Low-dose AtropIne for Myopia Control in Children (AIM): protocol for a randomised, controlled, double-blind, multicentre, clinical trial with two parallel arms

INTRODUCTION

Myopia is a major cause of degenerative eye disease and increases the risk of secondary visual impairment. Mitigating its progression therefore has great potential of clinically relevant benefit as shown by using highly diluted atropine eye drops in children of Asian origin. However, limited evidence is available regarding the efficacy and safety of low-dose atropine therapy in non-Asian populations. Hence, the Low-dose AtropIne for Myopia Control in Children (AIM) study will test the efficacy and safety of 0.02% atropine vs placebo in a German population.

METHODS AND ANALYSIS

AIM is a national, multicentre, prospective, randomised, placebo-controlled, double-blind trial with two parallel arms. The primary objective is to assess the efficacy of atropine 0.02% eyedrops for myopia control in children of Caucasian origin. The primary outcome is the change in cycloplegic refraction after 1 year of treatment (D/year). Secondary and tertiary outcome measures comprise the change in axial length (mm/year) in children treated with 0.02% atropine compared with placebo, the myopic progression of participants treated with 0.01% compared with 0.02% atropine (D/year and mm/year), and the safety profile of both 0.02% and 0.01% atropine. Furthermore, the myopic progression 1 year after cessation of therapy with 0.02% atropine will be evaluated. Inclusion criteria are an age of 8-12 years and myopia of -1 D to -6 D with an estimated annual myopia progression of ≥0.5 D. After randomisation, patients will receive either atropine 0.02% (arm A) or placebo eye drops (arm B) in the first year of treatment. In the second year, they will continue to receive atropine 0.02% (arm A) or switch to atropine 0.01% (arm B). In the third year, they will switch to placebo (arm A) or continue with atropine 0.01% (arm B). To achieve a statistical power of 80%, the calculated sample size is 300. The trial has started in October 2021 with a planned recruitment period of 18 months.

ETHICS AND DISSEMINATION

AIM has been approved by the Central Ethics Committee of the University Medical Center Freiburg (21-1106), local ethics committees of each participating centre and the German Federal Institute for Drugs and Medical Devices (61-3910-4044659). It complies with the Declaration of Helsinki, local laws and ICH-GCP. Results and underlying data from this trial will be disseminated through peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

NCT03865160.

[Detections of refractive risk factors for amblyopia with Plusoptix Autorefractor A09]

BACKGROUND

Amblyopia is the most frequent cause for decreased vision in childhood. Important risk factors for amblyopia (ARF) are refractive errors. The aim of this study was to examine the reliability of the Plusoptix Autorefractor A09 (POA09) to detect refractive ARF.

METHOD

This prospective non-blinded, one-armed study was conducted between February 2012 and September 2015. Children aged 6 months to 12 years were screened in kindergarten and schools for refractive errors. Thresholds for screening failure were hyperopia ≥ 3.5 diopters (D), myopia ≥ 3.0 D, anisometropia ≥ 1.5 D and astigmatism ≥ 1.5 D (axis 90° or 180° ± 10°) or ≥ 1.0 D (≥ 10° axis deviation of 90° or 180°). Children who failed screening were advised to see an ophthalmologist for a comprehensive eye examination. After the visit, parents were asked for the results of the examination. A reference group of children who did not fail screening also received a comprehensive eye examination. Based on the number of children who failed screening, we calculated the proportion of correctly detected refractive errors. Based on the children of the reference group we calculated the proportion of correctly excluded refractive errors and the false negative rate.

RESULTS

In this study 3170 children were screened, 715 children (22.3%) failed screening. For 460 of these (64.3%) follow-up was available and for 132 children information on refractive errors in cycloplegia was available. Most frequent refractive errors at screening were astigmatism (90.9%) and anisometropia (11.4%). Most frequent refractive errors in cycloplegia were astigmatism (56.8%) and hyperopia (18.9%). The proportion of correctly detected refractive errors in the screening was highest for astigmatism (60%) and anisometropia (53.3%), followed by hyperopia (33.3%) and myopia (25%).

