The relation of volume with outcome in phacoemulsification surgery

Impact of a handpiece with a built-in fluidics pressure sensor on phacoemulsification: a multicentre prospective comparative study

OBJECTIVE

We assessed whether the immediate pressure adjustments provided by a phacoemulsification handpiece with a built-in pressure sensor (Active Sentry, AS) could decrease the amount of energy delivered in the eye during cataract surgery.

METHODS AND ANALYSIS

The Study of Active Sentry in Cataract Surgery was a multicentre prospective clinical trial. The Centurion system (Alcon Labs) was used and we compared phacoemulsifications performed with the AS handpiece with procedures using a sensor placed in the phacoemulsifier (non-AS). The primary outcome measure was the cumulative dissipated energy (CDE) used during the procedures. The secondary outcome measures were the total, longitudinal and torsional ultrasound (US) times, the duration of the surgery and the amount of fluid used during the surgeries.

RESULTS

The study analysed 1432 (800 AS and 632 non-AS) procedures. The mean patient age was 72.4±10.0 years. The median CDE was respectively 6.3 (IQR 3.5-9.9) and 6.7 (IQR 4.5-11.5) with and without AS (p=0.0001). The median US time was, respectively, 48.0 s (IQR 34.0-68.0) and 55.0 s (IQR 38.0-80.0) with and without AS (p<0.0001). Torsional and longitudinal US times were reduced with AS. The median duration of the procedure was, respectively, 9.0 min (IQR 7.0-12.0) and 10.0 min (IQR 7.0-13.0) (p=0.0002) with and without AS. The median balanced salt solution volume used was 52.0 cm3 (IQR 41.0-72.0) and 57.0 cm3 (IQR 42.0-81.0) with and without AS (p=0.0018).

CONCLUSION

The phacoemulsifications performed with a pressure sensor built in the handpiece delivered less energy in the eye and were shorter.

TRIAL REGISTRATION NUMBER

NCT04732351.

When should cataract surgeons seek assistance from experienced colleagues?

PURPOSE

To assess which cases should be assorted exclusively to high-volume surgeons and identify when should a cataract surgeon seek assistance from a senior colleague.

METHODS

The medical records of 2853 patients with age-related cataract were reviewed. Preoperative risk factors were documented for each case, and they were divided into surgeons who had more (> 400 surgeries/year) or less experience (< 400 surgeries/year). Ophthalmology residents were excluded from this review. The cases that involved posterior capsule rupture, dropped nucleus, zonular dehiscence and anterior capsular tear with or without vitreous loss were defined as "complicated".

RESULTS

From the 3247 cataract extraction surgeries that were reviewed, we were unable to identify any statistically significant difference in the complication rates between the two surgeon groups. In the stepwise regression analysis, both groups supported advanced age (> 85) and mature cataracts with up to fourfold odds ratios (OR). Low-volume surgeons had a fivefold OR in the presence of phacodonesis and a fourfold OR in the case of posterior polar cataract. Finally, the low- and high-volume groups had their highest complication rates in the cumulative four and five risk factors, respectively.

CONCLUSION

In the presence of advanced age, mature cataracts, phacodonesis and posterior polar cataract, the complication rates appear to be higher for the less experienced surgeons. Meticulous preoperative assessment with detailed documentation of each patient's risk factors can result in fewer complications. The medical complexity of each case can be used as indicator of whether a more experienced surgeon should perform the surgery or not.

Preoperative Vision and Surgeon Volume as Predictors of Visual Outcomes after Cataract Surgery

PURPOSE

To evaluate the relationship between preoperative vision and surgeon volume with visual outcomes after cataract surgery.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Patients aged ≥18 years old enrolled in the Kaiser Permanente Southern California Health Plan who underwent cataract surgery by nontrainee surgeons.

METHODS

Patients who underwent cataract surgery between January 1, 2013 and December 31, 2015, were included. A multivariate analysis using Generalized Additive Mixed Models was performed to determine the relationship between surgeon volume and postoperative visual acuity after controlling for patient age, preoperative visual acuity, history of diabetes, and history of diabetic retinopathy. Modeling was done for the relationship between preoperative vision and visual outcomes while controlling for surgeon volume, patient age, history of diabetes, and history of diabetic retinopathy.

