Prophylactic antibiotics for ophthalmic surgery

Acute-Onset Postoperative Herpetic Endophthalmitis: A Case Report

Herpes simplex virus uveitis without corneal reactivation is more frequent than previously thought. Although herpes simplex virus has been implicated as a cause of postoperative uveitis and endophthalmitis, it has not been reported as a cause of acute postoperative endophthalmitis within the early postoperative period, specifically within one week following cataract extraction. A 55-year-old man with vascularized irregular central disc-shaped stromal corneal opacity with complicated cataracts underwent cataract surgery. Intraoperatively, there was posterior capsular rent, requiring anterior vitrectomy. On postoperative day three, the patient had an increase in inflammation in the anterior chamber (grade 4+) with marked vitreous haze (grade 4). Vitreous taps were negative for bacteria and fungi, and despite intravitreal injections of vancomycin and ceftazidime, the patient had worsening of inflammation with increasing exudates and the appearance of the fibrinous membrane in the anterior chamber. Polymerase chain reaction (PCR) of aqueous and vitreous samples at this point of time yielded positive serology for herpes viral DNA, and the patient was started on oral valacyclovir. The ocular inflammation resolved soon after switching to oral valacyclovir. Typical acute postoperative endophthalmitis starts two to seven days after surgery, and the most common isolate in vitreous biopsies is coagulase-negative staphylococci. We report a rare case of acute-onset herpetic endophthalmitis presenting within 72 hours following cataract surgery for a complicated cataract in a patient with a history of pre-existing healed viral keratitis. Our case highlights that a suspicion of viral endophthalmitis should be kept in mind as a cause of acute-onset post-cataract surgery endophthalmitis, especially in cases of surgery that fail to yield a positive result on Gram's stain, culture or PCR for bacteria and fungi.

Distribution and risk factors of postoperative endophthalmitis in people with diabetes

Purpose

To evaluate (i) the distribution of postoperative endophthalmitis (POE) in patients who underwent cataract surgery, (ii) risk factors in diabetic versus nondiabetic patients, and (iii) distribution of POE in those who had undergone rapid reduction of preoperative blood sugar levels versus those with normal blood sugar levels.

Methods

Medical records were reviewed from January 1995 to July 2021. In total, 391 eyes of 391 patients who developed POE after cataract surgery were studied. Patients with POE were divided into Group A, patients with diabetes (n = 128), and Group B, patients without diabetes (n = 263), and the associations of various clinical factors in the two groups were studied. Patients with diabetes with raised random blood sugars (RBS) preoperatively were subjected to a rapid reduction of blood sugar (RBS <200 mg%) to be considered eligible for surgery. Microbiological profile of patients was examined.

Results

The cumulative incidence of POE over 26 years was 0.09%. Those who underwent a rapid reduction in preoperative blood sugar levels had higher rates of POE (53.1%) compared with (46.9%) those with blood sugar levels under control (P = 0.486). Men with diabetes had 1.634 times higher odds of POE (P = 0.048), and those with diabetes and hypertension had 3.961 times greater odds of having POE (P < 0.001) when adjusted for age, alcohol, smoking, and socioeconomic strata and presence of posterior capsule rupture. Positive culture results were observed in 45/128 (35%) patients with diabetes and 71/263 (27%) patients without diabetes. Staphylococcus epidermidis was the most commonly identified organism and was detected in 10/45 (22%) in those with diabetes and 21/71 (29%) in those without diabetes of all the culture-positive cases.

Conclusion

In patients with POE, the odds are greater for men with diabetes, those with a history of hypertension, as well as those who undergo a rapid reduction of preoperative blood sugar.

Ion Exchange Nanoparticles for Ophthalmic Drug Delivery

We report here on ion-exchange polymeric nanoparticles from a linear copolymer of maleic anhydride methyl vinyl ether esterified with 30% octadecanol. The side chains for the polymer structure were optimized through metadynamics simulations, which revealed the use of octadecanol esters generates ideal free energy surfaces for drug encapsulation and release. Nanoparticles were synthesized using a solvent evaporation-precipitation method by mixing the polymer solution in acetone into water; upon acetone evaporation, a nanodispersion with an average particle size of ∼150 nm was obtained. Gentamicin sulfate, possessing five amino groups, was spontaneously entrapped in the nanocarrier by ionic interactions. Encapsulation efficiency increases significantly with the increase in pH and ionic strength. In vivo results demonstrate high gentamicin (GM) content in the enteric chamber (AUC 8207 ± 1334 (μg min)/mL) compared to 3% GM solution (AUC 2024 ± 438 (μg min)/mL). The formulation was also able to significantly extend the release of gentamicin when applied to rabbit cornea. These anionic nanoparticles can be used for extended-release of other cationic drugs.

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

PURPOSE

To determine the efficacy of intraoperative antibiotic use in irrigating solutions on aqueous humor contamination during phacoemulsification surgery and to evaluate the corresponding risk of postoperative endophthalmitis.

METHODS

644 eyes of 640 patients who underwent phacoemulsification surgery with foldable intraocular lens (IOL) implantation were included in this study. Preoperative conjunctival smears were taken and eyes were allocated to receive irrigating infusion fluid containing either balanced salt solution (BSS)-only (group 1; 322 eyes) or BSS with antibiotics (vancomycin and gentamycin) during surgery (group 2; 322 eyes). Bacterial contamination rates of aqueous humor samples taken in the beginning and at the end of operation were compared. Predictive factors for the development of postoperative endophthalmitis were determined by clinical and microbiologic analyses.