CONCLUSION

The reliability of POA09 to detect refractive ARF in children without cycloplegia was limited, highlighting the importance of a systematic amblyopia screening. A screening in cycloplegia can increase the proportion of correctly detected refractive ARF and should be studied.

Electrical neurostimulation in glaucoma with progressive vision loss

Background

The retrospective study provides real-world evidence for long-term clinical efficacy of electrical optic nerve stimulation (ONS) in glaucoma with progressive vision loss.

Methods

Seventy glaucoma patients (45 to 86 y) with progressive vision loss despite therapeutic reduction of intraocular pressure (IOP) underwent electrical ONS. Closed eyes were separately stimulated by bipolar rectangular pulses with stimulus intensities up to 1.2 mA sufficient to provoke phosphenes. Ten daily stimulation sessions within 2 weeks lasted about 80 min each. Right before ONS at baseline (PRE), vision loss was documented by static threshold perimetry and compared to the same assessment approximately 1 year afterwards (POST). Mean defect (MD) was defined as primary outcome parameter. Perimetries with a reliability factor (RF) of max. 20% were considered.

Results

Perimetry follow-up of 101 eyes in 70 patients fulfilled the criterion of a max. 20% RF. Follow-up was performed on average 362.2 days after ONS. MD significantly decreased from PRE 14.0 dB (median) to POST 13.4 dB (p < 0.01). 64 eyes in 49 patients showed constant or reduced MD as compared to baseline (PRE 13.4 dB vs. POST 11.2 dB). In 37 eyes of 30 patients, MD increased from PRE 14.9 dB to POST 15.6 dB.

Conclusions

Innovative treatments that preserve visual function through mechanisms other than lowering IOP are required for glaucoma with progressive vision loss. The present long-term data document progression halt in more than 63% of affected eyes after ONS and, thus, extend existing evidence from clinical trials.

[IVOM quality assurance in Westfalen-Lippe : Structure of quality assurance and results of the pilot study Q-VERA]

BACKGROUND

The KVWL-QS assists ophthalmologists in the transfer for good clinical praxis into real life. In addition the QS-commission initiated a pilotstudy "Qualitäts-Versorgung bei AMD" (Q‑VERA) in order to test new instruments for improvements. It was analized, if Reading Center (RC) based controls in combination with specific case-management modules can improve the results of IVOM treatment.

PATIENTS AND METHODS

In 5 treatment centers 878 consecutive patients with newly diagnosed AMD (Neu-Patienten) were included, who were treated with the IVAN-scheme. Initial FA and OCT images were transferred electronically to the RC. Also 781 retreatment patients (mean 20.7 IVOM before) with retreatment due to lesion activity were observed.

RESULTS

In 5% of the 878 newly treated patients a discrepancy between RC and treatment center was recorded. In this group the 481 patients, who finished up to the analysis date the 12-month follow-up, the visual function (increase in BCVA) and SD-OCT (reduction in central retinal thickness) results were comparable with large prospective cohorts. This was achieved with 6.5 injections and 10.6 visits over 12 months. In the group of 781 patients with repeated injections the number of injections over 12 months was 7.7 and the number of visits 11.6.

CONCLUSION

Quality assessment can improve the efficacy of IVOM therapy for AMD patients in real life. In addition to existing structures, electronical exchange by a RC assisted evaluation can further improve the quality by reducing the number of unnecessary treatment visits. The case-management with adherence control, re-call-system and specific information for patients and relatives can specifically increase the long-term adherence and thus the success of the therapy.

Telemetric Measurement of Intraocular Pressure via an Implantable Pressure Sensor-12-Month Results from the ARGOS-02 Trial

PURPOSE

The aim of this study was to investigate the safety and performance of the second generation of an implantable intraocular pressure (IOP) sensor in patients with primary open angle glaucoma (POAG).

