Impact of lens autofluorescence and opacification on retinal imaging

BACKGROUND

Retinal imaging, including fundus autofluorescence (FAF), strongly depends on the clearness of the optical media. Lens status is crucial since the ageing lens has both light-blocking and autofluorescence (AF) properties that distort image analysis. Here, we report both lens opacification and AF metrics and the effect on automated image quality assessment.

METHODS

227 subjects (range: 19-89 years old) received quantitative AF of the lens (LQAF), Scheimpflug, anterior chamber optical coherence tomography as well as blue/green FAF (BAF/GAF), and infrared (IR) imaging. LQAF values, the Pentacam Nucleus Staging score and the relative lens reflectivity were extracted to estimate lens opacification. Mean opinion scores of FAF and IR image quality were compiled by medical readers. A regression model for predicting image quality was developed using a convolutional neural network (CNN). Correlation analysis was conducted to assess the association of lens scores, with retinal image quality derived from human or CNN annotations.

RESULTS

Retinal image quality was generally high across all imaging modalities (IR (8.25±1.99) >GAF >BAF (6.6±3.13)). CNN image quality prediction was excellent (average mean absolute error (MAE) 0.9). Predictions were comparable to human grading. Overall, LQAF showed the highest correlation with image quality grading criteria for all imaging modalities (eg, Pearson correlation±CI -0.35 (-0.50 to 0.18) for BAF/LQAF). BAF image quality was most vulnerable to an increase in lenticular metrics, while IR (-0.19 (-0.38 to 0.01)) demonstrated the highest resilience.

CONCLUSION

The use of CNN-based retinal image quality assessment achieved excellent results. The study highlights the vulnerability of BAF to lenticular remodelling. These results can aid in the development of cut-off values for clinical studies, ensuring reliable data collection for the monitoring of retinal diseases.

Role of lens in early refractive development: evidence from a large cohort of Chinese children

AIMS

To document longitudinal changes in spherical equivalent refraction (SER) and related biometric factors during early refractive development.

METHODS

This was a prospective cohort study of Chinese children, starting in 2018 with annual follow-ups. At each visit, children received cycloplegic autorefraction and ocular biometry measurements. Lens power (LP) was calculated using Bennett's formula. Children were divided into eight groups based on baseline age: the 3-year-old (n=426, 49.77% girls), 4-year-old (n=834, 47.36% girls), 6-year-old (n=292, 46.58% girls), 7-year-old (n=964, 43.46% girls), 9-year-old (n=981, 46.18% girls), 10-year-old (n=1181, 46.32% girls), 12-year-old (n=504, 49.01%) and 13-year-old (n=644, 42.70%) age groups.

RESULTS

This study included right-eye data from 5826 children. The 3-year-old and 4-year-old age groups demonstrated an inflection point in longitudinal SER changes at a mild hyperopic baseline SER (+1 to +2 D), with children with more myopic SER showing hyperopic refractive shifts while those with more hyperopic SER showing myopic shifts. The hyperopic shift in SER was mainly attributed to rapid LP loss and was rarely seen in the older age groups. Axial elongation accelerated in the premyopia stage, accompanied by a partially counter-balancing acceleration of LP loss. For children aged 3-7 years, those with annual SER changes <0.25 D were all mildly hyperopic at baseline (mean: 1.23 D, 95% CI 1.20 to 1.27 D).

CONCLUSION

Our findings suggest that during early refractive development, refractions cluster around or above +1.00 D. There is a pushback process in which increases in the rate of LP occur in parallel with increases in axial elongation.

Long-term visual acuity outcomes following cataract surgery in eyes with ocular inflammatory disease

PURPOSE

To evaluate the long-term visual acuity (VA) outcome of cataract surgery in inflammatory eye disease.

SETTING

Tertiary care academic centres.

DESIGN

Multicentre retrospective cohort study.

METHODS

A total of 1741 patients with non-infectious inflammatory eye disease (2382 eyes) who underwent cataract surgery while under tertiary uveitis management were included. Standardised chart review was used to gather clinical data. Multivariable logistic regression models with adjustment for intereye correlations were performed to evaluate the prognostic factors for VA outcomes. Main outcome measure was VA after cataract surgery.

RESULTS

Uveitic eyes independent of anatomical location showed improved VA from baseline (mean 20/200) to within 3 months (mean 20/63) of cataract surgery and maintained through at least 5 years of follow-up (mean 20/63). Eyes that achieved 20/40 or better VA at 1 year were more likely to have scleritis (OR=1.34, p<0.0001) or anterior uveitis (OR=2.2, p<0.0001), VA 20/50 to 20/80 (OR 4.76 as compared with worse than 20/200, p<0.0001) preoperatively, inactive uveitis (OR=1.49, p=0.03), have undergone phacoemulsification (OR=1.45 as compared with extracapsular cataract extraction, p=0.04) or have had intraocular lens placement (OR=2.13, p=0.01). Adults had better VA immediately after surgery, with only 39% (57/146) paediatric eyes at 20/40 or better at 1 year.

CONCLUSIONS

Our results suggest that adult and paediatric eyes with uveitis typically have improved VA following cataract surgery and remain stable thereafter for at least 5 years.

High-risk factors for zonular complications during cataract surgery in eyes with pseudoexfoliation syndrome

AIMS

To predict high-risk factors for zonular complications during cataract surgery due to pre-existing severe zonular dehiscence in eyes with pseudoexfoliation (PXF) syndrome.

METHODS

315 eyes of 315 consecutive patients with PXF scheduled for phacoemulsification surgery underwent preoperative examination of various ocular parameters using an anterior segment-optical coherence tomography and other devices. When zonular complications occurred during surgery due to zonular dehiscence, scleral fixation of the intraocular lens (IOL) or implantation of a capsular tension ring (CTR) was performed. High-risk factors for these intraoperative zonular complications were examined using classification-tree and logistic regression analyses.

RESULTS

Of the 315 eyes, 31 (9.84%) underwent scleral IOL fixation or CTR implantation. High-risk factors identified by classification-tree analysis were a small pupillary diameter after mydriasis <6.30 mm, a shallow anterior chamber depth <2.074 mm and lens decentration >0.260 mm. Based on exact logistic regression analysis, the OR was 4.81-fold higher for eyes with poor mydriasis than for eyes without poor mydriasis (p=0.006, 95% CI 1.49 to 18.23), 23.99-fold higher for eyes with poor mydriasis and a shallow anterior chamber (p<0.001, 5.92 to 109.02) and 287.39-fold higher for eyes with poor mydriasis, a shallow chamber and great lens decentration (p<0.001, 50.46 to infinity).

CONCLUSION

In eyes with PXF, high-risk factors for zonular complications during cataract surgery due to pre-existing severe zonular dehiscence were poor mydriasis, shallow anterior chamber and large lens decentration, suggesting the importance of evaluating these conditions preoperatively.

Quantitative analysis of choriocapillaris flow deficits and choroidal thickness in children with Marfan syndrome

PURPOSE

To evaluate the characteristics and associated factors of choroidal thickness (ChT) and choriocapillaris flow deficit percentage (CC FD%) in children with Marfan syndrome (MFS).

METHODS

This is a cross-sectional study. The ChT of the subfoveal area and other areas 0.5, 1.5, and 2.5 mm away from the fovea were assessed. The CC FD% of quadrant and circular regions with diameters of 0.5, 1.5 and 2.5 mm were assessed with 3×3 mm macular choriocapillaris images. Best-corrected visual acuity (BCVA) and cardiac function factor such as Z score were measured to analyse the associations with ChT and CC FD%.

RESULTS

51 MFS children and 50 healthy controls were enrolled in this study. Compared with the healthy controls, the ChT in the MFS group was thinner in the subfoveal area, temporal 0.5, 1.5 and 2.5 mm (all p<0.001). The CC FD% was higher in circle 0.5, 1.5 and 2.5 mm (all p<0.001). Multivariate regression analysis showed that CC FD% in the circle 2.5 mm when the Z score ≥2 was associated with BCVA (β=9.08 (95% CI 3.96 to 14.20); p=0.005) and Z score (β=4.19 (95% CI 1.28 to 12.00); p=0.012).

CONCLUSIONS

Thinner ChT and a higher CC FD% were observed in children with MFS, and an increased CC FD% in circle 2.5 mm was significantly associated with worse BCVA and cardiac function. These findings may help identify future visual impairment and early cardiac events in MFS children.

Predicting the risk of glaucoma-related adverse events following secondary intraocular lens implantation in paediatric eyes: a 3-year study

AIMS

To establish and evaluate predictive models for glaucoma-related adverse events (GRAEs) following secondary intraocular lens (IOL) implantation in paediatric eyes.

METHODS

205 children (356 aphakic eyes) receiving secondary IOL implantation at Zhongshan Ophthalmic Center with a 3-year follow-up were enrolled. Cox proportional hazard model was used to identify predictors of GRAEs and developed nomograms. Model performance was evaluated with time-dependent receiver operating characteristic (ROC) curves, decision curve analysis, Kaplan-Meier curves and validated internally through C-statistics and calibration plot of the bootstrap samples.

