When gold standards change: time to move on from Goldmann tonometry?

Bilateral simultaneous acute angle closure glaucoma triggered by an over-the-counter cold and influenza medication

A woman in her mid-60s who is a high hypermetrope presented with bilateral eye pain and headache approximately 1 hour after taking a single dose of a widely available decongestant containing paracetamol, guaifenesin and phenylephrine hydrochloride for coryzal symptoms. She had previous successful bilateral peripheral iridotomies performed for narrow angles. At presentation, her intraocular pressures (IOPs) were significantly raised at 72 mm Hg and 66 mm Hg in the right and left eye, respectively, with bilateral corneal oedema. Her IOP was normalised with urgent treatment using 500 mg intravenous acetazolamide, pilocarpine 2%, dexamethasone 0.1% and IOP-lowering drops. She was listed for cataract surgery and was advised to avoid the precipitating agent and other over-the-counter decongestants. This is the first reported case of bilateral angle closure triggered by a decongestant with such a combination of ingredients. Clinicians should be aware of this rare side effect for prompt diagnosis and management.

Simulation techniques in optometric education: Is a model eye for tonometry a valuable instruction tool?

PURPOSE

Simulation techniques are used in healthcare education to support the development of clinical skills. The aim of this study was to investigate the perceived value of a tonometry model eye (TME) when used in teaching and learning the clinical skill of Goldmann applanation tonometry (GAT) in optometric education in the UK.

METHODS

A retrospective two-armed cross-sectional study was conducted to investigate the perceived value of using a model eye for teaching and learning GAT in optometric education. Focus group discussion (FGD) was employed to explore the views of academic experts experienced in teaching GAT using a TME. Semi-structured surveys were conducted to elicit the opinions of optometry students following GAT simulation training. Qualitative thematic analysis of the FGD and open-ended survey questions was undertaken. Quantitative data based on rated student responses was assessed using Chi-square analysis to examine differences between year-group responses.

RESULTS

The TME was reported to be a useful experiential tool, facilitating a safe learning environment for students to develop the technical skills required to perform GAT before moving on to real-eye experiences. Whilst limitations of the model eye were noted, these did not diminish the value of the model eye as an instructional tool. Students reported improved confidence (86%) and would highly recommend (82%) the TME to other students.

CONCLUSION

The model eye for tonometry was perceived by academic tutors and optometry students to be a valuable instruction tool as part of a scaffolded process for learning GAT. Irrespective of their learning stage, students reported a range of benefits from the model eye, such as being able to make mistakes, taking repeat measurements and getting used to the equipment, all whilst not having to worry about patient safety.

Long-term outcomes of canaloplasty and phaco-canaloplasty in the treatment of open angle glaucoma: a single-surgeon experience

PURPOSE

To evaluate and compare the long-term outcomes of canaloplasty and phaco-canaloplasty in the treatment of open angle glaucoma and assess the prognostic factors associated with surgical outcome.

METHODS

A 48-month retrospective analysis was performed on n = 133 open angle glaucoma eyes treated with canaloplasty and n = 57 open angle glaucoma eyes treated with phaco-canaloplasty by a single surgeon. Surgical success was defined according to six criteria, achieving a target intraocular pressure (IOP) ≤ 21, 18 or 15 mmHg on glaucoma medications (qualified success) or without any further treatment (complete success), including laser therapy or surgery. Kaplan-Meier survival analysis and Cox regression analysis were performed to evaluate surgical success and preoperative factors associated with surgical outcome. Surgical complications in the early postoperative period were compared between canaloplasty and phaco-canaloplasty.

RESULTS

Canaloplasty and phaco-canaloplasty significantly reduced postoperative IOP and number of glaucoma medications (p = 0.001 for both). Phaco-canaloplasty showed higher rates of cumulative surgical success over canaloplasty, but only for target IOP ≤ 21 and ≤ 18 (p = 0.018 and p = 0.011, respectively). A preoperative number of > 4 glaucoma medications predicted surgical failure. Phaco-canaloplasty was associated with a higher rate of IOP peaks in the first month compared with canaloplasty (40.4% vs 12.7%, p = 0.000).