DESIGN

prospective, noncomparative, open-label, multicenter clinical investigation.

METHODS

In this study, patients with POAG, regularly scheduled for cataract surgery, were implanted with a ring-shaped, sulcus-placed, foldable IOP sensor in a single procedure after intraocular lens implantation. Surgical complications as well as adverse events (AEs) during 12 months of follow-up were recorded. At each follow-up visit, a complete ophthalmic examination, including visual acuity, IOP, slit lamp examination, and dilated funduscopy as well as comparative measurements between Goldmann applanation tonometry and the EYEMATE-IO implant were performed.

RESULTS

The EYEMATE-IO implant was successfully implanted in 22 patients with few surgical complications and no unexpected device-related AEs. All ocular AEs resolved quickly under appropriate treatment. Comparative measurements showed good agreement between EYEMATE-IO and Goldmann applanation tonometry (GAT) with an intraclass correlation coefficient (ICC(3,k)) of 0.783 (95% confidence interval [CI]: 0.743, 0.817). EYEMATE-IO measurements were higher than GAT, with a mean difference of 3.2 mm Hg (95% CI: 2.8, 3.5 mm Hg).

CONCLUSIONS

The EYEMATE-IO sensor was safely implanted in 22 patients and performed reliably until the end of follow-up. This device allows for continual and long-term measurements of IOP.

Rotation of a toric intraocular lens with and without capsular tension ring: data from a multicenter non-inferiority randomized clinical trial (RCT)

BACKGROUND

Evaluation of clinical outcome in cohorts with versus without simultaneous implantation of a capsular tension ring (CTR) and a toric lens (Tecnis Toric). Main parameter was rotation referring - in contrast to misalignment - to the IOL axis change from immediately after implantation to the final postoperative position.

METHODS

Lens position was measured at baseline with the patient still in recumbent position, postoperative rotation was calculated by software. Postoperative evaluation included measurement three months after surgery or prior to an indicated revision surgery. Explorative re-evaluation of the underlying RCT's intent-to-treat population was performed for the entire sample and stratified for cohorts by 95% confidence intervals for binary endpoints' incidences (primary endpoint: absolute postoperative rotation ≤5 degrees; secondary endpoints: absolute deviation between achieved cylinder and target cylinder ≤0.5 dpt, postoperative corrected distance visual acuity (CDVA) ≥ 0.8). Data exploration was based on medians and quartiles.

SETTING

Outpatient study sites.

DESIGN

Re-evaluation based on data from a multicenter non-inferiority randomized clinical trial (RCT).

RESULTS

Sub cohorts (without CTR 89, with CTR 90 patients) did not present clinically relevant differences in preoperative characteristics: revision surgery was performed in 7 cases (3 without and 4 with CTR). Primary endpoint incidences for the total sample, without and with CTR were 90%/89%/90%; cylinder endpoint incidences were 46%/45%/46% and CDVA endpoint incidences 90%/92%/88%. Median absolute rotations were 1.74°/1.79°/1.72°, median absolute cylinder deviations 0.55/0.52/0.55 dpt and median visual acuity 1.0/1.0/1.0.

CONCLUSION

No clinically relevant differences between CTR subgroups were found; a satisfying three months rotational stability was achieved.

TRIAL REGISTRATION

The trial was registered retrospectively in the trial registry DRKS, trial registration number DRKS00015316 , date of registration 27. August 2018.

Noninferiority of Preservative-free Versus BAK-preserved Latanoprost-timolol Fixed Combination Eye Drops in Patients With Open-angle Glaucoma or Ocular Hypertension

PRéCIS:: Noninferiority of efficacy was demonstrated for a preservative-free latanoprost-timolol fixed combination compared with a BAK-containing formulation at 84 days after treatment in patients with open-angle glaucoma or ocular hypertension.