RESULTS

Older age at secondary IOL implantation (HR=1.5, 95% CI: 1.03 to 2.19), transient intraocular hypertension (HR=9.06, 95% CI: 2.97 to 27.67) and ciliary sulcus implantation (HR=14.55, 95% CI: 2.11 to 100.57) were identified as risk factors for GRAEs (all p<0.05). Two nomograms were established. At postoperatively 1, 2 and 3 years, model 1 achieved area under the ROC curves (AUCs) of 0.747 (95% CI: 0.776 to 0.935), 0.765 (95% CI: 0.804 to 0.936) and 0.748 (95% CI: 0.736 to 0.918), and the AUCs of model 2 were 0.881 (95% CI: 0.836 to 0.926), 0.895 (95% CI: 0.852 to 0.938) and 0.848 (95% CI: 0.752 to 0.945). Both models demonstrated fine clinical net benefit and performance in the interval validation. The Kaplan-Meier curves showing two distinct risk groups were well discriminated and robust in both models. An online risk calculator was constructed.

CONCLUSION

Two nomograms could sensitively and accurately identify children at high risk of GRAEs after secondary IOL implantation to help early identification and timely intervention.

Prediction of spectacle refraction uncertainties with discrete IOL power steps and manufacturing tolerances according to ISO using a Monte Carlo model

PURPOSE

The purpose of this study was to develop a concept for predicting the effects of both discrete intraocular lens (IOL) power steps (PS) and power labelling tolerances (LT) on the uncertainty of the refractive outcome (REFU).

DESIGN

Retrospective non-randomised cross-sectional Monte Carlo simulation study.

METHODS

We evaluated a dataset containing 16 669 IOLMaster 700 preoperative biometric measurements. The PS and the delivery range of two modern IOLs (Bausch and Lomb enVista and Alcon SA60AT) were considered for this Monte Carlo simulation. The uncertainties from PS or LT were assumed to be normally distributed according to ±½ the IOL PS or the ISO 11979 LT. REFU was recorded and analysed for all simulations.

RESULTS

With both lenses the REFU from discrete PS ranged from 0.11 to 0.12 dpt. Due to the larger PS for low/high power lenses with the enVista/SA60AT, REFU is more dominant in initially myopic/hyperopic eyes. REFU from LT ranged from 0.18 to 0.19 dpt for both lenses. Since LT increases stepwise with IOL power, REFU is more prevalent in initially hyperopic eyes requiring high IOL power values, and for lenses with a wide delivery range towards higher powers.

CONCLUSIONS

Since surgeons and patients are typically aware of the effect of discrete PS on REFU, these might be tolerated in cataract surgery. However, REFU resulting from LT is inevitable while the true measured IOL power is not reported on the package, leading to background noise in postoperative achieved refraction.

Immediate sequential bilateral cataract surgery: a 13-year real-life report of 56 700 cataract operations

BACKGROUND/AIMS

To assess the frequency of immediate sequential bilateral cataract surgery (ISBCS) and endophthalmitis during 13-year period in Tays Eye Centre, Tampere University Hospital, Tampere, Finland.

METHODS

All cataract surgeries performed between 1 January 2008 and 31 December 2020, and all endophthalmitis cases during the same period were searched from electronic patient records. Numbers and frequencies of ISBCS, and complications, including endophthalmitis and vitreous loss, were recorded and compared with unilateral operations.

RESULTS

The study included 56 700 cataract surgeries in 34 797 patients of whom 39% (n=13 445) had ISBCS. The median age of the patients was 75 (IQR 68-80, range 0.08-99) years at the time of surgery. The proportion of ISBCS patients increased from 4.2% in 2008 to 46% in 2020. Vitreous loss occurred in 480 (0.9%) of cataract surgeries. There were no postoperative endophthalmitis after cataract surgery (n=0) during the 13-year period.

CONCLUSION

The proportion of patients undergoing ISBCS increased from 4.2% in 2008 to 46% in 2020. No endophthalmitis were found to be associated with ISBCS.

Heteromeric formation with βA3 protects the low thermal stability of βB1-L116P

BACKGROUND/AIMS

Congenital cataract is the leading cause of visual disability and blindness in childhood. βB1-crystallin (CRYBB1) comprises about 1/10th of crystallin structural proteins, forming heteromers to maintain lens transparency. We previously reported a CRYBB1 mutation (c.347T>C, p.L116P) affecting 16 patients in a congenital nuclear cataract family. In this study, we investigate the underlying pathogenic mechanism of βB1-L116P.

METHODS

Protein isolation, size-exclusion chromatography, spectroscopy, Uncle stability screens and molecular dynamics simulations were used to assess βA3- and βB1-crystallin thermal stability, structural properties and heteromer formation.

RESULTS

Cells that overexpressed βB1-L116P tended to form aggregates and precipitations under heat-shock stress. Thermal denaturation and time-dependent turbidity experiments showed that thermal stability was significantly impaired. Moreover, protein instability appeared to increase with elevated concentrations detected by the Uncle system. Additionally, βA3 had a relative protective effect on βB1-L116P after heteromers were formed, although βA3 was relatively unstable and was usually protected by basic β-crystallins. Molecular dynamic simulations revealed that L116P mutation altered the hydrophobic residues at the surface around the mutant site, providing solvents more access to the internal and hydrophobic parts of the protein.

CONCLUSIONS

Decreased βB1-crystallin thermal stability in the presence of the cataract-related L116P mutation contributes significantly to congenital cataract formation. Moreover, its formation of heteromers with βA3 protects against the low thermal stability of βB1-L116P.

Investigating the determinants of iridolenticular contact area: a novel parameter for angle closure

BACKGROUND/AIMS

To identify ocular determinants of iridolenticular contact area (ILCA), a recently introduced swept-source optical coherence tomography (SSOCT) derived parameter, and assess the association between ILCA and angle closure.

METHODS

In this population-based cross-sectional study, right eyes of 464 subjects underwent SSOCT (SS-1000, CASIA, Tomey Corporation, Nagoya, Japan) imaging in the dark. Eight out of 128 cross-sectional images (evenly spaced 22.5° apart) were selected for analysis. Matlab (Matworks, Massachusetts, USA) was used to measure ILCA, defined as the circumferential extent of contact area between the pigmented iris epithelium and anterior lens surface. Gonioscopic angle closure (GAC) was defined as non-visibility of the posterior trabecular meshwork in two or more angle quadrants.

RESULTS

The mean age of subjects was 62±6.6 years, with the majority being female (65.5%). 143/464 subjects (28.6%) had GAC. In multivariable linear regression analysis, ILCA was significantly associated with anterior chamber width (β=1.03, p=0.003), pupillary diameter (β=-1.9, p<0.001) and iris curvature (β=-17.35, p<0.001). ILCA was smaller in eyes with GAC compared with those with open angles (4.28±1.6 mm2 vs 6.02±2.71 mm2, p<0.001). ILCA was independently associated with GAC (β=-0.03, p<0.001), iridotrabecular contact index (β=-6.82, p<0.001) or angle opening distance (β=0.02, p<0.001) after adjusting for covariates. The diagnostic performance of ILCA for detecting GAC was acceptable (AUC=0.69).

CONCLUSIONS

ILCA is a significant predictor of angle closure independent of other biometric factors and may reflect unique anatomical information associated with pupillary block. ILCA represents a novel biometric risk factor in eyes with angle closure.

Evaluation of the Nallasamy formula: a stacking ensemble machine learning method for refraction prediction in cataract surgery

AIMS

To develop a new intraocular lens power selection method with improved accuracy for general cataract patients receiving Alcon SN60WF lenses.

METHODS AND ANALYSIS

A total of 5016 patients (6893 eyes) who underwent cataract surgery at University of Michigan's Kellogg Eye Center and received the Alcon SN60WF lens were included in the study. A machine learning-based method was developed using a training dataset of 4013 patients (5890 eyes), and evaluated on a testing dataset of 1003 patients (1003 eyes). The performance of our method was compared with that of Barrett Universal II, Emmetropia Verifying Optical (EVO), Haigis, Hoffer Q, Holladay 1, PearlDGS and SRK/T.

RESULTS

Mean absolute error (MAE) of the Nallasamy formula in the testing dataset was 0.312 Dioptres and the median absolute error (MedAE) was 0.242 D. Performance of existing methods were as follows: Barrett Universal II MAE=0.328 D, MedAE=0.256 D; EVO MAE=0.322 D, MedAE=0.251 D; Haigis MAE=0.363 D, MedAE=0.289 D; Hoffer Q MAE=0.404 D, MedAE=0.331 D; Holladay 1 MAE=0.371 D, MedAE=0.298 D; PearlDGS MAE=0.329 D, MedAE=0.258 D; SRK/T MAE=0.376 D, MedAE=0.300 D. The Nallasamy formula performed significantly better than seven existing methods based on the paired Wilcoxon test with Bonferroni correction (p<0.05).

CONCLUSIONS

The Nallasamy formula (available at https://lenscalc.com/) outperformed the seven other formulas studied on overall MAE, MedAE, and percentage of eyes within 0.5 D of prediction. Clinical significance may be primarily at the population level.

Multimorbidity due to novel pathogenic variants in the WFS1/RP1/NOD2 genes: autosomal dominant congenital lamellar cataract, retinitis pigmentosa and Crohn's disease in a British family

BACKGROUND

A five generation family has been analysed by whole exome sequencing (WES) for genetic associations with the multimorbidities of congenital cataract (CC), retinitis pigmentosa (RP) and Crohn's disease (CD).

METHODS

WES was performed for unaffected and affected individuals within the family pedigree followed by bioinformatic analyses of these data to identify disease-causing variants with damaging pathogenicity scores.