MAIN OUTCOME MEASURE

Absolute letter change and percentage of patients to achieve ≥5 Early Treatment Diabetic Retinopathy Study (ETDRS) letter gain postoperatively.

RESULTS

There were 103 920 cataract surgeries performed by 136 surgeons included in this analysis. Patients whose surgeons performed <91.0 surgeries/year (95% confidence interval [CI], 61.1-139; P < 0.05) gained fewer letters postoperatively than the overall average, whereas those whose surgeons performed >91 but <227 surgeries/year (95% CI, 169-∞; P < 0.05) gained more letters than average. Although statistically significant, the difference between the lowest and highest performing surgeons was approximately 1.25 letters. Surgeons who performed <110 surgeries/year (95% CI, 81.7-149; P < 0.05) had fewer patients who gained ≥5 letters. Surgeons who performed >110 but <293 surgeries/year (95% CI, 232-∞; P < 0.05) were approximately 15% more likely to have patients who gained ≥5 letters. Patients with preoperative vision <74.7 letters (95% CI, 74.7-74.8; P < 0.05) and <75.8 letters (95% CI, 75.8-75.9; P < 0.05) gained more letters and were more likely to gain ≥5 letters postoperatively, respectively.

CONCLUSIONS

Patients whose vision is approximately 20/32 or worse are more likely to have significant visual gains after cataract surgery. Although statistically significant differences exist in postoperative vision based on surgeon volume, these do not appear to be clinically meaningful. Overall, visual outcomes are functionally comparable across a wide range of surgeon volumes.

Posterior capsular complication rates with femtosecond laser-assisted cataract surgery: a consecutive comparative cohort and literature review

Purpose

The aim of the study was to determine whether femtosecond-assisted laser cataract surgery (FLACS) reduces the posterior capsular complication (PCC) rate compared to manual cataract surgery when performed by an experienced surgeon.

Patients and methods

We reviewed 2,021 consecutive FLACS procedures between 1 June 2012 and 30 August 2017. All cases of posterior capsular rupture (PCR) with or without vitreous prolapse or zonular dialysis (ZD) that prevented an in-the-bag placement of the intraocular lens were included. Risk factors were noted and outcomes documented.

Results

Six eyes of 2,021 (0.3%) who underwent FLACS had either a PCR or ZD. One eye (0.25%) of 403 eyes that had manual cataract surgery had a PCR. There was no significant difference in outcomes. Risk factors included advanced age, dense nuclei, pseudoexfoliation and small pupil. Only a single case in the FLACS series may have been directly attributed to the FLACS procedure.

Conclusion

This study provides evidence that there is no significant difference in the PCC rate between FLACS and manual cataract surgery in the hand of an experienced surgeon who performs >350 cases annually. This low rate of complications may be achieved by less experienced surgeons adopting FLACS.

Postcataract endophthalmitis prophylaxis using irrigation, incision hydration, and eye pressurization with vancomycin

PURPOSE

This study aimed to determine whether switching from balanced salt solution (BSS) to vancomycin 20 g/mL BSS for incision hydration and eye pressurization reduces the rate of postcataract endophthalmitis.

METHODS

This was a patient safety/quality improvement project, including all patients undergoing cataract surgery at the Kaiser Permanente Colorado Ophthalmology Department from January 2002 to December 2014. Throughout the study, patients received vancomycin 20 μg/mL in the irrigating solution. During the baseline period from 2002 to 2005, surgeons pressurized eyes and hydrated incisions with plain BSS. During the intervention period from 2006 through 2014, surgeons switched from BSS to the vancomycin/BSS irrigating solution for eye pressurization and incision hydration.