PURPOSE

The purpose of this study was to compare the effect on intraocular pressure and safety of preservative-free latanoprost-timolol fixed combination (T2347) to benzalkonium chloride-preserved latanoprost-timolol fixed combination in patients with open-angle glaucoma or ocular hypertension.

METHODS

Phase III, randomized, parallel-group, investigator-masked study in 10 countries. A total of 242 patients aged 18 years or older with open-angle glaucoma or ocular hypertension in both eyes controlled with a preserved latanoprost-timolol fixed combination (15.7±2.4 mm Hg overall before inclusion) were randomized at day 0 with no washout period to receive the preservative-free alternative T2347 (N=127) or remain on the preserved comparator (N=115) for 84 days. Intraocular pressure changes from day 0 were measured at 9:00 am (±1 hour) on day 42 and day 84, and noninferiority of T2347 to the preserved comparator was analyzed statistically at day 84. Safety parameters were also reported.

RESULTS

The mean change in intraocular pressure from baseline to day 84 was -0.49±1.80 mm Hg for preservative-free T2347 and -0.49±2.25 mm Hg for the preserved comparator. These results met the noninferiority limits. Similar results were observed at day 42. There was no difference between groups in the incidence of adverse events or ocular signs. The total ocular symptoms score was better for T2347 than BPLT upon instillation at day 84 (45.9%/44.3%/9.8% of patients with improvement/no change/worsening vs. 33.6%/47.3%/19.1%; P=0.021), reflecting improvements in individual symptoms such as irritation/burning/stinging (P<0.001), and itching (P<0.01) on day 84.

CONCLUSIONS

Preservative-free latanoprost-timolol fixed combination T2347 showed noninferior efficacy compared with the preserved comparator and was well tolerated.

Efficacy and safety of dual-polymer hydroxypropyl guar- and hyaluronic acid-containing lubricant eyedrops for the management of dry-eye disease: a randomized double-masked clinical study

BACKGROUND

An artificial-tear formulation containing the dual polymers hydroxypropyl guar (HPG) and hyaluronic acid (HA) is approved for the treatment of dry-eye disease (DED). The present study compared the efficacy and safety of the HPG-HA dual-polymer formulation vs a sodium hyaluronate (SH)-containing artificial-tear formulation in patients with DED.

METHODS

In a prospective, 6-week, multicenter, double-masked, parallel-group study, patients with DED aged ≥18 years and total ocular surface staining (TOSS) score ≥4 and ≤9 were randomized (1:1) to receive either HPG-HA or SH four times a day for 42 days. Changes from baseline in TOSS (primary end point), impact of dry eye on everyday life (IDEEL) treatment-satisfaction scores (effectiveness and inconvenience), and tear-film breakup time (TFBUT) at day 42 were assessed using a fixed-sequence testing strategy. Noninferiority was assessed on the primary end point based on the upper limit of two-sided 95% CIs for mean treatment difference (HPG-HA or SH) <2 units.

RESULTS

In total, 99 patients were randomized (HPG-HA, n= 50; SH, n= 49). At day 42, the least square (LS) mean ± SE change from baseline in TOSS was -1.16±0.24 and -0.92±0.23 in the HPG-HA and SH groups, respectively, and the treatment difference was -0.24±0.33 (95% CI -0.90 to 0.42). Noninfe-riority was demonstrated as the upper limit of the 95% CI was <2 units. LS mean change from baseline at day 42 for HPG-HA vs SH was -3.18 (P=0.4817) in IDEEL treatment-effectiveness scores, -12.56 (P=0.0001) in treatment-inconvenience scores, and 0.30 seconds (P=0.5789) in TFBUT.

CONCLUSION

The HPG-HA dual-polymer formulation was noninferior to the SH lubricant eye-drops for improvement in ocular surface staining in DED. HPG-HA did not show improvement over SH in IDEEL treatment-satisfaction scores. No new safety findings were reported.

[Is it still Necessary to Discontinue Using Daily Wear Soft Contact Lenses for a Period before LASIK?]

