Using genetics to investigate the association between lanosterol and cataract

Background: Cataract is one of the most prevalent causes of blindness worldwide. Whilst surgery is the primary treatment for cataracts, it is not always an available option, particularly in developing countries. Non-surgical methods of treatment would increase treatment availability for more patients. Several studies have investigated how topical application of oxysterols, such as lanosterol, may break down aggregated proteins and restore lens transparency. However, the results are conflicting and inconclusive. Aim: In this study, we focus on combining genetic evidence for associations between lanosterol related genetic variation and cataract to explore whether lanosterol is a potentially suitable drug treatment option. Method: Using data from 45,449 available cataract cases from the UK Biobank, with participant ages ranging from 40-69, we conducted a genetic association study (GWAS) to assess the risk of cataract. Cataract cases were defined using diagnostic and operation codes. We focused on genetic variants in the lanosterol synthase gene region. We also compared our results with previously published genetic associations of phytosterol-to-lanosterol ratios. Finally, we performed a genetic risk score analysis to test the association between lanosterol within the cholesterol synthesis pathway and the risk of cataract. Results: No statistically significant single nucleotide polymorphisms (SNPs) associations with cataract were observed in the gene region of lanosterol synthase at a multiple testing adjusted significance threshold of p < 0.05/13. The comparison between cataract risk and genetic association of 8 phytosterol-to-lanosterol GWAS results also showed no evidence to support lanosterol's protective properties for cataract risk. No statistically significant association was found between the lanosterol within the cholesterol synthesis pathway genetic risk score and cataract outcomes (OR = 1.002 p = 0.568). Conclusion: There was no evidence observed for genetic associations between lanosterol and cataract risk. Our results do not support lanosterol's potential role in treating cataracts. Further research may be needed to address the effect of lanosterol on specific cataract subtypes.

Usability of an artificially intelligence-powered triage platform for adult ophthalmic emergencies: a mixed methods study

There is growing demand for emergency-based eyecare services where the majority of those attending do not require urgent ophthalmic management. The Royal College of Ophthalmologists have recommended upskilling and supporting of allied health professionals to support eyecare delivery, where machine learning algorithms could help. A mixed methods study was conducted to evaluate the usability of an artificial intelligence (AI) powered online triage platform for ophthalmology. The interface, usability, safety and acceptability were investigated using a Think Aloud interview and usability questionnaires. Twenty participants who actively examine patients in ophthalmic triage within a tertiary eye centre or primary care setting completed the interview and questionnaires. 90% or more of participants found the platform easy to use, reflected their triage process and were able to interpret the triage outcome, 85% found it safe to use and 95% felt the processing time was fast. A quarter of clinicians reported that they have experienced some uncertainty when triaging in their career and were unsure of using AI, after this study 95% of clinicians were willing to use the platform in their clinical workflow. This study showed the platform interface was acceptable and usable for clinicians actively working in ophthalmic emergency triage.

A machine learning system to optimise triage in an adult ophthalmic emergency department: a model development and validation study

Background

A substantial proportion of attendances to ophthalmic emergency departments are for non-urgent presentations. We developed and evaluated a machine learning system (DemDx Ophthalmology Triage System: DOTS) to optimise triage, with the aim of reducing inappropriate emergency attendances and streamlining case referral when necessary.

Methods

DOTS was built using retrospective tabular data from 11,315 attendances between July 1st, 2021, to June 15th, 2022 at Moorfields Eye Hospital Emergency Department (MEH) in London, UK. Demographic and clinical features were used as inputs and a triage recommendation was given ("see immediately", "see within a week", or "see electively"). DOTS was validated temporally and compared with triage nurses' performance (1269 attendances at MEH) and validated externally (761 attendances at the Federal University of Minas Gerais - UFMG, Brazil). It was also tested for biases and robustness to variations in disease incidences. All attendances from patients aged at least 18 years with at least one confirmed diagnosis were included in the study.

Findings

For identifying ophthalmic emergency attendances, on temporal validation, DOTS had a sensitivity of 94.5% [95% CI 92.3-96.1] and a specificity of 42.4% [38.8-46.1]. For comparison within the same dataset, triage nurses had a sensitivity of 96.4% [94.5-97.7] and a specificity of 25.1% [22.0-28.5]. On external validation at UFMG, DOTS had a sensitivity of 95.2% [92.5-97.0] and a specificity of 32.2% [27.4-37.0]. In simulated scenarios with varying disease incidences, the sensitivity was ≥92.2% and the specificity was ≥36.8%. No differences in sensitivity were found in subgroups of index of multiple deprivation, but the specificity was higher for Q2 when compared to Q4 (Q4 is less deprived than Q2).

Interpretation

At MEH, DOTS had similar sensitivity to triage nurses in determining attendance priority; however, with a specificity of 17.3% higher, DOTS resulted in lower rates of patients triaged to be seen immediately at emergency. DOTS showed consistent performance in temporal and external validation, in social-demographic subgroups and was robust to varying relative disease incidences. Further trials are necessary to validate these findings. This system will be prospectively evaluated, considering human-computer interaction, in a clinical trial.

Funding

The Artificial Intelligence in Health and Care Award (AI_AWARD01671) of the NHS AI Lab under National Institute for Health and Care Research (NIHR) and the Accelerated Access Collaborative (AAC).

Laser-assisted cataract surgery versus standard ultrasound phacoemulsification cataract surgery

BACKGROUND

Cataract is the leading cause of blindness in the world and, as such, cataract surgery is one of the most commonly performed operations globally. Surgical techniques have changed dramatically over the past half century with associated improvements in outcomes and safety. Femtosecond lasers can be used to perform the key steps in cataract surgery, such as corneal incisions, lens capsulotomy and fragmentation. The potential advantage of femtosecond laser-assisted cataract surgery (FLACS) is greater precision and reproducibility of these steps compared to manual techniques. The disadvantages are the costs associated with FLACS technology.

OBJECTIVES

To compare the effectiveness and safety of FLACS with standard ultrasound phacoemulsification cataract surgery (PCS) by gathering evidence from randomised controlled trials (RCTs).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; which contains the Cochrane Eyes and Vision Trials Register; 2022, Issue 5); Ovid MEDLINE; Ovid Embase; LILACS; the ISRCTN registry; ClinicalTrials.gov; the WHO ICTRP and the US Food and Drug Administration (FDA) website. We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 10 May 2022.

SELECTION CRITERIA

We included RCTs where FLACS was compared to PCS.

DATA COLLECTION AND ANALYSIS

Three review authors independently screened the search results, assessed risk of bias and extracted data using the standard methodological procedures expected by Cochrane. The primary outcome for this review was intraoperative complications in the operated eye, namely anterior capsule, and posterior capsule tears. The secondary outcomes included corrected distance visual acuity (CDVA), quality of vision (as measured by any validated patient-reported outcome measure (PROM)), postoperative cystoid macular oedema complications, endothelial cell loss and cost-effectiveness. We assessed the certainty of the evidence using GRADE.

