Salvageable waste associated with intravitreal injections: A local medical waste management approach.

BACKGROUND: Healthcare waste management is a globally challenging issue with an increased prevalence of disposable, single-use materials in developed countries and a rapidly ageing population continuing to drive an increase in the use of medical resources. One manifestation of this within ophthalmology is the increasing number of intravitreal injections given for conditions such as age-related macular degeneration and diabetic macular oedema. METHODS: A prospective controlled cohort study was performed over 5 weeks in 2021 during which two sites were selected to compare different approaches to sorting the waste generated by intravitreal injections. At Site A all waste associated with these injections was placed in standard hospital waste bins. Site B was the intervention arm where a real-time sorting of waste occurred. The number of injections given and waste amounts were recorded. RESULTS: 116 and 286 injections were given at Sites A and B, respectively over the study period. Site A generated an average of 470.7 g of waste per injection compared with 175.1 g at our intervention site. This represents a 62.8% reduction (p < 0.001). At Site B, where waste was sorted, a total of 50.1 kg of medical waste was generated from these injections during the study period of which 33.8 kg (67.5%) was salvageable. CONCLUSIONS: This is the first quantification of the medical waste associated with intravitreal injections, a burgeoning treatment for macular degeneration and diabetic retinopathy among other conditions. This study demonstrates a significant reduction in the amount of medical waste produced using an easily implementable real-world methodology.

Toric intraocular lenses: Evidence-based use.

Uncorrected refractive astigmatism degrades visual acuity. Spherical intraocular lenses (IOLs) leave astigmatic errors resident in the cornea manifest in refractive astigmatism. Toric IOLs, correcting for this corneal astigmatism, contribute to spectacle-free vision in the pseudophakic eye. This review provides information to assist surgeons in a rational choice of eyes suitable for toric IOL implantation, methods of IOL cylinder power calculation, surgical techniques for toric IOLs and management of complications. With appropriate application of this information, correction of visually detrimental astigmatism can be achieved routinely.

Enhanced Weak-Value Amplification via Photon Recycling.

In a quantum-noise limited system, weak-value amplification using postselection normally does not produce more sensitive measurements than standard methods for ideal detectors: the increased weak value is compensated by the reduced power due to the small postselection probability. Here, we experimentally demonstrate recycled weak-value measurements using a pulsed light source and optical switch to enable nearly deterministic weak-value amplification of a mirror tilt. Using photon counting detectors, we demonstrate a signal improvement by a factor of 4.4±0.2 and a signal-to-noise ratio improvement of 2.10±0.06, compared to a single-pass weak-value experiment, and also compared to a conventional direct measurement of the tilt. The signal-to-noise ratio improvement could reach around six for the parameters of this experiment, assuming lower loss elements.

Efficacy of intracameral antibiotics following manual small incision cataract surgery in reducing the rates of endophthalmitis: A meta-analysis.

BACKGROUND: Manual small incision cataract surgery (MSICS) is a widely used technique for cataract surgery in the developing world. Higher rates of postoperative endophthalmitis have been reported with this technique compared with phaco-emulsification. The purpose of this study was to evaluate the efficacy of prophylactic intracameral (IC) antibiotics in reducing the rates of postoperative endophthalmitis following MSICS. METHODS: Systematic review and meta-analysis of patients undergoing MSICS. A literature search in PubMed and EMBASE databases was performed to identify studies published from October 1992 to April 2020 evaluating MSICS with a minimum of 500 eyes reported. Two authors independently assessed eligibility, extracted data and assessed the risk of bias. Heterogeneity was assessed using the I2 test. RESULTS: Twelve studies enrolling 1 494 307 eyes were included. IC antibiotics were used in 725 324 (48.5%) eyes. The risk ratio of developing endophthalmitis was 2.94 (95% CI, 1.07-8.12; P = .037) in eyes that did not receive IC antibiotics. CONCLUSIONS: Routine use of IC antibiotics may help to reduce the rates of endophthalmitis following MSICS and significantly improve the safety of this effective form of cataract surgery.

Direct excitation of a single quantum dot with cavity-SPDC photons.