PURPOSE

The aim of this study was to verify whether soft contact lenses (SCL) can have a clinically significant impact on refraction before LASIK.

METHODS

Retrospective analysis of 113 eyes for which the refraction was measured initially and after discontinuing soft contact lenses for at least 7 days. Both spherical and cylindrical measurements were performed. In addition, the difference between postoperative refraction and the target refraction for these eyes was calculated for both spherical and cylindrical refraction.

RESULTS

In 8 % (18 %) of the eyes, the spherical or cylindrical refraction changed by 0.5 dioptre or more after a week of not wearing soft contact lenses. Total spherical refraction changed by an average of 0.15 dioptre (p = 0.58) and cylindrical refraction by 0.18 dioptre (p = 0.006). After LASIK, the difference between postoperative and target refraction was significantly different for both spherical refraction (0.3 dioptre) and for cylindrical refraction (0.21 dioptre).

DISCUSSION

The differences in the measurements during this study suggest that a modern soft contact lenses should still be discontinued before LASIK. The optimal duration of the discontinuation remains to be determined.

Impact of personality characteristics on patient satisfaction after multifocal intraocular lens implantation: results from the "happy patient study"

PURPOSE

This prospective multicenter study assessed personality characteristics that may influence patient satisfaction after implantation of multifocal intraocular lenses (MIOLs).

METHODS

One hundred eighty-three patients who underwent bilateral implantation of different MIOLs were enrolled. Uncorrected and corrected distance visual acuity for distance and near (ie, UDVA, UNVA, CDVA, and CNVA) were assessed preoperatively and 3 and 6 months after implantation. Before surgery, personality characteristics were evaluated using a questionnaire based on the NEO Personality Inventory Test and the Compulsiveness Inventory Test. At the 3- and 6-month postoperative visits, patients answered a questionnaire concerning overall satisfaction, need for spectacles at different distances, visual function at different distances and lighting conditions, photic phenomena, and ease of performing daily activities.

RESULTS

Three months after surgery (n = 163), mean CDVA was 0.03 ± 0.09 logMAR, UDVA was 0.05 ± 0.09 logMAR, and UNVA was 0.04 ± 0.11 logMAR. At the 6-month visit (n = 131), mean CDVA was 0.02 ± 0.07 logMAR, UDVA was 0.06 ± 0.09 logMAR, and UNVA was 0.05 ± 0.01 logMAR. Most patients (82.2%) would opt for an MIOL again, 3.7% would not, and 14.1% were uncertain. Overall satisfaction with the procedure was correlated to low astigmatism, good visual function, low spectacle dependence, and less halos or glare. The personality characteristics of compulsive checking, orderliness, competence, and dutifulness were statistically significantly correlated to subjective disturbance by glare and halos.

CONCLUSIONS

Postoperative patient satisfaction after MIOL implantation is correlated to visual performance, spectacle independence, and less photic phenomena. Personality characteristics have an impact on subjective disturbance by photic phenomena and thus are important for patient satisfaction.

[Case numbers and revenues of main and affiliated ophthalmological departments: Developments since 2005]

BACKGROUND

Currently, very little data exist on the development of healthcare-related and financial parameters of both types of inpatient treatment: clinical units run by affiliated physicians and those run by hospital physicians.

AIM

This study used a methodology based on published secondary data to estimate the annual number of cases and revenues for in inpatient ophthalmological treatment differentiated into clinical units run by affiliated physicians and those run by hospital physicians.

MATERIAL AND METHODS

The case-based flat-rate catalogs and accompanying research data published annually by the Institute for the Hospital Remuneration System (Institut für Entgeltsysteme im Krankenhaus, InEK) served as a data source. The numbers of annual cases according to major diagnostic categories (MDC) and diagnosis-related groups (DRG), stratified by the unit type are reported for the period 2005-2012. The cumulative total revenues were calculated based on the number of ophthalmological cases, the effective DRG cost weighting, the length of stay and the national basic case values.