MAIN RESULTS

We included 42 RCTs conducted in Europe, North America, South America and Asia, which enrolled a total of 7298 eyes of 5831 adult participants. Overall, the studies were at unclear or high risk of bias. In 16 studies the authors reported financial links with the manufacturer of the laser platform evaluated in their studies. Thirteen of the studies were within-person (paired-eye) studies with one eye allocated to one procedure and the other eye allocated to the other procedure. These studies were reported ignoring the paired nature of the data. There was low-certainty evidence of little or no difference in the odds of developing anterior capsular tears when comparing FLACS and PCS (Peto odds ratio (OR) 0.83, 95% confidence interval (CI) 0.40 to 1.72; 5835 eyes, 27 studies) There was one fewer anterior capsule tear per 1000 operations in the FLACS group compared with the PCS group (95% CI 4 fewer to 3 more).  There was low-certainty evidence of lower odds of developing posterior capsular tears with FLACS compared to PCS (Peto OR 0.50, 95% CI 0.25 to 1.00; 5767 eyes, 26 studies). There were four fewer posterior capsule tears per 1000 operations in the FLACS group compared with the PCS group (95% CI 6 fewer to same).  There was moderate-certainty evidence of a very small advantage for the FLACS arm with regard to CDVA at six months or more follow-up, (mean difference (MD) -0.01 logMAR, 95% CI -0.02 to 0.00; 1323 eyes, 7 studies). This difference is equivalent to 1 logMAR letter between groups and is not thought to be clinically important. From the three studies (1205 participants) reporting a variety of PROMs (Cat-PROMS, EQ-5D, EQ-SD-3L, Catquest9-SF and patient survey) up to three months following surgery, there was moderate-certainty evidence of little or no difference in the various parameters between the two treatment arms. There was low-certainty evidence of little or no difference in the odds of developing cystoid macular oedema when comparing FLACS and PCS (Peto OR 0.84, 95% CI 0.56 to 1.28; 4441 eyes, 18 studies). There were three fewer cystoid macular oedema cases per 1000 operations in the FLACS group compared with the PCS group (95% CI 10 fewer to 6 more).  In one study the incremental cost-effectiveness ratio (ICER) (cost difference divided by quality-adjusted life year (QALY) difference) was GBP £167,620 when comparing FLACS to PCS. In another study, the ICER was EUR €10,703 saved per additional patient who had treatment success with PCS compared to FLACS. Duration ranged from three minutes in favour of FLACS to eight minutes in favour of PCS (I2 = 100%, 11 studies) (low-certainty evidence).  There was low-certainty evidence of little or no important difference in endothelial cell loss when comparing FLACS with PCS (MD 12 cells per mm2 in favour of FLACS, 95% CI -40 to 64; 1512 eyes, 10 studies).  AUTHORS' CONCLUSIONS: This review of 42 studies provides evidence that there is probably little or no difference between FLACS and PCS in terms of intraoperative and postoperative complications, postoperative visual acuity and quality of life. Evidence from two studies suggests that FLACS may be the less cost-effective option. Many of the included studies only investigated very specific outcome measures such as effective phacoemulsification time, endothelial cell count change or aqueous flare, rather than those directly related to patient outcomes. Standardised reporting of complications and visual and refractive outcomes for cataract surgery would facilitate future synthesis, and guidance on this has been recently published.

Incidence of Microfolds Using a Standardized Three-Stage LASIK Flap Replacement Protocol

PURPOSE

To describe a standardized three-stage flap replacement protocol and report the incidence of microfolds after femtosecond laser-assisted laser in situ keratomileusis (LASIK) surgery.

METHODS

A retrospective analysis of 14,374 consecutive LASIK procedures with the VisuMax femtosecond laser (Carl Zeiss Meditec) by two surgeons was conducted. As per the standardized procedure, all eyes underwent the three-stage flap replacement protocol consisting of controlled standardized minimal irrigation and flap repositioning after ablation, followed by fluorescein-controlled slit-lamp adjustments and slit-lamp adjustments on day 1 (if required). Microfold incidence was recorded at all subsequent visits and recorded by independent observers classified using a standardized 6-point grading system including whether they were refractively or visually significant.

RESULTS

Flap thickness used was 80 to 89 µm (7.2%), 90 to 99 µm (51.7%), 100 to 109 µm (17.8%), and 110 to 130 µm (23.2%). Slit-lamp adjustment at day 1 was performed in 956 eyes (6.77%), with the highest incidence in 80 to 89 µm flaps (27.6%). A flap slip occurred in 23 eyes (0.16%) and was managed at the slit lamp for 21 eyes and in the operating room for 2 eyes. At 3 months after surgery, trace microfolds were present in 158 eyes (1.10%), grade 1 in 26 eyes (0.184%), and grade 2 in 2 eyes (0.016%). Grade 1 microfold incidence per flap thickness group was 39.1% for 80 to 89 µm, 30.4% for 90 to 99 µm, 13% for 100 to 109 µm, and 17.4% for 110 to 130 µm. No eyes required a flap lift for microfolds in the operating room. Multivariate regression analysis found microfold incidence to be higher for thinner flaps, higher correction, and larger optical zone.

CONCLUSIONS

The three-stage protocol for flap positioning and management resulted in a low incidence of clinically visible microfolds and no visually significant microfolds. Day 1 slit-lamp adjustment was required more frequently in ultra-thin 80 to 89 µm flaps. [J Refract Surg. 2023;39(6):388-396.].

Royal College of Ophthalmologists' National Ophthalmology Database study of cataract surgery: report 8, cohort analysis of the relationship between intraoperative complications of cataract surgery and axial length

OBJECTIVES

To describe the relationships between axial length and intraoperative complications in patients undergoing cataract surgery.

DESIGN

Cohort analysis of the Royal College of Ophthalmologists' National Ophthalmology Database (RCOphth NOD).

SETTING

110 National Health Service Trusts in England, Health Boards in Wales, Independent Sector Treatment Centres and Guernsey.

PARTICIPANTS

820 354 patients, aged 18 years or older, undergoing cataract surgery. Eligible operations were those from centres with at least 50 operations with a recorded axial length measurement and age at surgery between 1 April 2010 and 31 August 2019.

INTERVENTIONS

Phacoemulsification where the primary intention was cataract surgery alone.

OUTCOME MEASURES

Posterior capsule rupture (PCR) and other recorded intraoperative complications.

RESULTS

1 211 520 eligible operations were performed by 3210 surgeons. The baseline axial length was <21 mm (short eyes) for 17 170 (1.4%) eyes, 21-28 mm (medium eyes) for 1 182 513 (97.6%) eyes and >28 mm (long eyes) for 11 837 (1.0%) eyes. The median age at surgery was younger for patients with long eyes than those with short or medium eyes. The rate of any intraoperative complication was higher for short eyes than medium or long with complication rates of 4.5%, 2.9% and 3.3%, respectively (p<0.001). PCR occurred in 1.40% surgeries overall, and in 1.53%, 1.40% and 1.61% of short, medium and long eyes, respectively (p=0.043, not significant at the 1% level).

CONCLUSIONS

Overall PCR rates for cataract surgery in RCOphth NOD contributing centres are lower than previously reported and there is little change in PCR rates by axial length. Short eyes were more likely to have an intraoperative complication than medium or long eyes.

Alcohol Consumption and Incident Cataract Surgery in Two Large UK Cohorts

Purpose

To examine the association of alcohol consumption and type of alcoholic beverage with incident cataract surgery in 2 large cohorts.

Design

Longitudinal, observational study.

Participants

We included 469 387 participants of UK Biobank with a mean age of 56 years and 23 162 participants of European Prospective Investigation of Cancer (EPIC)-Norfolk with a mean age of 59 years.

Methods

Self-reported alcohol consumption at baseline was ascertained by a touchscreen questionnaire in UK Biobank and a food-frequency questionnaire in EPIC-Norfolk. Cases were defined as participants undergoing cataract surgery in either eye as ascertained via data linkage to National Health Service procedure statistics. We excluded participants with cataract surgery up to 1 year after the baseline assessment visit or those with self-reported cataract at baseline. Cox proportional hazards models were used to examine the associations of alcohol consumption with incident cataract surgery, adjusted for age, sex, ethnicity, Townsend deprivation index, body mass index (BMI), smoking, and diabetes status.

Main Outcome Measures

Incident cataract surgery.

Results

There were 19 011 (mean cohort follow-up of 95 months) and 4573 (mean cohort follow-up of 193 months) incident cases of cataract surgery in UK Biobank and EPIC-Norfolk, respectively. Compared with nondrinkers, drinkers were less likely to undergo cataract surgery in UK Biobank (hazard ratio [HR], 0.89; 95% confidence interval [CI], 0.85–0.93) and EPIC-Norfolk (HR, 0.90; 95% CI, 0.84–0.97) after adjusting for covariables. Among alcohol consumers, greater alcohol consumption was associated with a reduced risk of undergoing cataract surgery in EPIC-Norfolk (P < 0.001), whereas a U-shaped association was observed in the UK Biobank. Compared with nondrinkers, subgroup analysis by type of alcohol beverage showed the strongest protective association with wine consumption; the risk of incident cataract surgery was 23% and 14% lower among those in the highest category of wine consumption in EPIC-Norfolk and UK Biobank, respectively.

Conclusions

Our findings suggest a lower risk of undergoing cataract surgery with low to moderate alcohol consumption. The association was particularly apparent with wine consumption. We cannot exclude the possibility of residual confounding, and further studies are required to determine whether this association is causal in nature.

Femtosecond laser-assisted cataract surgery compared with phacoemulsification: the FACT non-inferiority RCT

BACKGROUND

Cataract surgery is one of the most common operations. Femtosecond laser-assisted cataract surgery (FLACS) is a technique that automates a number of operative steps.

