Antibiotic Choice for the Prophylaxis of Post-Cataract Extraction Endophthalmitis

Prophylactic Intracameral Antibiotics and Endophthalmitis After Cataract Surgery

Importance

Although the effectiveness of intracameral antibiotics to prevent postoperative endophthalmitis is described, selective use of antibiotics combined with 1% povidone iodine disinfection might be equally effective and could lead to cost reduction and avoidance of unnecessary use of antibiotics.

Objective

To compare the incidence of postoperative endophthalmitis when 1% povidone iodine disinfection is applied in combination with selective intracameral antibiotics with the incidence after routine use of intracameral antibiotics in combination with 5% povidone iodine.

Design, Setting, and Participant

This was a retrospective cohort study using incidence data from the ongoing endophthalmitis register of the Rotterdam Eye Hospital, a specialized hospital providing both secondary and tertiary ophthalmological care, when intracameral antibiotics were used only during cataract procedures with occurrence of a posterior capsular tear in comparison with results from cohorts described in the literature where routine antibiotics were used. All patients who had cataract (phacoemulsification) surgery at the Rotterdam Eye Hospital between 1993 and 2022 were included. No cataract surgical procedures combined with other intraocular procedures were included.

Exposure

Povidone iodine disinfection and intracameral antibiotics during cataract surgery either routinely or only in case of posterior capsular tears.

Main Outcome and Measure

Postoperative endophthalmitis incidence.

Results

Postoperative endophthalmitis incidence after 56 598 cataract (phacoemulsification) surgical procedures in the Rotterdam Eye Hospital between 2016 and 2022 was 0.000 (95% CI, 0.000-0.000). A PubMed literature search until September 2023 with respect to the incidence of postoperative endophthalmitis after routine antibiotic prophylaxis yielded 37 publications with an overall postoperative endophthalmitis incidence of 0.000 (95% CI, 0.000-0.000).

Conclusions and Relevance

No difference was observed between the postoperative endophthalmitis incidence during the last 7 years in the Rotterdam Eye Hospital and the overall postoperative endophthalmitis incidence after routine intracameral antibiotics prophylaxis as described in the literature. Disinfection with 1% povidone iodine in combination with selective antibiotic prophylaxis may be equally effective as routine antibiotic use and 5% povidone iodine.

Prophylactic antibiotics for postcataract surgery endophthalmitis: a systematic review and network meta-analysis of 6.8 million eyes

To reveal optimal antibiotic prophylactic regimen for postoperative endophthalmitis (POE), we conducted systematic review and network meta-analysis. A total of 51 eligible original articles, including two randomized controlled trials, were identified. In total, 4502 POE cases occurred in 6,809,732 eyes (0.066%). Intracameral injection of vancomycin had the best preventive effect (odds ratio [OR] 0.03, 99.6% confidence interval [CI] 0.00-0.53, corrected P-value = 0.006, P-score = 0.945) followed by intracameral injection of cefazoline (OR 0.09, 99.6% CI 0.02-0.42, corrected P-value < 0.001, P-score = 0.821), cefuroxime (OR 0.18, 99.6% CI 0.09-0.35, corrected P-value < 0.001, P-score = 0.660), and moxifloxacin (OR 0.36, 99.6% CI 0.16-0.79, corrected P-value = 0.003, P-score = 0.455). While one randomized controlled trial supported each of intracameral cefuroxime and moxifloxacin, no randomized controlled trial evaluated vancomycin and cefazoline. Sensitivity analysis focusing on the administration route revealed that only intracameral injection (OR 0.19, 99.4% CI 0.12-0.30, corrected P-value < 0.001, P-score = 0.726) significantly decreased the risk of postoperative endophthalmitis. In conclusion, intracameral injection of either vancomycin, cefazoline, cefuroxime, or moxifloxacin prevented POE.

Conjunctival sac bacterial culture of patients using levofloxacin eye drops before cataract surgery: a real-world, retrospective study

Background

The use of antibiotics preoperatively is effective to decrease the incidence of ocular bacterial infections but may lead to high resistance rate, especially on patients with multi-risk clinical factors. This study systematically analyzed real-world data (RWD) of patients to reveal the association between clinical factors and conjunctival sac bacterial load and offer prophylaxis suggestions.

Methods

We retrieved RWD of patients using levofloxacin eye drops (5 mL: 24.4 mg, 4 times a day for 3 days) preoperatively. Retrieved data included information on the conjunctival sac bacterial culture, sex, presence of hypertension and diabetes mellitus (DM), and history of hospital-based surgeries. Data was analyzed using SPSS 24.0.

Results

RWD of 15,415 cases (patients) were retrieved. Among these patients, 5,866 (38.1%) were males and 9,549 (61.9%) females. 5,960 (38.7%) patients had a history of hypertension, and 3,493 (22.7%) patients had a history of DM. 7,555 (49.0%) patients had a history of hospital-based operations. There were 274 (1.8%) positive bacterial cultures. Male patients with hypertension and DM may be at increased risk of having positive bacterial cultures (P < 0.05). Staphylococcus epidermidis (n = 56, 20.4%), Kocuria rosea (n = 37, 13.5%), and Micrococcus luteus (n = 32, 11.7%) were the top 3 isolated strains. Most bacterial strains were resistant to various antibiotics except rifampin, and 82.5% (33 of 40 isolates) of Staphylococcus epidermidis isolates had multidrug antibiotic resistance. Numbers of culture-positive Staphylococcus epidermidis isolates in the male group and non-DM group were greater than those in the female and DM groups, respectively. Micrococcus luteus (n = 11, 8.8%) was found less frequently in non-hypertension group than in hypertension group.

Conclusion

Sex (Male) and the presence of hypertension and DM are risk factors for greater conjunctival sac bacterial loads. We offer a prophylactic suggestion based on the combined use of levofloxacin and rifampin. However, this approach may aggravate risk of multidrug resistance.

Development of topical chitosan/ β-glycerophosphate-based hydrogel loaded with levofloxacin in the treatment of keratitis: An ex-vivo study

Staphylococcus species are responsible for most cases of post-operative endophthalmitis. Topical ocular drug was applied for post-operative infection prevention, but the way of delivery encounters many challenges in terms of patient's compliance, drug efficacy, and drug penetration. We used the levofloxacin-loaded chitosan/gelatin/β-glycerophosphate hydrogel sustained releasing system with good in vitro anti-bacterial efficacy and biocompatibility, which we had previously designed, for ex vivo keratitis model to test the preclinical drug efficacy and to determine drug level in the anterior chamber of the eye. The result showed that the ex-vivo corneal keratitis model with S. aureus infection revealed mild opacity over the central cornea with stromal infiltrate, but without obvious stromal infiltration post levofloxacin-loaded hydrogel treatment after 24 h of infection. Quantification of viable bacteria showed a significant anti-bacterial activity. The histological evidence also showed no visible S. aureus after levofloxacin-loaded hydrogel treatment, with a significant anti-inflammatory effect. We also examined the drug concentration in the aqueous humor 24 h after instilling one drop of the levofloxacin-loaded hydrogel. The concentration achieved to a desired drug level. These results suggested that by the ex-vivo model, levofloxacin-loaded hydrogel can be applied for treatment in post-operative endophthalmitis or keratitis after the ophthalmic surgery.