RESULTS

A novel pathogenic missense variant in WFS1: c.1897G>C; p.V633L, a novel pathogenic nonsense variant in RP1: c.6344T>G; p.L2115* and a predicted pathogenic missense variant in NOD2: c.2104C>T; p.R702W are reported. The three variants cosegregated with the phenotypic combinations of autosomal dominant CC, RP and CD within individual family members.

CONCLUSIONS

Here, we report multimorbidity in a family pedigree listed on a CC register, which broadens the spectrum of potential cataract associated genes to include both RP1 and NOD2.

Long-term effects of mild cataract extraction versus laser peripheral iridotomy on anterior chamber morphology in primary angle-closure suspect eyes

AIM

To compare lens extraction (LE) and laser peripheral iridotomy (LPI) on anterior segment morphology in primary angle-closure suspect (PACS) eyes.

METHODS

This prospective clinical trial included 144 patients with PACS who underwent either LPI or LE. Ultrasound biomicroscopy (UBM) and gonioscopy were performed before and 1 month and 2 years after operation. Main outcomes included UBM parameters and the percentage of residual angle closure.

RESULTS

At both 1 month and 2 years of follow-up, LE showed a better effect of relieving anterior chamber crowding and widening the drainage angle, as obtaining a larger anterior chamber depth (ACD), angle opening distance, trabecular iris angle (TIA), trabecular iris space area, trabecular ciliary process distance (TCPD) and a smaller iris curvature (I-Curv) and lens vault (LV) (p<0.001). In the LPI group, angle width increased (angle opening distance at 500 µm from the scleral spur, TIA and trabecular iris space area at 500 µm from the scleral spur) and I-Curv decreased (p<0.001) at 1 month postoperatively, with no significant changes in ACD, LV or TCPD. However, at 2 years after LPI, the angle narrowed with the increase in LV over time, and the proportion of residual angle closure also increased from 21.7% to 30.4% (p<0.001). In contrast, after LE, the widened angle width, flattened iris, deepened ACD, decreased LV and increased TCPD all showed good sustainability in the comparison between 1-month and 2-year follow-up. No residual angle closure was observed either at 1 month or 2 years after LE.

CONCLUSIONS

LE was prior to LPI in widening the drainage angle. After LPI, there was a narrowing of the angle and an increase in the proportion of residual angle closure over time. LE could achieve a wider angle with no residual angle closure, and the anterior segment parameters were sustainable.

TRIAL REGISTRATION NUMBER

ChiCTR1800016511.

Survival of the fittest: phacoemulsification outcomes in four corneal transplants by Dr Ramon Castroviejo

AIM

To evaluate and report the outcomes following phacoemulsification on four eyes, 45 years or more after corneal transplantation.

METHODS

A retrospective case series of four eyes in three patients (P1, P2, P3), undergoing phacoemulsification at least 45 years after corneal transplantation by Dr Ramon Castroviejo. Corneal graft survival outcome measures included central corneal thickness (CCT), best-corrected visual acuity (BCVA), corneal clarity and endothelial cell count (ECC).

RESULTS

Phacoemulsification was successfully completed in all four cases with no instances of graft failure during the postoperative follow-up period, which ranged from 17 months to 76 months. At the conclusion of the follow-up period, all four grafts remained clear, and BCVA remained better than or similar to preoperative values. Long-term follow-up revealed no meaningful changes in CCT after phacoemulsification. All but one case experienced a decrease in ECC, with ECC values in the four cases ranging from 538 cells/mm² to 1436 cells/mm² at the conclusion of postoperative follow-up.

CONCLUSION

Limited data have been published on the long-term survival of corneal grafts after intraocular surgery, especially for extremely 'mature' corneal transplants. This case series demonstrates that with appropriate preoperative, intraoperative and postoperative measures, successful phacoemulsification can be performed in these cases with excellent long-term results.

Knowledge, attitudes and eye health-seeking behaviours in a population-based sample of people with diabetes in rural China

AIMS

To assess knowledge of diabetes and acceptance of eye care among people with diabetes in rural China, to improve service uptake.

METHODS

Population-based study of people in Guangdong, China, with glycosylated haemoglobin A1c≥6.5% and/or known history of diabetes. Between August and November 2014, participants answered a questionnaire (based on Delphi process/previous focus groups) on medical history, demographic characteristics, self-rated health and vision, knowledge about diabetes and diabetic retinopathy, quality of local healthcare, barriers to treatment, likely acceptance of eye exams and treatment, and interventions rated most likely to improve service uptake. Presenting visual acuity was assessed, fundus photography performed and images graded by trained graders. Potential predictors of accepting care were evaluated and confounders adjusted for using logistic regression.

RESULTS

A total of 562 people (9.6% (256/5825), mean age 66.2±9.84 years, 207 (36.8%) men) had diabetes, 118 (22.3%) previously diagnosed. 'Very likely' or 'likely' acceptance of laser treatment (140/530=26.4%) was lower than for eye exams (317/530=59.8%, p<0.001). Predictors of accepting both exams and laser included younger age (p<.001) and prior awareness of diabetes diagnosis (p=0.004 and p=0.035, respectively). The leading barrier to receiving diabetes treatment was unawareness of diagnosis (409/454, 97.2%), while interventions rated most likely to improve acceptance of eye exams included reimbursement of travel costs (387/562, 73.0%), video or other health education (359/562, 67.7%) and phone call reminders (346/562, 65.3%).

CONCLUSIONS

Improving diagnosis of diabetes, along with incentives, education and communication strategies, is most likely to enhance poor acceptance of diabetic eye care in this setting.

Cataract service redesign in the post-COVID-19 era

COVID-19 pandemic of 2020 has impacted all aspects of clinical practice in the UK. Cataract services suffered severe disruption due to necessary measures taken to reduce elective surgery in order to release capacity to support intensive care requirements. Faced with a potential 50% increase in cataract surgery workload per week in the post-COVID-19 world, eye units should use this event to innovate, not just survive but to also evolve for a sustainable future. In this article, we discuss the inadequacies of existing service rationing options to tackle the COVID-19 cataract backlog. This includes limiting rationing based on visual acuity, limiting surgery to first or only seeing eyes, and postponing clinic and surgical dates according to referral dates. We propose units use the lockdown time to reset and develop a comprehensive patient-centred care pathway using principles of value-based healthcare: the cataract integrated practice units. Developing an agile surgical database that incorporates all aspects of patient need from education to follow-up in their individual cataract journey will allow units to react and plan quickly in the early phase of recovery and beyond. We also discuss the considerations units should bear in mind on telemedicine, modifications for face-to-face clinics, theatre organisation and options of expanding cataract throughput capacity. The pause in elective surgery due to the pandemic may have provided cataract services a rare opportunity to reset and transform cataract service pathways for the digital era.

Late-term topical tacrolimus for subepithelial infiltrates resistant to topical steroids and ciclosporin secondary to adenoviral keratoconjunctivitis

PURPOSE

Investigation of the efficacy and safety of 12 months of topical tacrolimus 0.03% ointment treatment against the subepithelial infiltrates (SEIs) due to adenoviral keratoconjunctivitis (AKC) resisting at least 2 years was aimed.

METHODS

This case series included consecutive patients with SEIs secondary to AKC who were resistant to topical steroid and ciclosporin-A (CSA) treatment and treated with topical 0.03% tacrolimus (Protopic; Fujisawa Healthcare, Teva, Deerfield, Illinois, USA) for 12 months, at least 2 years after AKC. For the evaluation of treatment efficacy, best-corrected visual acuity (BCVA), Fantes score, corneal subepithelial infiltrate score (CSIS), Oxford score, Schirmer and tear breakup time results were evaluated. Intraocular pressure and complaints of the patients were followed for evaluating the safety profile of the treatment. The patients were followed after the baseline visit at the 1st, 3rd, 6th and 12th month.

RESULTS

15 eyes of 11 patients with SEIs and 16 eyes of 16 healthy controls were included in this study. 1 patient (9.1%) could not tolerate the treatment. Significant improvements in BCVA, CSIS, Fantes score and Schirmer results were observed in the study group starting from the 3rd-month visit, and the improvements persisted until the end of 12 months of treatment.

CONCLUSION

Topical 0.03% tacrolimus might show efficacy against the SEIs persisting at least 2 years despite corticosteroid and/or CSA treatment without any prominent side effect. While at least a period of 3 months was necessary for a significant improvement in the BCVA, SEIs and Schirmer results, a period of 6 months was necessary for a decrease in Oxford score.

Epidemiology of visual impairment, sight-threatening or treatment-requiring diabetic eye disease in children and young people in the UK: findings from DECS

BACKGROUND

We investigated the incidence and causes of sight-threatening diabetes-related eye disease in children living with diabetes in the UK, to inform the national eye screening programme and enable monitoring of trends.

METHODS

We undertook a prospective active national surveillance via the British Ophthalmic Surveillance Unit. Eligible cases were children aged 18 years or younger, with type 1 or 2 diabetes, newly diagnosed between January 2015 and February 2017 with sight-threatening diabetic eye disease.

RESULTS

Eight children were reported. The annual incidence of all sight-threatening diabetes-related eye disease requiring referral to an ophthalmologist among children living with diabetes (n=8) in the UK was 1.21 per 10 000 person-years (95% CI 0.52 to 2.39) and was largely attributable to cataract (n=5) 0.76 per 10 000 person-years (95% CI 0.25 to 1.77). The incidence of sight-threatening diabetic retinopathy (n=3) among those eligible for screening (12 to 18 year-olds living with diabetes) was 1.18 per 10 000 person-years (95% CI 0.24 to 3.46). No subjects eligible for certification as visually impaired or blind were reported.

