The Effect of Intraoperative Antibiotics in Irrigating Solutions on Aqueous Humor Contamination and Endophthalmitis after Phacoemulsification Surgery

Ocular Drug Delivery: a Comprehensive Review

The human eye is a sophisticated organ with distinctive anatomy and physiology that hinders the passage of drugs into targeted ophthalmic sites. Effective topical administration is an interest of scientists for many decades. Their difficult mission is to prolong drug residence time and guarantee an appropriate ocular permeation. Several ocular obstacles oppose effective drug delivery such as precorneal, corneal, and blood-corneal barriers. Routes for ocular delivery include topical, intravitreal, intraocular, juxtascleral, subconjunctival, intracameral, and retrobulbar. More than 95% of marketed products exists in liquid state. However, other products could be in semi-solid (ointments and gels), solid state (powder, insert and lens), or mixed (in situ gel). Nowadays, attractiveness to nanotechnology-based carries is resulted from their capabilities to entrap both hydrophilic and lipophilic drugs, enhance ocular permeability, sustain residence time, improve drug stability, and augment bioavailability. Different in vitro, ex vivo, and in vivo characterization approaches help to predict the outcomes of the constructed nanocarriers. This review aims to clarify anatomy of the eye, various ocular diseases, and obstacles to ocular delivery. Moreover, it studies the advantages and drawbacks of different ocular routes of administration and dosage forms. This review also discusses different nanostructured platforms and their characterization approaches. Strategies to enhance ocular bioavailability are also explained. Finally, recent advances in ocular delivery are described.

Prospective evaluation of the prevalence of conjunctival and intraocular bacteria in dogs undergoing phacoemulsification following a standardized aseptic preparation with 0.5% povidone iodine

PURPOSE

To evaluate bacterial contamination of conjunctiva and aqueous humor in dogs undergoing phacoemulsification following asepsis with 0.5% povidone iodine and determine the influence of intravenous antibiotics on outcome of contamination.

METHODS

Client-owned dogs were prospectively enrolled and randomly assigned to a control group, receiving 22 mg/kg intravenous cefazolin at induction prior to sampling, or experimental group receiving no antibiotic prior to sampling, masked to the surgeon. Dogs receiving antimicrobials in the pre-operative period were excluded. Asepsis was performed on all operated eyes using 0.5% iodine with minimum 3 min contact time at induction of anesthesia and repeated before surgery. A conjunctival swab and aqueous humor sample were collected prior to incision and following incision closure, respectively. Samples were submitted for aerobic and anaerobic bacterial culture and susceptibility.

RESULTS

Seventy-one eyes of 42 dogs were included. Median age was 9 years. Thirty-nine and 32/71 eyes received intravenous cefazolin and no antibiotic, respectively. Median procedure time was 40 min per eye. Conjunctival cultures were positive in 6 eyes (8.5%): Serratia marcescens (5 eyes) and Cutibacterium acnes (1 eye). Aqueous humor cultures were positive in 5 eyes (7.0%): S. marcescens (2 eyes), Pseudomonas aeruginosa (2 eyes), Staphylococcus pseudointermedius (1 eye). Prevalence of positive culture did not differ between groups (p = .74), order of eyes for bilateral procedures (p = .74) and diabetic status (p = 1).

CONCLUSIONS

Bacterial contamination of the conjunctiva and aqueous humor was present in 8.5% and 7.0% of dogs undergoing phacoemulsification after asepsis. Lack of IV cefazolin was not significantly associated with positive culture.

Incidence, Prophylaxis and Prognosis of Acute Postoperative Endophthalmitis After Cataract Surgery: A Multicenter Retrospective Analysis in Northern China from 2013 to 2019

Objective

To investigate the incidence of acute postoperative endophthalmitis (POE) after cataract surgery in Northern China from 2013 to 2019, evaluate the efficacy of prophylaxis and analyze the predictors of visual prognosis among POE patients.

Methods

The study was conducted as a retrospective multi-center research, with seven hospitals in Northern China enrolled. The diagnosis of acute-onset POE was made on the basis of clinical manifestations within six weeks after initial surgery. By reviewing electronic medical system, the number of cataract surgeries and acute POE cases were recorded to estimate the overall incidence and incidences by different years and hospitals. Perioperative measures for preventing infection in different hospitals were collected. The correlations between unfavorable final vision and potential factors including basic information and clinical characteristics were examined to determine the predictive factors for final visual prognosis.

Results

Of 72,255 cataract surgeries performed during seven years in the seven hospitals, 19 cases developed acute POE, yielding an overall incidence of 0.026%. The average incidence of acute POE among seven hospitals significantly declined annually during the past 7 years (p = 0.021). In Hospital-D, the incidence of acute POE significantly decreased after the application of 0.5% povidone-iodine (PVP-I) for conjunctival washing (p = 0.003). Two hospitals adopting tobramycin in the irrigation solution achieved a significant lower incidence of POE than the other hospitals (p = 0.044). The positive rate of pathogen culture was just 17.6% (3/19). Patients with presenting BCVA of CF or better were more likely to present with unfavorable final vision than those with worse presenting BCVA (p = 0.003).

Conclusion

The overall incidence of acute POE after cataract surgery from 2013 to 2019 in Northern China was 0.026%, and the incidence declined annually over the period. Presenting BCVA could be a significant prognosis factor for predicting the final visual outcomes of acute POE patients.