The effect of postoperative oral antibiotic therapy on the incidence of postoperative endophthalmitis after phacoemulsification surgery in dogs: 368 eyes (1997-2010)

Purpose

To assess the effectiveness of postoperative administration of oral antibiotics at reducing the incidence of endophthalmitis following phacoemulsification cataract extraction in dogs.

Methods

Medical records of the University of Tennessee College of Veterinary Medicine were reviewed for cases having undergone phacoemulsification and divided according to whether or not they had received oral antibiotics postoperatively. Records were then evaluated for a diagnosis of endophthalmitis and incidence rates between the group receiving postoperative oral antibiotics and the group not receiving postoperative oral antibiotics were compared.

Results

A total of 215 patients (368 eyes) were identified by the search. One-hundred twelve patients (197 eyes) were treated with oral antibiotics postoperatively. One-hundred and three patients (171 eyes) were not treated with oral antibiotics postoperatively. Three cases of endophthalmitis were identified, with one in the antibiotic-treated group and two in the non-antibiotic treated group (P > 0.05, Fisher’s exact test).

Conclusions

The overall incidence of endophthalmitis at the University of Tennessee from 1997–2010 was 0.82%. The rate of post-phacoemulsification endophthalmitis was unaffected by the postoperative administration of oral antibiotics.

Macular and choroidal thickness after intracameral moxifloxacin for prevention of postcataract endophthalmitis

PURPOSE

To determine any changes in macular or choroidal thickness associated with the use of intracameral moxifloxacin as postcataract endophthalmitis prophylaxis.

SETTING

University of Campinas, Campinas, São Paulo, Brazil.

DESIGN

Prospective, randomized, partially masked, single-site clinical trial.

METHODS

Phacoemulsification surgery patients in the experimental group (Group A) received a 0.03 mL intracameral injection of undiluted moxifloxacin from a sealed bottle immediately after phacoemulsification surgery (150 μg in 0.03 mL-Vigamox solution), whereas the control group (Group B) did not. Investigators evaluated in masked fashion macular and choroidal thickness using spectral-domain optical coherence tomography preoperatively and postoperatively.

RESULTS

A total of 93 patients were included (48 in Group A and 45 in Group B). Baseline parameters were similar between the groups. Either of the 2 parameters assessed differed statistically between the groups or preoperatively vs postoperatively. On postoperative day 30, central macular thickness was 8.85 ± 14.78 μm in Group A and 10.26 ± 22.44 μm in Group B (P = .7232); choroidal thickness as measured by enhanced depth imaging (EDI) was 1.45 ± 16.13 μm in Group A and 3.74 ± 16.15 in Group B (P = .5017). On postoperative day 60, central macular thickness was 19.53 ± 39.28 μm in Group A and 17.14 ± 53.68 μm in Group B (P = .8363); EDI was 5.08 ± 21.96 μm in Group A and 5.24 ± 15.8 in Group B (P = .9752).

CONCLUSIONS

The application of intracameral injection of 0.03 mL of undiluted 0.5% moxifloxacin during phacoemulsification surgery as endophthalmitis prophylaxis induced no changes in macular or choroidal thickness.

Quantifying the cost of single-use minims and multidose bottles for eye drops in routine ophthalmic practice: a multicentre study

OBJECTIVE

To compare costs between two different eye drop delivery modalities: multidose bottles and single-use minims.

DESIGN

Retrospective cohort study.

METHODS

Monthly dilating eye drop costs and quantities (tropicamide 1%, phenylephrine 2.5%, cyclopentolate 1%) were studied over a 2-year period between April 2013 and March 2015 at 2 tertiary ophthalmic centres (Royal Alexandra Hospital [RAH, Edmonton] and Rockyview General Hospital [RGH, Calgary]). In April 2014, RAH switched its dilating eye drop practice from predominantly multidose bottles to single-use minims, whereas RGH continued using predominantly multidose bottles. Eye drop volume and total and per-patient eye drop costs were quantified at RAH before switching (pre-intervention) and after (post-intervention) using an interrupted time-series analysis with RGH as a control. A counterfactual analysis was also performed. Significance was obtained using independent t-testing.

RESULTS

After switching to single-use minims, RAH experienced changes in the following: an increase in single-use minims as a proportion of total eye drop utilization (from 5.6% to 89.1%; p = 0.001), an increase in total eye drop cost by $2117 per month (95% confidence interval [CI], $1354-$2880; p < 0.001), an increase in per-patient costs by $984 per 1000 patients per month (95% CI, $674-$1293). Contrastingly, RGH did not experience similar changes. Ultimately, the cost of switching to single-use minims was $22 481 (95% CI, $7830-$31 336) over a 12-month period.

CONCLUSIONS

If safe eye drop practices are enforced via proper protocols, the use of multidose bottles may be a more cost-effective option than single-use minims for routine clinical practice.

Incremental effect of topical and oral moxifloxacin administration with surgical intracameral prophylaxis

OBJECTIVE

To determine how supplemental perioperative topical or oral moxifloxacin administration impacts anterior chamber (AC) antibiotic concentrations beyond those achieved by intracameral (IC) administration alone for postoperative endophthalmitis (POE) prophylaxis.

DESIGN

Mathematical modeling.

METHODS

The mathematical model developed by Arshinoff, Modabber, and Felfeli was adapted to calculate all reported data. A literature review of pharmacokinetic data for topical and oral moxifloxacin was used to inform the expansion of the model.

RESULTS

Our previously constructed IC model yields a dose of moxifloxacin in the AC sufficient to confer bactericidal coverage against the most common POE pathogen, methicillin-sensitive Staphylococcus aureus (MSSA), for ∼40 hours postoperatively. Topical 0.5% moxifloxacin eye drops alone, administered every 4 or 6 hours, achieve an AC concentration just above or at the mutant prevention concentration (MPC) for MSSA, respectively, whereas 8-hour dosing produces levels generally below the MPC. Combining topical moxifloxacin with IC increases the AC concentration above IC alone only after 20 or more hours and maintains the AC concentration at, or just below, the MPC for MSSA for as long as the drops are continued. Combined perioperative oral moxifloxacin with IC increases AC levels over IC alone only after 16 hours and maintains the AC concentration above the MPC for MSSA for an additional 5 hours, owing to the systemic reservoir.