RESULTS

The rates of culture-positivity were similar between group 1 and group 2 for both preoperative conjunctival smears and aqueous samples (p > 0.05). Aqueous samples taken at the end of operation were found to be contaminated in 68 (21.1%) eyes in group 1 and 22 (6.8%) eyes in group 2, and the difference was significant (p = 0.0001; OR = 3.65 (2.1-6.0)). Capsular rupture was associated with higher rate of contamination in both groups (p = 0.0001; OR = 7.7 and p = 0.0001; OR = 8.1). Two eyes in the BSS-only group developed postoperative endophthalmitis and these cases had posterior capsular rupture during the surgery and culture-positivity for staphylococcus epidermidis throughout the study.

CONCLUSIONS

Intraoperative antibiotic irrigation decreases aqueous humor contamination during phacoemulsification. Further studies are warranted to determine the interrelationship between aqueous humor contamination and endophthalmitis in eyes with posterior capsular rupture.

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.

Aerobic bacterial flora of the normal conjunctiva at high altitude area of Shimla Hills in India: a hospital based study

AIM

To study the normal aerobic conjunctival flora in lower to mid Himalayan region of Shimla Hills.

METHODS

Samples from normal conjunctiva of 200 individuals above the age of 13 years who visited Indira Gandhi Medical College Hospital Shimla for refraction or cataract surgery were taken by anaesthetising the conjunctival sac with sterile 4% Xylocaine solution. Samples were obtained by gently rubbing lower fornix with a sterile cotton wool swab moistened with normal saline and keeping the eye lids wide apart to avoid contamination from lid margins. It was immediately inoculated in Brain Heart infusion and subjected to standard aerobic culture and identification techniques.

RESULTS

Totally, 72 eyes (36%) conjunctival sacs were sterile. Predominant aerobes isolated were Staphylococcus spp. in 120 (60%) followed by Haemophilus in 16 (8%), diphtheroids in 10 (5%), and Escherichia.coli (E. coli) in 4 (2%). A single aerobe was isolated from 98 eyes (49%) while 30 eyes (15%) yielded more than 1 aerobe. Staphylococcus epidermidis (S. epidermidis) was the most common bacterium, found alone in 58 eyes (29%) and in combination with another aerobe in 30 eyes (15%), followed by Staphylococcus aureus (S. aureus) in 18 (9%) and 10 eyes (5%) respectively.

CONCLUSION

S. epidermidis is the most common commensal organism followed by Haemophilus species. diphtheroids occupied the third position which otherwise are found more abundantly in literature. Pathogens like S. aureus, Staphylococcus citreus and E. coli were also found. Therefore, preoperative administration of topical broad spectrum antibiotics is extremely important in prophylaxis against ocular infection. The variation in microflora of normal conjunctiva in this part of world can be attributed to geographical, climatic and ethnic characteristics of the population under study.

Patterns of perioperative prophylaxis for cataract surgery in Canada

BACKGROUND

The objective of this study was to document prophylactic methods used for cataract surgery in Canada.

METHODS

The Web-based link to a password-protected, anonymous, online survey was e-mailed or mailed, between November 2004 and January 2005, to 800 ophthalmologists practicing in Canada.

RESULTS

Of the 239 respondents (30% response rate), 216 performed cataract surgery. Phacoemulsification was preferred by 99%. Topical antibiotics, of which moxifloxacin was the most common (32%), were used preoperatively by 78%. Intraoperatively, 98% used providone-iodine antisepsis of skin, 15% used intracameral antibiotics and 11% subconjunctival antibiotics. Postoperative topical antibiotics, of which moxifloxacin was the most common (30%), were used by 97%, and 1% routinely used postoperative systemic antibiotics. Prophylactic regimen was changed after vitreous loss by 39%, of whom 68% added systemic antibiotics. Reported mean rate of postoperative endophthalmitis occurring within the previous year was 0.088%. Community practicing ophthalmologists were more likely to use preoperative topical antibiotics (p = 0.0016, chi2). As case volume increased, surgeons were more likely to use intracameral antibiotics (p = 0.0185, exact Mantel-Haenszel chi2 test) and postoperative topical antibiotics (p = 0.0044, exact Mantel-Haenszel chi2 test), and less likely to use subconjunctival antibiotics (p = 0.0011, exact Mantel-Haenszel chi2). As time in practice decreased, surgeons were more likely to use postoperative topical antibiotics (p = 0.0319, exact Mantel-Haenszel chi2 test). Provincial region was associated with preoperative topical antibiotic use (p = 0.0076, Fisher's exact test), intracameral antibiotic use (p = 0.0314, Fisher's exact test), and subconjunctival antibiotic use (p = 0.0373, Fisher's exact test). There was no association between reported rate of postoperative endophthalmitis and any form of perioperative antibiotic use.

INTERPRETATION

Prophylactic methods commonly used for cataract surgery in Canada include providone-iodine antisepsis and perioperative topical antibiotics. Intracameral and subconjunctival antibiotics are currently not common prophylactic methods. Systemic antibiotics are used prophylactically by a subset of ophthalmologists for cases complicated by vitreous loss.

Retracted: Epidemiological evaluation of intraoperative antibiosis as a protective agent against endophthalmitis after cataract surgery

PURPOSE

To evaluate risk factors for endophthalmitis after cataract surgery and to retest recent findings on the protective effect of intraoperative antibiosis and the promoting effect of the clear corneal as compared to sclerocorneal incision.

DESIGN

Survey study.

PARTICIPANTS

Five hundred thirty-eight ophthalmosurgical centers in Germany.

MAIN OUTCOME MEASURE

Responder specific endophthalmitis incidence.