Recent advances in ophthalmic preparations: Ocular barriers, dosage forms and routes of administration

The human eye is a complex organ with unique anatomy and physiology that restricts the delivery of drugs to target ocular tissues/sites. Recent advances in the field of pharmacy, biotechnology and material science have led to development of novel ophthalmic dosage forms which can provide sustained drug delivery, reduce dosing frequency and improve the ocular bioavailability of drugs. This review highlights the different anatomical and physiological factors which affect ocular bioavailability of drugs and explores advancements from 2016 to 2020 in various ophthalmic preparations. Different routes of drug administration such as topical, intravitreal, intraocular, juxtascleral, subconjunctival, intracameral and retrobulbar are discussed with their advances and limitations.

Cataract Surgery by Intraoperative Surface Irrigation with 0.25% Povidone-Iodine

Postoperative endophthalmitis after cataract surgery is typically caused by the patient's own conjunctival normal bacterial flora. A three-step approach is recommended to prevent endophthalmitis: (1) "border control" to prevent microorganisms from entering the eye by disinfecting the ocular surface is the most important measure; (2) bacteria that have gained access into the anterior chamber are reduced by irrigation; (3) bacteria remaining in the anterior chamber and vitreous at the end of surgery are controlled by antibacterial drugs. We have devised a method, "the Shimada technique", for irrigating the ocular surface with povidone-iodine, a disinfectant with potent microbicidal effect and established effective and safe concentrations for eye tissues. Povidone-iodine exhibits a bactericidal effect for a wide concentration range of 0.005-10%, but 0.1% povidone-iodine has the highest activity and requires the shortest time of only 15 s to achieve microbicidal effect. When used to irrigate the ocular surface every 20-30 s during cataract surgery, 0.25% povidone-iodine is conceivably diluted to around 0.1%. Irrigation with 0.25% povidone-iodine during cataract surgery significantly reduced bacteria contamination rate in the anterior chamber compared with saline (p = 0.0017) without causing corneal endothelial damage.

Preoperative antisepsis in ophthalmic surgery (a review)

Endophthalmitis remains a serious complication following intraocular procedures. Preoperative prophylactic measures for endophthalmitis decrease the morbidity associated with this disease and represent a standard of care prior to ophthalmic surgery. The literature supports as measures for ocular antisepsis: povidone-iodine solution for ocular surface preparation, chlorhexidine in patients with iodine allergy and application of topical antibiotics. Povidone-iodine is regarded as the most effective antiseptic associated with significant reduction in ocular surface bacterial counts. Currently, the recommended preoperative management is the application of 5% povidone-iodine solution in the conjunctival fornix, prior to surgery. This paper reviews the preoperative measures for ocular antisepsis, used in order to decrease the risk of culture-proven endophthalmitis.

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.

Endophthalmitis after cataract surgery: Effect of behind-the-lens washout

PURPOSE

To analyze the outcomes of cataract surgery with emphasis on the relationship between surgery-related factors and the incidence of postoperative infectious endophthalmitis.

SETTING

Ninety-three surgical sites in Japan.

DESIGN

Prospective case series.

METHODS

Eyes that were scheduled to have cataract surgery from January 20 to September 30, 2014, were included. Phacoemulsification and implantation of a single-piece hydrophobic acrylic foldable intraocular lens (IOL) were performed. Patients were followed for 2 months.

RESULTS

Of the 9720 eyes enrolled, 9100 (93.6%) completed a 2-month follow-up. Three cases (0.033%) developed infectious endophthalmitis (95% confidence interval [CI], 0.000-0.070). The incidence of endophthalmitis was significantly associated with the removal method of ophthalmic viscosurgical devices (OVDs) after IOL implantation. The incidences of endophthalmitis in cases with and without the behind-the-lens technique were 0% (0/6147; 95% CI, 0%) and 0.084% (3/3570; 95% CI, 0.000-0.179), respectively, with a significant difference between them (P = .050, Fisher exact test). The incidence of infectious endophthalmitis did not correlate with any other patient-related and surgery-related factors.

CONCLUSION

The behind-the-lens technique to wash and clear the capsular bag for OVD removal significantly reduced the incidence of infectious endophthalmitis.

Povidone-iodine concentration and dosing in cataract surgery

Iodine has been recognized as an effective bactericide since the 1800s, and povidone-iodine (PI) solution has been applied to the ocular surface and periocular skin since the 1980s to prevent endophthalmitis in cataract surgery. In vitro, PI solution kills bacteria quickly at dilute concentrations (0.05%-1.0%). In many instances, PI kills bacteria more quickly at these dilute concentrations than more conventional (5%-10%) concentrations. This is due to greater availability of diatomic free iodine in dilute solution, the bactericidal component of PI. The toxicity of PI, both in vitro and clinically, has been shown to be related to concentration. Current American Academy of Ophthalmology and the European Society of Cataract and Refractive Surgeons recommendations regarding PI use suggest using 5% PI before surgery. An alternative dosing strategy uses dilute PI repetitively throughout cataract surgery (0.25% every 30 seconds). We review the povidone-iodine literature with attention to basic science and use of dilute PI.