CONCLUSIONS

The addition of topical or oral moxifloxacin supplemental to IC can extend the duration of bactericidal coverage for the most common, but not the most resistant POE-causing pathogens.

Postoperative Endophthalmitis and Toxic Anterior Segment Syndrome Prophylaxis: 2020 Update

Improved surgical techniques have led to an increase in the number of outpatient ophthalmic procedures. In spite of decreased surgical times and overall improved outcomes, endophthalmitis remains one of the most severe complications of ophthalmic surgery. Although there are well known risk factors for postoperative endophthalmitis, some prophylaxis strategies remain controversial. A category of noninfectious postoperative inflammation, known as toxic anterior segment syndrome (TASS), is a rare but important complication of cataract surgery. While several worldwide outbreaks of TASS have occurred, it is challenging to identify an etiology in order to reduce the risk of further cases. Endophthalmitis and TASS cannot be prevented completely, but their rates may be decreased through risk reduction strategies supported by peer-reviewed evidence. This review highlights the current evidence in the prevention strategies for postoperative endophthalmitis and TASS.

The Anterior Chamber Injection of Moxifloxacin Injection to Prevent Endophthalmitis after Cataract Surgery: A Meta-analysis

Purpose

A meta-analysis was performed to compare the efficacy of an anterior chamber injection of moxifloxacin in the prevention of endophthalmitis after cataract surgery.

Methods

A computer-based search of PubMed, Embase, the Cochrane Library, and the Clinical Trial database for articles related to anterior intraventricular injection of moxifloxacin for the prevention of endophthalmitis after cataract surgery was performed through April 2019. Study selection, data exclusion, and quality assessment were performed by two independent observers. Statistical analysis for the meta-analysis was performed by RevMan5.3 software.

Results

Eight studies were included, with a total of 123,819 eyes. The meta-analysis showed that an anterior chamber injection of moxifloxacin can prevent the incidence of endophthalmitis after cataract surgery (OR = 0.29, 95% CI (0.15, 0.56), P=0.0002), and the difference was statistically significant. There were no significant differences between the moxifloxacin injection and nonmoxifloxacin injection groups in regard to UCVA (log MAR) (SMD = −0.13, 95% CI (−0.62, 0.35), P=0.60), BCVA (log MAR) (SMD = −0.27, 95% CI (−1.28, 0.74), P=0.60), IOP (SMD = −0.04, 95% CI (−0.02, 0.01), P=0.22), corneal edema (OR = 1.03, 95% CI (0.23, 4.69), P=0.97), CCT (SMD = −0.01, 95% CI (−0.07, 0.05), P=0.77), or ECD (SMD = 0.00, 95% CI (−0.06, 0.07), P=0.94).

Conclusion

An anterior chamber injection of moxifloxacin can effectively prevent the incidence of endophthalmitis after cataract surgery, while the moxifloxacin injection and nonmoxifloxacin injection groups had similar results in regard to UCVA (log MAR), BCVA (log MAR), IOP, corneal edema, CCT, and ECD.

Intraoperative Cefuroxime Irrigation Prophylaxis for Acute-Onset Endophthalmitis After Phacoemulsification Surgery

Purpose

Acute-onset postoperative endophthalmitis usually compromises the visual function and anatomical integrity of the eye. The aim of this study was to evaluate the efficacy of intraoperative cefuroxime use in irrigating solution on prevention of acute-onset endophthalmitis after phacoemulsification.

Methods

This retrospective, comparative, interventional cohort study included patients who underwent phacoemulsification between January 1, 2012, and December 31, 2019. Under a uniform perioperative protocol, the patients who had surgery from January 1, 2012, to December 31, 2014, received irrigating infusion fluid containing balanced salt solution (BSS) only (group 1), and those from January 1, 2015, to December 31, 2019, received BSS with cefuroxime (1500 μg/mL) during surgery (group 2). All eyes were evaluated postoperatively, and the eyes suspected to have endophthalmitis were assessed and treated by a consultation team. The rates of postoperative endophthalmitis in these two groups were calculated.

Results

A total of 61,299 eyes were included over the eight years. Among these eyes, 11 in group 1 (0.07% of 15,948 eyes) and 5 in group 2 (0.01% of 45,351 eyes) developed endophthalmitis, and the difference was significant (P < 0.01). Five among 16 patients (31.25%) with endophthalmitis were positive in bacterial culture. The positive rate of bacterial culture was not significantly different between group 1 (4/11) and group 2 (1/5) (P > 0.05). No adverse events related to the irrigation of cefuroxime were found.

Conclusion

Intraoperative cefuroxime irrigation (1500 μg/mL) could decrease the rate of postoperative endophthalmitis after phacoemulsification by 7-fold. This study provides evidence that intraoperative irrigation with cefuroxime is effective as an antibiotic prophylaxis for endophthalmitis.

Commonly used intracameral antibiotics for endophthalmitis prophylaxis: A literature review

Endophthalmitis is a serious complication of cataract surgery that occurs in thousands of patients each year. To decrease the incidence of postoperative endophthalmitis, many surgeons inject intracameral antibiotics (cefuroxime, moxifloxacin, and vancomycin) routinely at the end of surgery. A large number of recently published retrospective studies and large database analyses have reported decreased endophthalmitis rates with routine antibiotic use, and the only prospective, multicenter, randomized trial performed by the European Society of Cataract and Refractive Surgery demonstrated that intracameral cefuroxime decreases the incidence of postoperative endophthalmitis. Routine cefuroxime use has become common in many European countries, whereas moxifloxacin is the most commonly used drug in India, and vancomycin use predominates in Australia. The decision regarding whether or not to use intracameral prophylaxis and the drug that is selected varies considerably throughout the world because of antibiotic availability and cost, and the spectrum of causative organisms. Adverse events due to intracameral antibiotics are infrequent, but complications such as hemorrhagic occlusive retinal vasculitis have been reported. Because additional prospective, comparative trials have not been performed, a consensus regarding best practices to prevent postoperative endophthalmitis has not been reached. Additionally, many surgeons do not routinely use intracameral antibiotics because they believe them unnecessary with modern aseptic techniques, small incision surgery, and shorter operating times. We discuss the most commonly used intracameral antibiotics, present the risks and potential benefits of this approach, and highlight challenges with drug compounding and safety.

