poisoning can mimic glaucomatous optic disc cupping. This is the first case report of methanol toxicity-related optic disc cupping from Iran.

Visual outcomes and associated factors of primary congenital glaucoma in children.

PURPOSE: We evaluated the long-term visual outcomes in children with primary congenital glaucoma and determined the factors associated with the final visual outcomes. METHODS: Medical records of children with primary congenital glaucoma between 2005 and 2016, seen at Seoul National University Children's Hospital in South Korea, were reviewed. The minimum follow-up period after surgery for primary congenital glaucoma was 3 years. Visual acuity (VA) was categorized into good (≧20/70) and poor (< 20/70). Factors including age, VA, refractive errors, intraocular pressure (IOP), laterality, and cup-to-disc (C/D) ratio were compared between the groups. RESULTS: A total of 71 eyes of 44 patients were included. The patients' age at the time of surgery was 14.7 ± 12.2 months. The mean IOP was 28.3 ± 7.0 mmHg. During 6.7 ± 2.7 years of mean follow-up after surgery, 39 eyes (54.9%) needed occlusion treatment. After occlusion, patients with lower IOP values, lesser additional surgeries, reversal of optic disc cupping, and better initially measured VA achieved a better visual outcome. At the final assessment, the mean age was 7.8 ± 2.6 years, and the mean VA gain was 15.0 ± 19.4 letters. There were 44 eyes (62.0%) with VA ≧20/70. CONCLUSIONS: In children with primary congenital glaucoma, IOP control and the optic disc configuration over time are important factors associated with visual outcome. Regular follow-up and correction of refractive errors-along with occlusion for those with difference in VA between the two eyes-might be helpful for achieving better visual outcomes.

Yogic Pranayama and Diaphragmatic Breathing: Adjunct Therapy for Intraocular Pressure in Patients With Primary Open-angle Glaucoma: A Randomized Controlled Trial.

PRCIS: Yogic pranayama and diaphragmatic breathing are potential adjunctive therapies for patients with glaucoma; however, they are not substitutes for medicine or eye drops. PURPOSE: Currently, medical or surgical lowering of intraocular pressure is the only therapeutic approach for treating primary open-angle glaucoma. Intraocular pressure maintenance is influenced by autonomic activity (sympathetic and parasympathetic). "Yogic pranayama" and "diaphragmatic breathing" are exercises that can affect autonomic activity by stimulating a wakeful hypometabolic state of parasympathetic dominance. We aimed to assess the effect of yogic pranayama and diaphragmatic breathing on intraocular pressure to determine whether it can be recommended for individuals with established glaucoma in combination with glaucoma medication as an adjuvant therapy. MATERIALS AND METHODS: In this prospective, randomized trial, 90 patients with primary open-angle glaucoma (180 eyes, age: above 40 y) were assigned to either the control or yogic pranayama and diaphragmatic breathing exercise group. In the latter group, yogic pranayama and diaphragmatic breathing were practiced daily for 6 months. We measured the intraocular pressure at presentation and subsequently after 1, 3, and 6 months. RESULTS: Compared with the wait-list group, the yogic pranayama and diaphragmatic breathing exercise group had significantly lowered intraocular pressure (right eye: 20.85±3.39 to 14.90±2.86 mm Hg; left eye: 20.30±4.12 to 14.25±3.85 mm Hg; P<0.001). CONCLUSION: Yogic pranayama and diaphragmatic breathing exercises can reduce intraocular pressure in patients with primary open-angle glaucoma and can therefore be recommended as an adjuvant therapy.

[The role of citicoline in glaucoma]. / Bedeutung von Citicolin bei der Glaukomerkrankung.

BACKGROUND: In recent years, many experimental and clinical studies have shown that in glaucoma, neuronal degeneration occurs not only at the level of the retina and optic nerve, but also along the entire visual pathway and the brain. OBJECTIVE: This article presents the neuroprotective effects of citicoline and their mechanisms in glaucoma disease. MATERIALS AND METHODS: The relevance of citicoline is explained against the background of neuroanatomy, neuroimaging, and the pathogenesis of glaucoma. Data from experimental and clinical studies are presented and a conclusion is drawn for clinical application. RESULTS: Citicoline has a neuroprotective effect via mechanisms relevant to glaucoma. The neuroprotective effect of citicoline in open-angle glaucoma can be demonstrated functionally and morphologically. It is independent of the glaucoma damage and intraocular pressure, and usually occurs only after 1 year. The effects of oral citicoline occur at a daily dose of 500-1000 mg. Citicoline can be taken permanently or in cycles. No side effects occurred in the studies when taking citicoline. Citicoline can improve cognitive performance and thus treatment adherence as well as quality of life in glaucoma patients. CONCLUSION: This relatively old nootropic drug, which is now marketed as a food supplement, seems to be a valuable addition to conventional treatment and also a rational option for prophylaxis of open-angle glaucoma.