Antibiotic prophylaxis in cataract surgery in the setting of penicillin allergy: A decision-making algorithm

Cataract surgery is the most commonly performed surgical procedure in many developed countries. Postoperative endophthalmitis is a rare complication with potentially devastating visual outcomes. Currently, there is no global consensus regarding antibiotic prophylaxis in cataract surgery despite growing evidence of the benefits of prophylactic intracameral cefuroxime at the conclusion of surgery. The decision about which antibiotic regimen to use is further complicated in patients reporting penicillin allergy. Historic statistics suggesting crossreactivity of penicillins and cephalosporins have persisted into modern surgery. It is important for ophthalmologists to consider all available antibiotic options and have an up-to-date knowledge of antibiotic crossreactivity when faced with the dilemma of choosing appropriate antibiotic prophylaxis for patients undergoing cataract surgery with a history of penicillin allergy. Each option carries risks, and the choice may have medicolegal implications in the event of an adverse outcome. We assess the options for antibiotic prophylaxis in cataract surgery in the setting of penicillin allergy and provide an algorithm to assist decision-making for individual patients.

Perioperative antibiotics for prevention of acute endophthalmitis after cataract surgery

BACKGROUND

Endophthalmitis is a severe inflammation of the anterior or posterior (or both) chambers of the eye that may be sterile or associated with infection. It is a potentially vision-threatening complication of cataract surgery. Prophylactic measures for endophthalmitis are targeted against various sources of infection.

OBJECTIVES

To evaluate the effects of perioperative antibiotic prophylaxis for endophthalmitis following cataract surgery compared with no prophylaxis or other form of prophylaxis.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2016, Issue 12), Ovid MEDLINE, Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Ovid MEDLINE Daily (January 1946 to December 2016), Embase (January 1980 to December 2016), Latin American and Caribbean Health Sciences Literature Database (LILACS) (1982 to December 2016),the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov), and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We used no date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 6 December 2016. We also searched for additional studies that cited any included trials using the Science Citation Index.

SELECTION CRITERIA

We included randomized controlled trials that enrolled adults undergoing cataract surgery (any method and incision type) for lens opacities due to any origin. We included trials that evaluated preoperative antibiotics, intraoperative (intracameral, subconjunctival or systemic), or postoperative antibiotic prophylaxis for acute endophthalmitis. We excluded studies that evaluated antiseptic preoperative preparations using agents such as povidone iodine or antibiotics for treating acute endophthalmitis after cataract surgery.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed abstracts and full-text articles for eligibility, assessed the risk of bias for each included study, and abstracted data.

MAIN RESULTS

Five studies met the inclusion criteria for this review, including 101,005 adults and 132 endophthalmitis cases. While the sample size was very large, the heterogeneity of the study designs and modes of antibiotic delivery made it impossible to conduct a formal meta-analysis. Interventions investigated included the utility of adding vancomycin and gentamycin to the irrigating solution compared with standard balanced saline solution irrigation alone, use of intracameral cefuroxime with or without topical levofloxacin perioperatively, periocular penicillin injections and topical chloramphenicol-sulfadimidine drops compared with topical antibiotics alone, and mode of antibiotic delivery (subconjunctival versus retrobulbar injections; fixed versus separate instillation of gatifloxacin and prednisolone). The risk of bias among studies was low to unclear due to information not being reported. We identified one ongoing study.Two studies compared any antibiotic with no antibiotic. One study, which compared irrigation with antibiotics in balanced salt solution (BSS) versus BSS alone, was not sufficiently powered to detect differences in endophthalmitis between groups (very low-certainty evidence). One study found reduced risk of endophthalmitis when combining intracameral cefuroxime and topical levofloxacin (risk ratio (RR) 0.14, 95% confidence interval (CI) 0.03 to 0.63; 8106 participants; high-certainty evidence) or using intracameral cefuroxime alone (RR 0.21, CI 0.06 to 0.74; 8110 participants; high-certainty evidence) compared with placebo, and an uncertain effect when using topical levofloxacin alone compared with placebo (RR 0.72, CI 0.32 to 1.61; 8103 participants; moderate-certainty evidence).Two studies found reduced risk of endophthalmitis when combining antibiotic injections during surgery and topical antibiotics compared with topical antibiotics alone (risk ratio (RR) 0.33, 95% confidence interval (CI) 0.12 to 0.92 (periocular penicillin and topical chloramphenicol-sulfadimidine; 6618 participants; moderate-certainty evidence); and RR 0.20, 95% CI 0.04 to 0.91 (intracameral cefuroxime and topical levofloxacin; 8101 participants; high-certainty evidence)).One study, which compared fixed versus separate instillation of gatifloxacin and prednisolone, was not sufficiently powered to detect differences in endophthalmitis between groups (very low-certainty evidence). Another study found no evidence of a difference in endophthalmitis when comparing subconjunctival versus retrobulbar antibiotic injections (RR 0.85, 95% CI 0.55 to 1.32; 77,015 participants; moderate-certainty evidence).Two studies reported any visual acuity outcome; one study, which compared fixed versus separate instillation of gatifloxacin and prednisolone, reported only that mean visual acuity was the same for both groups at 20 days postoperation. In the other study, the difference in the proportion of eyes with final visual acuity greater than 20/40 following endophthalmitis between groups receiving intracameral cefuroxime with or without topical levofloxacin compared with no intracameral cefuroxime was uncertain (RR 0.69, 95% CI 0.22 to 2.11; 29 participants; moderate-certainty evidence).Only one study reported adverse events (1 of 129 eyes had pupillary membrane in front of the intraocular lens and 8 eyes showed posterior capsule opacity). No study reported outcomes related to quality of life or economic outcomes.