CONCLUSIONS

Secondary prevention of visual disability due to retinopathy is currently the sole purpose of national eye screening programmes globally. However, the rarity of treatment-requiring retinopathy in children/young people living with diabetes, alongside growing concerns about suboptimal screening uptake, merit new consideration of the utility of screening for primary prevention of diabetes-related morbidity by using the screening event and findings as a catalyst for better diabetes self-management.

Universal artificial intelligence platform for collaborative management of cataracts

Purpose

To establish and validate a universal artificial intelligence (AI) platform for collaborative management of cataracts involving multilevel clinical scenarios and explored an AI-based medical referral pattern to improve collaborative efficiency and resource coverage.

Methods

The training and validation datasets were derived from the Chinese Medical Alliance for Artificial Intelligence, covering multilevel healthcare facilities and capture modes. The datasets were labelled using a three-step strategy: (1) capture mode recognition; (2) cataract diagnosis as a normal lens, cataract or a postoperative eye and (3) detection of referable cataracts with respect to aetiology and severity. Moreover, we integrated the cataract AI agent with a real-world multilevel referral pattern involving self-monitoring at home, primary healthcare and specialised hospital services.

Results

The universal AI platform and multilevel collaborative pattern showed robust diagnostic performance in three-step tasks: (1) capture mode recognition (area under the curve (AUC) 99.28%–99.71%), (2) cataract diagnosis (normal lens, cataract or postoperative eye with AUCs of 99.82%, 99.96% and 99.93% for mydriatic-slit lamp mode and AUCs >99% for other capture modes) and (3) detection of referable cataracts (AUCs >91% in all tests). In the real-world tertiary referral pattern, the agent suggested 30.3% of people be ‘referred’, substantially increasing the ophthalmologist-to-population service ratio by 10.2-fold compared with the traditional pattern.

Conclusions

The universal AI platform and multilevel collaborative pattern showed robust diagnostic performance and effective service for cataracts. The context of our AI-based medical referral pattern will be extended to other common disease conditions and resource-intensive situations.

Cataract surgery refractive outcomes: representative standards in a National Health Service setting

BACKGROUND/AIMS

To report refractive outcomes from an National Health Service (NHS) cataract surgery service and assess if results meet suggested benchmark standard.

METHODS

Details of all patients undergoing cataract surgery in the Southern General and New Victoria hospitals in Glasgow, UK, between November 2006 and December 2016 were prospectively entered into an electronic database. Patients were reviewed 4 weeks postoperatively in the eye clinic and underwent refraction at their local optometrist prior to this appointment. Surgically uncomplicated cases with in the bag' non-toric intraocular lens implantation were included. Patients with previous laser refractive procedures or failing to achieve 6/12 acuity or better postoperatively were excluded. Proximity to targeted postoperative refraction was documented.

RESULTS

Over this 10-year period, 11 083 eyes underwent cataract surgery. Of these, 8943 eyes of 6936 patients (80.69%) met the inclusion criteria and had both target and postoperative outcome refraction recorded. The mean difference between the targeted and outcome refraction was -0.07 D (SD 0.67). The mean absolute error was 0.50 D. Postoperative refraction was within 1 D of target refraction for 7938 eyes (88.76%) and within 0.50 D for 5577 eyes (62.36%).

CONCLUSION

Refractive outcomes following routine cataract surgery reported here are well within the targets recommended by the Royal College of Ophthalmologists and European guidelines, but suggest that higher cataract refractive outcome benchmark standards may not yet be a realistic expectation for all NHS units with current biometry practice.

Microinterventional endocapsular nucleus disassembly: novel technique and results of first-in-human randomised controlled study

Aim

To assess the safety and efficacy of microinterventional endocapsular nuclear fragmentation in moderate to severe cataracts.

Methods

This was a prospective single-masked multisurgeon interventional randomised controlled trial (ClinicalTrials.gov NCT02843594) where 101 eyes of 101 subjects with grade 3‒4+ nuclear cataracts were randomised to torsional phacoemulsification alone (controls) or torsional phacoemulsification with adjunctive endocapsular nuclear fragmentation using a manual microinterventional nitinol filament loop device (miLOOP group). Outcome measures were phacoemulsification efficiency as measured by ultrasound energy (cumulative dispersed energy (CDE) units) and fluidics requirements (total irrigation fluid used) as well as incidence of intraoperative and postoperative complications.

Results

Only high-grade advanced cataracts were enrolled with more than 85% of eyes with baseline best corrected visual acuity (BCVA) of 20/200 or worse in either group. Mean CDE was 53% higher in controls (32.8±24.9 vs 21.4±13.1 with miLOOP assistance) (p=0.004). Endothelial cell loss after surgery was low and similar between groups (7‒8%, p=0.561) One-month BCVA averaged 20/27 Snellen in miLOOP eyes and 20/24 in controls. No direct complications were caused by the miLOOP. In two cases, capsular tears occurred during IOL implantation and in all remaining cases during phacoemulsification, with none occurring during the miLOOP nucleus disassembly part of the procedure.

Conclusions

Microinterventional endocapsular fragmentation with the manual, disposable miLOOP device achieved consistent, ultrasound-free, full-thickness nucleus disassembly and significantly improved overall phaco efficiency in advanced cataracts.

Trial registration number

NCT02843594

Phacoemulsification compared with phacotrabeculectomy surgery: a within-person observational cohort study

AIM

To compare reduction in intraocular pressure (IOP) and gain in visual acuity (VA) following phacotrabeculectomy (PT) and phacoemulsification(phaco) in Tanzanian patients with primary open angle glaucoma(POAG).

SETTING

CCBRT Hospital, Dar es Salaam, Tanzania.

DESIGN

Within-person observational cohort study.

METHODS

Within each patient, one eye had PT and the other phaco. Patients were followed for up to 5-1/2 years, and IOP and VA in each eye were assessed. For a small group of patients, two additional postoperative time points were compared.

RESULTS

52 patients (34 male) with a mean age of 70 years (SD 8 years) were enrolled in the study. For those with 250 days or more follow-up, both operations resulted in lower IOPs and improved VA (p<0.001). The average drop in IOP was 50% (95%CI 45% to 55%) for PT and 41% (95% CI 36% to 46%) for phaco. Mean IOP was lower in the PT group 12.9 mm Hg vs 16.8 mm Hg (p=0.004). Extended follow-up in nine patients showed a rise in IOP of 1.8 mm Hg for PT and 4.2 mm Hg for phaco eyes between first (mean, 337 days) and second (mean 1482 days) follow-up (p=0.18).

CONCLUSION

In this small study in African patients, PT resulted in lower IOPs than phacoemulsification alone but the difference between the procedures was relatively small. Phacoemulsification alone was effective in reducing IOP and improving VA for several years in this population. Given the relative simplicity of phacoemulsification, it is a therapeutic option worthy of consideration in some settings.

In vivo crystalline lens measurements with novel swept-source optical coherent tomography: an investigation on variability of measurement

Objective

To evaluate the reproducibility of in vivo crystalline lens measurements obtained by novel commercially available swept-source (SS) optical coherence tomography (OCT) specifically designed for anterior segment imaging.

Methods and analysis

One eye from each of 30 healthy subjects was randomly selected using the CASIA2 (Tomey, Nagoya, Japan) in two separate visits within a week. Each eye was imaged twice. After image scanning, the anterior and posterior lens curvatures and lens thickness were calculated automatically by the CASIA2 built-in program at 0 dioptre (D) (static), -1 D, -3 D and -5 D accommodative stress. The intraobserver and intervisit reproducibility coefficient (RC) and intraclass correlation coefficient (ICC) were calculated.

Results

The intraobserver and intervisit RCs ranged from 0.824 to 1.254 mm and 0.789 to 0.911 mm for anterior lens curvature, from 0.276 to 0.299 mm and 0.221 to 0.270 mm for posterior lens curvature and from 0.065 to 0.094 mm and 0.054 to 0.132 mm for lens thickness, respectively. The intraobserver and intervisit ICCs ranged from 0.831 to 0.865 and 0.828 to 0.914 for anterior lens curvature, from 0.832 to 0.898 and 0.840 to 0.933 for posterior lens curvature and from 0.980 to 0.992 and 0.942 to 0.995 for lens thickness. High ICC values were observed for each measurement regardless of accommodative stress. RCs in younger subjects tended to be larger than those in older subjects.

Conclusions

This novel anterior segment SS-OCT instrument produced reliable in vivo crystalline lens measurement with good repeatability and reproducibility regardless of accommodation stress.

Cataract surgery in uveitis: a multicentre database study

BACKGROUND/AIMS

Cataract is an important source of visual loss in patients with uveitis. Whether or not outcomes of cataract surgery in eyes with uveitis are worse compared with non-uveitic eyes have to date been compromised by lack of reliable estimates of benefit and harm, which require data from large cohorts.

METHODS

Electronic medical record data were extracted from eight independent UK clinical sites for eyes undergoing cataract extraction between January 2010 and December 2014. 1173 eyes with a recorded diagnosis of uveitis were compared with a reference group of 95 573 eyes from the same dataset.

RESULTS

Uveitic eyes represented 1.2% of all eyes undergoing cataract surgery. Eyes in the uveitic group had worse preoperative visual acuity (0.87 vs 0.65 logarithm of the minimum angle of resolution (logMAR) units), were from younger patients and had shorter axial lengths and a higher incidence of ocular copathology including glaucoma. A greater number had documented small pupils, required additional surgical procedures, developed more intraoperative complications and had poorer postoperative visual acuity at all time points measured up to 6 months (0.41 vs 0.27 logMAR units at 12-24 weeks).