OBJECTIVES

To compare FLACS with phacoemulsification cataract surgery (PCS).

DESIGN

Multicentre, outcome-masked, randomised controlled non-inferiority trial.

SETTING

Three collaborating NHS hospitals.

PARTICIPANTS

A total of 785 patients with age-related cataract in one or both eyes were randomised between May 2015 and September 2017.

INTERVENTION

FLACS (n = 392 participants) or PCS (n = 393 participants).

MAIN OUTCOME MEASURES

The primary outcome was uncorrected distance visual acuity in the study eye after 3 months, expressed as the logarithm of the minimum angle of resolution (logMAR): 0.00 logMAR (or 6/6 if expressed in Snellen) is normal (good visual acuity). Secondary outcomes included corrected distance visual acuity, refractive outcomes (within 0.5 dioptre and 1.0 dioptre of target), safety and patient-reported outcome measures at 3 and 12 months, and resource use. All trial follow-ups were performed by optometrists who were masked to the trial intervention.

RESULTS

A total of 353 (90%) participants allocated to the FLACS arm and 317 (81%) participants allocated to the PCS arm attended follow-up at 3 months. The mean uncorrected distance visual acuity was similar in both treatment arms [0.13 logMAR, standard deviation 0.23 logMAR, for FLACS, vs. 0.14 logMAR, standard deviation 0.27 logMAR, for PCS, with a difference of -0.01 logMAR (95% confidence interval -0.05 to 0.03 logMAR; p = 0.63)]. The mean corrected distance visual acuity values were again similar in both treatment arms (-0.01 logMAR, standard deviation 0.19 logMAR FLACS vs. 0.01 logMAR, standard deviation 0.21 logMAR PCS; p = 0.34). There were two posterior capsule tears in the PCS arm. There were no significant differences between the treatment arms for any secondary outcome at 3 months. At 12 months, the mean uncorrected distance visual acuity was 0.14 logMAR (standard deviation 0.22 logMAR) for FLACS and 0.17 logMAR (standard deviation 0.25 logMAR) for PCS, with a difference between the treatment arms of -0.03 logMAR (95% confidence interval -0.06 to 0.01 logMAR; p = 0.17). The mean corrected distance visual acuity was 0.003 logMAR (standard deviation 0.18 logMAR) for FLACS and 0.03 logMAR (standard deviation 0.23 logMAR) for PCS, with a difference of -0.03 logMAR (95% confidence interval -0.06 to 0.01 logMAR; p = 0.11). There were no significant differences between the arms for any other outcomes, with the exception of the mean binocular corrected distance visual acuity with a difference of -0.02 logMAR (95% confidence interval -0.05 to 0.00 logMAR) (p = 0.036), which favoured FLACS. There were no significant differences between the arms for any health, social care or societal costs. For the economic evaluation, the mean cost difference was £167.62 per patient higher for FLACS (95% of iterations between -£14.12 and £341.67) than for PCS. The mean QALY difference (FLACS minus PCS) was 0.001 (95% of iterations between -0.011 and 0.015), which equates to an incremental cost-effectiveness ratio (cost difference divided by QALY difference) of £167,620.

LIMITATIONS

Although the measurement of outcomes was carried out by optometrists who were masked to the treatment arm, the participants were not masked.

CONCLUSIONS

The evidence suggests that FLACS is not inferior to PCS in terms of vision after 3 months' follow-up, and there were no significant differences in patient-reported health and safety outcomes after 12 months' follow-up. In addition, the statistically significant difference in binocular corrected distance visual acuity was not clinically significant. FLACS is not cost-effective.

FUTURE WORK

To explore the possible differences in vision in patients without ocular co-pathology.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN77602616.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 6. See the NIHR Journals Library website for further project information. Moorfields Eye Charity (grant references GR000233 and GR000449 for the endothelial cell counter and femtosecond laser used).

Femtosecond Laser-Assisted Deep Anterior Lamellar Keratoplasty for Keratoconus: Multi-surgeon Results

PURPOSE

To compare the clinical outcomes in femtosecond laser-assisted deep anterior lamellar keratoplasty (F-DALK) to manual non-laser deep anterior lamellar keratoplasty (M-DALK) for keratoconus in a multi-surgeon public healthcare setting.

DESIGN

Single-center, comparative, retrospective interventional case series.

METHODS

Population: Consecutive cases of keratoconus treated with big-bubble F-DALK from August 1, 2015, to September 1, 2018 and big-bubble M-DALK from September 1, 2012, to September 30, 2016.

SETTING

Moorfields Eye Hospital, London.

OBSERVATIONS

Data on preoperative status, operative details, intraoperative and postoperative complications, secondary interventions, and visual outcomes were archived on a customized spreadsheet for analysis. MainOutcomeMeasures: Rate of intraoperative perforation and conversion to penetrating keratoplasty (PK) and the percentage of patients, post removal of sutures (ROS), with corrected distance visual acuity (CDVA) ≥20/40.

RESULTS

We analyzed 58 eyes of 55 patients who underwent F-DALK and 326 eyes of 309 patients who underwent M-DALK. Intraoperative perforation of Descemet membrane occurred in 15 of 58 (25.9%) F-DALK cases compared to 148 of 326 (45.4%) M-DALK cases (P = .006). Intraoperative conversion to PK was carried out in 2 of 58 (3.4%) F-DALK cases compared to 80 of 326 (24.5%) M-DALK cases (P = .001). Post ROS, 86.5% of F-DALK eyes had a CDVA of ≥20/40 (15 ± 7.3 months after surgery) compared to 83.7% of M-DALK eyes (24.9 ± 10.6 months) (P = .825).

CONCLUSION

Laser automation of some steps in DALK for keratoconus may reduce the rate of intraoperative Descemet perforation and the conversion to PK in a multi-surgeon setting.

Femtosecond laser-assisted cataract surgery: A review

PURPOSE

Review scientific literature concerning femtosecond laser-assisted cataract surgery.

METHODS

Following databases were searched: CENTRAL (Cochrane Eyes and Vision Trials Register; Cochrane Library: Issue 2 of 12, June 2019), Ovid MEDLINE^® without Revisions (1996 to June 2019), Ovid MEDLINE^® (1946 to June 2019), Ovid MEDLINE^® Daily Update June 2019, MEDLINE and MEDLINE Non-Indexed Items, Embase (1980-2019), Embase (1974 to June 2019), Ovid MEDLINE^® and Epub Ahead of Print, in-Process & Other Non-Indexed Citations and Daily (1946 to June 2019), Web of Science (all years), the metaRegister of Controlled Trials ( www.controlled-trials.com ), ClinicalTrials.gov ( www.clinicaltrial.gov ) and World Health Organization International Clinical Trials Registry Platform ( www.who.int/ictrp/search/en ). Search terms/keywords included 'Femtosecond laser' combined with 'cataract', 'cataract surgery'.

RESULTS

Based on quality of their methodology and their originality, 121 articles were reviewed, including randomised controlled trials, cohort studies, case-controlled studies, case series, case reports and laboratory studies. Each step of the femtosecond laser-assisted cataract surgery procedure (corneal incisions, arcuate keratotomies, capsulotomy and lens fragmentation) has been discussed with relevance to published outcomes, as well as complication rates of femtosecond laser-assisted cataract surgery, and what we can learn from the larger studies/meta-analyses and the economics of femtosecond laser-assisted cataract surgery within different healthcare settings.

CONCLUSION

Studies suggest that the current clinical outcomes of femtosecond laser-assisted cataract surgery are not different to conventional phacoemulsification surgery and it is not cost effective when compared with conventional phacoemulsification surgery. In its current technological form, it is a useful surgical tool in specific complex cataract scenarios, but its usage has not been shown to translate into better clinical outcomes.

Frequency and distribution of corneal astigmatism and keratometry features in adult life: Methodology and findings of the UK Biobank study

Purpose

To describe corneal astigmatism in the UK Biobank population and to look for associations with other biometric variables and socio-demographic factors.

Methods

This analysis included a subsample of 107,452 participants of the UK Biobank study who underwent an enhanced ophthalmic examination including autorefractor keratometry (Tomey RC 5000, Tomey Corp., Nagoya, Japan). Participants were recruited from across the United Kingdom between 2006 and 2010, and all were between 40 to 69 years. After quality control and applying relevant exclusions, data on corneal astigmatism on 83,751 participants were included for analysis. Potential associations were tested through univariable regression and significant parameters carried forward for multivariable analysis.