CONCLUSION

Canaloplasty and phaco-canaloplasty demonstrated long-term efficacy in the treatment of open angle glaucoma, with phaco-canaloplasty showing higher rates of surgical success compared to canaloplasty, but not for target IOPs lower than 16 mmHg. Patients on more than 4 preoperative glaucoma medications may not be good candidates for canaloplasty and may benefit from other surgical options.

Minimally invasive bleb surgery versus minimally invasive glaucoma surgery: a 12-month retrospective study

This study aimed to compare the IOP-lowering effectiveness and safety of standalone Preserflo MicroShunt and iStent 1st generation implantation combined with phacoemulsification in Caucasian patients with a 12-month follow-up period. This retrospective study analyzed the medical histories of patients undergoing antiglaucoma surgery at the Department of Ophthalmology, Medical University of Bialystok, between January 2019 and January 2022. The main outcome measures were success rates (complete: proportion of eyes with IOP < 18 mmHg (criterion A) and < 15 mmHg (criterion B) or 20% reduction in IOP without any glaucoma medication; qualified: proportion of eyes achieving IOPs < 18 mmHg and < 15 mmHg or 20% reduction in IOP from baseline with or without medications), mean reduction (%) in IOP, medication burden, number of complications and additional interventions. In both groups, a significant decrease in IOP and medication burden were observed at 6 and 12 months when compared with baseline. At 12 months, qualified surgical success in criterion A was recorded in 67.4% and 85.7% of patients in the Preserfo and iStent groups, respectively (p = 0.045). Complete surgical success in criterion B at 12 months accounted to 61.4% of patients from Prserflo group and 32.7% patients in iStent group (p = 0.04). Surgical failure at 12 months was documented in 30.2% and 6.3% of patients, respectively (p = 0.003). There was a significant difference between groups in %IOP reduction after 12 months. Greater reduction was observed in Preserflo group, MD = - 8.41 CI95 [- 15.88; - 0.95], p = 0.028, (- 33.49% ± 21.59 vs - 25.07% ± 14.15 in iStent group). Both procedures effectively reduced IOP and postoperative use of antiglaucoma medications in glaucoma patients.

Two-year outcomes of Xen 45 gel stent implantation in patients with open-angle glaucoma: real-world data from the Fight Glaucoma Blindness registry

OBJECTIVE

To evaluate efficacy and safety outcomes of the Xen 45 gel stent implant over 24 months of follow-up.

METHODS

A retrospective analysis of prospectively collected data from the Fight Glaucoma Blindness observational registry. Complete success (CS) was defined as intraocular pressure (IOP) reduction ≥20% from preoperative and an IOP ≤18 mm Hg and ≥6 mm Hg with no secondary procedure at 2 years and without IOP-lowering medications. Qualified success (QS) was defined similarly, allowing the use of IOP-lowering medications.

RESULTS

The Xen 45 gel stent implant was implanted in 646 eyes of 515 patients. Preoperative IOP was 21.4±7.6 (mean±SD) mm Hg on 2.7±1.3 IOP-lowering medication and mean deviation was -10.2±8.4 dB. After 24-month follow-up, IOP was 16.8±7.3 mm Hg (mean reduction of 21.7%) on 1.2±1.4 IOP-lowering medications. CS and QS rates at 24 months were 26% and 48%, respectively. CS and QS were higher in the Xen stand-alone group (33% and 52%, respectively) than in the Xen+cataract group (16% and 42%, respectively). Bleb needling was performed in 28.4% of cases, and 18% underwent a secondary procedure.

CONCLUSIONS

The Xen 45 gel stent implant offers acceptable long-term efficacy for the treatment of open-angle glaucoma. However, there is a significant rate of reoperation and needling, and outcomes are less effective if combined with cataract surgery.