RESULTS

A total of 310 (58%) questionnaires were computed resulting in an overall count of 404 356 cataract surgeries and 291 self-reported endophthalmitis cases (crude rate 0.072%). The risk of postoperative endophthalmitis for sclerocorneal versus clear corneal incisions was not significantly reduced (relative risk 0.97, 99% confidence interval 0.69-1.38). The hypothesis of a protective effect of intraocular antibiosis could be confirmed by a significantly decreased risk ratio of 0.69 (99% confidence interval 0.48-0.99) indicating a significant benefit from intraoperative intraocular antibiosis. A similar tendency was observed for an intraoperative periocular antibiosis with a significantly reduced risk ratio of 0.68 (99% confidence interval 0.49-0.96). These risk estimates had been adjusted for the size of the surgical center: a significantly reduced risk ratio of 0.70 (99% confidence interval 0.49-0.98) for postoperative endophthalmitis was observed for local centers.

CONCLUSIONS

Whereas this 2001 appraisal of a survey in 1996 could not reproduce the benefit of sclerocorneal incision, the protective effect of intraoperative intraocular antibiotic prophylaxis could be confirmed. However, the results of this survey have to be interpreted with care, since it is not based on individual case information, but rather on aggregate questionnaire data.

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.

Comparison of topical tobramycin—dexamethasone with dexamethasone—neomycin—polymyxin and neomycin—polymyxin—gramicidin for control of inflammation after cataract surgery: Results of a multicenter, prospective, three-arm, randomized, double-masked, controlled, parallel-group study

BACKGROUND

Intraocular inflammation is typically treated with a combination of anti-inflammatory and anti-infective drugs. Tobramycin-dexamethasone (TD) has not been associated with any serious adverse events, indicating good tolerability.

OBJECTIVE

The aims of this study were the following: (1) to demonstrate noninferiority of TD compared with dexamethasone-neomycin-polymyxin (DNP) in terms of anti-inflammatory efficacy, (2) to compare the anti-inflammatory efficacy of TD and DNP with that of a "placebo" control (antibiotic without anti-inflammatory agent), and (3) to provide additional safety data on TD.

METHODS

This prospective, double-masked, parallel-group study was conducted at 22 ophthalmology clinics across Europe and Brazil. Patients aged > 18 years undergoing cataract surgery were randomly assigned, in a 2:2:1 ratio, to receive tobramycin 3 mg/mL plus dexamethasone 1 mg/mL, dexamethasone 1 mg/mL plus neomycin sulfate 3500 IU/mL plus polymyxin B sulfate 6000 IU/mL, or neomycin sulfate 3500 IU/mL plus polymyxin B sulfate 7500 IU/mL plus gramicidin 20 microg/mL. All treatments were given as 1 drop instilled in the operated eye q.i.d. for 21 days. The primary efficacy end point, intraocular inflammation (determined using the sum of scores on anterior chamber cells and aqueous flare), was assessed at days 3, 8, 14, and 21 after surgery.

RESULTS

A total of 271 patients were enrolled (158 women, 113 men; age range 42-90 years) (TD, 104 patients; DNP, 110 patients; and neomycin-polymyxin-gramicidin [NPG], 57 patients). Intraocular inflammation was similar in the TD and DNP groups at all time points. At days 8, 14, and 21, inflammation scores were significantly lower with TD than with NPG (all, P < 0.05). At day 8, the inflammation score was significantly lower with DNP than with NPG (P < 0.05). A greater number of patients receiving NPG experienced treatment-related ocular allergic reactions compared with patients receiving TD (P < 0.05). One patient receiving TD (1.0%) and 5 given NPG (9.0%) were withdrawn due to ocular allergic reactions. None of the patients experienced an increase in intraocular pressure > or =10 mm Hg from baseline.

CONCLUSIONS

In this study of patients undergoing cataract surgery combination therapy with TD was noninferior to DNP and was well tolerated.

Prophylactic Effectiveness of Tobramycin-Dexamethasone Eye Drops Compared with Tobramycin/Vehicle Eye Drops in Controlling Post-Surgical Inflammation in Cataract Patients

OBJECTIVE

To demonstrate the superiority of TobraDex((R)) (tobramycin 3 mg/mL, dexamethasone 1 mg/mL) eye drops over Tobrex((R)) (tobramycin 3 mg/mL)/vehicle (placebo) eye drops in the prophylaxis of inflammation after cataract surgery, and to provide additional safety data on TobraDex((R)).

SETTING

Twenty-two ophthalmology clinics from Brazil, Belgium, Germany, Ireland, Portugal, Spain and Sweden.

PATIENTS AND METHODS

Prospective, randomised, double-masked, two-arm, parallel-group, placebo-controlled, multicentre study in 417 patients undergoing extracapsular cataract extraction with intraocular lens implantation. Patients were randomised (1 : 1) to TobraDex((R)) or to Tobrex((R))/vehicle. One drop of TobraDex((R)) or Tobrex((R)) was instilled in the operative eye (four times daily) on the day before surgery (day -1), one drop immediately following surgery in the operated eye (day 0), and then treatment (four times daily) was continued until day 7 (inclusive). From day 8 through day 21, patients in the TobraDex((R)) group continued with the same treatment, but patients in the Tobrex((R))/vehicle arm received the inactive ingredient only. Efficacy was assessed at 1, 3, 8, 14 and 21 days. The primary efficacy variable was the percentage of patients without post-surgical anterior chamber inflammation (i.e. with a sum of cells and flare scores of zero) on the day 8 visit.