Results

In univariable analysis, the characteristics significantly associated with higher corneal astigmatism (P<0.001), by order of magnitude were, female gender, white ethnicity, lighter skin colour, use of UV protection, lower alcohol intake, lower corneal-compensated intraocular pressure (ccIOP), older age at completion of education, younger age, higher Townsend deprivation index, lower height and lower systolic blood pressure. After inclusion in the multivariable analysis, gender, skin colour, alcohol intake, age at completion of full-time education, ccIOP, age and Townsend deprivation score remained significant (all P<0.001). Increased corneal astigmatism was also found to be significantly associated with amblyopia or strabismus.

Conclusions

This analysis confirms previous associations with astigmatism such as younger age and female gender, and identified novel risk factors including lighter skin colour, lower alcohol intake, later age having completed full time education later, lower ccIOP and higher Townsend deprivation index. Further research is needed to investigate these novel associations.

Deep Anterior Lamellar Keratoplasty for Keratoconus: Multisurgeon Results

PURPOSE

To examine clinical outcomes in deep anterior lamellar keratoplasty (DALK) for keratoconus using contemporary techniques in a multisurgeon public healthcare setting.

DESIGN

Consecutive, retrospective case series.

METHODS

Setting: Moorfields Eye Hospital, London, United Kingdom.

STUDY POPULATION

Consecutive cases of keratoconus treated with non-laser assisted DALK from September 1, 2012, to September 31, 2016.

OBSERVATION PROCEDURE

Data on preoperative status, operative details, intraoperative and postoperative complications, secondary interventions, and visual outcomes were archived for analysis.

MAIN OUTCOME MEASURES

Graft failure rate and percentage of patients with corrected distance visual acuity (CDVA) ≥20/40 within 1 year of surgery and at final review after suture removal.

RESULTS

Three hundred fifty-seven eyes of 338 patients undergoing DALK (91.3% big-bubble technique attempted) were analyzed. A total of 4.2% (95% confidence interval [CI] 2.4%-6.8%) of corneal transplants had failed within the follow-up period (21.8 ± 11.4 months), and 75.9% of eyes had CDVA ≥20/40 within 1 year of surgery, rising to 81% after suture removal. Forty-two primary surgeons (31 trainees) participated. Intraoperative perforation of Descemet membrane occurred in 45.4% of eyes. A total of 24.1% were converted to penetrating keratoplasty (PK) intraoperatively. Conversion to PK increased the risk of transplant rejection (P = .026; odds ratio [OR] 1.94; 95% CI 1.1-3.5) and secondary glaucoma (P = .016; OR 4.0; 95% CI 1.3-12.4). Transplant rejection increased the risk of graft failure both overall (P = .017; OR = 3.9; 95% CI 1.4-11.0) and when cases converted to PK were excluded (P = .028; OR = 3.35; 95% CI 1.1-9.9).

CONCLUSION

DALK for keratoconus achieves early results similar to those published for PK in a multisurgeon setting. Conservative management of intraoperative Descemet membrane perforation, where possible, may be safer than conversion to PK.

Small Incision Lenticule Extraction for Hyperopia: 3-Month Refractive and Visual Outcomes

PURPOSE

To evaluate visual and refractive outcomes of small incision lenticule extraction (SMILE) for hyperopia.

METHODS

This prospective study of vertex-centered hyperopic SMILE used the VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany). Inclusion criteria were maximum attempted hyperopic meridian of between +1.00 and +7.00 diopters (D) and corrected distance visual acuity (CDVA) of 20/40 or better. Lenticule parameters were 6.3- to 6.7-mm diameter, 2-mm transition zone, 30-µm minimum thickness, and 120-µm cap thickness. Standard outcomes analysis was performed for the 3-month data, including contrast sensitivity using the Functional Vision Analyzer.

RESULTS

For 93 eyes treated, 3-month data were available for 82 (88%). Attempted spherical equivalent refraction was +5.62 ± 1.20 D (range: +1.00 to +6.90 D) and cylinder was -0.91 ± 0.68 D (range: 0.00 to -3.50 D). For eyes targeted for emmetropia (n = 36), uncorrected distance visual acuity was 20/40 or better in 89%. Spherical equivalent refraction relative to target was -0.17 ± 0.85 D (range: -2.20 to +3.00 D), with 59% within ±0.50 D and 76% within ±1.00 D. There was one line loss of CDVA in 17% of eyes, and one eye lost three lines (1.2%) but recovered to one line lost at 9 months. There was no clinically significant change in contrast sensitivity.

CONCLUSIONS

Refractive and visual outcomes 3 months after SMILE for hyperopia were promising, given the high degree of hyperopia corrected and relatively reduced CDVA in this population. Undercorrection of more than 1.00 D in 5 eyes might be partly explained by latent hyperopia in these young patients. [J Refract Surg. 2019;35(1):24-30.].

Outcomes for Mixed Cylinder LASIK With the MEL 90® Excimer Laser

PURPOSE

To report the outcomes of LASIK for mixed cylinder using the Triple-A ablation profile with the MEL 90 excimer laser (Carl Zeiss Meditec, Jena, Germany).

METHODS

This was a retrospective analysis of all eyes treated by LASIK for mixed cylinder using the Triple-A ablation profile with the MEL 90 laser between July 2013 and October 2016. Patients were observed for 1 year after surgery. Standard outcomes analysis and vector analysis by the Alpins method were performed.

RESULTS

The database review identified 105 eyes (82 patients) treated by LASIK for mixed cylinder using the MEL 90 laser. Mean age was 40 ± 11 years (range: 18 to 65 years). Mean attempted spherical equivalent was +0.30 ± 0.90 diopters (D) (range: -2.30 to +1.75 D). Mean cylinder was -2.93 ± 1.47 D (range: -0.75 to -7.00 D). Preoperative corrected distance visual acuity (CDVA) was 20/20 or better in 81% of eyes. Postoperative uncorrected distance visual acuity was 20/20 or better in 69% and 20/25 or better in 86% of eyes. Mean postoperative spherical equivalent relative to the intended target was -0.21 ± 0.38 D (range: -1.25 to +1.13 D), with 83% within ±0.50 D. Mean postoperative cylinder was -0.57 ± 0.41 D (range: 0.00 to -1.75 D). Geometric mean was 1.12 for the correction index and 0.25 for the index of success. For angle of error, the arithmetic mean was -0.6° ± 4.2° (range: -13.5° to 9.5°) and the absolute mean was 2.9° ± 3.0° (range: 0.0° to 13.5°). There was loss of one line of CDVA in 3% of eyes and no eyes lost two or more lines CDVA. There was a small increase in contrast sensitivity after surgery at 3, 6, 12, and 18 cycles per degree (P < .05).

CONCLUSIONS

One-year outcomes of LASIK using the MEL 90 laser for mixed cylinder up to -7.00 D demonstrated excellent efficacy, safety, and predictability. Vector analysis found a 12% overcorrection in magnitude of refractive cylinder. Given the high accuracy for angle of error, a nomogram could be applied to reduce the over-correction and further improve the uncorrected distance visual acuity outcomes. [J Refract Surg. 2018;34(10):672-680.].

Outcomes for Hyperopic LASIK With the MEL 90® Excimer Laser

PURPOSE

To report the outcomes of laser in situ keratomileusis (LASIK) for hyperopia using the Triple-A ablation profile with the MEL 90 excimer laser (Carl Zeiss Meditec, Jena, Germany).

METHODS

This retrospective analysis included 1,383 eyes treated by LASIK for hyperopia using the Triple-A ablation profile with the MEL 90 at London Vision Clinic, London, United Kingdom, between September 2013 and December 2016. Inclusion criteria were attempted hyperopic correction of +0.25 diopters (D) or higher and corrected distance visual acuity (CDVA) of 20/40 or better. Patients were observed for 1 year after surgery. Standard outcomes analysis was performed.