Cost comparison of commonly used postoperative topical ophthalmic antibiotics

PURPOSE

To provide information on the actual fill level and cost of currently available antibiotic drops used perioperatively.

DESIGN

Prospective laboratory investigation.

SETTING

Robert Cizik Eye Clinic, Houston, Texas USA.

METHODS

The following 9 medications were tested: moxifloxacin, gatifloxacin (branded and generic), besifloxacin, levofloxacin, ciprofloxacin, ofloxacin, trimethoprim/polymyxin B, tobramycin, and gentamicin. Actual bottle-fill volume and number of drops per bottle were measured using 10 bottles of each formulation. The percentage of the bottle used and the perioperative cost (using average wholesale price) were calculated for 3 times a day and 4 times a day dosing for 7-day, 10-day, and 14-day courses. Formulations were compared using 1-way analysis of variance with Tukey multiple comparisons.

RESULTS

For medications with sticker volumes of at least 5 mL, all but 2 medications (ofloxacin, 4 times a day for 14 days; gentamicin, 4 times a day for 14 days) covered 2 perioperative courses. Besifloxacin had a fill volume less than the sticker volume. The most cost-effective perioperative antibiotic prophylaxis was trimethoprim-polymyxin B (4 times a day: $12.87 for 7-day, 10-day, and 14-day courses, and $46.88 for 4-day course; 3 times a day: $12.87 for 7-day, 10-day, and 14-day courses).

CONCLUSIONS

Most antibiotics had an actual fill volume greater than sticker volume, which is a sufficient drug regimen for 2 perioperative courses. The costs of common postoperative topical antibiotic regimens vary widely depending on the drug and dosing regimen. Cost considerations for perioperative antibiotics will be increasingly important because the number of cataract surgeries is expected to increase with the growing and aging population.

Conjunctival colonisation and antibiotic resistance of coagulase-negative Staphylococcus after cataract surgery: a 6-month longitudinal study at a medical centre in Taiwan

OBJECTIVE

To explored 6-month longitudinal changes in conjunctival colonisation and antibiotic resistance profiles of coagulase-negative Staphylococcus (CNS) after cataract surgery with 1 month tobramycin treatment.

DESIGN

Prospective cohort study between 1 August 2012, and 31 July 2013.

SETTING

A single medical centre in Taiwan.

PARTICIPANTS

A total of 128 Taiwanese patients with 46.9% of male participants.

INTERVENTIONS

Samples from the conjunctival sacs of both operation (OP) and non-OP eyes were obtained separately before cataract surgery and at 1, 3 and 6 months after surgery. Tobramycin (0.3%) treatment was applied four times daily for 1 month postoperatively.

MAIN OUTCOME MEASURE

Identification of CNS isolates and their antibiotic susceptibility by using disk diffusion or E-test.

RESULTS

CNS was detected in 24.2% of patients at baseline. During postoperative follow-up, the CNS colonisation rate did not decrease in either eye but showed an increasing trend in the OP eyes at 1 month (p=0.06). The colonisation rate showed no significant difference between the OP and non-OP eyes from baseline to a specific follow-up. We observed a significant increase (p<0.05) in resistance to tobramycin at 1 month and to ciprofloxacin at 3 months in the OP eyes and to trimethoprim/sulfamethoxazole at 1 month and 3 months and to oxacillin at 6 months in the non-OP eyes.

CONCLUSIONS

During the 6-month postoperative follow-up, 0.3% tobramycin administration failed to reduce CNS colonisation but increased resistance to several antibiotics. Postoperative antibiotic treatment may be replaced by other evidence-endorsed prophylactic routines.

Endophthalmitis after dropless (Tri-Moxi injection) cataract surgery

INTRODUCTION

A case of endophthalmitis after dropless cataract surgery with intravitreal Tri-Moxi associated with severe vision loss.

CASE SUMMARY

An 82-year-old male developed severe vision loss in the left eye 24 days after dropless cataract surgery with intravitreal Tri-Moxi injection. Best corrected visual acuity was hand motion in the left eye. Intraocular pressure was 13, with inferior keratic precipitates, 4 + cell with 1 mm layered hypopyon, and a plaque on the posterior capsule that blocked direct exam of the posterior segment. Ultrasonography revealed extensive vitritis without retinal or choroidal detachments.

CONCLUSION

Endophthalmitis resolved and vision improved after management with vitreous tap, intravitreal and fortified topical antibiotics, and subsequent prompt pars plana vitrectomy. Vitreous sample grew fluoroquinolone-resistant staphylococcus epidermidis.

Safety and efficacy of intracameral moxifloxacin for prevention of post-cataract endophthalmitis: Randomized controlled clinical trial

PURPOSE

To evaluate the safety and efficacy of intracameral (IC) 0.5% moxifloxacin in the prevention of post-cataract endophthalmitis.

SETTING

University of Campinas, São Paulo, Brazil.

DESIGN

Prospective randomized partially masked single-site clinical trial.

METHODS

Patients who had phacoemulsification were randomized into two groups in block sizes of 4. Group A (moxifloxacin group) consisted of patients who received an IC injection of 0.03 mL (150 μg) of undiluted 0.5% moxifloxacin at the end of surgery. Group B (control group) consisted of patients who received no IC medication. The postoperative prescription for both groups consisted of 0.5% moxifloxacin and 0.1% dexamethasone. Patients were monitored for 6 weeks after surgery. The primary outcome was the incidence of acute endophthalmitis in each group. Secondary outcomes were corrected distance visual acuity (CDVA), endothelial cell density (ECD), intraocular pressure (IOP), and central corneal thickness (CCT).

RESULTS

The study comprised 3640 eyes from 3640 patients. There were 1818 patients in Group A and 1822 patients in Group B. The incidence of endophthalmitis within 6 weeks of follow-up was 1 (0.05%) of 1818 eyes in the moxifloxacin group and 7 (0.38%) of 1822 eyes in the control group (P = .035). There was no significant difference in CDVA (P = .202), ECD (P = .482), IOP (P = .105), or CCT (P = .558). No ocular or systemic study-related adverse events were observed.

CONCLUSIONS

The IC injection of undiluted 0.5% moxifloxacin can be safely applied as the last step of phacoemulsification. It was found to be effective in reducing the risk for endophthalmitis. This study represents the first controlled randomized clinical trial to evaluate the safety and efficacy of IC moxifloxacin in the prevention of post-cataract endophthalmitis.

Comparative analysis of the safety and efficacy of intracameral cefuroxime, moxifloxacin and vancomycin at the end of cataract surgery: a meta-analysis

BACKGROUND

Current practice methods are unclear as to the most safe and effective prophylactic pharmacotherapy and method of delivery to reduce postoperative endophthalmitis occurrence.