RESULTS

TobraDex((R)) was significantly better (p < 0.05) than Tobrex((R))/vehicle in controlling post-surgical inflammation at day 8 as shown by the percentage of patients with an inflammation score of zero (51% vs 21%, respectively). The percentage of patients with treatment failure was 4% vs 16% (p < 0.001) in favour of TobraDex((R)). In the safety population (n = 415), 19% of patients reported a total of 52 adverse events while receiving TobraDex((R)) and 35.3% patients reported 103 adverse events while receiving Tobrex((R))/vehicle. One patient receiving Tobrex((R))/vehicle discontinued the study due to an ocular allergic reaction. No patient experienced clinically relevant changes in visual acuity, fundus parameters, cup/disc ratio or intraocular pressure related to treatment following the day of surgery.

CONCLUSIONS

TobraDex((R)) eye drops were superior to Tobrex((R))/vehicle in controlling post-surgical inflammation following cataract extraction. TobraDex((R)) administered four times daily over 21 days post-surgery was safe and well tolerated in patients treated for the prevention of post-surgical inflammation following cataract extraction.

Aqueous humor levels of topically applied levofloxacin, norfloxacin, and lomefloxacin in the same human eyes

PURPOSE

To assess the relative penetration of topical eyedrops of 3 fluoroquinolones into the aqueous humor in human eyes.

SETTING

Department of Ophthalmology, Sano-Kosei Hospital, Sano, Japan.

METHODS

Fifty-nine cataract patients (36 women, 23 men) received 3 drops each of levofloxacin 0.5%, norfloxacin 0.3%, and lomefloxacin 0.3% in the same eye at 15-minute intervals beginning 90 minutes before cataract surgery. At the beginning of surgery, 50 microL of aqueous humor was aspirated from the anterior chamber and stored at -80 degrees C until analyzed. The drug concentrations in the samples were analyzed using high-performance liquid chromatography.

RESULTS

Five patients were excluded from the study because their sample volumes were insufficient. Norfloxacin was detected in 3 patients; the mean aqueous humor level was 0.10 microg/mL +/- 0.02 (SD). Levofloxacin was detected in all cases; the mean aqueous humor level was 0.60 +/- 0.28 microg/mL (n = 54). Lomefloxacin was not detected in 10 patients; the mean aqueous humor level was 0.23 +/- 0.11 microg/mL (n = 44).

CONCLUSION

Topically applied levofloxacin had better penetration into the aqueous humor than lomefloxacin and norfloxacin.

A 10 year retrospective survey of cataract surgery and endophthalmitis in a single eye unit: injectable lenses lower the incidence of endophthalmitis

AIM

To study the incidence of endophthalmitis following cataract surgery over a 10 year period, and to examine ways in which this may be related to changes in surgical technique.

METHODS

All cases of endophthalmitis occurring over a 10 year period within a single ophthalmic unit in the United Kingdom were reviewed, and possible risk factors identified.

RESULTS

During the study period, as the technique of extracapsular cataract surgery was replaced by phacoemulsification, there was a commensurate reduction in the incidence of endophthalmitis. Injectable IOLs were associated with the lowest risk of postoperative endophthalmitis (0.028%).

CONCLUSIONS

Injectable intraocular lenses do not make contact with the ocular surface and this may result in the observed lower rate of endophthalmitis. This, and the ease with which they can be inserted through small incisions, support their use as the first line method of lens insertion.

Topical ciprofloxacin-dexamethasone combination therapy after cataract surgery: randomized controlled clinical trial

PURPOSE

To determine the efficacy of a combination of ciprofloxacin 0.3% and dexamethasone 0.1% eyedrops in controlling immediate inflammation after cataract surgery.

SETTING

Dr. Rajendra Prasad Centre for Ophthalmic Sciences and Department of Pharmacology, All India Institute of Medical Sciences, New Delhi, India.

METHODS

This randomized controlled clinical trial comprised 61 patients, 31 of whom were treated with a combined ciprofloxacin-dexamethasone suspension (study group) and 30, with a standard formulation of betamethasone and neomycin eyedrops (control group). One and 7 days postoperatively, pain, lid edema, lacrimation, conjunctival congestion, aqueous flare and cells, and side effects were noted. A conjunctival swab for bacteria and a fungus culture were sent for evaluation 7 days postoperatively.

RESULTS

At 7 days, there was no statistically significant difference between groups in lid edema, conjunctival congestion, anterior segment inflammation, lacrimation, or pain. Two patients in the ciprofloxacin-dexamethasone group noted white deposits in and around the eye that resolved after the dose was reduced to 4 times a day. No patient reported or developed an allergic reaction to either drug combination.

CONCLUSION

A ciprofloxacin-dexamethasone combination was effective in controlling inflammation after cataract surgery.

Does surgical technique influence cataract surgery contamination?

PURPOSE

To compare cataract surgery contamination rates in large-incision extracapsular cataract extraction (ECCE) and phacoemulsification (PE), we studied 65 cases prospectively.

METHODS

Thirty-five cases were operated by large-incision ECCE (Group I) and 30 by PE (Group II). Conjunctival swab cultures were taken immediately before surgery and anterior chamber aspirate was taken for culture upon completion of surgery for each case.

RESULTS

Anterior chamber cultures were positive in 22.8% of the cases in group I and 23% in Group II. Frequencies of contamination in each group were no different (x2: 0.22, p>0.05). When the contaminations were evaluated in relation to operating time, prolongation of the operating time raised the contamination rate in Group I (p<0.05) but not in Group II (p>0.05). Silicone and PMMA intraocular lenses (IOL) were tested to see whether they had any additional risk of contamination. The frequencies of contaminated silicone IOL implanted cases (6/26) and contaminated PMMA IOL implanted cases (8/39) were similar (x2: 0.36, p>0. 05).