RESULTS

One-year data were available for 1,350 (97%) eyes. Mean attempted spherical equivalent refraction (SEQ) was +2.77 ± 1.34 D (range: +0.13 to +6.50 D) and mean cylinder was -0.67 ± 0.66 D (range: 0.00 to -5.00 D). Mean age was 54 ± 11 years (range: 21 to 75 years), and 57% were female. Postoperative spherical equivalent was ±0.50 D in 73% and ±1.00 D in 93% of eyes. Uncorrected distance visual acuity was 20/20 or better in 75% of eyes, relative to 93% with preoperative CDVA of 20/20 or better. One line of CDVA was lost in 17% of eyes and two lines were lost in 0.6% of eyes. There was a clinically insignificant but statistically significant increase (P < .01) in contrast sensitivity at 3 and 6 cycles per degree (cpd) and no change for 12 and 18 cpd.

CONCLUSIONS

LASIK for hyperopia with the MEL 90 excimer laser was found to satisfy accepted criteria for safety, efficacy, and stability. [J Refract Surg. 2018;34(12):799-808.].

Distribution of preoperative and postoperative astigmatism in a large population of patients undergoing cataract surgery in the UK

Purpose

To assess the prevalence and severity of preoperative and postoperative astigmatism in patients with cataract in the UK.

Setting

Data from 8 UK National Health Service ophthalmology clinics using MediSoft electronic medical records (EMRs).

Design

Retrospective cohort study.

Methods

Eyes from patients aged ≥65 years undergoing cataract surgery were analysed. For all eyes, preoperative (corneal) astigmatism was evaluated using the most recent keratometry measure within 2 years prior to surgery. For eyes receiving standard monofocal intraocular lens (IOLs), postoperative refractive astigmatism was evaluated using the most recent refraction measure within 2–12 months postsurgery. A power vector analysis compared changes in the astigmatic 2-dimensional vector (J₀, J₄₅) before and after surgery, for the subgroup of eyes with both preoperative and postoperative astigmatism measurements. Visual acuity was also assessed preoperatively and postoperatively.

Results

Eligible eyes included in the analysis were 110 468. Of these, 78% (n=85 650) had preoperative (corneal) astigmatism ≥0.5 dioptres (D), 42% (n=46 003) ≥1.0 D, 21% (n=22 899) ≥1.5 D and 11% (n=11 651) ≥2.0 D. After surgery, the refraction cylinder was available for 39 744 (36%) eyes receiving standard monofocal IOLs, of which 90% (n=35 907) had postoperative astigmatism ≥0.5 D and 58% (n=22 886) ≥1.0 D. Visual acuity tended to worsen postoperatively with increased astigmatism (ρ=−0.44, P<0.01).

Conclusions

There is a significant burden of preoperative astigmatism in the UK cataract population. The available refraction data indicate that this burden is not reduced after surgery with implantation of standard monofocal IOLs. Measures should be taken to improve visual outcomes of patients with astigmatic cataract by simultaneously correcting astigmatism during cataract surgery.

Surgical efficiency in femtosecond laser cataract surgery compared with phacoemulsification cataract surgery: a case-control study

OBJECTIVES

To investigate differences in surgical time, the distance the surgical instrument travelled and number of movements required to complete manual phacoemulsification cataract surgery versus femtosecond laser cataract surgery.

DESIGN

Non-randomised comparative case series.

SETTING

Single surgery site, Moorfields Eye Hospital, UK.

PARTICIPANTS

40 cataract surgeries of 40 patients.

INTERVENTIONS

Laser-assisted and manual phacoemulsification cataract surgery. Laser-assisted surgery cases were performed using the AMO Catalys platform.

PRIMARY AND SECONDARY OUTCOME MEASURES

Computer vision tracking software PhacoTracking were applied to the recordings to establish the distance the instrument travelled, total number of movements (the number of times an instrument stops and starts moving) and time taken for surgery steps including phacoemulsification, irrigation-aspiration (IA) and overall surgery time. The time taken for laser docking and delivery was not included in the analyses.

RESULTS

Data on 19 laser-assisted and 19 manual phacoemulsification surgeries were analysed (two cases were excluded due to insufficient video-recording quality). There were no differences in the number of instrument moves, the distance the instrument travelled or time taken to complete the phacoemulsification stage. However for IA, the number of instrument moves (manual: mean 20 (SD 15) vs laser: mean 38 (SD 22), P=0.008) and time taken (manual: mean 75 s (SD 24) vs laser: mean 108 s (SD 36), P=0.003) were significantly greater for laser cases. For laser versus manual cases overall, there was no difference in number of moves or the distance the instrument travelled, but laser cases took longer (mean 88 s, P=0.049).

CONCLUSIONS

Laser cataract surgery cases took longer to complete without accounting for the time taken to complete the laser procedure itself. This appears to be in part due to IA requiring more instrument manoeuvres and taking longer to complete. Data from a large randomised series would better elucidate this relationship.

Clear lens extraction for the management of primary angle closure glaucoma: surgical technique and refractive outcomes in the EAGLE cohort

BACKGROUND

To describe the surgical technique and refractive outcomes following clear lens extraction (CLE) in the Effectiveness, in Angle-closure Glaucoma, of Lens Extraction trial.

METHODS

Review of prospectively collected data from a multicentre, randomised controlled trial comparing CLE and laser peripheral iridotomy. Eligible participants were ≥50 years old and newly diagnosed with (1) primary angle closure (PAC) with intraocular pressure above 30 mm Hg or (2) PAC glaucoma. We report the postoperative corrected distance visual acuity (CDVA) and refractive outcomes at 12 and 36 months postoperatively for those who underwent CLE.

RESULTS

Of the 419 participants, 208 were randomised to CLE. Mean baseline CDVA was 77.9 (SD 12.4) letters and did not change significantly at 36 months when mean CDVA was 79.9 (SD 10.9) letters. Mean preoperative spherical equivalents were +1.7 (SD 2.3) and +0.08 (SD 0.95) diopters (D) at 36 months. Fifty-nine per cent and 85% eyes were within ±0.5D and ±1.0D of predicted refraction, respectively, at 36 months.

CONCLUSIONS

Mean CDVA in patients undergoing CLE for angle-closure glaucoma appeared stable over the 3-year study period. Refractive error was significantly reduced with surgery but refractive predictability was suboptimal.

TRIAL REGISTRATION NUMBER

Changes in UK ophthalmology surgical training: analysis of cumulative surgical experience 2009-2015

OBJECTIVE

To investigate changes in the patterns of cumulative surgical experience for ophthalmologists in the UK following the introduction of a new national training scheme.

DESIGN

Retrospective review of all surgical training records submitted to the UK Royal College of Ophthalmologists by trainees for the award of Certificate of Completion of Training (CCT) for the period 2009-2015.

SETTING

Secondary level care, UK.

PARTICIPANTS

539 trainees achieving CCT over the 7-year study period.

INTERVENTIONS

Higher specialist training or ophthalmology specialist training.

OUTCOME MEASURES

Number of CCT awards by years and procedures performed for cataract surgery, strabismus, corneal grafts, vitreoretinal (VR) procedures, oculoplastics and glaucoma.

RESULTS

Cataract surgical experience showed little change with median number performed/performed supervised (P/PS) 592, IQR: 472-738; mean: 631. Similarly, the median number of strabismus (P/PS 34), corneal grafts (assisted, 9) and VR procedures (assisted, 34) appeared constant. There was a trend towards increasing surgical numbers for oculoplastics (median 116) and glaucoma (57). Overall case numbers for ophthalmic specialist training (OST) trainees (7-year training programme) were higher than higher surgical training (HST) trainees (4.5-year programme) with the exception of squint (P/PS), corneal grafts (P/PS) and VR cases (P/PS).

CONCLUSIONS

Overall case numbers reported at time of CCT application appear stable or with a marginal trend towards increasing case numbers. HST (4.5-year programme) case numbers do not include those performed before entry to HST, and although case numbers tended to be higher for OST trainees (7-year programme) compared with HST trainees, they were not proportionately so.

The incidence of acute angle closure in Scotland: a prospective surveillance study

PURPOSE

To estimate the incidence, and describe the clinical features and short-term clinical outcomes of acute angle closure (AAC).

METHODS

Patients with newly diagnosed AAC were identified prospectively over a 12-month period (November 2011 to October 2012) by active surveillance through the Scottish Ophthalmic Surveillance Unit reporting system. Data were collected at case identification and at 6 months follow-up.