AUTHORS' CONCLUSIONS

Multiple measures for preventing endophthalmitis following cataract surgery have been studied. High-certainty evidence shows that injection with cefuroxime with or without topical levofloxacin lowers the chance of endophthalmitis after surgery, and there is moderate-certainty evidence to suggest that using antibiotic eye drops in addition to antibiotic injection probably lowers the chance of endophthalmitis compared with using injections or eye drops alone. Clinical trials with rare outcomes require very large sample sizes and are quite costly to conduct; thus, it is unlikely that many additional clinical trials will be conducted to evaluate currently available prophylaxis. Practitioners should rely on current evidence to make informed decisions regarding prophylaxis choices.

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.

Endophthalmitis caused by Gram-positive organisms with reduced vancomycin susceptibility: literature review and options for treatment

BACKGROUND

Endophthalmitis caused by Gram-positive organisms with reduced vancomycin susceptibility and/or resistance is an important clinical issue worldwide.

PURPOSE

To review the published literature on endophthalmitis caused by Gram-positive organisms with reduced vancomycin susceptibility and/or vancomycin resistance.

METHODS

The data were analysed from a PubMed search of endophthalmitis cases caused by Gram-positive organisms with reported reduced vancomycin susceptibility and/or vancomycin resistance from 1990 to 2015.

RESULTS

From 18 publications identified, a total of 27 endophthalmitis cases caused by Gram-positive organisms with reduced vancomycin susceptibility and/or vancomycin resistance were identified. The aetiologies of endophthalmitis were exogenous in 19/27 cases (11 post-cataract surgery, 2 post-penetrating keratoplasty, 1 post-glaucoma surgery, 4 post-open globe injury, 1 post-intravitreal injection of ranibizumab), and endogenous in 4/24 cases; no details were available about the four remaining patients. The causative organisms included Enterococcus species (7/27), coagulase-negative staphylococci (4/27), Staphylococcus aureus (4/27), Bacillus species (4/27), Streptococcus species (3/27), Leuconostoc species (3/27), Staphylococcus hominis (1/27), and unidentified Gram-positive cocci (1/27). Visual acuity of 20/400 or better at the final follow-up was recorded in 10/26 patients (38.5%; data were not available for one patient). Treatment options include fluoroquinolones, penicillin, cephalosporins, tetracyclines, and oxazolidinones.

CONCLUSIONS

In the current study, visual acuity outcomes were generally poor. Enterococcus and Staphylococcus species were the most common organisms reported and postoperative endophthalmitis after cataract surgery was the most common clinical setting.

Evaluation of a new method of irrigation and aspiration for removal of ophthalmic viscoelastic device during cataract surgery in a porcine model

BACKGROUND

To determine if a method for irrigation and aspiration (I/A) during cataract surgery provides effective removal of ophthalmic viscoelastic device (OVD).

METHODS

Japanese porcine eyes were used to evaluate I/A performance with Technique 1 (the I/A tip placed on the center of the anterior surface of the IOL), Technique 2 (the I/A tip alternately pressed near the edge of the IOL optic anterior surface on one side and then the other to tilt the IOL back and forth), and Technique 3 (the I/A tip inserted behind the IOL optic, between it and the posterior capsule). Techniques 1 and 2 were compared using the Miyake-Apple posterior view video technique to visualize the flow of irrigation fluid containing triamcinolone acetonide particles behind the IOL. To check the efficacy of OVD removal from behind the IOL for of all three I/A techniques, OVD with fluorescein beads were inserted inside the lens capsule before implantation of the IOL. After each I/A technique, eyes were prepared for Miyake-Apple viewing and pictures of the lens capsule were taken using fluorescent microscopy. Residual fluorescein beads in the capsular bag were analyzed.

RESULTS

Technique 1 resulted in a straight flow of fluid behind the IOL, while Technique 2 resulted in a vortex flow. The average amount of OVD retained inside the capsule after using Technique 2 or 3 was significantly lower than after using Technique 1 (p <0.0001).

CONCLUSIONS

Technique 2 proved to remove more effectively fluorescein bead-labelled OVD under the IOL than Technique 1.

Ocular penetration and efficacy of levofloxacin using different drug-delivery techniques for the prevention of endophthalmitis in rabbit eyes with posterior capsule rupture

PURPOSE

To evaluate the effects of different drug-delivery techniques for levofloxacin (LVFX) in ocular penetration and the prevention of endophthalmitis using an aphakic rabbit model with posterior capsule rupture (PCR).

METHODS

LVFX was administered to aphakic rabbit eyes with or without PCR using eye drops (EDs), subconjunctival injection (SCI), or intracameral (IC) injection. The concentration of the drug in the vitreous and aqueous humors was estimated at 2 h after injection. In another study, aphakic rabbit eyes with PCR were inoculated with Enterococcus faecalis, immediately followed by 0.5% LVFX ED, 0.5% moxifloxacin (MFLX) ED, LVFX IC (500 μg/0.1 mL), or IC saline. EDs were administered 0, 3, and 6 h after surgery. Changes on electroretinography (ERG) and intraocular bacterial growth were determined sequentially until 48 h after inoculation.

RESULTS

The concentrations of LVFX at 2 h after IC were higher in the aqueous humor and the vitreous cavity of eyes with or without PCR, compared with EDs or SCI. Eyes treated with LVFX ED, MFLX ED, or IC saline showed a significantly greater reduction in b-wave amplitude on ERG at 48 h compared with eyes treated with LVFX IC. The number of bacteria recovered from the vitreous humor in eyes treated with IC LVFX at 48 h was significantly less than from eyes that received other treatments.

CONCLUSION

The LVFX IC was effective at suppressing endophthalmitis caused by E. faecalis in eyes with a PCR.