CONCLUSIONS

Although the architecture of the incision and irrigation dynamics provided an advantage to the PE technique as the operating time became longer, routine PE was not superior to classical ECCE with respect to contamination when performed in the same circumstances. Prolonging the operating time raised the contamination rate in classical ECCE.

Improved detection of microorganisms by polymerase chain reaction in delayed endophthalmitis after cataract surgery

OBJECTIVE

To evaluate whether the use of polymerase chain reaction (PCR) improves the identification of the causative pathogen in eyes developing delayed endophthalmitis after cataract surgery.

DESIGN

Prospective, noncomparative case series.

PARTICIPANTS

Consecutive series of 25 eyes with the clinical diagnosis of delayed endophthalmitis after cataract.

MAIN OUTCOME MEASURE

Presence of bacterial or fungal DNA in aqueous humor and vitreous samples.

RESULTS

In the aqueous humor the causative pathogen was identified in 84% (n = 21) of the eyes by PCR compared with 0% by diagnostic culture and 0% by microscopy. In the vitreous samples the pathogen was identified in 92% (n = 23) of the eyes by PCR compared with 24% by diagnostic culture (n = 6) and 0% by microscopy.

CONCLUSIONS

PCR is useful for the identification of the causative pathogen in delayed endophthalmitis and had a higher rate of positive identification of the causative organism than microscopy or diagnostic culture.

Endophthalmitis in cataract surgery: results of a German survey

OBJECTIVE

To document perioperative prophylactic treatment and to evaluate the risk factors for endophthalmitis after cataract surgery.

DESIGN

Cross-sectional study via anonymous survey.

PARTICIPANTS

Four hundred sixty-nine centers in Germany were queried.

RESULTS

A total of 311 (67%) questionnaires were received, with each center reporting an average of 900 cataract surgeries per year (total, 340,633 surgeries in 1996). Respondents reported a total of 267 cases of endophthalmitis, which resulted in a mean responder-specific endophthalmitis rate of 0.148% versus a median rate of 0%. Statistical analysis via Poisson regression suggested that sclerocorneal incisions were associated with a reduced incidence of endophthalmitis (odds ratio, 0.35; 95% confidence interval, 0.24-0.51). Antibiotics used intraocularly (odds ratio, 0.65; 95% confidence interval, 0.43-0.98) and the preoperative application of diluted povidone-iodine on the conjunctiva (odds ratio, 0.59; 95% confidence interval, 0.36-0.99) were associated with a reduced risk of postoperative infection. Immune deficiencies (66%), diabetes mellitus (62%), occlusion of the lacrimal system (40%), and skin diseases (33%) were regarded as risk factors for endophthalmitis by the respondents. When cataract surgery is performed solely under inpatient conditions, the use of systemic antibiotics as well as the periocular injection of antibiotics at the end of the operation were associated (although not significantly) with a trend toward reducing the incidence of postoperative infection. Conversely, flushing the lacrimal drainage system, using eye shields, and cutting the eyelashes had no demonstrable effect in preventing endophthalmitis. The use of preoperative topical antibiotics (odds ratio, 2.38; 95% confidence interval, 1.21-4.68) and the performance of more than 20% of the surgeries in an outpatient center (odds ratio, 2.0; 95% confidence interval, 1.24-3.21) were associated with a detrimental effect on the development of endophthalmitis.

CONCLUSIONS

Although the appropriate antibiotic agent and dosage are not yet established, the administration of intracameral antibiotics and the application of povidone-iodine on the conjunctiva significantly reduced the relative risk of postoperative endophthalmitis in this survey. Because the study was not individual based but rather on aggregate questionnaire, the results have to be interpreted with care.

Prospective evaluation of external ocular microbial growth and aqueous humor contamination during cataract surgery

PURPOSE

To analyze the route of aqueous humor contamination leading to the development of postoperative endophthalmitis.

SETTING

Department of Ophthalmology, University of Helsinki, Finland.

METHODS

Forty-nine eyes of 49 patients (31 having phacoemulsification and 18 extracapsular cataract extraction [ECCE]) participated in the study. Four bacterial cultures were taken: preoperative conjunctival swab, lid margin culture, intraoperative lacrimal lake sample, and immediate postoperative anterior chamber fluid sample.

RESULTS

Preoperative lid margin cultures were positive in 59.2% of eyes, conjunctival cultures in 69.4%, and lacrimal lake cultures in 24.9%. Four aqueous humor samples (8.2%) showed bacterial growth in the anterior chamber aspirate: 3 in the phacoemulsification and 1 in the ECCE group. The bacteria isolated in this study, Staphylococcus epidermidis and Propionibacterium acnes (2 positive isolates each) were sensitive to the preoperative topical antibiotics used. No aqueous humor sample or any from other locations showed gram-negative microbe growth. The most frequently recovered microbes in all samples collected from the 3 other sources were S epidermidis and other coagulase-negative staphylococcus species, followed by P acnes and other propionibacterium species. Staphylococcus aureus, and diptheroids.

CONCLUSION

The ocular surface significantly contributed to the transmission of microbes into the eye during cataract surgery. These microbes could not be eradicated by topical preoperative antibiotics. However, no patient developed postoperative endophthalmitis. Natural defense mechanisms appear to fend off a minor inoculum with these microbes of relatively low pathogenicity.