RESULTS

There were 114 cases (108 patients) reported, giving an annual incidence of 2.2 cases (95% CI 1.8 to 2.6) or 2 patients (95% CI 1.7 to 2.4) per 1 00 000 in the whole population in Scotland. Precipitating factors were identified in 40% of cases. Almost one in five cases was associated with topical dilating drops. Best-corrected visual acuity (BCVA) at presentation ranged from 6/6 to perception of light. The mean presenting intraocular pressure (IOP) was 52 mm Hg (SD 11). Almost 30% cases had a delayed presentation of 3 or more days. At 6 months follow-up, 75% had BCVA of 6/12 or better and 30% were found to have glaucoma at follow-up. Delayed presentation (≥3 days) was associated with higher rate of glaucoma at follow-up (22.6% vs 60.8%, p<0.001), worse VA (0.34 vs 0.74 LogMAR, p<0.0001) and need for more topical medication (0.52 vs 1.2, p=0.003) to control IOP.

CONCLUSION

The incidence of AAC in Scotland is relatively low compared with the Far East countries, but in line with previous European data. Almost one in five cases were associated with pupil dilation for retinal examination.

Initial experience using a femtosecond laser cataract surgery system at a UK National Health Service cataract surgery day care centre

OBJECTIVES

To describe the initial outcomes following installation of a cataract surgery laser system.

SETTING

National Health Service cataract surgery day care unit in North London, UK.

PARTICIPANTS

158 eyes of 150 patients undergoing laser-assisted cataract surgery.

INTERVENTIONS

Laser cataract surgery using the AMO Catalys femtosecond laser platform.

PRIMARY OUTCOME MEASURE

intraoperative complications including anterior and posterior capsule tears.

SECONDARY OUTCOME MEASURES

docking to the laser platform, successful treatment delivery, postoperative visual acuities.

RESULTS

Mean case age was 67.7±10.8 years (range 29-88 years). Docking was successful in 94% (148/158 cases), and in 4% (6/148 cases) of these, the laser delivery was aborted part way during delivery due to patient movement. A total of 32 surgeons, of grades from junior trainee to consultant, performed the surgeries. Median case number per surgeon was 3 (range from 1-20). The anterior capsulotomy was complete in 99.3% of cases, there were no anterior capsule tears (0%). There were 3 cases with posterior capsule rupture requiring anterior vitrectomy, and 1 with zonular dialysis requiring anterior vitrectomy (4/148 eyes, 2.7%). These 4 cases were performed by trainee surgeons, and were either their first laser cataract surgery (2 surgeons) or their first and second laser cataract surgeries (1 surgeon).

CONCLUSIONS

Despite the learning curve, docking and laser delivery were successfully performed in almost all cases, and surgical complication rates and visual outcomes were similar to those expected based on national data. Complications were predominately confined to trainee surgeons, and with the exception of intraoperative pupil constriction appeared unrelated to the laser-performed steps.

Laser-assisted cataract surgery versus standard ultrasound phacoemulsification cataract surgery

BACKGROUND

Cataract is the leading cause of blindness in the world, and cataract surgery is one of the most commonly performed operations in the Western world. Preferred surgical techniques have changed dramatically over the past half century with associated improvements in outcomes and safety. Femtosecond laser platforms that can accurately and reproducibly perform key steps in cataract surgery, including corneal incisions, capsulotomy and lens fragmentation, are now available. The potential advantages of laser-assisted surgery are broad, and include greater safety and better visual outcomes through greater precision and reproducibility.

OBJECTIVES

To compare the effectiveness of laser-assisted cataract surgery with standard ultrasound phacoemulsification cataract surgery by gathering evidence on safety from randomised controlled trials (RCTs).

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2016, Issue 4), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to May 2016), EMBASE (January 1980 to May 2016), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to May 2016), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov), the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en) and the U.S. Food and Drugs Administration (FDA) website (www.fda.gov). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 10 May 2016.

SELECTION CRITERIA

We included randomised controlled trials where laser-assisted cataract surgery was compared to standard ultrasound phacoemulsification cataract surgery. We graded the certainty of the evidence using GRADE.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the search results, assessed risk of bias and extracted data using the standard methodological procedures expected by Cochrane. The primary outcome for this review was intraoperative complications in the operated eye, namely anterior capsule and posterior capsule tears. The secondary outcomes were visual acuity (corrected distance visual acuity (CDVA) and uncorrected distance visual acuity (UDVA)), refractive outcomes, quality of vision (as measured by any validated visual function score), postoperative complications and cost-effectiveness.

MAIN RESULTS

We included 16 RCTs conducted in Germary, Hungary, Italy, India, China and Brazil that enrolled a total of 1638 eyes of 1245 adult participants. Overall, the studies were at unclear or high risk of bias. In 11 of the studies the authors reported financial links with the manufacturer of the laser platform evaluated in their studies. Five of the studies were within-person (paired-eye) studies with one eye allocated to one procedure and the other eye allocated to the other procedure. These studies were reported ignoring the paired nature of the data.The number of anterior capsule and posterior capsule tears reported in the included studies for both laser cataract surgery and manual phacoemulsification cataract surgery were low. There were four anterior capsule tears and one posterior capsule tear in 1076 eyes reported in 10 studies (2 anterior capsule tears in laser arms, 2 anterior capsule tears and 1 posterior capsule tear in standard phacoemulsification arms). We are very uncertain as to the effect of laser-assisted surgery compared to standard phacoemulsification surgery with respect to these two outcomes. For postoperative cystoid macular oedema and elevated postoperative intraocular pressures, again the evidence was inconclusive (odds ratio (OR) 0.58, 95% confidence interval (CI) 0.20 to 1.68; 957 eyes, 9 studies, low certainty evidence; and OR 0.57, 95% CI 0.11 to 2.86; 903 eyes, 8 studies, low certainty evidence).We found little evidence of any important difference in postoperative visual acuity between laser-assisted and standard phacoemulsification arms. There was a small advantage for laser-assisted cataract surgery at six months in CDVA. However, the mean difference (MD) was -0.03 logMAR (95% CI -0.05 to -0.00; 224 eyes, 3 studies, low certainty evidence) which is equivalent to 1.5 logMAR letters and is therefore, clinically insignificant. No studies reported patient-reported outcome measures such as visual function.There were no data reported on costs or resource use but three studies reported the time taken to do the surgery. There was little evidence of any major difference between the two procedures in this respect (MD 0.1 minutes, 95% CI -0.02 to 0.21; 274 eyes, low certainty evidence).

AUTHORS' CONCLUSIONS

The evidence from the 16 randomised controlled trials RCTs included in this review could not determine the equivalence or superiority of laser-assisted cataract surgery compared to standard manual phacoemulsification for our chosen outcomes due to the low to very low certainty of the evidence available from these studies. As complications occur rarely, large, adequately powered, well designed, independent RCTs comparing the safety and efficacy of laser-assisted cataract surgery with standard phacoemulsification cataract surgery are needed. Standardised reporting of complications and visual and refractive outcomes for cataract surgery would facilitate future synthesis. Data on patient-reported outcomes and cost-effectiveness are needed. Paired-eye studies should be analysed and reported appropriately.

United Kingdom National Ophthalmology Database Study of Cataract Surgery: Report 3: Pseudophakic Retinal Detachment

PURPOSE

To investigate time to pseudophakic retinal detachment (RD) after cataract surgery with posterior capsule rupture (PCR) to provide an evidence-based guide for postoperative management.

DESIGN

Retrospective case series.

PARTICIPANTS

A total of 61 907 eyes of 46 824 patients undergoing cataract surgery.

METHODS

Subanalysis of the United Kingdom Royal College of Ophthalmologists' National Ophthalmology Database from 13 sites where data on both cataract and vitreoretinal surgery were recorded on the same electronic medical records system. Overall, 61 907 cataract operations were performed between October 2006 and August 2010. Analyses were restricted to cases with at least 3 months of potential postoperative follow-up.

RESULTS

Pseudophakic RD surgery was performed on 131 eyes of 129 patients (0.21%; 95% confidence interval [CI], 0.18%-0.25%). Of these, 36 were in eyes that had PCR during cataract surgery (3.27%; 95% CI, 2.37%-4.50%) and 95 were in eyes that did not have PCR (0.16%; 95% CI, 0.13%-0.19%). For eyes that progressed to RD surgery, the median time to pseudophakic RD surgery was 44 days for eyes with PCR, and 6.3 months for eyes without PCR. For all eyes (both with and without PCR), pseudophakic RD occurred earlier in cases performed by a trainee cataract surgeon.