The ability to generate mode-engineered single photons to interface with disparate quantum systems is of importance for building a quantum network. Here we report on the generation of a pulsed, heralded single photon source with a sub-GHz spectral bandwidth that couples to indium arsenide quantum dots centered at 942 nm. The source is built with a type-II PPKTP down-conversion crystal embedded in a semi-confocal optical cavity and pumped with a 76 MHz repetition rate pulsed laser to emit collinear, polarization-correlated photon pairs resonant with a single quantum dot. In order to demonstrate direct coupling, we use the mode-engineered cavity-SPDC single-photon source to resonantly excite an isolated single quantum dot.

Patient-reported Outcomes for Assessment of Quality of Life in Refractive Error: A Systematic Review.

SIGNIFICANCE: This review has identified the best existing patient-reported outcome (PRO) instruments in refractive error. The article highlights the limitations of the existing instruments and discusses the way forward. PURPOSE: A systematic review was conducted to identify the types of PROs used in refractive error, to determine the quality of the existing PRO instruments in terms of their psychometric properties, and to determine the limitations in the content of the existing PRO instruments. METHODS: Articles describing a PRO instrument measuring 1 or more domains of quality of life in people with refractive error were identified by electronic searches on the MEDLINE, PubMed, Scopus, Web of Science, and Cochrane databases. The information on content development, psychometric properties, validity, reliability, and responsiveness of those PRO instruments was extracted from the selected articles. The analysis was done based on a comprehensive set of assessment criteria. RESULTS: One hundred forty-eight articles describing 47 PRO instruments in refractive error were included in the review. Most of the articles (99 [66.9%]) used refractive error-specific PRO instruments. The PRO instruments comprised 19 refractive, 12 vision but nonrefractive, and 16 generic PRO instruments. Only 17 PRO instruments were validated in refractive error populations; six of them were developed using Rasch analysis. None of the PRO instruments has items across all domains of quality of life. The Quality of Life Impact of Refractive Correction, the Quality of Vision, and the Contact Lens Impact on Quality of Life have comparatively better quality with some limitations, compared with the other PRO instruments. CONCLUSIONS: This review describes the PRO instruments and informs the choice of an appropriate measure in refractive error. We identified need of a comprehensive and scientifically robust refractive error-specific PRO instrument. Item banking and computer-adaptive testing system can be the way to provide such an instrument.

Impact of refractive error on quality of life: a qualitative study.

IMPORTANCE: This study qualitatively explores the impact of refractive error on adults, particularly after correction. BACKGROUND: The study aimed to explore the impact of refractive error on quality of life. DESIGN: Cross-sectional; in-depth telephone and face-to-face semistructured interviews; qualitative study with inductive and deductive processes. PARTICIPANTS: Forty-eight adults with refractive error (including presbyopia) were recruited from the Flinders Vision, the Ashford Advanced Eye Care and among Flinders University staff and students, in South Australia. METHODS: The interviews were audio-recorded, transcribed verbatim, coded and analysed using thematic analysis. MAIN OUTCOME MEASURES: Themes and categories RESULTS: The median age of the participants was 49 years (min: 22 years; max: 76 years). Most of them were female: (29; 59%). Most of them (36; 75.0%) had myopia followed by hyperopia (12; 25.0%). Twenty-two (45.8%) participants had astigmatism. Similarly, 23 (47.9%) of them were presbyopes. Most of the participants (39; 81.3%) wore glasses; 17 (35.4%) used contact lenses, and 17 (35.4%) had undergone refractive surgery. A total of 2367 comments were coded. Thematic analysis resulted into six themes that informed about quality of life issues in people with refractive error. Concerns about cosmetic appearance, personal health and safety, difficulties in day-to-day activities and inconveniences rendered in daily life were identified as the most important themes. CONCLUSIONS AND RELEVANCE: The findings of this study enrich the understanding on the issues important in people with refractive error. The quality of life issues identified will be used to develop a refractive error-specific item bank.

Adjustment of anterior corneal astigmatism values to incorporate the likely effect of posterior corneal curvature for toric intraocular lens calculation.