RESULTS

A total of 57,263 cataract operations were performed by 24 surgeons at seven surgical centers: 12,400 in the baseline period and 44,863 in the intervention period. The rate of post-cataract endophthalmitis declined significantly from 5/12,400 (rate: 0.4/1,000) in the baseline period to 1/44,863 (rate: 0.022/1,000) during the intervention period (odds ratio [OR]: 18.1, 95% confidence interval [CI]: 2.11-154.9; χ (2)=13.5, P=0.00024). Accounting for an estimated 2.05-fold risk reduction due to confounding variables, the risk reduction attributed to the intervention remained significant: (adjusted OR: 8.78, 95% CI: 1.73-44.5; χ (2)=10.06, P=0.0015). Since 2009, we have not experienced any cases of postcataract endophthalmitis after 32,753 operations.

CONCLUSION

We experienced a significant reduction in postcataract endophthalmitis when we switched from BSS to the vancomycin/BSS irrigating solution for incision hydration and eye pressurization. The pharmacokinetics profile indicates that this switch was important for effective prophylaxis.

Complication rate of posterior capsule rupture with vitreous loss during phacoemulsification at a Hawaiian cataract surgical center: a clinical audit

PURPOSE

To compare the complication rate of posterior capsule rupture (PCR) with vitreous loss during phacoemulsification at an ambulatory surgical center with published results as a clinical audit for quality control.

METHODS

A retrospective chart review of 3,339 consecutive patients who underwent routine phacoemulsification by four experienced private practice surgeons from January 1, 2011 to June 30, 2012 at The Surgical Suites, Honolulu, HI, USA. All cases with PCR and vitreous loss were identified and selected for the study. Risk factors of this complication were further examined. Data were sent to John H Stroger Jr Hospital of Cook County, Division of Ophthalmology, for literature review, analysis, and write-up.

RESULTS

Twenty-three of the 3,339 cases incurred PCR and vitreous loss during phacoemulsification, for an incidence rate of 0.68%. Miosis, shallow chamber, restlessness, pseudoexfoliation syndrome, floppy iris syndrome, and zonulopathy were the main causes. In addition, surgeon volume (number of cases) was inversely correlated with PCR.

CONCLUSION

The rate of PCR with vitreous loss during phacoemulsification in this study may be lower than other published results done at academic centers. However, there was no compatible study available for comparison, as existing studies performed at academic centers included resident cases. This study identified risk factors for PCR/vitreous loss both preoperatively and postoperatively that may assist in application of preventive measures to decrease rates of PCR/vitreous loss.

The outcome of trachomatous trichiasis surgery in Ethiopia: risk factors for recurrence

BACKGROUND

Over 1.2 million people are blind from trachomatous trichiasis (TT). Lid rotation surgery is the mainstay of treatment, but recurrence rates can be high. We investigated the outcomes (recurrence rates and other complications) of posterior lamellar tarsal rotation (PLTR) surgery, one of the two most widely practised TT procedures in endemic settings.

METHODOLOGY/PRINCIPAL FINDINGS

We conducted a two-year follow-up study of 1300 participants who had PLTR surgery, conducted by one of five TT nurse surgeons. None had previously undergone TT surgery. All participants received a detailed trachoma eye examination at baseline and 6, 12, 18 and 24 months post-operatively. The study investigated the recurrence rates, other complications and factors associated with recurrence. Recurrence occurred in 207/635 (32.6%) and 108/641 (16.9%) of participants with pre-operative major (>5 trichiatic lashes) and minor (<5 lashes) TT respectively. Of the 315 recurrences, 42/315 (3.3% overall) had >5 lashes (major recurrence). Recurrence was greatest in the first six months after surgery: 172 cases (55%) occurring in this period. Recurrence was associated with major TT pre-operatively (OR 2.39, 95% CI 1.83-3.11), pre-operative entropic lashes compared to misdirected/metaplastic lashes (OR 1.99, 95% CI 1.23-3.20), age over 40 years (OR 1.59, 95% CI 1.14-2.20) and specific surgeons (surgeon recurrence risk range: 18%-53%). Granuloma occurred in 69 (5.7%) and notching in 156 (13.0%).

CONCLUSIONS/SIGNIFICANCE

Risk of recurrence is high despite high volume, highly trained surgeons. However, the vast majority are minor recurrences, which may not have significant corneal or visual consequences. Inter-surgeon variation in recurrence is concerning; surgical technique, training and immediate post-operative lid position require further investigation.