METHODS

A systematic review and meta-analysis using Meta-analysis of Observational Studies in Epidemiology guidelines was performed to compare the efficacy of intracameral cefuroxime, moxifloxacin and vancomycin in preventing postphacoemulsification cataract surgery endophthalmitis. A safety analysis of intracameral antibiotics was concurrently performed.

DATA SOURCES

BIOSIS Previews, CINAHL, ClinicalTrials.gov, Cochrane Library, Dissertations & Theses, EMBASE, PubMed, ScienceDirect and Scopus were searched from inception to January 2017. Data were pooled using a random effects model. All articles were individually reviewed and data were extracted by two independent reviewers. Funnel plot, risk of bias and quality of evidence analyses were performed.

RESULTS

Seventeen studies with over 900 000 eyes were included, which favoured the use of intracameral antibiotics at the end of cataract surgery (OR 0.20; 95% CI 0.13 to 0.32; P<0.00001). The average weighted postoperative endophthalmitis incidence rates with intracameral cefuroxime, moxifloxacin and vancomycin were 0.0332%, 0.0153% and 0.0106%, respectively. Secondary analyses showed no difference in efficacy between intracameral plus topical antibiotics versus intracameral alone (P>0.3). Most studies had low to moderate risk of bias. The safety analysis showed minimal toxicity for moxifloxacin. Dosing errors led to the majority of toxicities with cefuroxime. Although rare, vancomycin was associated with toxic retinal events.

CONCLUSION

Intracameral cefuroxime and moxifloxacin reduced endophthalmitis rates compared with controls with minimal or no toxicity events at standard doses. Additionally, intracameral antibiotics alone may be as effective as intracameral plus topical antibiotics.

Serial Swept-Source Optical Coherence Tomography Features of Gentamicin Macular Toxicity: A Glimpse Into the Injury Cascade

The early clinical manifestations of macular infarction secondary to subconjunctival gentamicin (Gentak; Akorn, Lake Forest, IL) use in an aphakic eye were documented sequentially on swept-source optical coherence tomography (OCT) and fundus fluorescein angiography. The first recorded event after drug toxicity was macular detachment, along with disorganization of outer retinal layers in about 12 hours. The changes in inner retinal layers occurred after 36 hours had elapsed. OCT-documented initial damage to outer retinal layers could be due to the susceptibility of first order retinal neurons, followed by subsequent inner retinal layer involvement and ischemia. This helps in understanding pathogenesis of a catastrophic complication of subconjunctival gentamicin injection commonly used for endophthalmitis prophylaxis. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:456-459.].

More Antisepsis, Less Antibiotics Whenever Possible

Increasing bacterial resistance to antibiotics has recently become an important medical challenge. In ophthalmology antibiotics are widely used for treatment and prophylaxis of ocular infections. In many cases antiseptics may be a valuable adjunct and sometimes even an alternative to antibiotics for the prevention and treatment of infections, reducing the overuse of antibiotics. This review aims to highlight the available literature on the subject of antibiotic resistance in ophthalmology. Full understanding of this growing problem is necessary for tailoring effective pre-, intra-, and postoperative management to improve antibiotic stewardship programs.

Comparative efficacy of two different topical povidone-iodine 5% regimens in reducing conjunctival bacterial flora: A randomized parallel double-masked clinical trial

INTRODUCTION

The increasing prevalence of multi-resistant bacteria is a major public health concern. Infections acquired during ophthalmic surgery are devastating. The purpose of the current study is to compare the proportion of eyes with negative bacterial cultures on all tested media after 1 versus 3 sequential drops of povidone-iodine (PI) 5% into the inferior conjunctival fornix.

METHODS

Patients were randomly assigned to receive 1 (PI group) drop (at time 28 minutes) or 3 (PI plus group) sequential drops (at time 0, 20 minutes and 28 minutes) of PI 5% into the inferior conjunctival sac of one randomly selected eye. A swab culture was obtained from the inferior conjunctival fornix 5 minutes before and 30 minutes after time 0. Central corneal thickness (CCT) was measured shortly before time 0 and shortly after time 30. Conjunctival swabs were incubated aerobically in enriched Thioglycolate liquid medium (meat broth) and in three solid culture media (chocolate agar, trypticase soy agar with 5% sheep blood, and Sabouraud agar).

RESULTS

There was no significant difference in the proportion of negative cultures after intervention between groups (p = 0.1638). Also in the PI group (n = 59), the proportion of eyes with negative cultures after PI (79.7%) did not differ significantly from baseline (76.3%; p = 0.7539). However in the PI plus group (n = 61), the proportion of eyes with all negative cultures after PI (85.3%) was significantly higher than before PI (70.5%) (p = 0.0177). There was no significant difference in mean CCT before and after the intervention in both groups.

CONCLUSION

Instillation of 3 sequential drops of PI was associated with a significant increase in the proportion of eyes with all negative cultures, while instillation of a single drop of PI was not associated with a significant increase in the proportion of negative cultures. Further study is warranted to determine whether the difference between the PI administration regimens is also associated with differences in the rates of postoperative ocular infections.

Do evidence-based guidelines change clinical practice patterns?

In 2013, the Danish Health and Medicines Authorities published a National Clinical Guideline on the treatment of age-related cataracts. The guideline provided evidence-based recommendations on the indication for cataract surgery, cataract surgery in patients with age-related macular degeneration, on the use of toric intraocular lenses (IOLs) to correct preoperative corneal astigmatism, the use of intracameral and topical antibiotics to prevent endophthalmitis, choice of anti-inflammatory medication to control postoperative inflammation and prevent cystoid macular oedema, the use of immediate sequential bilateral cataract surgery and on the postoperative check-up of patients. A questionnaire was sent to all members of the Danish Ophthalmological Society before and after publication of the guideline. The responses showed that the guideline had changed practice patterns so that surgeons were more likely to prescribe non-steroidal anti-inflammatory eye drops and to not prescribe topical antibiotic eye drops after the guideline was published. Other parameters, most notably the use of toric IOLs and use of postoperative examinations were more guided by reimbursement standards than by evidence-based medicine. Thus, evidence-based guidelines do change practice patterns unless they are counteracted by the reimbursement system.

Perioperative Antibiotics to Prevent Acute Endophthalmitis after Ophthalmic Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

Post-operative endophthalmitis is a rare and dreaded complication in ophthalmic operations because it often induces irreparable vision loss. Although many ophthalmological studies aimed at reducing the rate of endophthalmitis have been performed around the world, controversy continues to surround some issues, including the choice of antimicrobials and their route of administration, duration and timing. The aim of this study is to investigate some of these unresolved issues.