CONCLUSIONS

This large study cohort of eyes with a diagnosis of uveitis undergoing cataract surgery highlights more precisely the complex surgical demands, copathology and worse visual outcomes in this group. These data will allow more accurate preoperative counselling and planning. Although improvement in visual acuity is achieved in most cases, prognosis should be guarded, so that patient expectations are met. Compared with the non-uveitic population, the mean postoperative visual acuity is between one and two lines worse at all time points.

Cataract surgery in children with retinopathy of prematurity (ROP): surgical outcomes

PURPOSE

To report the outcomes of cataract surgery in children with retinopathy of prematurity (ROP).

METHODS

A retrospective case review of all children diagnosed with ROP from January 2001 to December 2014 was done and those who underwent cataract surgery were included in the study. Details of ROP and cataract treatment, postoperative complications and outcomes were analysed.

RESULTS

Of the 2258 children diagnosed to have ROP, 28 eyes of 22 children were included, 14 boys and 8 girls. Mean age at cataract surgery was 18.9 months (range 2 months to 12 years). Most common grade of ROP was stage 4 (13 eyes). Nineteen eyes underwent retinal surgery, scleral buckle (one eye) and laser (three eyes). Five eyes showed spontaneous regression. Mean duration for the development of cataract postretinal surgery was 7.76 months (range 2-32 months). Nine eyes did not receive a primary intraocular lens (IOL). Intraoperative posterior capsular rupture occurred in two eyes. Postoperative complications included visual axis opacification (four), secondary glaucoma (two) and IOL capture (one). Postoperative visual acuity assessment was possible in 23 eyes, 11 had better than 20/200 vision. Eleven patients had a follow-up of at least 2 years and the mean myopic shift at 2 years was -3.07 D in pseudophakes and -8.75 D in aphakes.

CONCLUSIONS

Cataracts may develop in children with ROP regardless of the modality of intervention. Postoperative complications and refractive changes are similar to those in eyes without ROP.

Aqueous outflow facility after phacoemulsification with or without goniosynechialysis in primary angle closure: a randomised controlled study

BACKGROUND

Goniosynechialysis (GSL) to remove peripheral anterior synechiae (PAS) alongside standard cataract surgery has potential theoretical advantages, Published randomised trials, however, have not shown conclusive functional benefits and aqueous outflow changes following GSL are unknown. This study aimed to compare electronic Shiøtz tonographic aqueous outflow facility (TOF) following phacoemulsification with or without GSL in patients with primary angle closure (PAC) and PAC glaucoma. Secondary outcomes were changes in intraocular pressure (IOP) and use of glaucoma medications.

METHODS

Prospective randomised pilot study of 26 patients on glaucoma medication, with ≥90° PAS and significant lens opacity. Patients were randomised 1:1 to receive phacoemulsification with intraocular lens (IOL) implantation only (phaco) or phacoemulsification with IOL plus GSL (phaco-GSL).

RESULTS

Fourteen patients were randomised to phaco-GSL and 12 to phaco alone. TOF increased with phaco-GSL from 0.099±0.07 μL/min/mm Hg to 0.194±0.07, μL/min/mm Hg, p=0.0006, while the phaco group showed no significant change. IOP reduced in both groups, but reduced significantly more following phaco-GSL (46.0%) compared with phaco alone (27.6%, p=0.04). Medication use and extent of PAS only reduced with phaco-GSL, from 0.923±0.86 to 0.384±0.18 medications, p=0.0279, and from 249.2±83.4 to 110.8±53.9° PAS, 6 months postoperatively. No serious adverse events occurred in either group.

CONCLUSIONS

Eyes randomised to both surgical groups had similar and good outcomes at 6 months in this pilot study. However, only eyes undergoing GSL combined with standard phacoemulsification had significantly increased TOF, reduced glaucoma medication dependence and PAS postoperatively. GSL should therefore be considered in such patients.

TRIAL REGISTRATION NUMBER

NCT00719290, Results.

Cataracts induced by neodymium-yttrium-aluminium-garnet laser lysis of vitreous floaters

BACKGROUND

Neodymium-yttrium-aluminium-garnet (Nd:YAG) laser vitreolysis has been proposed as a treatment modality for symptomatic vitreous floaters. The purpose of this paper is to report two cases of cataracts associated with posterior capsular compromise, induced by Nd:YAG laser vitreolysis for symptomatic vitreous floaters.

METHOD

Case series.

RESULTS

Two patients who underwent ND:YAG laser vitreolysis for symptomatic floaters, presented with decline in visual acuity in the treated eye after the laser procedure. At the slit-lamp biomicroscope, each patient was found to have a posterior subcapsular cataract in the treated eye, with obvious loss of integrity of the posterior capsule. These two patients underwent cataract extraction by the same surgeon via phacoemulsification. Both eyes were found to have a defect in the posterior capsule intraoperatively. In both cases, a three-piece acrylic intraocular lens implant was placed in the sulcus, achieving optic capture. The best-corrected visual acuity (BCVA) was 20/20 in both patients, at 1 month following the surgery. At 2 months, one patient had a BCVA of 20/15. The second patient maintained a BCVA of 20/20 at 3 months.

CONCLUSIONS

Secondary cataract formation accompanied by loss of integrity of the posterior capsule is a potential complication of Nd:YAG laser vitreolysis for symptomatic floaters.

Is prophylactic laser peripheral iridotomy for primary angle closure suspects a risk factor for cataract progression? The Chennai Eye Disease Incidence Study

BACKGROUND

To report the risk of cataract progression among primary angle closure suspects (PACS) 6 years after they underwent laser peripheral iridotomy (LPI).

METHODS

In the Chennai Eye Disease Incidence Study, 6 years after their baseline evaluation, 4421 subjects were examined again. As part of a detailed evaluation cataract was graded using the Lens Opacities Classification System II; progression was defined as change of cataract by two or more grades or history of cataract surgery in the 6-year period. Only bilaterally phakic subjects with less than N2 or C2 or P2 cataract at baseline with no history of any form of glaucoma, primary angle closure and pseudoexfoliation were included.

RESULTS

There were 3205 eligible subjects. Of these, 190 had undergone LPI for PACS. In comparison to the study population, they were significantly older (p<0.001), female (p=0.008), urban residents (p=0.001) and patients with hypertension (p<0.001). During the intervening period, 53 subjects had undergone cataract surgery. The cataract progression rate was significantly greater (OR 1.7, 95% CI 1.3 to 2.4, p<0.001) in those who had undergone LPI. For the study population the baseline risk factors for progression of cataract were age (p<0.001), female gender (p=0.01), diabetes (p<0.001) and LPI (p<0.001). Diabetes and female gender were significant risk factors for nuclear and cortical cataract progression; LPI was a risk factor only for cortical cataract (OR 1.6, 95% CI 1.1 to 2.3, p=0.007).

CONCLUSIONS

There was significant cataract progression in 6 years following LPI for PACS.

Blindness, cataract surgery and mortality in Ethiopia

PURPOSE

To examine the relationships between blindness, the intervention of cataract surgery and all-cause mortality in a rural Ethiopian population.

DESIGN

Population-based, interventional prospective study.

METHODS

Community-based detection methods identified blind Ethiopian persons from two selected kebeles in Amhara region, Ethiopia. Data from 1201 blind patients were collected-628 cataract-blind and 573 blind from other conditions. Free cataract surgery was provided for consenting, cataract-blind patients. Follow-up surveys were conducted after 12 months (±1 month)-the main outcome measure for this report is all-cause mortality at 1 year.

RESULTS

During the follow-up period, 110 persons died from the selected population (mortality 9.2%), which consisted of those cataract-blind patients who received cataract surgery (N=461), cataract-blind patients who did not receive surgery (N=167) and all non-cataract-blind patients (N=573). Of the 461 patients who received cataract surgery, 44 patients died (9.5%). Of the 740 patients who did not receive surgery, 66 died (8.9%)-28 patients from the cohort of cataract-blind patients who did not receive surgery (16.8%) and 38 patients from the cohort of non-cataract blind (6.6%). Subgroup analysis revealed significantly increased odds of mortality for cataract-blind patients over 75 years of age who did not receive surgery and for unmarried patients of all age groups.

CONCLUSIONS

In this population, mortality risk was significantly elevated for older cataract-blind patients when compared with non-cataract-blind patients-an elevation of risk that was not noted in an age-matched cohort of cataract-blind patients who underwent cataract surgery as early as 1-year follow-up.

Objective and subjective visual quality after implantation of all optic zone diffractive multifocal intraocular lenses: a prospective, case-control observational study

BACKGROUND AND AIMS

To evaluate the objective and subjective optical quality of all optic zone diffractive multifocal intraocular lens (IOL).

METHODS

Fifty patients (50 eyes) having phacoemulsification and IOL implantation surgery were enrolled. 25 patients were implanted with all optic zone diffractive multifocal IOL and 25 patients with monofocal IOL. Objective optical quality parameters under 4 mm pupil using Optical Quality Analysis System (OQAS), subjective visual acuity (VA) at 85 cd/m² luminance and questionnaire concerning halo and visual function were assessed.