Surgical outcomes in phacoemulsification after application of a risk stratification system

Background

The purpose of this study was to determine whether application of a risk stratification system during preoperative assessment of cataract patients and subsequent allocation of patients to surgeons with matching experience may reduce intraoperative complications.

Methods

Nine hundred and fifty-three consecutive patients (1109 eyes) undergoing phacoemulsification cataract surgery were assigned to two groups, ie, group A (n = 498 patients, 578 eyes) and group B (n = 455 patients, 531 eyes). Patients from group A were allocated to surgeons with varying experience with only a rough estimate of the complexity of their surgery. Patients from group B were assigned to three risk groups (no added risk, low risk, and moderate-high risk) according to risk factors established during their preoperative assessment and were respectively allocated to resident surgeons, low-volume surgeons, or high-volume surgeons. Data were collected and entered into a computerized database. The intraoperative complication rate was calculated for each group.

Results

The intraoperative complication rate was significantly lower in group B than in group A (group A, 5.88%; group B, 3.2%; P < 0.05). Patients from group B with no added risk and allocated to resident surgeons had a significantly lower rate of intraoperative complications than those from group A allocated to resident surgeons (group A, 7.2%; group B, 3.08%; P < 0.05).

Conclusion

Our study demonstrates that allocation of cataract patients to surgeons matched for experience according to a uniform and reliable preoperative assessment of their risk of complications allows for better surgical outcomes, especially for resident surgeons.

Serious adverse events after cataract surgery

PURPOSE OF REVIEW

Over the past several decades, there have been many advances in the equipment, instrumentation and techniques of performing cataract surgery. This review will address the impact of these advances on the safety profile of cataract surgery.

RECENT FINDINGS

Recent studies have demonstrated a decline in the risk of serious postoperative adverse events (endophthalmitis, suprachoroidal hemorrhage, retinal detachment) following cataract surgery. Factors that increase the risk of serious complications from cataract surgery include patient-related factors (male sex, concomitant diabetic retinopathy, same day cataract surgery combined with another intraocular surgery, tamsulosin use) and surgeon-related factors (low surgical volume, limited experience, operating on patients who are most prone to adverse events).

SUMMARY

Cataract surgery continues to be a very well tolerated surgical procedure with few patients experiencing serious sight-threatening adverse events. Studies in the literature have helped surgeons identify patients who are at high risk for surgical complications and develop strategies to limit surgical complications when operating on these patients. As multifocal intraocular lenses, femtosecond laser technology, and other surgical innovations continue to gain popularity, it will be interesting in the coming years to determine whether there will be a continued reduction in complications of cataract surgery.

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.

Six year Trend in Cataract Surgical Techniques in Iran

Purpose

To determine the cataract surgery techniques performed in Iran from 2000 to 2005.

Materials and Methods

This study was part of the Iranian Cataract Surgery Survey (ICSS) which was a retrospective cross-sectional study. All major ocular surgery units and 10% of randomly selected minor units throughout Iran were included. Excluding the 2 week Iranian New Year holiday, 1 week per season between 2000 and 2005 (a total of 24 weeks) was selected for each center, and data on all cataract surgeries performed during these weeks were collected by reviewing patient records. The ANOVA repeated measure test was performed to determine longitudinal changes with a P<0.05 denoting statistical significance.

Results

Phacoemulsification with intraocular lens (IOL) implantation has become the surgical method of choice in Iran, increasing from less than 7% in 2000 to 57% in 2005 (P<0.0001). Extracapsular cataract extraction showed a reverse trend compared to phacoemulsification, decreasing from greater than 91% in 2000 to 41% in 2005 (P<0.0001). Intracapsular cataract extraction and lensectomy were rarely performed without significant changes over time (P>0.05).

Conclusion

Phacoemulsification with IOL implantation has become the preferred cataract surgery method in Iran during recent years.

Role of clear lens extraction in adult angle closure disease: a review

Treatments for angle closure include eye drops, laser procedures, trabeculectomy and other drainage procedures, and now lens extraction. A 2006 Cochrane review of the role of lens extraction in angle closure disease concluded that there was no published evidence supporting the efficacy of lens extraction in chronic primary angle closure glaucoma. More recent randomized controlled trials have suggested greater promise. We wish to address the rationale, evidence base and philosophy for lens extraction - especially clear lens extraction - in preventing vision loss from glaucoma in angle closure disease.