Comparative efficacy and safety of different anti-VEGF agents combined with different delivery methods for neovascular glaucoma: a systematic review and Bayesian network meta-analysis

OBJECTIVE

To compare the efficacy and safety of different anti-vascular endothelial growth factor (VEGF) agents combined with different delivery methods for neovascular glaucoma (NVG).

DESIGN

Systematic review and Bayesian network meta-analysis (NMA).

DATA SOURCES

PubMed, Embase, Cochrane Library, Web of Science, ClinicalTrials.gov, ISRCTN and Chinese databases including the China National Knowledge Infrastructure, China Science Periodical Database (Wanfang Database), VIP Journal Integration Platform and China Biology Medicine Database were searched from inception to 5 September 2022.

ELIGIBILITY CRITERIA

We included randomised controlled trials (RCTs) that investigated the treatment of NVG using different anti-VEGF agents combined with various methods of drug administration, without any language limitations. All patients included underwent panretinal laser photocoagulation and there were no restrictions on prior glaucoma surgery.

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers extracted data and assessed the risk of bias. Random-effect Bayesian NMA was conducted to compare the efficacy and safety and rank priority of anti-VEGF regimens. The source of heterogeneity and the related factors affecting the stability of the results were also explored. CINeMA (Confidence in Network Meta-Analysis) was used to assess the certainty of evidence.

RESULTS

Our analysis included 17 RCTs involving a total of 1311 eyes from 1228 patients. We examined five different treatment regimens, which used three different anti-VEGF drugs. The following treatments showed a significant decrease in intraocular pressure (IOP) compared with the control group at 1 month after glaucoma surgery: simultaneous intravitreal and intracameral injection of conbercept (ICCIVC) (mean difference (MD)=-11.56, 95% credible interval (CrI) -20.8 to -2.24), intravitreal injection of conbercept (MD=-8.88, 95% CrI -13.93 to -3.78), intravitreal injection of ranibizumab (MD=-7.62, 95% CrI -10.91 to -4.33) and intravitreal injection of bevacizumab IVB) (MD=-5.51, 95% CrI -10.79 to -0.35). The surface under the cumulative ranking curve (SUCRA) analysis indicated that ICCIVC (82.0%) may be the most effective regimen in reducing IOP. In terms of safety, there were no statistically significant differences among the interventions. According to the SUCRA analysis, ICCIVC (68.0%) was considered the safest choice with the fewest complications. Subgroup and meta-regression analyses showed that mean age was the main source of heterogeneity. Sensitivity analysis demonstrated the robustness of the study results.

CONCLUSION

ICCIVC was more effective and safer than other anti-VEGF regimens for NVG. Simultaneous intravitreal and intracameral injection was found to be the best route of administration, and conbercept was found to be the superior drug selection when compared with ranibizumab and bevacizumab.

PROSPERO REGISTRATION NUMBER

CRD42022309676.

Differentiating stages of functional vision loss from glaucoma using the Disc Damage Likelihood Scale and cup:disc ratio

BACKGROUND

Glaucoma staging is critical for treatment planning but has rarely been tested in severe/end-stage disease. We compared the performance of the Disc Damage Likelihood Scale (DDLS) and cup:disc ratio (CDR) using a functional glaucoma staging system (GSS) as the reference standard.

METHODS

Post hoc analysis of a randomised controlled trial at the Eye Department of Kilimanjaro Christian Medical Centre, Tanzania. Eligible participants (aged ≥18 years) with open-angle glaucoma, intraocular pressure (IOP) of >21 mm Hg, were randomised to timolol 0.5% eye drops or selective laser trabeculoplasty. Fundoscopy established vertical and horizontal CDRs and DDLS. Visual acuity and static visual fields were graded (GSS). The study used area under the receiver operating characteristic (AROC) curves and Spearman's rank correlation coefficients to compare staging systems. Logistic regression with generalised estimating equations determined risk factors of functional severe/end-stage glaucoma.