METHODS

A systematic review and meta-analysis of randomized controlled trials and observational studies was performed. The PubMed, EMBASE, Cochrane Library and Clinical Trials databases were searched to identify studies published until Feb. 2016. The relative risk (RR) for each clinical outcome data is presented with 95% confidence intervals (CIs). Pooled estimates of effects were calculated using random-effect models.

RESULTS

Thirty-four studies from twenty-four reports involving 1264797 eyes were included in this analysis. Endophthalmitis occurred, on average, in one out of 6177 eyes when intracameral vancomycin/moxifloxacin were used and in one out of 1517 eyes when intracameral vancomycin/moxifloxacin were not used. The relative risk (95% CI) of endophthalmitis was reduced to 0.20 (0.10, 0.42) when intracameral antibiotics were used (p<0.0001). The subconjunctival injection of antibiotics was not superior to other administration routes included in this study (RR = 1.67, 95% CI (0.55, 5.05), p = 0.36). A statistically significant difference was found in the rate of endophthalmitis between the use and lack of use of topical antibiotics (RR = 0.65, 95% CI (0.43, 0.99), p = 0.04). However, no statistically significant difference was found in microbial isolation rates between these groups (RR = 0.77, 95% CI (0.34, 1.75), p = 0.53). When long-term and short-term use of topical antibiotics before surgery were compared, a statistically significant difference was found in microbial isolation rates (RR = 0.57, 95% CI (0.44, 0.74), p<0.0001).

CONCLUSIONS

This meta-analysis concluded intracameral antibiotics are effective at preventing endophthalmitis in ocular surgery. A randomized controlled trial confirms the efficacy of cefuroxime but recent large cohort studies support the efficacy of vancomycin/moxifloxacin intracamerally. Intracameral antibitoics are superior to subconjunctival injections but that irrigation antibitoic data are not of enough quality to make a comparison. Different results were found in two clinical outcomes between the use or lack of use of topical antibiotic therapy, we did not find sufficient evidence to conclude that its use prevents endophthalmitis.

Pros and cons of immediately sequential bilateral cataract surgery (ISBCS)

Immediately sequential bilateral cataract surgery (ISBCS) is currently a "hot topic" in ophthalmology. There are well-documented advantages in terms of quicker visual rehabilitation and reduced costs. The risk of bilateral simultaneous endophthalmitis and bilateral blindness is now recognized to be minuscule with the advent of intracameral antibiotics and modern management of endophthalmitis. Refractive surprises are rare for normal eyes and with the use of optical biometry. Where a general anesthetic is indicated for cataract surgery, the risk of death from a second anesthetic is much higher than the risk of blindness. A widely recognized protocol from the International Society of Bilateral Cataract Surgeons needs to be adhered to if surgeons wish to start practicing ISBCS.

Vancomycin in infusion during vitrectomy in surgical treatment of acute postoperative and posttraumatic endophthalmitis

Background

Endophthalmitis is potentially devastating intraocular inflammation following eye trauma or surgery. We describe the visual outcomes and causative pathogens in acute bacterial postoperative and posttraumatic endophthalmitis treated with immediate pars plana vitrectomy (PPV) with Vancomycin dissolved in the infusion fluid.

Methods

Clinical records of consecutive 30 patients with postoperative endophthalmitis and 15 patients with posttraumatic endophthalmitis were evaluated. Vancomycin was administered constantly in the infusion fluid at the time of complete PPV. Cultures were prepared from anterior chamber paracentesis. The mean follow-up period was 13 months.

Results

The visual acuities were improved in 38 cases (84 %) and remained stable in seven cases (16 %). Median post-PPV visual acuity was 1.0 logMAR in a group with postoperative endophthalmitis and 1.3 logMAR in a group with posttraumatic endophthalmitis (p < 0.05). Twenty cases (44 %) were culture-positive (Staphylococcus, Streptococcus, Enterococcus and Bacillus spp).

Conclusions

Early PPV with Vanomycin in infusion leads to vision improvement in patients with both posttraumatic and postoperative endophthalmitis. In our series of 45 cases culture was positive only in half of the cases.

Adherence to European Society for Cataract and Refractive Surgery Recommendations among Italian Cataract Surgeons: A Survey

Purpose

To survey the surgical routines with regards to prophylactic strategies in a sample of Italian hospitals and compare these with European Society for Cataract and Refractive Surgery (ESCRS) guidelines.

Methods

Six private and 18 public hospitals were included in this clinical-based retrospective study. The overall volume of cataract operations in the 24 centers in 2013 was 43,553. Main outcome measure was incidence of endophthalmitis per 1,000. An incidence of less than 0.13% was considered acceptable.

Results

Our study provides the first Italian data on the use of intracameral antibiotics in cataract surgery as recommended by the ESCRS. Thirteen centers (54%) used intracameral cefuroxime at the end of surgery. Of the 13 centers that used cefuroxime, 8 (62%) had an incidence of endophthalmitis less than 0.13%. Of the 7 (29%) centers that did not use intracameral cefuroxime, all had an endophthalmitis rate of greater than 0.13%. This difference was statistically significant (p<0.05). Among the 4 centers not included, 2 used vancomycin in the infusion bottle, 1 a fluoroquinolone, and the last a combination of antibiotics. The majority of surgeons (71%) used preoperative antibiotic eyedrops, but this measure was not shown to be significantly protective.

Conclusions

Slightly more than half of the centers surveyed in this study adhered to the recommendations of the ESCRS and routinely employed prophylactic intracameral cefuroxime. An incidence of endophthalmitis greater than 0.13% was encountered significantly more frequently among centers that did not employ intracameral cefuroxime.

Transzonular vitreous injection vs a single drop compounded topical pharmaceutical regimen after cataract surgery

Purpose

To compare the relative effectiveness of a Tri-Moxi-Vanc intraocular solution injected transzonularly into the vitreous with the topical formulation of Pred-Moxi-Ketor (given for the first week postoperatively) followed by Pred-Ketor (given for weeks 2–4 after surgery).

Patients and methods

This was a single-site, single-surgeon, prospective, randomized, subject-masked contralateral eye study with an active comparator and was approved by an appropriate ethics committee. Twenty-five subjects with uncomplicated cataract who were scheduled for cataract surgery were enrolled. If surgery was uneventful, subjects received either an injection in that eye or followed a minimum drop postoperative pharmaceutical regimen. The second eye surgery was performed with the opposite treatment. Subjects were followed for 1 month. Measures of interest were the changes in intraocular pressure (IOP) from baseline and the changes in corneal and macular thickness. Subjects were also asked to evaluate pain perception, visual quality, and overall satisfaction with surgery. They were also asked which regimen they preferred.