RESULTS

The multifocal group gained similar objective optical outcomes, such as OQAS values at contrast 100%, 20%, 9%, modulation transfer function cut-off and Strehl ratio, as the monofocal group. Objective scatter index (OSI) was significantly better in the monofocal group. Distance corrected near VA, uncorrected near VA, distance corrected intermediate VA and uncorrected intermediate VA were significantly better in the multifocal group. The difference in uncorrected distance VA and best corrected distance VA between the monofocal and multifocal groups was not significant. Mild halos and glare were reported in both groups and a significant difference between the two groups was not observed; however, moderate glare and halos were reported only in the multifocal group (2/25). There was no significant difference between the two groups when visual function was compared.

CONCLUSIONS

All optic zone diffractive multifocal IOLs provided almost the same objective optical quality as monofocal IOLs did under 4 mm pupil besides good all distance visual performance, but with greater OSI, indicating that implantation provides good optical quality in daytime but with more intraocular scatter light.

TRIAL REGISTRATION NUMBER

NCT02234635, post-results.

Risk factors for retinal detachment following cataract surgery: the impact of posterior capsular rupture

AIM

To investigate risk factors for retinal detachment (RD) after cataract surgery, particularly posterior capsular rupture (PCR) with or without vitreous loss.

METHODS

Single centre electronic medical record database study of 18 065 consecutive first eye cataract operations performed between 2005 and 2014. Survival analysis was performed with Kaplan-Meier curves and a Cox proportional hazard regression analysis to calculate HRs with respect to RD.

RESULTS

The RD rate at 3 months and 7 years was 0.067% and 0.30%, respectively, with a median time to RD of 15 months (mean: 18 months, range: 0-84 months). Men had a higher RD risk (HR 2.00; 95% CI 1.03 to 3.88; p=0.03) in the univariate model. Patients <60 years and those >80 years had an HR of 5.12 (95% CI 2.60 to 10.07; p<0.001) and 0.16 (95% CI 0.38 to 0.69; p=0.01), respectively, compared with patients 60-80 years of age. Eyes longer than 25 mm had an HR of 3.98 (95% CI 1.93 to 8.20; p<0.001) compared with eyes 23-25 mm. PCR occurred in 400 (2.2%) eyes. The HR for RD was 12.83 (95% CI 5.62 to 29.30; p<0.001) for PCR with vitreous loss. There were no RD events in eyes with PCR without vitreous loss.

CONCLUSIONS

The risk for RD after cataract surgery is higher in younger patients and eyes with longer axial length or PCR with vitreous loss during surgery.

Anterior chamber interleukin 1β, interleukin 6 and prostaglandin E2 in patients undergoing femtosecond laser-assisted cataract surgery

PURPOSE

To evaluate the interleukin (IL) 1β, IL-6 and prostaglandin E2 (PGE2) concentrations in aqueous humour in patients undergoing femtosecond laser-assisted cataract surgery.

METHODS

In 27 eyes of 27 patients undergoing femtosecond laser-assisted cataract surgery (femto group), aqueous humour of 100 μL was collected after laser treatment. In 15 eyes of 15 subjects undergoing routine cataract surgery (control group), aqueous humour of 100 μL was also collected. The IL-1β, IL-6 and Prostaglandin E2 (Human Interleukin 1β, Interleukin 6 and Prostaglandin E2 ELISA Kits, Bio-Swamp Life Science) were used to determine the concentrations of IL-1β, IL-6 and PGE2 in the aqueous humour. All patients were treated with non-steroidal anti-inflammatory drugs prior to surgery.

RESULTS

For IL-1β, IL-6 and PGE2, respectively, the mean concentration values in aqueous humour were 25.6, 24.6 and 64.2 pg/mL in the femto group, and 17.1, 15.2 and 45.7 pg/mL in the control group (table 2). Concentrations of IL-1β, IL-6 and PGE2 were significantly higher in the femto group than those in the control group (all p<0.01). There were no significant correlations between concentrations of IL-1β, IL-6 or PGE2 and age, cataract densities, suction time or laser time (all p>0.05).

CONCLUSIONS

Inflammatory cytokines IL-1β, IL-6 and PGE2 significantly increased after femtosecond laser-assisted cataract surgery, which maybe the cause of intraoperative miosis seen in these patients.

Scleral fixation of intraocular lenses using Gore-Tex suture: clinical outcomes and safety profile

BACKGROUND/AIMS

To report the short-term safety profile and clinical outcomes of scleral fixation of intraocular lenses (IOLs) using Gore-Tex suture.

METHODS

Retrospective, interventional case series. 85 eyes of 84 patients undergoing ab externo scleral fixation of a Bausch and Lomb Akreos AO60 or Alcon CZ70BD IOL using Gore-Tex suture. Primary outcome measures were change in visual acuity and occurrence of intraoperative and postoperative complications with minimum follow-up of 90 days.

RESULTS

85 eyes of 84 patients were identified. Mean logarithm of the minimum angle of resolution visual acuity improved from 1.43±0.72 (20/538 Snellen equivalent) preoperatively to 0.64±0.61 (20/87 Snellen equivalent) postoperatively (p<0.001). Mean follow-up was 325 days (median 264 days, range 90-996 days). There were no intraoperative complications noted. Postoperative complications included hypotony in eight patients (9.4%), ocular hypertension in six eyes (7%), vitreous haemorrhage in six eyes (7%), hyphema in two eyes (2%), serous choroidal detachment in two eyes (2%), cystoid macular oedema in two eyes (2%) and corneal oedema in one eye (1%). There were no cases of postoperative endophthalmitis, suture erosion/breakage, retinal detachment, suprachoroidal haemorrhage, uveitis-glaucoma-hyphema syndrome or persistent postoperative inflammation in the follow-up period.

CONCLUSIONS

Ab externo scleral fixation of IOLs with Gore-Tex suture was well tolerated in all cases. No suture-related complications were encountered. This procedure led to improvement in visual acuity and was not associated with significant intraoperative or postoperative complications.

Factors influencing 1-year rotational stability of AcrySof Toric intraocular lenses

PURPOSE

To investigate the 1-year rotational stability of AcrySof Toric intraocular lenses (IOLs) and factors influencing their stability.

METHODS

This retrospective study enrolled 75 patients who underwent phacoemulsification, and were implanted with an AcrySof Toric IOL for 1 year. Their preoperative clinical data were reviewed. The 1-year clinical outcomes included uncorrected visual acuity, best-corrected visual acuity and residual astigmatism. Rotation of the IOL and the grade of anterior capsular opacification (ACO; graded from 0=none to 3=severe) were evaluated after mydriasis.

RESULTS

Of the 75 eyes analysed, 29.33% had high myopia. Residual astigmatism at 1 year (-0.76±0.47 dioptre(D)) was significantly reduced compared with the preoperative corneal astigmatism (2.08±0.71 D). The mean absolute rotation of the IOL was 8.83±5.26°. Toric IOL rotation was significantly and positively correlated with the degree of residual astigmatism in the T3 (Pearson's r=0.552, p<0.001) and T4 groups (Pearson's r=0.622, p=0.003). Regarding factors associated with IOL rotation, toric IOL rotation was positively correlated with axial length (AXL; Pearson's r=0.335, p=0.003) and negatively correlated with ACO grade (Spearman's r=-0.541, p<0.001). On multiple linear regression analysis, only AXL (B=0.889, p=0.031) and ACO grade (B=-3.216, p<0.001) were predictors of toric IOL rotation (R(2)=0.397).

CONCLUSIONS

Long AXL is a risk factor for toric IOL rotation, while higher ACO grade may decrease toric IOL rotation, indicating that reducing the polishing of anterior capsule may improve the rotational stability of a toric IOL.

TRIAL REGISTRATION NUMBER

NCT02182921.

Risks and outcomes associated with primary intraocular lens implantation in children under 2 years of age: the IoLunder2 cohort study

BACKGROUND/AIMS

To investigate outcomes following cataract surgery with and without primary intraocular lens (IoL) implantation in children under 2 years of age with congenital or infantile cataract.

METHOD

Prospective population based cohort study undertaken through the British Isles Congenital Cataract Interest Group, with systematic data collection on children undergoing surgery in UK and Ireland between January 2009 and December 2010. ORs for the association between IoL implantation and visual acuity, postoperative glaucoma and reoperation at 1 year after surgery were estimated using multivariable regression analysis to control for potential confounders.

RESULTS

Of 221 children, 56/131 with bilateral and 48/90 with unilateral cataract underwent primary IoL implantation. IoL implantation was independently associated with better visual outcome in bilateral (OR 4.6, 95% CI 1.6 to 13.1, p=0.004) but not unilateral disease. IoL use increased the odds of reoperation requiring repeat general anaesthetic (bilateral OR 5.5, p<0.01; unilateral OR 16.7, p<0.01). IoL implantation did not reduce the odds of postoperative glaucoma.

CONCLUSIONS

The use of IoLs in cataract surgery in young children should be critically reassessed, particularly used in settings/communities where close, long-term follow-up is challenging. The absence of visual benefit and the lack of a previously postulated protective effect against postoperative glaucoma serve to question the value of IoLs in unilateral disease. The potential association between IoL use and better early visual outcomes in bilateral disease needs to be balanced against the risk of reoperation and exposure to additional general anaesthetics during a key period of neurodevelopment.