RESULTS

382 eyes (201 participants) were evaluated; 195 (51%) had severe or end-stage glaucoma; mean IOP was 26.7 (SD 6.9) mm Hg. DDLS yielded an AROC of 0.90 (95% CI 0.87 to 0.93), vertical cup:disc ratio (vCDR) of 0.88 (95% CI 0.85 to 0.91, p=0.048) for identifying severe/end-stage disease. Correlation coefficients comparing GSS to DDLS and vCDRs were 0.73 and 0.71, respectively. Advanced structural stages, vision impairment, higher IOP and less financial resources were risk factors of functional severe/end-stage glaucoma.

CONCLUSION

This study indicates that both structural staging systems can differentiate severe/end-stage glaucoma from less severe disease, with a moderate advantage of DDLS over CDR. Clinical examination of the optic disc plays an important role in addition to functional assessment when managing severe/end-stage glaucoma.

Glaucoma: now and beyond

The glaucomas are a group of conditions leading to irreversible sight loss and characterised by progressive loss of retinal ganglion cells. Although not always elevated, intraocular pressure is the only modifiable risk factor demonstrated by large clinical trials. It remains the leading cause of irreversible blindness, but timely treatment to lower intraocular pressure is effective at slowing the rate of vision loss from glaucoma. Methods for lowering intraocular pressure include laser treatments, topical medications, and surgery. Although modern surgical innovations aim to be less invasive, many have been introduced with little supporting evidence from randomised controlled trials. Many cases remain undiagnosed until the advanced stages of disease due to the limitations of screening and poor access to opportunistic case finding. Future research aims to generate evidence for intraocular pressure-independent neuroprotective treatments, personalised treatment through genetic risk profiling, and exploration of potential advanced cellular and gene therapies.

Validity of a novel optical coherence tomography angiography flow index in a cohort of primary open angle glaucoma

BACKGROUND

Vascular mechanisms are implicated in many ocular diseases. Therefore, different vascular imaging modalities are used in management of such conditions. Optical coherence tomography angiography (OCTA) has high spatial resolution and segmentable 3D volumetric sampling enabling isolation of retinal and peripapillary vascular beds. However, OCTA only indirectly derives quantitative flow data i.e. velocimetry through methods and algorithms liable to limitations like signal saturation. This study introduces and validates novel mathematical OCTA flow indices that may compensate for some OCTA velocimetric limitations.

METHODS

Thirty-seven eyes of 23 POAG patients were included. Each underwent baseline and follow-up assessment one month thereafter. Assessment comprised full ophthalmological examination, intraocular pressure (IOP), systemic arterial blood pressure (SABP) and OCTA macula and ONH. Angiograms were processed using ImageJ to calculate OCTA intensity-based flow indices (FIOs), for superficial vascular plexus (SVP), deep vascular plexus (DVP) and optic nerve head vascular plexus (ONH-RPC), i.e. SFIO, DFIO and ONHFIO respectively. Mean ocular perfusion pressure (MOPP) was calculated using IOP and SABP. OCTA vascular densities (VD) and MOPP were used to calculate three respective mathematical flow indices (FIMs) for SVP, DVP and ONH-RPC, based on Hagen-Poiseuille law, i.e. SFIM, DFIM, ONHFIM respectively. Pearson test was used for correlation between the two sets of indices. Intraclass correlation coefficient (ICC) was tested for baseline and follow-up values for each index.

RESULTS

There was positive correlation between the three FIMs and their respective FIOs at baseline and follow-up ranging between high and moderate. Correlation coefficients (CCs) were 0.773 and 0.609 for SFIM and SFIO P-value < 0.001, 0.829 and 0.624 for DFIM and DFIO P-value < 0.001 and 0.516 and 0.737 for ONHFIM P-value = 0.001 for baseline and follow-up respectively. ICCs were 0.772 P-value < 0.001, 0.328 P-value = 0.022 and 0.888 P-value < 0.001 for SFIM, DFIM and ONHFIM respectively. For SFIO, DFIO and ONHFIO, ICCs were 0.420 P-value = 0.004, 0.079 P-value = 0.320 and 0.833 P-value < 0.001 respectively.