PURPOSE: To establish if average refractive overcorrection or undercorrection of corneal astigmatism based on the "rule" of the astigmatism occurs if toric intraocular lenses (IOLs) are calculated on the basis of anterior corneal measurements, and to calculate an adjustment for individual eyes to avoid this systematic error. METHODS: One hundred forty-three consecutive eyes of 115 patients underwent phacoemulsification with IOL powers calculated using anterior corneal curvature data alone. Eyes were grouped as either "with-the-rule" or "against-the-rule" on the basis of the steep anterior corneal meridian. Targeted versus achieved astigmatic outcomes were compared. Main outcome measure was residual refractive astigmatism following the insertion of a toric IOL due to the likely effect of posterior corneal astigmatism. RESULTS: Significant prediction errors in astigmatic outcome occurred only with IOL cylinders of 2 diopters or less. Overcorrection occurred by a factor of 1.38 in with-the-rule eyes and undercorrection occurred by a factor of 0.65 in against-the-rule eyes. CONCLUSIONS: A coefficient of adjustment of 0.75 for with-the-rule eyes and 1.41 for against-the-rule eyes can be applied to the corneal astigmatism power value to calculate a more appropriate IOL cylinder power than that calculated by using unadjusted anterior corneal curvature measurements. These adjustment coefficients apply only to those eyes that would have received IOLs with 2 diopters of cylinder or less and calculated with such unadjusted measurements. Greater IOL cylinder powers are sufficiently accurately calculated using unadjusted values.

Cataract surgery audit at an Australian urban teaching hospital.

BACKGROUND: To provide local data on visual acuity and surgical outcomes for cataract surgery performed in an Australian teaching hospital. DESIGN: Continuous audit over 7 years in a public teaching hospital. PARTICIPANTS: A total of 3740 eyes had cataract surgery performed at The Queen Elizabeth Hospital, South Australia, from May 2006 to September 2013. METHODS: Visual acuity and complication rates were recorded for cataract surgery cases operated on between May 2006 and September 2013 on a digital database with data entry contemporaneous with final follow-up. MAIN OUTCOME MEASURES: Visual acuity and surgical complications. RESULTS: Of the patients, 91.4% achieved postoperative best-measured vision better than preoperative best-measured vision. The rate of posterior capsular tear was 2.59%, endophthalmitis was 0.11% and the overall complication rate was 11.7%. CONCLUSIONS: This audit is the first to document modern cataract surgery, overwhelmingly dominated by phacoemulsification in an Australian population and can be used to benchmark cataract surgery outcome in an urban Australian population.

Manual small incision extracapsular cataract surgery in Australia.

BACKGROUND: Examination of the results and describing the technique of manual small incision extracapsular cataract extraction on patients with advanced cataracts in urban Australia. DESIGN: A descriptive case series. PARTICIPANTS: Thirty-eight patients at three public hospitals, one tertiary and two secondary ophthalmic units in urban Australia. METHODS: Forty eyes with dense mature cataracts with hand movement vision or worse underwent a planned manual small incision extracapsular cataract extraction instead of traditional phaco-emulsification. MAIN OUTCOME MEASURES: Postoperative visual aquity, surgically induced astigmatism and complications. RESULTS: Seventy-eight per cent of patients had an uncorrected visual acuity of 6/12 or better on the first postoperative day. Eighty-three per cent of patients had a distance corrected visual acuity of 6/9 or better 3 months postoperatively. One case was complicated by a posterior capsule rupture. No cases of endophthalmitis were reported. The summated vector mean of the surgically induced astigmatism was 0.089D at 93°. CONCLUSION: Manual small incision extracapsular cataract extraction is an efficacious cataract surgery technique with good visual outcome and is a safe alternative to phaco-emulsification in suitable cases in a first-world setting.

The Homburg-Adelaide toric IOL nomogram: How to predict corneal power vectors from preoperative IOLMaster 700 keratometry and total corneal power in toric IOL implantation.