RESULTS

Between 2005 and 2012 the units run by affiliated physicians showed a contrasting trend to those run by hospital physicians: the number of cases in units run by hospital physicians increased by  14 %, while those in units run by affiliated physicians decreased by  6 %. Up to 2012 the effective cost weighting for cases in units run by hospital physicians decreased to 0.60 (- 3 %) and increased to 0.43 (+ 5 %) for units run by affiliated physicians. In 2012 the corresponding effective case revenue accounted for 1767 euros and 1271 euros, respectively. Total revenue estimates for all inpatient ophthalmological treatment increased from 549 million euros in 2005 to 630 million euros in 2012, while the share of units run by affiliated physicians amounted to 10.6 % and 9.7 %, respectively.

CONCLUSION

According to the indicators "number of cases" and "total revenue", the affiliated ophthalmologists lost ground compared with inpatient units run by hospital physicians over the period from 2005-2012.

A methodological approach to identify external factors for indicator-based risk adjustment illustrated by a cataract surgery register

BACKGROUND

Risk adjustment is crucial for comparison of outcome in medical care. Knowledge of the external factors that impact measured outcome but that cannot be influenced by the physician is a prerequisite for this adjustment. To date, a universal and reproducible method for identification of the relevant external factors has not been published. The selection of external factors in current quality assurance programmes is mainly based on expert opinion. We propose and demonstrate a methodology for identification of external factors requiring risk adjustment of outcome indicators and we apply it to a cataract surgery register.

METHODS

Defined test criteria to determine the relevance for risk adjustment are "clinical relevance" and "statistical significance". Clinical relevance of the association is presumed when observed success rates of the indicator in the presence and absence of the external factor exceed a pre-specified range of 10%. Statistical significance of the association between the external factor and outcome indicators is assessed by univariate stratification and multivariate logistic regression adjustment.The cataract surgery register was set up as part of a German multi-centre register trial for out-patient cataract surgery in three high-volume surgical sites. A total of 14,924 patient follow-ups have been documented since 2005. Eight external factors potentially relevant for risk adjustment were related to the outcome indicators "refractive accuracy" and "visual rehabilitation" 2-5 weeks after surgery.

RESULTS

The clinical relevance criterion confirmed 2 ("refractive accuracy") and 5 ("visual rehabilitation") external factors. The significance criterion was verified in two ways. Univariate and multivariate analyses revealed almost identical external factors: 4 were related to "refractive accuracy" and 7 (6) to "visual rehabilitation". Two ("refractive accuracy") and 5 ("visual rehabilitation") factors conformed to both criteria and were therefore relevant for risk adjustment.

CONCLUSION

In a practical application, the proposed method to identify relevant external factors for risk adjustment for comparison of outcome in healthcare proved to be feasible and comprehensive. The method can also be adapted to other quality assurance programmes. However, the cut-off score for clinical relevance needs to be individually assessed when applying the proposed method to other indications or indicators.

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.

Longitudinal change of refraction over at least 5 years in 15,000 patients

BACKGROUND

To report the natural, longitudinal history of shifts in refractive errors in different age groups in a large western European cohort over at least 5 years in the same patients.

METHODS

The electronic database of a large regional clinic containing 225,000 patients was searched for records of patients with a follow-up of at least 5 years, excluding all patients who had received any surgical interventions in any eye. This search retrieved 15,799 patients aged 3 months to 79 years (median 37.8 years) with refractive follow up of at least 5 years (mean 8.8 years) and no surgical interventions. Differences in spherical equivalents (sum of sphere +1/2 cylinder) and cylinder between first and last visit in the same patients in only the right eye were calculated, and used as the measure of refractive shift. Subsequently differences in change between the right and left eye were also determined.