The role of clinical examination of the optic nerve head in glaucoma today.

PURPOSE OF REVIEW: The study was undertaken to assess the current importance of clinical examination of the optic nerve head (ONH) in glaucoma management. RECENT FINDINGS: ONH changes in glaucoma are easily assessed with good specificity on examination, whereas imaging has not been able to identify pallor of the neuroretinal rim (NRR), disc hemorrhages, or vascular signs of acquired cupping. Glaucomatous neuropathy in primary open angle glaucoma (POAG) has extensive databases on imaging machines, however, other glaucomas such as primary angle closure glaucoma (PACG), juvenile open angle glaucoma (JOAG), congenital, and secondary glaucomas have been reported to have a significantly different ONH morphology. Clinical evaluation with knowledge of the underlying cause of glaucoma allows easy diagnosis of any abnormality, whereas the absence of an imaging database in such eyes makes diagnosis difficult on optical coherence tomography (OCT) and so forth. In eyes with congenital anomalies and dysplastic discs, clinical examination and history provide better identification of glaucomatous damage. Staging of glaucoma on ONH examination when perimetry is unreliable provides a means of determining the amount of damage and appropriate reduction of intraocular pressure (IOP). SUMMARY: Clinical examination of the ONH is very relevant for screening, diagnosis, staging, and management of all glaucomas, and is irreplaceable in detecting nonglaucomatous causes of ONH cupping and visual field defects similar to those in glaucoma.

Effect of dietary modification and antioxidant supplementation on intraocular pressure and open-angle glaucoma.

Primary open-angle glaucoma (POAG) is an age-dependent, intraocular pressure (IOP)-related degeneration of the retinal ganglion cells (RGC). At present, IOP is the only modifiable factor that has been identified to prevent glaucomatous vision loss. Though the pathogenesis of glaucomatous optic neuropathy is still not well understood, increasing evidence suggests oxidative stress may contribute to the induction and progression of glaucoma. Furthermore, antioxidant use may be protective against glaucoma through various mechanisms, including reducing IOP, preserving vascular health, and preventing ganglion cell loss. This article provides a comprehensive review of the effect of oxidative stress, diet, and antioxidant therapy on IOP and open-angle glaucoma.

[Transscleral laser therapy in the treatment of glaucoma]. / Lazernye transskleral'nye tekhnologii v lechenii glaukomy.

Nowadays glaucoma is one of the leading causes of irreversible blindness worldwide. The main goal in preservation of vision in glaucoma patients is reducing intraocular pressure (IOP), which is considered the main controlled risk factor for progression of glaucomatous optic neuropathy. The article discusses the effectiveness and safety of various transscleral laser technologies in the treatment of glaucoma. Modern transscleral laser technologies that affect the uveoscleral drainage and scleral hydro-permeability are less traumatic and more gentle making them promising in the treatment of patients with early stages of glaucoma, and not only in terminal glaucoma with pain syndrome resistant to conventional treatment ("last resort surgery").

Longitudinal assessment of optic nerve head changes using optical coherence tomography in a primate microbead model of ocular hypertension.

In humans, the longitudinal characterisation of early optic nerve head (ONH) damage in ocular hypertension (OHT) is difficult as patients with glaucoma usually have structural ONH damage at the time of diagnosis. Previous studies assessed glaucomatous ONH cupping by measuring the anterior lamina cribrosa depth (LCD) and minimal rim width (MRW) using optical coherence tomography (OCT). In this study, we induced OHT by repeated intracameral microbead injections in 16 cynomolgus primates (10 unilateral; 6 bilateral) and assessed the structural changes of the ONH longitudinally to observe early changes. Elevated intraocular pressure (IOP) in OHT eyes was maintained for 7 months and serial OCT measurements were performed during this period. The mean IOP was significantly elevated in OHT eyes when compared to baseline and compared to the control eyes. Thinner MRW and deeper LCD values from baseline were observed in OHT eyes with the greatest changes seen between month 1 and month 2 of OHT. Both the mean and maximum IOP values were significant predictors of MRW and LCD changes, although the maximum IOP was a slightly better predictor. We believe that this model could be useful to study IOP-induced early ONH structural damage which is important for understanding glaucoma pathogenesis.