PURPOSE: The purpose of this study is to compare the reconstructed corneal power (RCP) by working backwards from the post-implantation spectacle refraction and toric intraocular lens power and to develop the models for mapping preoperative keratometry and total corneal power to RCP. METHODS: Retrospective single-centre study involving 442 eyes treated with a monofocal and trifocal toric IOL (Zeiss TORBI and LISA). Keratometry and total corneal power were measured preoperatively and postoperatively using IOLMaster 700. Feedforward neural network and multilinear regression models were derived to map keratometry and total corneal power vector components (equivalent power EQ and astigmatism components C0 and C45) to the respective RCP components. RESULTS: Mean preoperative/postoperative C0 for keratometry and total corneal power was -0.14/-0.08 dioptres and -0.30/-0.24 dioptres. All mean C45 components ranged between -0.11 and -0.20 dioptres. With crossvalidation, the neural network and regression models showed comparable results on the test data with a mean squared prediction error of 0.20/0.18 and 0.22/0.22 dioptres2 and on the training data the neural network models outperformed the regression models with 0.11/0.12 and 0.22/0.22 dioptres2 for predicting RCP from preoperative keratometry/total corneal power. CONCLUSIONS: Based on our dataset, both the feedforward neural network and multilinear regression models showed good precision in predicting the power vector components of RCP from preoperative keratometry or total corneal power. With a similar performance in crossvalidation and a simple implementation in consumer software, we recommend implementation of regression models in clinical practice.

Objective accommodation measurement of the Crystalens HD compared to monofocal intraocular lenses.

PURPOSE: Objective evaluation of accommodation with a bilateral accommodating intraocular lens (IOL) versus monofocal IOLs. METHODS: Patients received accommodating IOL (Crystalens HD; Bausch & Lomb, Rochester, NY) bilaterally after cataract surgery. These were compared to a matched group receiving monofocal IOLs. Preoperative and postoperative distance corrected distance, intermediate, and near vision were evaluated. Objective accommodation was measured with the WAM-5500 Binocular Autorefractor/Keratometer (Grand Seiko, Pty Ltd., Hiroshima, Japan). RESULTS: Nineteen patients were included. Ten received the Crystalens HD in both eyes and nine received one of three monofocal lenses in each eye. Mean postoperative distance corrected distance visual acuity was not statistically different between the two groups. Mean distance corrected intermediate vision was better in the Crystalens HD group (logMAR 0.24 ± 0.11 [control], logMAR 0.11 ± 0.10 [Crystalens HD], P = .033). The groups did not differ significantly for mean distance corrected near vision (logMAR 0.54 ± 0.12 [control], logMAR 0.42 ± 0.15 [Crystalens HD], P = .087). However, a significantly greater proportion of Crystalens HD eyes achieved 0.4 or 0.3 logMAR for near wearing their distance correction (P = .013). With distance correction, the mean spherical equivalent failed to show any myopia with accommodative effort in either group. Low contrast and low luminance contrast acuity were not significantly different. CONCLUSION: The Crystalens HD showed some benefit for intermediate visual function compared to the monofocal IOLs with both groups wearing full correction for distance. There were no significant signs of accommodation in either group.

Hyaluronidase toxicity: a possible cause of postoperative periorbital inflammation.

BACKGROUND: Periorbital inflammation following regional anaesthesia is commonly attributed to hyaluronidase allergy. This case series suggests an alternative explanation in some patients. DESIGN: Retrospective case series. PARTICIPANTS: Seven patients presenting with postoperative non-infectious periorbital inflammation following peribulbar or sub-tenons anaesthesia, presenting at four different institutions, are described. METHODS: Data on patient demographics, operative data, clinical presentation, treatment and allergy testing were collected among the four institutions. MAIN OUTCOME MEASURES: Response to treatment and allergy testing were noted among the patients included in this study. RESULTS: Seven patients (five female) underwent uneventful phacoemulsification under a peribulbar or sub-tenon's block, all including hyaluronidase with concentrations ranging 50-250 IU/mL. The onset of inflammatory symptoms and signs varied from 12 h to 3 days after the surgery. The most common form of presentation was lid swelling and chemosis. Patients were treated with oral corticosteroids, with good clinical response. Four patients underwent skin prick and intradermal testing to the local anaesthetic used, and to the suspect and a control hyaluronidase batch. The results were all negative, excluding allergy as the aetiology of this toxic periorbital syndrome, in at least these four patients. CONCLUSION: Hyaluronidase toxicity, potentially related to concentration of hyaluronidase, may be a cause of postoperative periorbital inflammation after cataract surgery, rather than hypersensitivity.

Analysis of Posterior Corneal Surgically Induced Astigmatism Following Cataract Surgery With a 1.8-mm Temporal Clear Corneal Incision.