Prevalence and predictors of ocular complications associated with cataract surgery in United States veterans

PURPOSE

To investigate the prevalence and predictors of intraoperative and 90-day postoperative ocular complications associated with cataract surgery performed in the United States Veterans Health Administration (VHA) system.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Forty-five thousand eighty-two veterans who underwent cataract surgery in the VHA.

METHODS

The National Patient Care Database was used to identify all VHA patients who underwent outpatient extracapsular cataract surgery and who underwent only 1 cataract surgery within 90 days of the index surgery between October 1, 2005, and September 30, 2007. Data collected include demographics, preoperative systemic and ocular comorbidities, intraoperative complications, and 90-day postoperative complications. Adjusted odds ratios (ORs) of factors predictive of complications were calculated using logistic regression modeling.

MAIN OUTCOME MEASURES

Intraoperative and postoperative ocular complications within 90 days of cataract surgery.

RESULTS

During the study period, 53786 veterans underwent cataract surgery; 45082 met inclusion criteria. Common preoperative systemic and ocular comorbidities included diabetes mellitus (40.6%), chronic pulmonary disease (21.2%), age-related macular degeneration (14.4%), and diabetes with ophthalmic manifestations (14.0%). The most common ocular complications were posterior capsular tear, anterior vitrectomy, or both during surgery (3.5%) and posterior capsular opacification after surgery (4.2%). Predictors of complications included: black race (OR, 1.38; 95% confidence interval [CI], 1.28-1.50), divorced status (OR, 1.10; 95% CI, 1.03-1.18), never married (OR, 1.26; 95% CI, 1.14-1.38), diabetes with ophthalmic manifestations (OR, 1.33; 95% CI, 1.23-1.43), traumatic cataract (OR, 1.80; 95% CI, 1.40-2.31), previous ocular surgery (OR, 1.29; 95% CI, 1.02-1.63), and older age.

CONCLUSIONS

In a cohort of United States veterans with a high preoperative disease burden, selected demographic factors and ocular comorbidities were associated with greater risks of cataract surgery complications. Further large-scale studies are warranted to investigate cataract surgery outcomes for non-VHA United States patient populations.

Orthopaedic surgeons prefer to participate in expertise-based randomized trials

Empiric data and theoretical arguments suggest an alternative randomized clinical trial (RCT) design, called expertise-based RCT, has enhanced validity, applicability, and ethical integrity compared with conventional RCT. Little is known, however, about whether physicians will participate in an expertise-based RCT. In a cross-sectional survey of Canadian orthopaedic surgeons, we evaluated preference for and willingness to participate in an expertise-based versus a conventional RCT if given the opportunity to participate in a trial investigating the effectiveness of high tibial osteotomy versus unicompartmental knee arthroplasty. Using an electronic survey ((c)2005 SurveyMonkey.com), we invited all 767 members of the Canadian Orthopaedic Association (2005) to participate; 276 surgeons completed the questionnaire (37.5% response rate). One hundred two surgeons (53.4%) were willing to participate in an expertise-based RCT compared with 35 surgeons (18.3%) willing to participate in a conventional RCT. Ninety-seven surgeons (52.4%) strongly or moderately preferred the expertise-based design compared with 25 (13.5%) who preferred the conventional design. For the clinical example we presented, the majority of Canadian orthopaedic surgeons were willing to participate in and preferred the expertise-based design. The expertise-based randomized clinical trial design may overcome some of the barriers to conducting clinical trials in orthopaedic surgery and improve the validity of their conclusions.