Results

IOP was not statistically significantly different between the groups (P=0.81); there was also no statistically significant difference in IOP over time (P=0.74). There was no statistically significant difference in central macular thickness at 1 week and 1 month between the groups (P=0.18). The central corneal thickness was significantly greater 1 day postoperatively relative to baseline, but there was no statistically significant difference between the groups at any time point (P=0.92). The difference in reported pain was also not statistically significantly different between the groups (P=0.67). Satisfaction with surgery was similar for both groups, but significantly more subjects preferred the injection for overall experience (P<0.01).

Conclusion

Cataract surgery completed with the two pharmaceutical regimens was similar in outcome. Significantly more subjects preferred the injection, presumably as a function of the greater convenience with no apparent difference in the therapeutic effect.

Antibiotic prophylaxis: different practice patterns within and outside the United States

Endophthalmitis remains a rare but important cause of visual loss. Prophylaxis strategies are important to reduce rates of endophthalmitis after cataract surgery, intravitreal injection, and other procedures. There is substantial variability between the US and the rest of the world. During cataract surgery, intracameral antibiotics are commonly used in many nations, especially in Europe, but are less commonly used in the US. A randomized clinical trial from the European Society of Cataract and Refractive Surgeons reported an approximately fivefold reduction in endophthalmitis rates associated with intracameral cefuroxime but these results are controversial. There are no randomized clinical trials regarding endophthalmitis associated with intravitreal injection. Topical antibiotics are commonly used in many nations, but are less commonly used in the US. At this time, there is no global consensus and it appears unlikely that additional major clinical trials will conclusively define the optimal endophthalmitis prophylaxis techniques.

Safety of undiluted intracameral moxifloxacin without postoperative topical antibiotics in cataract surgery

The objective of this study is to evaluate the safety of undiluted 0.5 % intracameral moxifloxacin for postoperative endophthalmitis prophylaxis in cataract surgery patients without the use of additional postoperative topical antibiotics. All phacoemulsification cataract surgeries performed by a single surgeon (B.A.) at the John A. Moran Eye Center from June 2012 to May 2015 were reviewed retrospectively. From June 2012 to April 2014, patients were given topical 0.5 % moxifloxacin postoperatively. From May 2014 to May 2015, all patients were given moxifloxacin intracamerally with no antibiotics postoperatively. The follow-up period was 1 month after surgery. Preoperative visual acuity and postoperative visual acuity, corneal edema, and anterior chamber reaction were recorded and compared between the two groups. 384 cataract surgeries were performed during the study period. None of the 384 eyes in the study developed endophthalmitis. Of those 384 eyes, 222 were included in the study for analysis based on the inclusion and exclusion criteria. 131 were part of the topical antibiotic group and 91 were part of the intracameral group. The differences in uncorrected visual acuity at 1 day postoperatively (p = 0.595) and best corrected visual acuity at 1 month postoperatively (p = 0.099) were not statistically significant. Differences in corneal edema (p = 0.370) and anterior chamber reaction (p = 0.069) at 1 day postoperatively and corneal edema (p = 0.512) and anterior chamber reaction (p = 0.512) at 1 month postoperatively were also not statistically significant. Undiluted 0.5 % moxifloxacin can be safely injected intracamerally following cataract surgery without additional postoperative antibiotic prophylaxis to prevent endophthalmitis without adverse effects on patient outcomes.

Endophthalmitis today: a multispecialty ophthalmology department perspective

PURPOSE

To portray the current scene of endophthalmitis in a multispecialty ophthalmology department regarding etiologies and treatment guidelines.

METHODS

Retrospective chart review of all patients diagnosed with endophthalmitis or suspected endophthalmitis from 2009 to 2012.

RESULTS

A total of 24 eyes were diagnosed with endophthalmitis or suspected endophthalmitis during a 4-year period. The etiologies included endogenous endophthalmitis (6), blebitis (3), Ahmed valve implantation (3, 2 of them with late infection), postcataract surgery (3), intravitreal injections (4), penetrating injury (2), and other surgical procedures (3). Of the postcataract surgery cases, 1 was a congenital cataract surgery, and 2 were referrals. There were no endophthalmitis cases in 4603 adults undergoing cataract surgery in our department during this period. There were 14 positive cultures: 1 was candida and the rest bacteria. Ten of the bacteria cases were Gram-positive cocci (predominantly strep species), 3 were Gram-negative, and coagulase negative staphylococci were detected in 2 cases.

CONCLUSIONS

Our study indicates a significant change in the case mix of endophthalmitis. The past leading cause, cataract surgery, was dramatically reduced, and intravitreal injections became a major cause. The change in etiologies, and possibly in the microbial flora, warrants reconsideration of the rules that guided the management of endophthalmitis since the Endophthalmitis Vitrectomy Study.

Cataract

Cataract is the leading cause of reversible blindness and visual impairment globally. Blindness from cataract is more common in populations with low socioeconomic status and in developing countries than in developed countries. The only treatment for cataract is surgery. Phacoemulsification is the gold standard for cataract surgery in the developed world, whereas manual small incision cataract surgery is used frequently in developing countries. In general, the outcomes of surgery are good and complications, such as endophthalmitis, often can be prevented or have good ouctomes if properly managed. Femtosecond laser-assisted cataract surgery, an advanced technology, can automate several steps; initial data show no superiority of this approach over current techniques, but the results of many large clinical trials are pending. The greatest challenge remains the growing 'backlog' of patients with cataract blindness in the developing world because of lack of access to affordable surgery. Efforts aimed at training additional cataract surgeons in these countries do not keep pace with the increasing demand associated with ageing population demographics. In the absence of strategie that can prevent or delay cataract formation, it is important to focus efforts and resources on developing models for efficient delivery of cataract surgical services in underserved regions. For an illustrated summary of this Primer, visit: http://go.nature.com/eQkKll.