Asian-specific vertical cup-to-disc ratio cut-off for glaucoma screening: An evidence-based recommendation from a multi-ethnic Asian population.

IMPORTANCE: Evidence-based guidelines are essential for glaucoma screening to work effectively. BACKGROUND: To derive a vertical cup-to-disc ratio (VCDR) cut-off for glaucoma screening in a multi-ethnic Asian population. DESIGN: The Singapore Epidemiology of Eye Diseases (SEED) study is a population-based study conducted from 2004 to 2011 in a single tertiary care research institute. PARTICIPANTS: SEED comprised of 10 033 Chinese, Malay and Indian adults aged ≥40 (response rate 75.6%). After excluding participants with a history of glaucoma medication or surgery, 9673 participants were included for analysis. METHODS: A systematic eye examination, which included applanation tonometry, visual field testing, gonioscopy and dilated fundus examination was conducted. MAIN OUTCOME MEASURE: Diagnosis of glaucoma. RESULTS: The distribution of VCDR and VCDR asymmetry were relatively homogenous in this multi-ethnic Asian population, with a 97.5th percentile value of 0.67 and 0.17, respectively. In the absence of more definite signs of glaucoma, VCDR ≥0.60 and VCDR asymmetry ≥0.20 provided the best balance between sensitivity (95.1%) and specificity (90.9%) in detecting glaucoma. For larger optic disc (≥2.0 mm), VCDR ≥0.65 with VCDR asymmetry ≥0.20 provided the best balance between sensitivity (84.8%) and specificity (93.2%). CONCLUSION AND RELEVANCE: Overall, VCDR ≥0.60 with VCDR ≥0.20 asymmetry provides a good balance between sensitivity and specificity in detecting glaucoma. For larger optic disc, VCDR ≥0.65 should be considered instead to mitigate against false-referrals due to larger physiological disc cupping. Our findings may act as a reference to populations with similar VCDR distribution.

Effect of Intravenous Dexmedetomidine on Intraocular Pressure in Patients Undergoing Glaucoma Surgery Under Local Anesthesia: A Pilot Study.

PRECIS: Preoperative intravenous (IV) dexmedetomidine produced a 33% reduction in intraocular pressure (IOP) within 15 minutes of administration in patients with glaucoma. PURPOSE: To evaluate the effect of preoperative IV dexmedetomidine on IOP in adult patients undergoing glaucoma surgery under local anesthesia. METHODS: In a prospective interventional case series, 12 patients with uncontrolled IOP (IOP>24 mm Hg in both the eyes) with the systemic status of American Society of Anesthesiologists (ASA) classification I-II, received IV dexmedetomidine 0.6 µg/kg 30 minutes preoperatively. The IOP of the nonsurgical eye (measured with Perkins tonometer), the heart rate (HR), and blood pressure (BP) were recorded 5 minutes prior, 15 minutes and 2 hours after IV dexmedetomidine administration, and were compared using analysis of variance and Tukey honestly significant difference tests. RESULTS: There were 4 women and 8 men with a mean age (±SD) of 60.6±10.4 years. The mean number of antiglaucoma medications was 4.3±1.3. The mean pre-dexmedetomidine IOP was 31.5±5.6 mm Hg. At 15 minutes post-dexmedetomidine administration, the mean and percentage drop in IOP were 10.2±3.2 mm Hg (P=0.001) and 33%±11%, respectively. The mean and percentage drop in systolic BP were 18±20 mm Hg (P=0.01) and 12%±14%, and drop in diastolic BP were 6.5±10 mm Hg (P=0.05) and 7%±11%, respectively. The mean and percentage drop in HR were 2±0.6 bpm (P=0.48) and 2%±13%, respectively. None of the subjects experienced any medication-related adverse effects. At 2 hours, the mean and percentage drop in IOP were 5.3±3 mm Hg and 17%±11%, respectively. CONCLUSION: In the small sample of (ASA I-II) patients studied, preoperative dexmedetomidine produced a significant drop in IOP (33%) within 15 minutes of IV administration in patients with glaucoma that was reversing at 2 hours, with a good safety profile.