The incidence of postoperative endophthalmitis after cataract surgery in China: a multicenter investigation of 2006-2011

AIMS

To estimate the cumulative incidence of postoperative endophthalmitis, identify risk factors and determine clinical outcomes in China.

METHODS

Medical records were reviewed for all patients with acute-onset endophthalmitis after cataract surgery from January 2006 to December 2011 at eight eye centres of tertiary care hospitals in China.

RESULTS

Sixty-six cases of presumed endophthalmitis occurred after 201 757 cataract surgeries, yielding a cumulative incidence of 0.033% (95% CI 0.025 to 0.041). Logistic regression analysis revealed that the risk of endophthalmitis increased with intraoperative communication with vitreous (multivariate OR 9.96; 95% CI 4.54 to 21.84; p<0.001). After a median follow-up of 153 days, best-corrected visual acuity in the affected eye was more than 20/70 in 29/65 (44.6%) patients, and more than 20/40 in 20/65 (30.8%). A predictor of good visual acuity was baseline acuity of counting fingers or better (OR 6.25; 95% CI 2.13 to 18.33). Of 64 cases, 25 (39.1%) were culture positive. Coagulase-negative Staphylococcus and Pseudomonas species were the most common organisms isolated, accounting for 72.0% of the culture-positive cases (18/25). Two eye centres that used a combination of a high concentration vancomycin (1 mg/0.1 mL intracameral vancomycin injection or 100 µg/mL vancomycin in irrigating solution) and tobramycin as infection prophylaxis achieved a lower incidence of endophthalmitis than other centres (p<0.001).

CONCLUSIONS

The incidence of acute postoperative endophthalmitis after cataract surgery in tertiary care hospitals of China was 0.033%. Intraoperative communication with vitreous was a major risk factor for developing endophthalmitis. Prophylactic use of a high-concentration vancomycin and tobramycin may play a positive role in the prevention of postoperative endophthalmitis after cataract surgery.

Perioperative antibiotics for prevention of acute endophthalmitis after cataract surgery

BACKGROUND

Endophthalmitis is a severe inflammation of the anterior and/or posterior chambers of the eye that may be sterile or associated with infection. It is a potentially vision-threatening complication of cataract surgery. Prophylactic measures for endophthalmitis are targeted against various sources of infection.

OBJECTIVES

The objective of this review was to evaluate the effects of perioperative antibiotic prophylaxis for endophthalmitis following cataract surgery.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 10), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE, (January 1950 to October 2012), EMBASE (January 1980 to October 2012), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to October 2012), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 25 October 2012. We also searched for additional studies that cited any included trials using the Science Citation Index.

SELECTION CRITERIA

We included randomized controlled trials that enrolled adults undergoing cataract surgery (any method and incision type) for lens opacities due to any origin. Trials that evaluated preoperative antibiotics, intraoperative (intracameral, subconjunctival or systemic) or postoperative antibiotic prophylaxis for acute endophthalmitis were included. We did not include studies that evaluated antiseptic preoperative preparations using agents such as povidone iodine, nor did we include studies that evaluated antibiotics for treating acute endophthalmitis after cataract surgery.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed abstracts and full-text articles for eligibility, assessed the risk of bias for each included study, and abstracted data.

MAIN RESULTS

Four studies met the inclusion criteria for this review, including 100,876 adults and 131 endophthalmitis cases. While the sample size is very large, the heterogeneity of the study designs and modes of antibiotic delivery made it impossible to conduct a formal meta-analysis. Interventions investigated in the studies included the utility of adding vancomycin and gentamycin to the irrigating solution compared with standard balanced saline solution irrigation alone, use of intracameral cefuroxime and/or topical levofloxacin perioperatively, periocular penicillin injections and topical chloramphenicol-sulphadimidine drops compared with topical antibiotics alone, and mode of antibiotic delivery (subconjunctival versus retrobulbar injections). Two studies with adequate sample sizes to evaluate a rare outcome found reduced risk of endophthalmitis with antibiotic injections during surgery compared with topical antibiotics alone: risk ratio (RR) 0.33, 95% confidence interval (CI) 0.12 to 0.92 (periocular penicillin versus topical chloramphenicol-sulphadimidine) and RR 0.21, 95% CI 0.06 to 0.74 (intracameral cefuroxime versus topical levofloxacin). Another study found no significant difference in endophthalmitis when comparing subconjunctival versus retrobulbar antibiotic injections (RR 0.85, 95% CI 0.55 to 1.32). The fourth study which compared irrigation with balanced salt solution (BSS) alone versus BSS with antibiotics was not sufficiently powered to detect differences in endophthalmitis between groups. The risk of bias among studies was low to unclear due to information not being reported.

AUTHORS' CONCLUSIONS

Multiple measures for preventing endophthalmitis following cataract surgery have been studied. One of the included studies, the ESCRS (European Society of Cataract and Refractive Surgeons) study, was performed using contemporary surgical technique and employed cefuroxime, an antibiotic commonly used in many parts of the world. Clinical trials with rare outcomes require very large sample sizes and are quite costly to conduct; thus, it is unlikely that additional clinical trials will be conducted to evaluate currently available prophylaxis. Practitioners should rely on current evidence to make informed decisions regarding prophylaxis choices.