PURPOSE: To determine posterior corneal surgically induced astigmatism (SIA) when using a temporal clear corneal incision and the IOLMaster 700 (Carl Zeiss Meditec AG) for biometric measurements and to determine whether posterior corneal SIA can be predicted from preoperative data. METHODS: A total of 258 consecutive eyes of 258 patients underwent cataract surgery with a 1.8-mm temporal clear corneal incision. Biometry measurements were taken preoperatively and 6 weeks postoperatively using the IOLMaster 700. Using vector analysis, the SIA of the posterior cornea was calculated. RESULTS: The centroid of posterior corneal SIA was 0.01 diopters (D) @159 ± 0.14 D. The mean posterior corneal SIA was 0.12 D ± 0.07 D. Posterior corneal SIA magnitude was 0.25 D or less in 95% of patients. There was no correlation found between posterior corneal SIA magnitude and any preoperative measurement. CONCLUSIONS: The authors suggest not adjusting for posterior corneal SIA if using a small caliber, temporal incision. It was not possible to predict posterior corneal SIA from preoperative biometric measurements. [J Refract Surg. 2023;39(6):381-386.].

Accuracy of the Goggin Nomogram for 0.50 D Steps in Toric IOL Cylinder Power Calculation.

PURPOSE: To examine the accuracy of the cylinder power choice for toric intraocular lenses (IOLs) using the Goggin Nomogram, which adjusts anterior keratometric astigmatic power values for the likely effect of posterior corneal and non-corneal, non-lenticular astigmatism. METHODS: A consecutive, retrospective case series was based at the Queen Elizabeth Hospital and Ashford Advanced Eye Care in Adelaide, Australia. A total of 586 consecutive eyes of 586 patients underwent phacoemulsification surgery with implantation of a Zeiss AT TORBI 709MP or AT LISA Tri Toric 939 MP toric IOL, calculated using the Goggin Nomogram. The median absolute magnitude of error and geometric mean astigmatic correction index in consecutive eyes with toric IOL cylinder powers of 1.00 to 3.00 diopters (D) were analyzed. RESULTS: Overall, all eyes receiving IOL cylinder powers of 1.00 to 3.00 D inclusive had a median magnitude of error value of 0.19 D (IQR: 0.31) and astigmatic correction index value of 1.03 (IQR: 0.33). For eyes with with-the-rule, against-the-rule, and oblique astigmatism, the median magnitude of error was 0.18 D (interquartile range [IQR]: 0.29), 0.19 D (IQR: 0.31), and 0.17 D (IQR: 0.39), respectively, and the astigmatic correction index was 1.06 (IQR: 0.28), 1.01 (IQR: 0.35) and 1.08 (IQR: 0.32), respectively. CONCLUSIONS: Goggin Nomogram adjusted keratometry provided optimal refractive astigmatic outcome in IOL cylinder powers of 1.00 to 3.00 D in eyes with with-the-rule, against-the-rule, and oblique astigmatism. Goggin Nomogram adjusted keratometry compensates for both posterior corneal astigmatism and any other source of ocular astigmatism. [J Refract Surg. 2022;38(5):298-303.].

Leftover Astigmatism: The Missing Link Between Measured and Calculated Posterior Corneal Astigmatism.

PURPOSE: To quantify the total eye astigmatism that is not accounted for by measurement of anterior corneal astigmatism and posterior corneal astigmatism and knowledge of intraocular lens (IOL) astigmatism and assess whether it is correlated with candidate sources of or correlates with leftover astigmatism. METHODS: Vector subtraction of anterior corneal, posterior corneal, and IOL astigmatism from total eye astigmatism as represented by spectacle astigmatism to yield a value of "leftover" astigmatism that is neither corneal nor lenticular. This value was derived in a series of eyes following cataract surgery. This novel entity was examined for correlation with candidate sources of or correlates with leftover astigmatism. RESULTS: In 103 pseudophakic eyes with known IOL toricity, mean leftover astigmatism was 0.71 ± 0.43 diopters. This was significantly correlated with against-the-rule anterior corneal astigmatism (P < .001). CONCLUSIONS: Leftover astigmatism is clinically substantial. Because it is included in IOL cylinder power calculations based on refractive outcome, it may explain why methods of IOL cylinder power calculation using refractive outcome-based adjustments to anterior corneal astigmatism (previously described as adjustments for "posterior corneal astigmatism") are more successful than adjustment on the basis of measured posterior corneal astigmatism. [J Refract Surg. 2022;38(9):559-564.].