Endophthalmitis

Endophthalmitis is an inflammatory reaction of intraocular fluids or tissues. Infectious endophthalmitis is one of the most serious complications of ophthalmic surgery. Occasionally, infectious endophthalmitis is the presenting feature of an underlying systemic infection. Successful management of infectious endophthalmitis depends on timely diagnosis and institution of appropriate therapy. Recognition of the different clinical settings in which endophthalmitis occurs and awareness of the highly variable presentation it may have facilitate timely diagnosis. Biopsy of intraocular fluid/tissue is the only method that permits reliable diagnosis and treatment. The different presenting clinical settings, a rational approach to diagnosis (i.e., when, what, and how to biopsy), and the treatment of infectious endophthalmitis are reviewed.

Diagnosis of infectious endophthalmitis after cataract surgery by polymerase chain reaction

PURPOSE

To ascertain whether the use of the polymerase chain reaction (PCR) technique leads to more rapid diagnosis of infectious endophthalmitis after cataract surgery.

SETTING

University Eye Clinic Regensburg, Germany.

METHODS

The aqueous humor and vitreous of 16 eyes with infectious endophthalmitis (10 acute, 6 delayed) were evaluated by microscopy, diagnostic culture, and PCR to detect the infectious agent.

RESULTS

Microscopy of the vitreous was positive in 3 eyes and the culture media results were positive in 7 eyes, all with acute endophthalmitis. Significantly fewer positive results were obtained in the aqueous humor. Using PCR, an infectious agent was detected in the aqueous humor of all 16 eyes and in the vitreous of 14. The vitreous sample was negative in 2 eyes with delayed endophthalmitis.

CONCLUSIONS

Detection of the infectious agent was more successful using PCR than using conventional microbiological tests, especially in the diagnosis of delayed endophthalmitis where the pathogen was detected in the aqueous humor in all eyes.

Prophylactic antibiotics in cataract operations

The rationale for prophylactic antibiotics in cataract operations must be continually reevaluated in light of cost-effectiveness and adverse reactions. The principles learned from wound infections associated with general surgical procedures should be applied to the limited knowledge about the rare event of endophthalmitis. Herein the literature on experimental and clinical wound infections in general surgical procedures is reviewed, with analysis of microbial flora, pathophysiology of wound infections, and pharmacokinetics of antibiotics. Experimental and clinical studies on prophylactic antibiotics to prevent endophthalmitis are reviewed, including information on topically applied antibiotics, chemical antisepsis, and administration of subconjunctival, intracameral, and systemic antibiotics. In addition, the benefits, limitations, and risks of the various types of prophylactic antibiotics are discussed. Because of the limited data on prophylactic antibiotics in cataract operations, providing dogmatic statements is difficult. General recommendations are offered based on the currently available literature, and a stratified approach is suggested based on wound construction and number of anterior segment maneuvers.

Endophthalmitis: immediate management using posterior capsulorhexis and anterior vitrectomy through reopened cataract surgery incision

An alternative tap/biopsy technique for early management of endophthalmitis is described. The technique uses the cataract surgery wound for anterior chamber washout and for a posterior continuous curvilinear capsulorhexis through which anterior vitrectomy, removal of part or all the vitreous abscess, and injection of antibiotics can be performed. The approach is safe, avoids pars plana incisions, and maintains capsule support for the intraocular lens or for removal and reimplantation of a posterior chamber lens in the bag.

Acute endophthalmitis outbreak after cataract surgery

PURPOSE

To evaluate the source of organisms causing an epidemic of postoperative endophthalmitis and to emphasize the importance of prompt intervention with an early diagnosis.

SETTING

S.B. Ankara Hospital Eye Department, Ankara, Turkey.

METHODS

Thirteen patients who had surgery on the same day and developed acute postoperative endophthalmitis were evaluated. Clinical patterns were observed and intraocular cultures and stains performed in 10 eyes. Broad-spectrum intravitreal antibiotics were injected on an empirical basis.

RESULTS

Intravitreal cultures showed Pseudomonas aeruginosa in four cases and coagulase-negative staphylococci in three cases; three cases were culture negative. P. aeruginosa were also isolated from irrigation solutions used on the same day. Two patients with P. aeruginosa had a visual acuity of 20/200 and 20/300, respectively.

CONCLUSION

The different culture results were probably related to the amount of inoculation, individual risk factors, and the subconjunctival antibiotic injection given at the end of surgery. That one patient with P. aeruginosa endophthalmitis retained a visual acuity of 20/200 shows the importance of rapid intravitreal antibiotic treatment.

Comparative intraocular penetration of topical and injected cefuroxime

AIMS

The choice of a prophylactic antibiotic for cataract surgery is dependent on its antibacterial activity and tissue penetration. The influence of the route and timing of administration of cefuroxime on its intraocular concentrations was examined.

METHODS

120 patients were recruited before cataract surgery into a prospective trial to compare the anterior chamber concentration of cefuroxime at a fixed time after administration by three routes. In a further 110 patients, the interval before sampling was varied in order to permit an examination of the kinetics of penetration. In another 10 patients, cefuroxime was given topically at the completion of surgery to assess the effect of a corneal wound on aqueous penetration. Cefuroxime concentrations were measured by high performance liquid chromatography on 0.2 ml samples of aqueous aspirated from the anterior chamber. Mean aqueous concentrations of cefuroxime for each group were compared using Student's t test.

RESULTS

After 25 mg cefuroxime, mean aqueous concentrations increased in the order forniceal (< 0.1 microgram/ml) < topical (0.18 microgram/ml) < subconjunctival (2.31 microgram/ml) when sampled 12-24 minutes after administration. Aqueous concentrations of cefuroxime reached a peak between 80 and 110 minutes after both forniceal and peribulbar injection but were still rising at this time after subconjunctival injection. Topical application of 12.5 mg cefuroxime to eyes with a 10 mm corneal wound resulted in a mean aqueous concentration of 9.34 micrograms/ml.