Vancomycin-resistant Gram-positive bacterial endophthalmitis: epidemiology, treatment options, and outcomes

Background

The purpose of this study is to evaluate the microbiological profile and treatment outcomes of vancomycin-resistant Gram-positive bacterial endophthalmitis. Medical records of all patients with Gram-positive bacterial endophthalmitis resistant to vancomycin presenting between 1 January 2005 and 31 December 2010 were reviewed in this noncomparative, consecutive, retrospective case series. Favorable outcome was defined as a best-corrected visual acuity of ≥20/200.

Results

Out of 682 culture-positive endophthalmitis isolates, 448/682 (65.6%) were associated with Gram-positive bacteria. In vitro resistance to vancomycin was noted in 7/448 (1.56%). Three cases were posttraumatic, three were postoperative, and one was endogenous in origin. Four Bacillus isolates, two Staphylococcus isolates, and an Enterococcus isolate were resistant. Isolates resistant to vancomycin were sensitive in vitro to ciprofloxacin in 6/7 (86%) patients. Presenting visual acuity was light perception in all seven cases. Favorable outcome was achieved in only 1/7 (14.3%) cases.

Conclusions

Vancomycin-resistant endophthalmitis is uncommon and usually associated with poor visual outcome. Bacillus sp. is the most frequent Gram-positive bacteria resistant to vancomycin. Fluoroquinolones like ciprofloxacin may be considered as a useful alternative in vancomycin-resistant endophthalmitis.

Residual lens cortex material: potential risk factor for endophthalmitis after phacoemulsification cataract surgery

PURPOSE

To evaluate the bacterial growth potential of residual lens cortex after phacoemulsification with the development of endophthalmitis.

SETTING

University medical center.

DESIGN

Experimental study.

METHOD

Staphylococcus aureus and Staphylococcus epidermidis were dispensed into aqueous humor or serial dilutions of lens cortex that were obtained from cataract patients during phacoemulsification. After a 24-hour incubation, the colony-forming unit (CFU) was quantified. Eighty rabbits had phacoemulsification. Complete lens cortex removal was performed in 40 rabbits, while a quarter of lens cortex was retained in 40 rabbits. Staphylococcus aureus, with an inoculum size of 32 CFU, 56.3 CFU, and 108.6 CFU, was injected intracamerally at the conclusion of surgery and the production of endophthalmitis was measured 72 h later. The aqueous and vitreous humor samples were collected for microbiological diagnosis.

RESULTS

The increase in bacterial growth of S aureus and S epidermidis was statistically significantly greater in each dilution of lens cortex than in aqueous humor (P < .001, Student t test). With inoculum of 32.0 CFU or 56.3 CFU of S aureus, there was a statistically higher incidence of bacterial culture-proven endophthalmitis in the residual lens cortex eye group than in the normal aphakic eye group (P < .05, Fisher exact test).

CONCLUSIONS

Lens cortex was associated with a significant increase in bacterial growth compared with aqueous humor. Therefore, eyes with residual lens cortex seem more prone to develop endophthalmitis if anterior chamber bacterial contamination occurs during phacoemulsification.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Comparison of different techniques of cataract surgery in bacterial contamination of the anterior chamber in diabetic and non-diabetic population

Aim:

To compare the bacterial contamination of the anterior chamber (AC) between manual small incision cataract surgery (SICS) and phacoemulsification (Phaco). To study the conjunctival flora and bacterial contamination of AC between well-controlled diabetics and non-diabetics.

Materials and Methods:

Three hundred and sixty-eight patients were randomized to manual SICS and Phaco. Sixty-eight patients were excluded for not completing follow-up or for intraoperative complications like posterior capsule rupture. One hundred and fifty patients in each group were finally analyzed. Conjunctival swabs were taken on admission, after one day of topical ofloxacin and 15 min after 5% Povidone Iodine (PI) instillation. AC aspirate at the end of the surgery was also cultured.

Results:

Fifty-six (18.66%) patients had positive conjunctival swab on admission which was reduced to 19 (6.33%) with topical ofloxacin and to five (1.66%) with instillation of 5% PI. AC contamination in both manual SICS and Phaco was 0.66%. The conjunctival flora in diabetics was similar to non-diabetics. None of the diabetics had AC contamination. Statistical analysis was performed by Chi-Square test (with Yates’ correction).

Conclusion:

Statistically significant reduction in conjunctival flora was achieved with topical ofloxacin and 5% PI instillation and AC contamination in both manual SICS and Phaco was minimal (0.66%). Well-controlled diabetics who underwent cataract surgery in this study had similar conjunctival flora and AC contamination as non-diabetics.

Preoperative Antisepsis With Povidone-Iodine 5% in Cataract Surgery

PURPOSE

This study aimed to evaluate the efficacy of povidone-iodine (PI) 5% as the only preoperative antiseptic in cataract surgery.

DESIGN

Prospective interventional case series.

METHODS

Fifty patients undergoing phacoemulsification under topical anesthesia in an outpatient surgery setting in a teaching hospital participated in the study. The preoperative antiseptic regimen consisted of instillation into the conjunctival sac and periorbital scrub with PI 5%. No topical antibiotic was given. Eyelid margin swabs were obtained for bacteriological culture before and after PI antisepsis and at the conclusion of surgery. The number of bacterial species isolated was compared with the Wilcoxon test. Anterior chamber aspirates were taken immediately before and after surgery to determine the rate of contamination.

RESULTS

Bacteria were isolated from the eyelid margins of 48 patients (96%; 95% exact confidence interval, 86.3%-99.5%) before surgery, from the eyelid margins of 28 patients (56%) after antisepsis with PI 5%, and from the eyelid margins of 26 patients (56%; 95% exact confidence interval, 41.3%-70.0%) at the conclusion of surgery. The reduction of positive eyelid margin culture was statistically significant (P < 0.0001). Anterior chamber aspirates were positive in 3 patients. One patient with negative growth from anterior chamber aspirates developed culture-negative postoperative endophthalmitis.