A review of the surgical options for the correction of presbyopia

Presbyopia is an age-related eye condition where one of the signs is the reduction in the amplitude of accommodation, resulting in the loss of ability to change the eye's focus from far to near. It is the most common age-related ailments affecting everyone around their mid-40s. Methods for the correction of presbyopia include contact lens and spectacle options but the surgical correction of presbyopia still remains a significant challenge for refractive surgeons. Surgical strategies for dealing with presbyopia may be extraocular (corneal or scleral) or intraocular (removal and replacement of the crystalline lens or some type of treatment on the crystalline lens itself). There are however a number of limitations and considerations that have limited the widespread acceptance of surgical correction of presbyopia. Each surgical strategy presents its own unique set of advantages and disadvantages. For example, lens removal and replacement with an intraocular lens may not be preferable in a young patient with presbyopia without a refractive error. Similarly treatment on the crystalline lens may not be a suitable choice for a patient with early signs of cataract. This article is a review of the options available and those that are in development stages and are likely to be available in the near future for the surgical correction of presbyopia.

An 8-year retrospective study of cataract surgery and postoperative endophthalmitis: injectable intraocular lenses may reduce the incidence of postoperative endophthalmitis

BACKGROUND/AIMS

Postoperative endophthalmitis (POE) is a rare but potentially devastating complication of modern cataract surgery. We examine whether the use of injectable intraocular lenses (IOLs) is associated with a lower rate of POE after cataract surgery compared with forceps-inserted foldable IOLs.

METHODS

A single-centre retrospective cohort study of 25 410 cataract operations was performed over an 8-year period when standard practice in cataract surgery changed from the use of forceps-inserted foldable IOLs to injectable IOLs. Cases of POE were identified and the rates compared between the two groups.

RESULTS

Twelve cases of POE were identified in the study period. The rate of POE was significantly lower in the injectable IOL group compared with the forceps-inserted foldable IOL group (0.008% vs 0.081%, p=0.008). This difference remained significant when controlling for posterior capsular rupture and lens material.

CONCLUSIONS

This study, the largest of its kind to date, supports the use of injectable IOLs over forceps-inserted foldable IOLs as a significant measure in reducing the risk of POE.

Suction posterior capsulorhexis: an audit of 15 years' experience

AIMS

To audit the results of 15 years' experience of suction posterior capsulorhexis (SPC) during phacoemulsification and compare the outcomes with a recently published multicentre audit of cataract surgery, the Cataract National Dataset (CND).

METHODS

Prospective cohort observational study.

SETTING

Ophthalmology department of a district general hospital.

RESULTS

Data collection ran from June 1998 to November 2013, and 866 eyes of 786 patients were included. The mean (SD) age was 70.7 (12.4) years with 62% women. Low levels of perioperative and postoperative complications were noted, and the visual outcomes at 2 weeks in this audit were significantly better than those of the CND, with 75.4% achieving a best-corrected vision of ≥6/6 and 87.3% ≥6/12, improving to 95.8% and 100%, respectively, for best-case analysis (p<0.001 for all comparisons). 99% achieved the same or a better postoperative visual acuity than preoperatively compared with 95% in the CND (p<0.001) and none lost two lines of Snellen acuity (versus 1.24%; p<0.001). Patients receiving one of the two designs of square-edged hydrophobic acrylic intraocular lenses used in this audit did not require later YAG laser treatment compared with 2.72% of those who had a polymethylmethacrylate intraocular lens (p<0.02). Biometry accuracy was within ±1.0 D of the predicted refraction in 89.3%.

CONCLUSIONS

SPC, when performed by an experienced surgeon, appears to achieve better visual outcomes than the CND without causing harm to patients nor adversely affecting biometry accuracy. Use of a hydrophobic acrylic intraocular lens with SPC may avoid the need for subsequent YAG laser therapy.

Measurement of lens density using Scheimpflug imaging system as a screening test in the field of health examination for age-related cataract

PURPOSE

To assess Pentacam (Oculus, Wetzlar, Germany) Scheimpflug quantitative images in evaluating lens density and providing objective measurements to suggest optimal time of cataract surgery in the field of health examination.

METHODS

Two hundred and twenty-nine eyes with age-related cataract were enrolled. Lens density was measured using Pentacam. All Pentacam images were exported to ImageJ (NIH, Bethesda, Maryland, USA) for quantitative analysis. Average lens density (ALD) and nuclear lens density (NLD) were calculated. Lens density was also evaluated by built-in Pentacam Nucleus Staging (PNS) software. Slit-lamp microscopy was performed for cataract grading according to Lens Opacification Classification System III (LOCS III). The best-corrected visual acuity (BCVA) was measured. All measurements were compared between the cataract surgery and non-cataract surgery groups.

RESULTS

The measurements of Pentacam images significantly correlated with LOCS III for nuclear opalescence (NO) and nuclear colour (NC) grading (p<0.01). Pentacam ImageJ showed higher correlation than PNS. The mean NLD was most highly correlated with NO (r=0.8833) and NC (r=0.6815). The maximum ALD was most highly correlated with cortical opacity (r=0.5381). All Pentacam measurements of lens density and BCVA were significantly different between the cataract surgery and non-surgery groups (p<0.01). The optimised cut-off values to perform cataract surgery for mean NLD and maximum ALD were 26 and 74, respectively (p<0.01).

CONCLUSIONS

The Pentacam ImageJ method provided objective measurements to evaluate cataracts needing surgery. The method has the potential to be generally applied in the field of health examination and is effective in screening patients with cataract.

Cataract surgery outcomes in adult patients with Down's syndrome

PURPOSE

To describe the outcomes of cataract surgery in adult patients with Down's syndrome at a tertiary eye hospital in Hong Kong.

METHODS

Retrospective case-file analysis was performed to identify patients with Downs's syndrome who underwent cataract surgery between January 2002 and December 2012. Morphology of cataract, associated ocular features and surgical and visual outcomes were analysed.

RESULTS

Cataract surgery was performed in 33 eyes of 20 patients (12 males, 8 females, mean age 42.9±10.6 years) over a 10-year period. Nine patients (9/20, 45.0%) had bilateral cataracts at the time of diagnosis. White cataracts were noted in 12 eyes of 10 patients (12/33, 36.3%) at the time of presentation. Associated ocular problems included myopic maculopathy (18 eyes, 54.5%), keratoconus (12 eyes, 36.3%), nystagmus (2 eyes, 6.0%), corneal scar (2 eyes, 6.0%) and glaucoma (2 eyes, 6.0%). Five eyes (15.1%) underwent extracapsular cataract extraction whereas a phacoemulsification was performed in 28 (84.9%) eyes. Intraocular lens implantation was performed in 32/33 eyes. The most common postoperative complication was posterior capsular opacification (8 eyes, 24.2%). The mean best-corrected visual acuity improved from 0.07±0.11 preoperatively to 0.17±0.19 at 3 months postoperatively (p=0.000).

CONCLUSIONS

A high incidence of bilateral cataracts as well as white cataracts was observed in patients with Down's syndrome in our study. Although the surgical outcomes of cataract surgery were good, the visual outcomes were suboptimal in our cases due to associated ocular comorbidities.

Prevalence and causes of vision loss in sub-Saharan Africa: 1990-2010

AIM

To estimate the magnitude, temporal trends and subregional variation in the prevalence of blindness, and moderate/severe vision impairment (MSVI) in sub-Saharan Africa.

METHODS

A systematic review was conducted of published and unpublished population-based surveys as part of the Global Burden of Disease, Risk Factors and Injuries Study 2010. The prevalence of blindness and vision impairment by country and subregion was estimated.

RESULTS

In sub-Saharan Africa, 52 studies satisfied the inclusion criteria. The estimated age-standardised prevalence of blindness decreased by 32% from 1.9% (95% CI 1.5% to 2.2%) in 1990 to 1.3% (95% CI 1.1% to 1.5%) in 2010 and MSVI by 25% from 5.3% (95% CI 0.2% to 0.3%) to 4.0% (95% CI 0.2% to 0.3%) over that time. However, there was a 16% increase in the absolute numbers with blindness and a 28% increase in those with MSVI. The major causes of blindness in 2010 were; cataract 35%, other/unidentified causes 33.1%, refractive error 13.2%, macular degeneration 6.3%, trachoma 5.2%, glaucoma 4.4% and diabetic retinopathy 2.8%. In 2010, age-standardised prevalence of MSVI in Africa was 3.8% (95% CI 3.1% to 4.7%) for men and 4.2% (95% CI 3.6% to 5.3%) for women with subregional variations from 4.1% (95% CI 3.3% to 5.4%) in West Africa to 2.0% (95% CI 1.5% to 3.3%) in southern Africa for men; and 4.7% (95% CI 3.9% to 6.0%) in West Africa to 2.3% (95% CI 1.7% to 3.8%) in southern Africa for women.

CONCLUSIONS

The age-standardised prevalence of blindness and MSVI decreased substantially from 1990 to 2010, although there was a moderate increase in the absolute numbers with blindness or MSVI. Significant subregional and gender disparities exist.

Clinical outcomes of sleeveless phacotip assisted levitation of dropped nucleus

BACKGROUND/AIM

To demonstrate the feasibility of a sleeveless phacotip-assisted approach to levitate dropped nucleus.

METHODS

This single-centre, retrospective, interventional, non-comparative case series reviewed the medical records of 34 eyes of 34 patients. Corrected and uncorrected distance visual acuity (CDVA, UDVA), early and late postoperative complications and ultrasound biomicroscopic (UBM) evaluation of the sclerotomy site was analysed.