CONCLUSIONS

Pseudophakic RD occurs earlier after cataract surgery complicated by PCR. Surgeon grade is a risk factor for pseudophakic RD. Posterior vitreous detachment and RD symptoms should be discussed with patients who undergo cataract surgery and have PCR to facilitate early attendance, and careful dilated postoperative examination for retinal tears is recommended in the first 2 months after surgery.

Characterizing the lacrimal punctal region using anterior segment optical coherence tomography

PURPOSE

Abnormalities of lacrimal punctum size and morphology probably contribute to excess tearing, with significant effects on quality-of-life for affected individuals. Our current understanding of normal punctal morphology originates from ex vivo studies, which are unlikely to capture the true nature of the living punctum. This study used enhanced depth anterior segment optical coherence tomography (OCT) to give improved characterization and understanding of lacrimal punctal structure.

METHODS

Qualitative and quantitative assessments were performed on spectral domain OCT images collected prospectively from 40 lower puncta of 20 healthy volunteers.

RESULTS

The average external lower lid punctal diameter was 0.646 mm (SD 150 μm) on OCT imaging, measured at the largest diameter, which was in parallel to the mucocutaneous junction. Fifty-five per cent of puncta appeared closed, whilst the eyelids were open. Fluid menisci were visible within 73% of puncta. A postpunctal 'ampulla' was visible within three systems, one of which was imaged through the conjunctival surface. Ampullary dilatation occurred laterally, rather than at the medial wall.

CONCLUSION

Optical coherence tomography provides quick and non-invasive assessment of the lacrimal punctum and its neighbouring tissue layers. This assessment of punctal size and morphology has the potential for further investigation of punctal physiology, for aiding diagnosis, and for monitoring the results of treatment. The average external diameter of the punctal opening measured in this study is greater than that recorded in anatomical textbooks.

Randomised, single-masked non-inferiority trial of femtosecond laser-assisted versus manual phacoemulsification cataract surgery for adults with visually significant cataract: the FACT trial protocol

INTRODUCTION

Cataract is one of the leading causes of low vision in the westernised world, and cataract surgery is one of the most commonly performed operations. Laser platforms for cataract surgery are now available, the anticipated advantages of which are broad and may include better visual outcomes through greater precision and reproducibility, and improved safety. FACT is a randomised single masked non-inferiority trial to establish whether laser-assisted cataract surgery is as good as or better than standard manual phacoemulsification.

METHODS AND ANALYSIS

808 patients aged 18 years and over with visually significant cataract will be randomised to manual phacoemulsification cataract surgery (standard care) or laser-assisted cataract surgery (intervention arm). Outcomes will be measured at 3 and 12 months after surgery. The primary clinical outcome is uncorrected distance visual acuity (UDVA, logMAR) at 3 months in the study eye recorded by an observer masked to the trial group. Secondary outcomes include UDVA at 12 months, corrected distance visual acuity at 3 and 12 months, complications, endothelial cell loss, patient-reported outcome measures and a health economic analysis conforming to National Institute for Health and Care Excellence standards.

ETHICS AND DISSEMINATION

Research Ethics Committee Approval was obtained on 6 February 2015, ref: 14/LO/1937. Current protocol: v2.0 (08/04/2015). Study findings will be published in peer-reviewed journals.

ISRCTN

77602616.

The Royal College of Ophthalmologists' National Ophthalmology Database Study of cataract surgery: report 2, relationships of axial length with ocular copathology, preoperative visual acuity, and posterior capsule rupture

PURPOSE

To describe the relationships of axial length with ocular copathology, preoperative visual acuity, and posterior capsule rupture rates in patients undergoing cataract surgery.DesignThe Royal College of Ophthalmologists' National Ophthalmology Database (NOD) study.

METHODS

Anonymised data on 180 114 eyes from 127 685 patients undergoing cataract surgery between August 2006 and November 2010 were collected prospectively from 28 sites. Data parameters included: demographics, biometry, ocular copathology, visual acuity measurements, and surgical complications including posterior capsule rupture, or vitreous loss or both (PCR).

RESULTS

Consultant surgeons performed a higher proportion of operations on eyes whose axial length were at the extremes. Glaucoma and age related macular degeneration were more common in eyes with shorter axial lengths, whilst previous vitrectomy was associated with longer axial lengths. Eyes with brunescent or white cataracts or amblyopia were more common at both axial length extremes. Preoperative visual acuities were similar for eyes with axial length measurements up to approximately 28 mm and worse for eyes with longer axial length measurements. PCR rates showed little change with axial length (overall mean 1.95%, 95% CI: 1.89 to 2.01%), except for a borderline increase in eyes with axial length <20.0 mm where rates were 3.6% (95% CI: 2.0 to 6.3%). The likelihood of PCR in eyes with axial length <20.0 mm was 1.88 times higher than those of ≥20.0 mm (P=0.0373).

CONCLUSION

Rates of ocular comorbidities vary by axial length. PCR rates in eyes with very short or long axial lengths were lower than expected.

Genotype-phenotype analysis of SNPs associated with primary angle closure glaucoma (rs1015213, rs3753841 and rs11024102) and ocular biometry in the EPIC-Norfolk Eye Study

AIMS

To investigate if the single nucleotide polymorphisms rs3753841, rs1015213 and rs11024102, recently implicated in the development of acute primary angle closure or primary angle closure glaucoma, are associated with ocular biometric characteristics of British adults in the European Prospective Investigation of Cancer-Norfolk eye study.

METHODS

Genotyping data on rs1015213 (between PCMTD1 and ST18), rs11024102 (at PLEKHA7) and rs3753841 (at COL11A1) were available on 3268 participants. Direct genotypic data was available for rs1015213 and rs3753841. Data was imputed for rs11024102. Ocular biometric data was available on 1137 participants who attended the third European Prospective Investigation of Cancer health examination and 988 (87%) of these participants had no previous cataract surgery either eye. Axial length (AL), anterior chamber depth (ACD) and corneal keratometry were measured by using the Zeiss IOLMaster.

RESULTS

Presence of at least one A allele (AG or AA genotype) for rs1015213 was associated with a shallower ACD (-0.07 mm, 95% CI -0.01 to -0.14 mm, p=0.028) after adjusting for age and sex (both p≤0.001). There was no association with AL or corneal keratometry for rs1015213 genotypes. AL, ACD and keratometry were not associated with rs3753841 or rs11024102 genotypes including after adjusting for age and sex.

CONCLUSIONS

This study suggests that primary angle closure glaucoma susceptibility at the PCMTD1-ST18 locus may be partly explained by an association between rs1015213 and ACD in European populations. This effect is equivalent to almost 20% of the SD of the mean ACD of phakic individuals in this cohort. We were not able to identify any association between rs3753841 or rs11024102 and ocular biometry.

The small eye phenotype in the EPIC-Norfolk eye study: prevalence and visual impairment in microphthalmos and nanophthalmos

OBJECTIVE

To describe the prevalence and phenotypic characteristics of small eyes in the European Prospective Investigation of Cancer (EPIC)-Norfolk Eye Study.

DESIGN

Community cross-sectional study.

SETTING

East England population (Norwich, Norfolk and surrounding area).

PARTICIPANTS

8033 participants aged 48-92 years old from the EPIC-Norfolk Eye Study, Norfolk, UK with axial length measurements. Participants underwent a standardised ocular examination including visual acuity (LogMAR), ocular biometry, non-contact tonometry, autorefraction and fundal photography. A small eye phenotype was defined as a participant with one or both eyes with axial length of <21 mm.

OUTCOME MEASURES

Prevalence of small eyes, proportion with visual impairment, demographic and biometric factors.

RESULTS

Ninety-six participants (1.20%, 95% CI 0.98% to 1.46%) had an eye with axial length less than 21 mm, of which 74 (77%) were women. Prevalence values for shorter axial lengths were <20 mm: 0.27% (0.18% to 0.41%); <19 mm: 0.17% (0.11% to 0.29%); <18 mm: 0.14% (0.08% to 0.25%). Two participants (2.1%) had low vision (presenting visual acuity >0.48 LogMAR) and one participant was blind (>1.3 LogMAR). The prevalence of unilateral visual impairment was higher in participants with a small eye. Multiple logistic regression modelling showed presence of a small eye to be significantly associated with shorter height, lower body mass index, higher systolic blood pressure and lower intraocular pressure.