CONCLUSIONS

Because 56% of eyelids still have positive culture after PI 5% antisepsis, it might not be relied on as the sole preoperative antiseptic measure. Meticulous surgical technique, together with other modalities of preoperative and intraoperative antisepsis, should be used to prevent postoperative endophthalmitis.

Acute Postoperative Endophthalmitis Following Cataract Surgery: A Review

Endophthalmitis following cataract surgery is rare but continues to be a serious complication following cataract surgery. Over the years, the incidence of endophthalmitis has declined because of various preoperative and perioperative measures. They include use of antiseptic and appropriate surgical draping techniques. In this review, we have focused on the incidence, existing risk factors, various clinical features, management strategies, and prophylaxis pertaining to postoperative endophthalmitis following cataract surgery. Outcomes and pitfalls of 2 landmark studies, namely, the Endophthalmitis Vitrectomy Study and the European Society of Cataract and Refractive Surgeons Endophthalmitis Study, are briefly mentioned.Infectious endophthalmitis following cataract surgery is a dreaded complication. Preoperative identification of risk factors and effective prophylaxis could help in reducing its incidence. Early diagnosis followed by management of these patients either with vitreous tap or vitrectomy coupled with intravitreal antibiotics holds the key.

Reduction of anterior chamber contamination rate after cataract surgery by intraoperative surface irrigation with 0.25% povidone-iodine

PURPOSE

To prove the hypothesis that during cataract surgery, repeated irrigation of the operative field with povidone-iodine of 0.25% reduces the anterior chamber bacterial contamination rate at completion of operation.

DESIGN

Prospective, interventional case series.

METHODS

In 404 consecutive eyes, the operative field was irrigated with infusion fluid in 202 eyes (group A) and with 0.25% povidone-iodine in 202 eyes (group B). Bacteriologic culture was performed using the following samples: ocular surface fluid after lid speculum placement and anterior chamber fluid at the completion of surgery. Anterior chamber fluid samples were collected at the beginning and completion of surgery for iodide ion concentration measurement. Corneal endothelial cell density was measured using a specular microscope before surgery and on day 7 after surgery.

RESULTS

Bacterial detection rate in ocular surface fluid was not significantly different between group A (5.5%) and group B (6.0%), but the rate in anterior chamber fluid was significantly (P = .0017) reduced in group B (0%) compared with group A (5.0%). Iodide ion concentrations at the start and end of surgery were 7.5 ± 0.7 μg/mL and 3.5 ± 0.7 μg/mL, respectively, in group B and less than 0.1 μg/mL both at the start and end of surgery in group A. Corneal endothelial cell densities were not significantly difference between groups A and B before surgery (2614 ± 233/mm² vs 2534 ± 173/mm²; P = .2254) and 7 days after surgery (2463 ± 269/mm² vs 2338 ± 204/mm²; P = .4044).

CONCLUSIONS

In cataract surgery, repeated irrigation of the operative field with povidone-iodine at a concentration of 0.25% achieved an extremely low bacterial contamination rate in the anterior chamber at the completion of surgery.

Randomized controlled trial on the safety of intracameral cephalosporins in cataract surgery

Objective:

To compare the safety profiles of intracameral cephalosporins in cataract surgery.

Patients and methods:

In this controlled trial, 129 patients were randomized to one of four groups to receive 1 mg of one of three cephalosporins – cefazolin, cefuroxime, or ceftazidime, or normal saline – given intracamerally during cataract surgery. Central endothelial cell density (ECD) and retinal center point thickness (CPT) were determined by specular microscopy and ocular coherence tomography, respectively, before and at 3 months after surgery.

Results:

There were no statistical significant differences in the changes of ECD and CPT between eyes receiving intracameral cephalosporin and control.

Conclusion:

The use of intracameral cefazolin, cefuroxime, or ceftazidime (1 mg in 0.1-mL solution) at the time of cataract surgery had no significant effect on ECD and CPT postoperatively.

Contribution of secreted proteases to the pathogenesis of postoperative Enterococcus faecalis endophthalmitis

PURPOSE

To determine how a secreted protease contributes to the pathogenesis of post-cataract endophthalmitis caused by Enterococcus faecalis using an aphakic rabbit endophthalmitis model.

SETTING

Department of Ophthalmology, Ehime University School of Medicine, Ehime, Japan.

METHODS

The pathogenesis of E faecalis OG1S (secreted protease-positive) and E faecalis OG1X (secreted protease-negative derivative of OG1S) was compared. After lens removal by phacoemulsification, either strain was inoculated into the lens bag. Changes in bacterial growth, electroretinography (ERG), and pathology of eyes were comparatively monitored throughout the course of the infection. Alternatively, culture fluid from either strain was injected into the vitreous body and ERG and pathology of the eyes were also examined.

RESULTS

The levels of growth in the anterior chamber and vitreous cavity were similar for both strains. However, infection with OG1S resulted in a significantly greater reduction in ERG b-wave amplitude than OG1X. Histological examination showed that the posterior lens capsules were severely affected in eyes infected with OG1S, and inflammatory cells and cocci were found in the anterior vitreous cavity 24 hours after the infection. By 48 hours, the retina architecture was profoundly affected in eyes infected with OG1S. In contrast, few pathological changes were noted in the posterior lens capsules and retina of eyes infected with OG1X. Culture fluid in which OG1S had grown decreased ERG b-wave amplitude and caused morphological changes of the posterior capsule and retina similar to those in the infected eye.