RESULTS

At 18 months follow-up, the mean postoperative UDVA and CDVA in Snellen's decimal equivalent was 0.42 ± 0.16 and 0.91 ± 0.2, respectively. There was a significant improvement in the UDVA (p=0.001) and CDVA (p=0.002). Nucleus drop occurred following intraoperative posterior capsular rupture in 25 eyes (73.5%), zonular weakness in 5 eyes (14.8%) and post-trauma in 4 eyes (11.7%). In the early postoperative period, corneal oedema was seen in 2 eyes, pigment dispersion in 3 eyes and vitritis in 2 eyes. There was loss of CDVA in 1 (2.9%) eye due to persistent cystoid macular oedema. UBM did not reveal any vitreous incarceration into the sclerotomy site.

CONCLUSION

Dropped nucleus was successfully levitated into anterior chamber with this technique, resulting in a significant visual outcome with a favourable complication rate.

Using continuous intraoperative optical coherence tomography measurements of the aphakic eye for intraocular lens power calculation

BACKGROUND/AIMS

To include intraoperative measurements of the anterior lens capsule of the aphakic eye into the intraocular lens power calculation (IPC) process and to compare the refractive outcome with conventional IPC formulae.

METHODS

In this prospective study, a prototype operating microscope with an integrated continuous optical coherence tomography (OCT) device (Visante attached to OPMI VISU 200, Carl Zeiss Meditec AG, Germany) was used to measure the anterior lens capsule position after implanting a capsular tension ring (CTR). Optical biometry (intraocular lens (IOL) Master 500) and ACMaster measurements (Carl Zeiss Meditec AG, Germany) were performed before surgery. Autorefraction and subjective refraction were performed 3 months after surgery. Conventional IPC formulae were compared with a new intraoperatively measured anterior chamber depth (ACD) (ACDIntraOP) partial least squares regression (PLSR) model for prediction of the postoperative refractive outcome.

RESULTS

In total, 70 eyes of 70 patients were included. Mean axial eye length (AL) was 23.3 mm (range: 20.6-29.5 mm). Predictive power of the intraoperative measurements was found to be slightly better compared to conventional IOL power calculations. Refractive error dependency on AL for Holladay I, HofferQ, SRK/T, Haigis and ACDintraOP PLSR was r(2)=-0.42 (p<0.0001), r(2)=-0.5 (p<0.0001), r(2)=-0.34 (p=0.010), r(2)=-0.28 (p=0.049) and r(2)<0.001 (p=0.866), respectively,

CONCLUSIONS

ACDIntraOP measurements help to better predict the refractive outcome and could be useful, if implemented in fourth-generation IPC formulae.

Clinical evaluation of a multifocal aspheric diffractive intraocular lens

AIM

To evaluate the performance of an aspheric diffractive multifocal acrylic intraocular lens (IOL), ZMB00 1-Piece Tecnis.

SETTING

Five sites across Europe.

METHODS

Fifty-two patients with cataracts (average age 68.5±10.5 years, 35 female) were bilaterally implanted with the aspheric diffractive multifocal IOL after completing a questionnaire regarding their optical visual symptoms, use of visual correction and their visual satisfaction. The questionnaire was completed again 4-6 months after surgery along with measures of uncorrected and best-corrected distance and near visual acuity, under photopic and mesopic lighting, reading ability, defocus curve testing and ocular examination for adverse events.

RESULTS

The residual refractive error was 0.01±0.47D with 56% of eyes within ±0.25D and 97% within ±1.0D. Uncorrected visual acuity was 0.02±0.10logMAR at distance and 0.15±0.30 logMAR at near, only reducing to 0.07±0.10logMAR at distance and 0.21±0.25logMAR at near in mesopic conditions.The defocus curve showed a near addition between 2.5-3.0 D allowing a reading acuity of 0.08±0.13 logMAR, with a range of clear vision <0.3 logMAR of ∼4.0 D. The average reading speed was 121.4±30.8 words per minute. Spectacle independence was 100% for distance and 88% for near, with high levels of satisfaction reported. Overall rating of vision without glasses could be explained (r=0.760) by preoperative best-corrected distance acuity, postoperative reading acuity and postoperative uncorrected distance acuity in photopic conditions (p<0.001). Only two minor adverse events occurred.

CONCLUSIONS

The ZMB00 1-Piece Tecnis multifocal IOL provides a good visual outcome at distance and near with minimal adverse effects.

Long-term outcome of scleral-fixated intraocular lens implantation

PURPOSE

Implantation of a scleral-fixated intraocular lens (SFIOL) for the surgical management of aphakia in the absence of capsular support is a safe procedure with a low risk of complications in the early postoperative period. However, data on long-term functional outcome are limited. The purpose of this study is to assess the long-term outcome and complication profile of SFIOL implantation in a cohort of Chinese patients.

METHODS

All patients who had undergone primary or secondary SFIOL implantation between 1997 and 2008 were retrospectively reviewed for visual outcomes and complications. Patients' demographic data and information on baseline preoperative visual acuity, indication for surgery, postoperative complications, latest postoperative visual acuity and indication for any subsequent surgical procedures were collected and analysed.

RESULTS

104 eyes of 99 patients (51 males and 48 females) were identified. Mean age at surgery was 67.1 ± 13 years (range 32-88 years), with a mean follow-up of 73.4 ± 43 months (range 12-180 months). 72% of patients had unchanged or improved final postoperative visual acuity. 25 of 104 eyes (24.0%) had postoperative complications, with suture-related complications being the most common. 13 eyes (12.5%) required further procedures for postoperative complications. Suture breakage leading to lens subluxation occurred in two eyes (1.9%).

CONCLUSIONS

SFIOL implantation is valuable for the management of aphakia in the absence of capsular support, and our visual outcomes and complication rates are comparable to other case series. The long-term outcomes and safety profile are favourable, but potential long-term suture-related problems should be discussed with the patients before surgery.

Familial acorea, microphthalmia and cataract syndrome

PURPOSE

To describe the clinical features of members of a family with acorea, microphthalmia and cataract syndrome. In addition, to perform linkage analysis on family members to determine possible candidate genes.

METHODS

Comprehensive ophthalmic examinations were performed on five affected members of a family consisting of a paternal grandmother, father and three children. In addition, DNA was extracted from nine family members (the five affected and four normal members) and used for genome-wide single nucleotide polymorphism genotyping and linkage analysis.

RESULTS

All of the affected patients had acorea or fibrous occlusion of the pupil, microphthalmia and cataracts in both eyes. They also had microcornea and iridocorneal dysgenesis. Examination of the crystalline lens was hindered by the abnormal iris surface, but cataracts were detected by ultrasound biomicroscopy. Surgical reconstruction of the pupil allowed a better view of the posterior pole of the eye, and ophthalmoscopy showed a normal retina and optic disc. No systemic abnormalities were observed. Linkage analysis did not reach significance but narrowed the location of possible candidate genes to chromosomes 1, 5, 8, 11 and 17.

CONCLUSIONS

This acorea, microphthalmia and cataract syndrome has not previously been reported. Genetic analyses indicate that this syndrome is probably due to an autosomal dominant mutation.

Blindness and visual impairment due to age-related cataract in sub-Saharan Africa: a systematic review of recent population-based studies

AIM

We aimed to evaluate age-related cataract as a contributor to blindness and visual impairment (VI) in sub-Saharan Africa (SSA).

METHODS

A systematic review of population-based studies published between 2000 and October 2012. Prevalence and proportions of blindness and VI due to cataract, cataract surgical coverage (CSC), per cent intraocular lens (IOL) implantation and visual outcomes of surgery in accordance with WHO criteria were ascertained.

RESULTS

Data from 17 surveys (subjects mostly aged ≥ 50-years-old) from 15 different countries in SSA were included, comprising 96 402 people. Prevalence of blindness (presenting visual acuity <3/60 in better eye) ranged from 0.1% in Uganda to 9.0% in Eritrea, and the proportion of total blindness due to cataract ranged between 21% and 67%. Cataract was the principal cause of blindness and VI in 15 and 14 studies, respectively. There was a strong positive correlation between good visual outcomes and IOL use (R=0.69, p=0.027). Considerable inter-study heterogeneity was evident in CSC and visual outcomes following surgery, and between 40% and 100% of operations had used IOL.

CONCLUSIONS

Cataract represents the principal cause of blindness and VI and should remain a priority objective for eye care in SSA. However, the prevalence of blindness and VI due to cataract was variable and may reflect differences in the availability of cataract surgical programmes and cataract incidence.

Aqueous flare is increased in patients with clinically significant cystoid macular oedema after cataract surgery

BACKGROUND

To analyse the relationship of clinically significant cystoid macular oedema (CME after phacoemulsification to blood-aqueous barrier breakdown as determined by aqueous flare, visual acuity and retinal thickness in optical coherence tomography (OCT).

MATERIALS AND METHODS

30 eyes of 30 consecutive patients with clinically significant CME and vision loss were included. 46 pseudophakic and 45 phakic eyes without CME served as controls. Clinical data included age, gender, best-corrected visual acuity (BCVA) and spectral domain OCT volume scans. Retinal thickness measuring of the foveal central subfield was determined. Aqueous flare was measured quantitatively with the Kowa FM-500 Laser Flare-Cell Meter.

RESULTS

Patients with CME had significantly higher flare values compared with pseudophakic patients (p<0.0001). For patients with CME, aqueous flare values correlated significantly with BCVA (Spearman rs=0.4, p=0.041), while there was no correlation with retinal thickness. Using flare values to predict CME, receiver operating characteristic analysis returned an area under the curve of 0.976.

CONCLUSIONS

Aqueous flare as a marker for inflammation and breakdown of the blood-retinal barrier is increased in patients with CME after cataract surgery.