Antibiotic prevention of postcataract endophthalmitis: a systematic review and meta-analysis

Endophthalmitis is one of the most feared complications after cataract surgery. The aim of this systematic review was to evaluate the effect of intracameral and topical antibiotics on the prevention of endophthalmitis after cataract surgery. A systematic literature review in the MEDLINE, CINAHL, Cochrane Library and EMBASE databases revealed one randomized trial and 17 observational studies concerning the prophylactic effect of intracameral antibiotic administration on the rate of endophthalmitis after cataract surgery. The effect of topical antibiotics on endophthalmitis rate was reported by one randomized trial and one observational study. The quality and design of the included studies were analysed using the Cochrane risk of bias tool. The quality of the evidence was evaluated using the GRADE approach. We found high-to-moderate quality evidence for a marked reduction in the risk of endophthalmitis with the use of intracameral antibiotic administration of cefazolin, cefuroxime and moxifloxacin, whereas no effect was found with the use of topical antibiotics or intracameral vancomycin. Endophthalmitis occurred on average in one of 2855 surgeries when intracameral antibiotics were used compared to one of 485 surgeries when intracameral antibiotics were not used. The relative risk (95% CI) of endophthalmitis was reduced to 0.12 (0.08; 0.18) when intracameral antibiotics were used. The difference was highly significant (p < 0.00001). Intracameral antibiotic therapy is the best choice for preventing endophthalmitis after cataract surgery. We did not find evidence to conclude that topical antibiotic therapy prevents endophthalmitis.

Antibacterial efficacy of prophylactic besifloxacin 0.6% and moxifloxacin 0.5% in patients undergoing cataract surgery

Background

The purpose of this study was to investigate the ocular bacterial flora in patients scheduled to undergo cataract surgery and compare the antibacterial effects of besifloxacin ophthalmic suspension 0.6% and moxifloxacin ophthalmic solution 0.5% in these patients.

Methods

This was a prospective, randomized, laboratory-masked clinical trial. Patients received besifloxacin or moxifloxacin “quater in die” or QID (four times a day) for 3 days before cataract surgery in the surgical eye and 1 hour before surgery in the nonsurgical fellow eye. Conjunctival and eyelid swabs were obtained from both eyes at baseline and after treatment, on the day of surgery (Visit 2). Swabs were processed for bacterial colony counts (in terms of colony-forming units) and species identification. In vitro antibiotic susceptibilities of isolates were determined using Clinical and Laboratory Standards Institute breakpoints.

Results

Fifty-nine patients (n=28 besifloxacin, n=31 moxifloxacin) completed the study. The majority (73%) of conjunctival samples were culture negative at baseline. The most frequent isolates were coagulase-negative staphylococci (CoNS, 89%), specifically Staphylococcus epidermidis (72%). Both fluoroquinolones reduced the lid CFU values when administered QID for 3 days (P≤0.019), but only besifloxacin reduced the lid CFU estimate 1 hour following instillation of a single drop (P=0.039). Fewer besifloxacin-treated eyes had lids that were culture positive for CoNS at Visit 2 compared with moxifloxacin-treated eyes regardless of dosing regimen (P≤0.03). The minimum inhibitory concentration (MIC₉₀) of besifloxacin against methicillin-resistant S. epidermidis (MRSE) was eightfold lower than that of moxifloxacin.

Conclusion

Besifloxacin appeared more effective in reducing bacterial counts on eyelids of patients undergoing cataract surgery, with significant reductions as early as 1 hour postdose, compared with moxifloxacin. Besifloxacin was more active in vitro against MRSE.

Quality assessment of cataract surgery in Denmark - risk of retinal detachment and postoperative endophthalmitis

The main purpose of this thesis was to examine whether the Danish National Patient Registry (NPR) could be used to monitor and assess the quality of cataract surgery in Denmark by studying the risks of two serious postoperative complications following cataract surgery - retinal detachment (RD) and postoperative endophthalmitis (PE). The thesis consists of four retrospective studies. In the first study (paper I), we used data from the NPR in the calendar period 2000-2010 to investigate the risk of pseudophakic retinal detachment (PRD) using the fellow non-operated eyes of the patients as reference. The study showed that over a 10-year study period, the risk of PRD was increased by a factor of 4.2 irrespective of sex and age. The risk of PRD was highest in the first part of the postoperative period and then gradually decreased but remained statistically significantly higher than the risk of RD in non-operated fellow eyes up to 10 years after cataract surgery. The epidemiology of RD in the non-operated fellow eyes was different from the epidemiology of RD in the background population as young men had the highest risk of RD in the non-operated fellow eyes. This means that the absolute risk of PRD was highest for young men because they had a higher risk of RD before they underwent cataract surgery. In the second study (paper II), we used data from the NPR and reviewed patient charts to assess the risk of PE after cataract surgery performed in public eye departments and private hospitals/clinics in the study period 2002-2010. The overall risk of PE among the seven public eye departments was 0.36 per 1000 registered cataract operations, and the PE risk among the departments was homogeneous. The overall risk of PE among the 28 private hospitals/clinics was 0.73 per 1000 registered cataract operations, and the risk among the private hospitals/clinics was heterogeneous. Most private hospitals/clinics had a risk of PE that was lower than or similar to the risk of PE after registered cataract surgery in public eye departments, but six private hospitals/clinics had a statistically significantly higher risk of PE compared to the public eye departments. We used PE as a proxy measure of the registration of cataract surgery and found that 98% of the cataract operations performed in public eye departments were registered in the NPR while only 38% of the cataract operations performed in private hospitals/clinics were registered in the NPR. In general, the coding of the PE cases was not uniform and the lack of registration by the private hospitals/clinics meant that the NPR could not be used to monitor the true risk of PE. NPR data were also used in the third study (paper III) to examine whether patients who had surgical intervention for PE following cataract surgery with either a pars plana vitrectomy (PPV) or a vitreous tap (VT) had a higher risk of subsequent surgical complications. There was no statistically significant difference in the overall risk of complications among the two groups, but the risk of surgery for vitreous opacities was statistically significantly higher for patients who underwent a VT. A surgical complication occurred in 27.3% of the patients and 9.9% of the patients developed more than one surgical complication. Ninety-seven per cent of the primary surgical complications occurred within the first 5 months. The risk of surgical complications in this study was similar to or higher than the risk of complications in the landmark Endophthalmitis Vitrectomy Study from the early 1990s. In the fourth study (paper IV), we used data from all three Danish cataract registries to describe the epidemiology of cataract operations performed in public hospitals and private hospitals/clinics in the study period 2004-2012. Again, PE was used as a proxy measure of the registration of cataract surgery. There were several noticeable differences in the epidemiology of the cataract operations performed in public hospitals and private hospitals/clinics. Patients who had cataract surgery in public hospitals had a statistically significantly higher mortality compared to patients who had cataract surgery in private hospitals/clinics during the entire period. The decrease in the mean age at first eye cataract surgery in private hospitals/clinics was statistically significantly greater compared to public hospitals during the study period. There was a statistically significantly shorter median time interval between first and second eye cataract surgery at private hospitals/clinics compared to public hospitals during the entire study period. The study showed that only 54% of the cataract operations performed in private hospitals/clinics that led to PE were registered. The lack of registration of cataract surgery is the main reason why the NPR has limitations when used as a tool to monitor and assess the quality of cataract surgery in Denmark.