Vitreous loss during cataract surgery: prevention and optimal management

Vitreous loss during cataract surgery is associated with a poor visual outcome. Experienced surgeons and those performing a high volume of cataract operations have lower rates of vitreous loss. Risk stratification systems, which allow prediction of intraoperative complications from preoperative criteria exist, so that less experienced surgeons can avoid higher risk cases. The management of vitreous loss includes counselling patients before surgery of the potential risks and complications. When vitreous loss occurs, it is important for the surgeon to avoid actions [corrected] which increase the chance of disaster for the eye. These include phacoemulsification in the presence of vitreous and attempts to recover dropped lens fragments from the posterior segment without vitrectomy. There are advantages in performing an anterior vitrectomy by the pars plana route rather than through the anterior chamber and this approach is facilitated by sutureless 23-gauge instruments. Dislocation of lens nuclear fragments into the vitreous is associated with a high incidence of retinal detachment as well as secondary glaucoma and cystoid macular oedema. Early involvement of a retinal surgeon in the management of these eyes is recommended.

Surgeon Volumes and Selected Patient Outcomes in Cataract Surgery

OBJECTIVE

To study the association of annual surgeon volume of cataract procedures with the risk of postoperative adverse events.

DESIGN

We used population-based administrative health records to conduct a retrospective cohort study from 2001 through 2003.

PARTICIPANTS

The number of surgeons who performed more than 50 cataract surgeries annually ranged from 231 to 243 over the 3 years. There were 284 797 cataract surgeries in patients older than 20 years performed at 70 hospitals or eye surgery centers in the province of Ontario, Canada.

METHODS

We calculated cataract surgery volume for each surgeon and tested for the presence of a volume-outcome association. We used generalized estimating equations to account for the effect of clustering of patients according to individual surgeons and to adjust estimates for the potential confounding effects of patient age and gender.

MAIN OUTCOME MEASURES

We used a composite outcome of postoperative adverse events from cataract surgery that included billing claims for vitrectomy, vitreous aspiration or injection of medication, vitreous air or fluid exchange, and dislocated lens extraction performed by any ophthalmologist between 1 and 14 days after cataract surgery. These procedures are surrogate markers for the outcomes of retinal detachment, lost lens or lens fragment, and suspected endophthalmitis.

RESULTS

In each year, fewer than 1 in 200 patients experienced an adverse event (range, 0.33%-0.41%). Surgeons performing 50 to 250 cataract surgeries per year had an adverse event rate of 0.8%. Surgeons performing 251 to 500 cataract surgeries per year had an adverse event rate of 0.4% and an adjusted odds ratio of postoperative adverse events of 0.52 (95% confidence interval [CI], 0.39-0.69) compared with surgeons performing 50 to 250 procedures per year. Surgeons performing 501 to 1000 cataract surgeries per year had an adverse event rate of 0.2% and an adjusted odds ratio of 0.31 (95% CI, 0.22-0.43), and surgeons performing more than 1000 cataract surgeries per year had an adverse event rate of 0.1% and an adjusted odds ratio of 0.14 (95% CI, 0.09-0.23).

CONCLUSIONS

Selected adverse event rates for surgeons performing more than 50 cataract surgeries per year are low. There is a volume-outcomes relationship for cataract surgery, and this relationship persists even for very high-volume surgeons.

The relation of volume and outcome in trabeculectomy

BACKGROUND/AIMS

Higher case volume has been associated with improved outcomes for a number of procedures. This study was designed to investigate whether this relationship existed for trabeculectomy.

METHODS

The study was retrospective and conducted at an ophthalmic unit in the UK. All patients who had unenhanced trabeculectomy between 1996 and 2000 were identified. From their notes, the surgeon who performed the trabeculectomy was ascertained as were any unplanned interventions (eg conjunctival suturing, anterior chamber reformation, repeated attendances) within the first month of surgery.

RESULTS

Two hundred and eleven trabeculectomies were performed over the study period. Twenty nine had unplanned interventions within the first postoperative month. Analysis of the data indicated that surgeons who performed less than eight operations per year had more complications than those who performed more than 10 per annum. This difference was only significant (chi(2)=4.0, P=0.045) when the data were aggregated. When separated per year, although not significant, the complication rate of the lower volume group was always higher than the group performing more than 10 per year.

CONCLUSIONS

The results suggest that trabeculectomy can be added to the list of procedures in which larger case volume is associated with fewer early complications and potentially a better outcome. The findings, if replicated, tend to strengthen the argument for subspecialisation in glaucoma with its implications for training and revalidation.