CONCLUSIONS

The prevalence of people with small eyes is higher than previously thought. While small eyes were more common in women, this appears to be related to shorter height and lower body mass index. Participants with small eyes were more likely to be blind or to have unilateral visual impairment.

Spectral domain optical coherence tomography imaging of the aqueous outflow structures in normal participants of the EPIC-Norfolk Eye Study

PURPOSE

To measure the dimensions of aqueous outflow structures and to investigate associations with intraocular pressure (IOP) and ocular biometry parameters in an older British population.

METHOD

Fifty-two participants from the European Prospective Investigation of Cancer-Norfolk eye study underwent imaging using the Heidelberg Spectralis optical coherence tomographer with an anterior segment module. Pseudophakic participants and those known or suspected to have glaucoma were excluded, leaving 46 participants for analysis. Schwalbe's line (SL), scleral spur (SS), Schlemm's canal (SC) diameter and the trabecular meshwork cross-sectional area (TM cross-sectional area (CSA)) were identified and traced using ImageJ software. IOP was measured using the Ocular Response Analyser. Ocular biometry was measured by partial coherence interferometry.

RESULTS

The mean (SD) subject age was 65.7 years (5.6). The SL and SS were identifiable in all nasal and temporal scans. The mean SL-SS distance was 800 μm (104) nasally and 808 μm (102) temporally. Repeatability of SS-SL, SS-SC, SC and TM CSA was good to excellent, and reproducibility fair to good. Nasal SL-SS distance was inversely associated with anterior chamber depth (ACD) (p=0.007, -116 μm per mm ACD, R(2)=0.18). Multiple linear regression showed nasal TM CSA was significantly associated with age and IOP (age: p=0.025, 0.007 mm(2) per decade of age; IOP: p=0.029, -0.0012 mm(2) per mm Hg, R(2)=0.23).

CONCLUSIONS

Aqueous outflow structures can be measured by optical coherence tomography, and their dimensions vary significantly with ocular biometric characteristics and IOP. Further investigation is required to determine associations between outflow structure sizes in different populations and pathologies, including ocular hypertension and glaucoma.

Accuracy of intraocular lens power calculations in eyes with axial length <22.00 mm

BACKGROUND

To assess the accuracy of Haigis, Holladay 1, Hoffer Q and SRK/T formulae in eyes with axial length of <22.00 mm.

DESIGN

Retrospective comparative analysis.

PARTICIPANTS

163 eyes of 97 patients undergoing phacoemulsification and intraocular lens (IOL) implantation.

METHODS

Ocular biometry was performed using IOLMaster laser interferometry. Predicted refractive outcomes before and after lens constant adjustment were compared to actual refractive outcomes.

MAIN OUTCOME MEASURES

Mean prediction (ME) and mean absolute errors (MAE) with standard deviations (±SD).

RESULTS

Mean preoperative spherical equivalent was +5.44D ± 1.97D. Mean axial length was 21.20 mm ± 0.60 mm. Using standard IOL constants the MAE for Hoffer Q (0.62D, ±0.52D) and Holladay 1 (0.66D ± 0.52D) were significantly lower than SRK/T (MAE 0.91D ± 0.64D; P = <0.0005 and P = 0.001 respectively), but not Haigis (MAE 0.82D ± 0.83D, P = 0.071 and 0.22 respectively). MAEs for all formulae were significantly reduced by IOL constant adjustment (all P = <0.001). Following this there was no statistically significant difference in MAEs between formulae (range 0.50-0.57D, P = 0.57). Increasing MAE was significantly associated with reducing axial length and increasing IOL power for all formulae. For bilateral cases, prediction errors between eyes were significantly correlated across all formulae (all P = <0.0001) and explained 32-42% of the variance in prediction error between eyes.

CONCLUSIONS

Prediction of postoperative refraction in patients with short axial lengths is challenging and at the limit of current, popular IOL formulae. There is now a clear need for prospective studies to assess latest generation IOL formulae such as Holladay 2 or Olsen in small eyes.

Eyelid necrotizing fasciitis: what were the early signs?

BACKGROUND

Necrotizing fasciitis is a rare, life-threatening subcutaneous soft tissue infection that causes massive tissue destruction.

OBJECTIVES

To illustrate the warning signs of this condition by reporting a rare case of eyelid necrotizing fasciitis.

CASE REPORT

A previously healthy 22-year-old man presented with a preseptal eyelid infection that spread rapidly despite prompt treatment with several intravenous antibiotics. He developed the characteristic clinical and radiologic features of necrotizing fasciitis, and required surgical debridement to cure the infection. Histology confirmed the diagnosis.

CONCLUSION

In this article, we suggest the indicators that may enable physicians to think of the development of necrotizing fasciitis in patients with infections of the skin and subcutis.

Pilocarpine induced acute angle closure

A 34-year-old Caucasian female with advanced primary angle closure glaucoma developed acute angle closure following administration of g.pilocarpine 2% given as preparation for laser peripheral iridotomies. Subsequent investigations supported an underlying diagnosis of spherophakia with no systemic associations. She required peripheral iridotomies, bilateral clear lens extractions and left cyclodiode laser to control her intraocular pressures. This case highlights the situations when pilocarpine should be given with caution and also the increasing role of phacoemulsification as an alternative to filtration surgery in primary angle closure glaucoma management.

Electrodiagnostic and two-wavelength fundus autofluorescence imaging investigations in acute idiopathic maculopathy

The aim is to characterise a case of acute idiopathic maculopathy (AIM) using detailed electrophysiology and 2-wavelength fundus autofluorescence (FAF) imaging. A 32-year-old woman presented with reduced visual acuity in her right eye. Imaging investigations performed included 1 & 2 wavelength FAF, fluorescein and ICG angiography and Fourier domain OCT imaging. International-standard pattern and full-field electroretinography (PERG; ERG), electro-oculography (EOG) and multifocal ERG testing were performed. Multifocal ERGs demonstrated evidence of localised macular dysfunction consistent with mild right pattern ERG P50 reduction. Full-field ERGs were within normal limits. The EOG was normal bilaterally. The use of 1 & 2 wavelength FAF imaging revealed a low density macular area, not explained by luteal pigment absorption, that was associated with macular dysfunction. Two-wavelength FAF imaging allows the accurate quantification of macular pigment and the imaging of the underlying relative distribution of lipofuscin. AIM was characterised by a discrete area of disrupted retinal pigment epithelium metabolism and atrophy associated with localised macular dysfunction. Complimentary use of dual-wavelength FAF imaging and electrophysiology may have application to disorders other than AIM.

A detailed phenotypic assessment of individuals affected by MFRP-related oculopathy

PURPOSE

To determine the spectrum of mutations and phenotypic variability within patients with mutations in membrane-type frizzled related protein gene (MFRP).

METHODS

Individuals were initially ascertained based on a phenotype similar to that previously published in association with MFRP mutations. Affected patients underwent a full ophthalmic examination (best-corrected visual acuity, slit-lamp examination, applanation tonometry, and fundoscopy), color fundus photography, optical coherence tomography, autofluorescence imaging, and electrophysiology. MFRP was identified by a genome-wide scan in the fourth-largest autozygous region in one consanguineous family. Sanger sequencing of all the exons and intron-exon boundaries of MFRP was undertaken in the affected individuals.

RESULTS

Seven affected individuals from four families were identified as having mutations in MFRP. Patients from two families were homozygous for mutations already previously described (c.1143_1144 insC and c.492 delC), while those from the other two were compound heterozygous for mutations (c.201G>A and c.491_492 insT, and c.492 delC, and c.1622_1625 delTCTG), three of which were novel. There was considerable phenotypic variability within and among families. Autofluorescence imaging revealed the central macula to be relatively well preserved. Foveal cysts and optic nerve head drusen were present in two of the four families. Electrophysiology results showed rod-cone dystrophy with mild to moderate reduction in macular function in all affected members.

CONCLUSIONS

We report three novel MFRP mutations and expand the phenotypic data available on patients with MFRP mutations.

Frontal sinus pneumocoele: a rare cause of orbital emphysema

Sudden onset nonaxial proptosis and diplopia is alarming and orbital haemorrhage or a rapidly expanding orbital tumour should be excluded. We present a case of a young man aged 15 years who attended the Accident and Emergency Department with a 6-h history of sudden onset proptosis and diplopia in whom the aetiology was orbital emphysema.