RESULTS

Refractions were found to be mostly stable from 25 to 39 years (n = 3,155 right eyes), with 50% of these patients not changing their refraction. In patients aged 20-24 (n = 825 right eyes), only 39% of the refractions remained stable, whereas 49% experienced a myopic shift. In the age group 40-69 years (n = 6,694), 40-45% remained stable, with an increase in hyperopic shifts. Eighty-five percent of all patients had bilateral symmetric shifts, and 61% showed stable cylindrical values.

CONCLUSIONS

This report documents clinical relevant changes in spherical equivalents in all age groups within 5 to 10 years in the largest examined European cohort. Refractive surgery patients in particular should be selected accordingly, and be informed about the physiological changes which might still occur during their lifetime.

Determination of valid benchmarks for outcome indicators in cataract surgery: a multicenter, prospective cohort trial

OBJECTIVE

To evaluate a systematic approach to derive valid benchmarks for 2 outcome indicators intended to ascertain quality in cataract surgery and to propose benchmark levels drawn from the study results.

DESIGN

Prospective, multicenter cohort trial.

PARTICIPANTS

A total of 1685 patients (206-239 eyes per trial site) were recruited consecutively at 7 study sites. The patients featured age-related cataracts and were undergoing unilateral cataract surgery in the period between January 2007 and August 2008.

METHODS

Only patients with uncomplicated age-related cataracts were included. Cataract surgery was performed by phacoemulsification. The SN60AT (Alcon, Inc., Fort Worth, TX) intraocular lens (IOL) was used as a study lens. The IOL power was calculated using the SRK-T formula with a standardized A constant. Biometry was performed with the IOL Master (Carl Zeiss Meditex, Jena, Germany). Only highly experienced senior surgeons were involved.

MAIN OUTCOME MEASURES

The outcome indicators 1 month and 3 months after surgery were the respective achievement of: (1) maximum absolute deviation of 0.5 diopter (D) between target refraction and postoperative spherical equivalent (primary end point, refractive accuracy); (2) best-corrected visual acuity of at least 0.8 (secondary end point, visual acuity outcome).

RESULTS

In the pooled data, maximum absolute deviation of ± 0.5 D from target refraction was achieved in 80% (95% confidence interval, 78%-82%) of cases. Visual acuity of 0.8 or more was reached in 87% (95% confidence interval, 80%-93%) of cases. The results from the trial centers differed significantly in the outcomes of the primary and secondary end points (P<0.001).

CONCLUSIONS

The study quantified benchmark levels for 2 outcome indicators in a standardized cataract surgery procedure. External confounding factors such as the comorbidity of patients, which cannot be influenced by the surgeon, were excluded. The derived benchmarks selectively illustrate the quality of the surgery and are superior to success rates published in the literature from unspecific data collections. This method is more suited for improving outcome quality by benchmarking. General methodologic problems are discussed, leading to recommendations for future study designs.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Pathological examination of an explanted phakic posterior chamber intraocular lens

PURPOSE

To report the clinicopathological correlation of an explanted phakic posterior chamber intraocular lens (PPC IOL) and to study the conformation of this lens implanted into human eyes obtained postmortem.

SETTING

Center for Research on Ocular Therapeutics and Biodevices, Department of Ophthalmology, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA.

METHODS

Three silicone PPC IOLs were explanted. One lens, explanted from a 38-year-old woman with complicated cataract, was submitted for pathological analysis. In addition to gross and scanning electron microscopy (SEM), the lens was studied after experimental implantation in human eyes obtained postmortem using frontal, posterior, and side-view techniques.

RESULTS

Although gross and SEM showed that the IOL was well polished, examination of the lens in human cadaver eyes showed it was oversized and poorly fixated. It was relatively bulky in its anterior-posterior dimension and revealed evidence of significant contact with the iris and crystalline lens.

CONCLUSIONS

This study illustrates many pitfalls to be avoided in the design of a plate PPC IOL. The lens in this report was too large, and instead of ciliary sulcus fixation, it showed poor fixation through the zonules onto the posterior face of the pars plicata. Present and future PPC IOLs should be submitted for similar preclinical studies to clarify the type and site of fixation.