Do variations in the theatre team have an impact on the incidence of complications?

Background

To examine whether variations in non-medical personnel influence the incidence of complications in a cataract theatre.

Methods

A retrospective Case-Control study was undertaken in a single-site, designated cataract theatre. Staffing variations within theatre were examined and the incidence of cataract complications was assessed.

Results

100 complicated lists and 200 uncomplicated control lists were chosen. At least 7 nurses were present for every list. Mean experience of the nurses was 6.4 years for case lists and 6.5 years for control lists. Average scrub nurse experience in years was 7.6 years for complicated lists and 8.0 years for controls. 26% of complicated case lists were affected by unplanned leave and 17% in control lists. Odds ratio 1.7 (1.0 to 3.1) 95% CI.

Conclusion

Unplanned leave can have a detrimental effect on the operating list. The impact of this may be modifiable with careful planning.

The role of case mix in the relation of volume and outcome in phacoemulsification

BACKGROUND/AIM

The authors previously demonstrated a decrease in complication rate with an increase in volume of cases performed by a surgeon. All studies of volume and outcome are potentially hampered by the issue of case mix, in that some lower volume surgeons may in fact do fewer cases because they have more complex patients. This study was designed to assess the influence of case mix on the volume-outcome relation in phacoemulsification surgery that had previously been demonstrated.

METHODS

This study took place wholly in Sunderland Eye Infirmary. 667 cases from between 1996 and 2001 were randomly selected from the operative lists of the six surgeons involved in a previous study. The case complexity was assessed using a potential difficulty score (PDS) devised from preoperative data predictive of potential surgical difficulty. The PDS was validated by a retrospective analysis of a sample of 100 cases.

RESULTS

528 complete sets of notes were retrieved. The overall PDS scores ranged from 1 to 6. There was a difference between the proportions of patients with each PDS value (p=0.015) in the two groups, which suggested that the low volume surgeons were doing potentially more difficult cases. The median PDS for each volume group were the same (=1.0). Retrospective validation analysis of the PDS score revealed higher mean and median values in complicated cases compared to uncomplicated cases.

CONCLUSION

This follow up study re-emphasises the importance of case mix adjustment in comparative assessment of healthcare quality. These results may explain in part the trend previously demonstrated of lower complication rates for higher volume surgeons.

Association of hospital and surgeon operation volume with the incidence of postoperative endophthalmitis: Taiwan experience

PURPOSE

To determine the association between hospital and surgeon volume with the incidence of postoperative endophthalmitis.

METHODS

A prospective cohort study was conducted to analyse the national health insurance claims data of those patients receiving cataract surgery in 2000 in Taiwan. A total of 108,705 patients who received cataract surgery by 1004 surgeons at 494 hospitals were followed to the end of 2002. Stepwise Cox regression was used to analyse the effects of hospital and surgeon volume of cataract surgery on postoperative endophthalmitis after adjustment for patient's age, gender, education, ophthalmic comorbidities, general comorbidities, and surgical factors including operative methods, different types of intraocular lenses, and surgeon's age.

RESULTS

The 2-year incidence of postoperative endophthalmitis at high-volume hospitals (0.90%) was lower than low-volume hospitals (1.16%). The incidence of postoperative endophthalmitis by high-volume surgeons (0.59%) was lower than those by middle-high-volume (0.73%), middle-low-volume (0.80%), or low-volume surgeons (1.16%). After controlling for case mix, the risk of postoperative endophthalmitis of the low-volume hospitals (hazard ratio (HR) = 1.39) was higher than that of the high-volume hospitals. The risk of postoperative endophthalmitis of low-volume surgeons (HR = 1.67) was higher than that of the high-volume surgeons.

CONCLUSIONS

The provider volume (hospital and surgeon volume) is associated with the risk of postoperative endophthalmitis. The patients who receive cataract surgery at low-volume hospitals or by low-volume surgeons have significantly higher risk of postoperative endophthalmitis than at high-volume hospitals or by high-volume surgeons. Provider volume can be considered in further postoperative endophthalmitis study as a risk factor.