CONCLUSION

An extracellular protease plays a major role in the pathogenesis of E faecalis-induced postoperative endophthalmitis.

Efficacy of intraoperative vancomycin in irrigating solutions on aqueous contamination during phacoemulsification

Purpose:

To study the efficacy of adding vancomycin in irrigating solutions, in comparison to topical antibiotic given preoperatively for a day, during phacoemulsification, in reducing the anterior chamber (AC) contamination.

Settings and Design:

This was a prospective, interventional, hospital-based study.

Materials and Methods:

This was a study involving 400 eyes of 400 paitens, undergoing routine phacoemulsification between January 2004 and June 2006. The patients were non-randomly assigned to two groups: Group 1 included 180 patients, who received topical ciprofloxacin eye-drops (four-hourly) for a day preoperatively and Group 2 included 220 patients, who underwent phacoemulsification with vancomycin (20 µg/ml) in the irrigating solution. Anterior chamber aspirate obtained at the end of the surgery was sent for microbial workup. The number of positive cultures in both the groups was determined.

Statistical analysis:

This was performed using Chi-square test.

Results:

Aqueous samples showed microbial growth in 38 (21.1%) out of 180 eyes in Group 1 and in 17 (7.7%) out of 220 eyes in Group 2 (P = 0.001). Coagulase-negative staphylococcus was the most common organism in both the groups. Aqueous samples from four eyes in group 1 showed multiple organisms, while none of the sample from group 2 showed more than one organism. None of the eyes in either group showed fungal contamination. One patient in Group 1 developed endophthalmitis, and the causative organism was Alcaligenes faecalis. All patients were followed up for a minimum of six months (range: 6 to 14 months and mean: 9.3 months).

Conclusion:

Addition of vancomycin in irrigating solutions is more efficacious in reducing AC contamination in comparison to topical antibiotic administered a day preoperatively.

Clustering of invasiveAspergillus ustuseye infections in a tertiary care hospital: A molecular epidemiologic study of an uncommon species

Aspergillus infections are being increasingly recognized as an important cause of morbidity and blindness. We report here the first cluster of Aspergillus ustus endophthalmitis cases which occurred in a large tertiary care hospital during the period October 2003 to June 2004. In three of the cases, the patients required enucleation following cataract surgery, while the fourth involved a fatal infection in a pediatric patient hospitalized for osteopetrosis. Patient charts from the four cases were reviewed retrospectively and indicated that postoperative signs of fungal endophthalmitis developed in the patients 1-11 weeks after surgery. The molecular characterization of the isolates and their epidemiological relatedness were evaluated by Random Amplification of Polymorphic DNA (RAPD). A source investigation of this mini outbreak was performed by environmental sampling, but no isolates of A. ustus were recovered from these studies. All A. ustus strains isolated from three patients with fungal endophthalmitis had the same RAPD pattern suggesting a common source. The strain from the pediatric patient differed from the ophthalmic isolates in five electrophoretic loci. The latter was included solely as an outbreak, unrelated control to evaluate the discriminatory power of the molecular typing method employed in the analysis of the ophthalmic strains. These cases illustrate the potential for uncommon species like A. ustus to cause high morbidity and mortality in some clinical settings. Aspergillus ustus endophthalmitis is a serious and devastating complication of ocular surgery. It is unknown whether ongoing hospital construction may have contributed to this cluster of cases. Random amplification of polymorphic DNA may give valuable clues about the clonality of A. ustus strains.

Endophtalmie : étiopathogénie et antibioprophylaxie

Postoperative endophthalmitis is still one of the most fearsome complications of cataract surgery. The present review's aims are to study the etiology and pathogenesis of endophthalmitis and the criteria for antibiotic prophylaxis. Endophthalmitis prevalence is 0.07%-0.32% in cataract surgery. The clinical presentation needs to be perfectly known, even if none of the signs is pathognomonic. Bacteria predominantly cultured in postoperative endophthalmitis are gram-positive, especially Staphylococcus epidermidis. Most of the bacteria come from the patient. Bacterial adhesion to intraocular lenses (IOLs) takes place during their implantation, a prominent etiological factor. Polypropylene was the first biomaterial that proved this relation of cause and effect between bacterial adhesion and endophthalmitis. The benefit of antibiotic prophylaxis during cataract surgery has yet not been proven, since the low prevalence of endophthalmitis makes controlled studies with a large cohort difficult. The criteria and the four possible administration approaches (topical, subconjunctival, irrigation liquid, systemic) are analyzed.

Endophthalmitis: incidence and prevention

PURPOSE OF REVIEW

To present current peer-reviewed articles related to the incidence and prevention of postoperative endophthalmitis.

RECENT FINDINGS

Recent literature indicates that the incidence of postoperative endophthalmitis may be on the rise. Although the preoperative use of antibiotics as prophylaxis is still controversial, it is becoming more common.

SUMMARY

The reports of endophthalmitis analyzed from peer-reviewed ophthalmic journals suggest that the incidence of endophthalmitis has increased, ranging from 0.1 to 0.18% in different countries. This may be related to factors associated with the incision. Although some resistance has been detected, fourth-generation fluoroquinolones seem to be a proper antibiotic for endophthalmitis prophylaxis because of their spectrum, mode of action, and penetration.