CONCLUSION

In the intact eye, only sub-conjunctival injection resulted in clinically significant aqueous concentrations of cefuroxime (> 1 microgram/ml) between 12 and 24 minutes after administration. For all routes, maximal aqueous concentrations were delayed by at least 80 minutes from administration. In the presence of a corneal wound, high aqueous levels of cefuroxime were rapidly attained after topical application.

Endophthalmitis and orbital cellulitis after radial keratotomy

PURPOSE

To report the findings concerning three patients with endophthalmitis and one with panophthalmitis and orbital cellulitis radial keratotomy surgery.

METHODS

One man referred with panophthalmitis and orbital cellulitis and three women referred with endophthalmitis were treated.

RESULTS

After radial keratotomy surgery, during which no microperforation or macroperforation had been reported, a severe Pseudomonas panophthalmitis and orbital cellulitis developed in the man. All vision was lost in that eye. Staphylococcus epidermidis endophthalmitis developed in one woman, Streptococcus pneumoniae endophthalmitis in the second woman and Pseudomonas endophthalmitis in the third woman, after undergoing radial keratotomy procedures during which microperforations occurred. In the latter patient, bilateral simultaneous surgery was performed, but only one eye became infected. The latter two infections resulted in light perception and hand motion vision respectively. In three cases, an initial keratitis was located in the inferior cornea.

CONCLUSIONS

Severe bacterial endophthalmitis can occur after radial keratotomy surgery, even in the absence of microperforation during the procedure. Any evidence of postoperative keratitis must be regarded seriously and treated aggressively. Despite use of this approach, the effect on final visual acuity can be devastating.

The effect of povidone-iodine solution applied at the conclusion of ophthalmic surgery

PURPOSE

Povidone-iodine 5% solution decreases the incidence of postoperative endophthalmitis when used on the eye for preoperative preparation. We sought to determine whether it also minimized conjunctival bacterial flora immediately after surgery by preventing bacteria present on the surface of the eye from entering surgical wounds.

METHODS

In 42 eyes of 40 patients, at the conclusion of surgery, on an alternating basis, each patient received either a drop of a broad-spectrum antibiotic solution (polymyxin B sulfate-neomycin sulfate-gramicidin) or a 5% povidone-iodine solution in the operated-on eye. Bacterial cultures were taken before and after surgery and 24 hours later. The 38 unoperated-on eyes in the unilateral cases served as control eyes.

RESULTS

Relative to the control group, povidone-iodine was effective in preventing an increase in the number of colony-forming units (P = .035), while the antibiotic was not. At 24 hours after surgery, the species count was lower in the eyes receiving povidone-iodine than in the antibiotic-treated eyes (P = .034) and was increased in the antibiotic group since the completion of surgery (P = .013), but was lower in the povidone-iodine and antibiotic groups than in the control eyes for both groups (P < .01).

CONCLUSIONS

Povidone-iodine 5% solution applied to the eye at the conclusion of surgery was more effective at minimizing the number of colony-forming units and species for the first postoperative day than was a broad-spectrum antibiotic. While not true for the antibiotic, the antimicrobial effect of povidone-iodine lasted for at least 24 hours after the completion of surgery.

Antimicrobial prophylaxis for ophthalmic surgery

Preoperative, intraoperative, and postoperative antibiotic agents have been used by ophthalmic surgeons routinely as prophylaxis for postoperative endophthalmitis. The rationale for such prophylaxis and the evidence which supports its efficacy are well founded. The optimal choice of antibiotic agent--from the standpoint of efficacy, route of delivery, adverse reactions, and cost--is far less established. This review considers these issues, as well as the role of topical disinfectants, including povidone-iodine, in preoperative prophylaxis.

Microorganisms cultured from the anterior chamber of ruptured globes at the time of repair

PURPOSE

We studied events leading to the development of posttraumatic endophthalmitis by examining the significance of 15 factors on microbial contamination of injured eyes.

METHODS

A prospective study was done of 30 ruptured globes in patients admitted to an urban medical center. Cultures were taken from the conjunctiva before and after preoperative disinfection and from the anterior chamber at the beginning and end of wound repair. Twenty-five of 30 patients received a three-day regimen of intravenous antibiotics that were begun before surgery.

RESULTS

Anterior chamber samples grew microorganisms in ten (33%) of 30 eyes, with positive cultures recovered from specimens taken at the beginning of wound repair in eight eyes and at the end of wound repair in six eyes. Contamination with indigenous flora may have occurred at the time of injury in one eye and during repair in another eye. Microbes recovered included Staphylococcus, Corynebacterium, and Aspergillus species. No patient developed endophthalmitis. Of the 15 factors studied, only intravenous antibiotics significantly decreased the incidence of positive anterior chamber cultures in eyes treated before wound repair compared with eyes not receiving such therapy (P = .002).

CONCLUSIONS

Despite the frequency of anterior chamber microbial contamination during injury or repair of the wound, with our treatment protocol and the presence of physiologic mechanisms to reduce intraocular microbes, no eyes developed clinical endophthalmitis. With our limited sample size only intravenous antibiotic therapy was found significantly to reduce anterior chamber microorganisms at the time of surgical repair, supporting their prophylactic use against the development of posttraumatic endophthalmitis.

Lack of effect of preoperative norfloxacin on bacterial contamination of anterior chamber aspirates after cataract surgery

Eighty patients undergoing routine standardised extracapsular cataract surgery with lens implantation were divided randomly into two groups in a prospective double blind study comparing effects of preoperative norfloxacin eyedrops with placebo on bacterial contamination of anterior chamber aspirates after surgery. Pathogenic organisms were identified from 19 (24%) of the aspirates. The most commonly isolated organisms were coagulase negative Staphylococcus species. There was no statistical difference between the norfloxacin treated and placebo groups. This study demonstrates that routine use of topical preoperative antibiotics to eliminate the entry of bacteria into the eye during surgery is debatable.