CONCLUSION

The novel FIMs are reliable alternatives to FIOs and may compensate for OCTA signal saturation in extremes of MOPP. SFIM and ONHFIM showed high ICCs with excellent reliability. While DFIM demonstrated low ICC indicating poor reliability, it still performed better than its corresponding DFIO.

Methods for measuring intraocular pressure: disadvantages and advantages

This review of the literature is devoted to the comparison of tonometers based on various operating principles, their advantages and disadvantages. The principles of operation of each considered in the review tonometer are discussed. The features of the structure and mechanisms for measuring the intraocular pressure of various tonometers are highlighted, on the basis of which the anatomical features and other factors that have the greatest impact on the reliability of measurement and accounting of the data obtained in clinical practice are determined.

[Angle-closure glaucoma]

Angle-closure glaucoma is a rare form of glaucoma characterized by a narrow or an occlusion of the anterior chamber angle and subsequently an obstruction of the outflow of aqueous humor resulting in an increase in intraocular pressure. Symptoms can include severe eye pain and/or headache, blurred vision, a medium-sized and rigid pupil, conjunctival hyperemia, and nausea. Treatment options include pressure-lowering topical and systemic medications as well as surgical interventions, especially cataract surgery and laser iridotomy. Besides parasympathomimetics (pilocarpine), all topical antiglaucoma medications can principally be used (beta-receptor antagonists, carbonic anhydrase inhibitors, alpha‑2 selective adrenergic antagonists, prostaglandins and prostaglandin analogues). Carbonic anhydrase inhibitors and osmotic agents (e.g., mannitol) can be systemically used.

The effectiveness of a three-step sterilization method for Goldmann tonometer prism: A cross-sectional study

Purpose:

To propose a three-step sterilization method for Goldmann tonometer prism (GTP) and to analyze the sterilization effects of each step.

Methods:

120 patients (240 eyes) who underwent Goldmann applanation tonometer (GAT) IOP measurement were enrolled in this study. GTPs were used individually for each patient and wiped by swabs soaked with 75% ethyl alcohol, ofloxacin eye drops, and 75% ethyl alcohol for at least 5 s. GTPs were directly pressed onto the surface of agar plates before (W0) and after three-step sterilization (W1, W2, and W3). All the agars were sent to the laboratory in 2 h and incubated at 37°C for 48 h. Subsequently, the growth of microbial species was assessed through visual inspection of the colonies at the inoculation points on the agar surface.

Results:

Staphylococcus. epidermidis was the most frequently isolated bacterium and was observed in 23.33% of all prisms. Most of the bacteria were eliminated at W3 except Staphylococcus. epidermidis and Kocuria roseus in one case. The isolation rates of Staphylococcus genus and Staphylococcus. epidermidis were significantly decreased (both with P < 0.001). The number of bacteria types isolated from prisms at time point W2 and W3 had a statistically significant difference compared with W1 and W (both with P < 0.05), while W2 and W3 exhibited no significant difference.

Conclusion:

This three-step sterilization method for GTP proved to be effective and safe for repeated use. We recommend using ofloxacin to prevent the transmission of pathogens based on ethyl alcohol, which could also bring some economic benefits.

How to Measure Intraocular Pressure: An Updated Review of Various Tonometers

Intraocular pressure (IOP) is an important measurement that needs to be taken during ophthalmic examinations, especially in ocular hypertension subjects, glaucoma patients and in patients with risk factors for developing glaucoma. The gold standard technique in measuring IOP is still Goldmann applanation tonometry (GAT); however, this procedure requires local anesthetics, can be difficult in patients with scarce compliance, surgical patients and children, and is influenced by several corneal parameters. Numerous tonometers have been proposed in the past to address the problems related to GAT. The authors review the various devices currently in use for the measurement of intraocular pressure (IOP), highlighting the main advantages and limits of the various tools. The continuous monitoring of IOP, which is still under evaluation, will be an important step for a more complete and reliable management of patients affected by glaucoma.