A comparative trial between diclofenac-gentamicin and betamethasone-neomycin drops in patients undergoing cataract extraction

Eighty patients were randomised in a single-masked parallel-group study to receive topically either the test drug, a diclofenac and gentamicin combination, or a betamethasone and neomycin combination after routine cataract extraction and intraocular lens implantation. Each group was assessed over a 6 week period for post-operative inflammation. The two drug combinations were equally effective in suppressing inflammation in the early post-operative stages and the diclofenac-gentamicin combination was slightly more effective in the later stages. The test drug was well tolerated and showed no adverse effects. We feel it is an effective and relatively safe drug which has a role as an anti-inflammatory agent after cataract extraction and has potential advantages in certain circumstances.

Ocular penetration of topical ciprofloxacin and norfloxacin drops and their effect upon eyelid flora

A double blind, prospective study was undertaken to compare aqueous humour penetration of topical 0.3% norfloxacin and 0.3% ciprofloxacin and their effect upon normal eyelid flora in 39 patients undergoing cataract surgery. Lid swabs were taken before and after six 1 hourly applications of single drops of ciprofloxacin or norfloxacin given before surgery. Aqueous humour was aspirated at surgery and antibiotic concentration assayed using high performance liquid chromatography. The mean aqueous humour concentrations were: ciprofloxacin 220 ng ml-1, norfloxacin 140 ng ml-1. Although this difference was not statistically significant (p = 0.112) the trend demonstrated may be relevant clinically, especially considering the greater activity of ciprofloxacin. Both coagulase negative staphylococcal (p = 0.004) and total bacterial (p = 0.019) lid counts dropped sixfold after ciprofloxacin treatment but the smaller reductions noted after norfloxacin application did not achieve statistical significance (p > 0.1). The reduction of external eye flora experienced with ciprofloxacin suggests that this may be a useful presurgical prophylactic agent.

Nursing intervention in the treatment of cataracts

Cataract remains the leading cause of blindness in the world, affecting around half of the world's 27-35 million blind people (WHO, 1991). The only effective treatment currently available is the surgical extraction of the opacified lens. This article re-examines the condition and looks at the nursing action that is taken before and after cataract surgery.

Postoperative endophthalmitis in association with diabetes mellitus

BACKGROUND

Endophthalmitis continues to be a potentially devasting complication of ocular surgery, despite advances in microsurgical technique and infection-preventing measures. Patients with diabetes have altered immunity at various levels and may be more susceptible to infection after ocular surgery. The authors evaluate the associations between diabetes mellitus and postoperative endophthalmitis.

METHODS

The records of 162 consecutive patients treated over a 5-year period for endophthalmitis occurring within 2 weeks of ocular surgery were retrospectively reviewed.

RESULTS

Twenty-one percent of this consecutive series of patients with endophthalmitis after surgery had diabetes mellitus. Both the diabetic and nondiabetic groups were similar with respect to age, type of primary surgery, duration from surgery to onset of symptoms, presenting visual acuity, and management of endophthalmitis. Seventy-nine percent of the patients with diabetes and 68% of those without diabetes had culture-proven endophthalmitis. Staphylococcus was responsible for 74% and 71% of the culture-positive cases, respectively. The patients with diabetes were more likely to have endophthalmitis secondary to a gram-negative organism (P < 0.001) than those without diabetes (18.5% versus 5.7%). Visual outcome was worse in the diabetic group, although this may be related to preoperative visual status.

CONCLUSIONS

Twenty-one percent of this consecutive series of patients with endophthalmitis after surgery had diabetes mellitus. The patients with diabetes mellitus were more likely to have endophthalmitis caused by gram-negative organisms and appear to have a poorer visual prognosis after treatment for endophthalmitis.

[Prophylactic antibiotic therapy in ocular surgery]

Prophylactic antibiotics have been used by ophthalmic surgeons routinely before and after surgery. However, the optimal type of antibiotics and route of administration have not yet been clearly established. In this article, ocular surgery patterns, bacteriology and pharmacokinetics of antibiotics within the eye are reviewed, to try to provide rationale for antimicrobial prophylaxis.

Postoperative endophthalmitis resulting from prosthesis contamination in a monocular patient

Monocular patients who wear an ocular prosthesis may harbor pathogenic conjunctival flora both in the socket and in the contralateral eye. They may therefore be at increased risk of developing endophthalmitis after intraocular procedures. We studied a monocular, prosthesis-wearing, 86-year-old man who underwent cataract extraction, subtotal transpupillary vitrectomy, and intraocular lens insertion. Fulminant endophthalmitis ensued postoperatively, and despite complete vitrectomy and administration of intraocular antibiotics, the eye lost light perception. Intravitreal as well as conjunctival cultures bilaterally grew Proteus mirabilis. The patient disclosed that he cleaned the prosthesis frequently because of discharge. We considered an association between this bacterial colonization and the risk of developing postoperative endophthalmitis and suggest prophylactic measures for treatment of monocular patients undergoing intraocular procedures.

Preoperative ophthalmic procedures: ritualistic or necessary?

Routine ophthalmic nursing tasks are often seen as unnecessary, degrading the skill of the ophthalmic nurse in assessing, planning and implementing the care of the patient. Many ophthalmic departments have discontinued such tasks, but the reasoning and the consequences do not appear to have been documented.