Bacterial contamination in the anterior chamber after povidone–iodine application and the effect of the lens implantation device

Clinical Results of Cataract Surgery Using the ARTIS ® PL E Intraocular Lens

Purpose: To compare the clinical outcomes of cataract surgery using the ARTIS ® PL E (Cristalens Industrie, Lannion, France) intraocular lens (IOL) and conventional Tecnis ® ZCB00 (Johnson & Johnson Vision, Santa Ana, CA, USA) IOL.Methods: This retrospective study examined patients who underwent in-the-bag implantation of either an ARTIS ® PL E (33 eyes, group A) or Tecnis ® ZCB00 (45 eyes, group B) IOL after phacoemulsification performed by a single surgeon. Best-corrected visual acuity (BCVA), spherical equivalent, and higher-order aberrations (HOA) were measured 1 and 3 months after cataract surgery.Results: Preoperative BCVA did not differ significantly in groups A and B. Postoperative BCVA at 1 and 3 months improved significantly (p < 0.001) in both groups compared to preoperative baseline BCVA. At 1 and 3 months postoperatively, total HOA, spherical aberration, and coma were significantly lower compared to the preoperative baseline HOA (p < 0.05) in both groups. However, there were no significant differences in the trefoil values 1 and 3 months postoperatively compared to the preoperative baseline in both groups. The absolute refractive error 3 months postoperatively was 0.27 ± 0.20 (group A) and 0.28 ± 0.20 (group B), both within ± 0.50 diopters of the targeted goal diopter; there were no significant differences in the accuracy or predictability of the IOL power calculation in both groups (p = 0.390, p = 0.959). The absolute refractive error 1 and 3 months postoperatively did not differ significantly; there were no significant differences in the stability of both IOLs (p = 0.482, p = 0.372).Conclusions: Conventional cataract surgery using the ARTIS ® PL E IOL significantly increased the BCVA, while obtaining comparable clinical results to the verified Tecnis ® ZCB00 IOL in postoperative visual acuity and HOA.

RNA-Seq analysis of differentially expressed genes of Staphylococcus epidermidis isolated from postoperative endophthalmitis and the healthy conjunctiva

Staphylococcus epidermidis (S. epidermidis) is one of the primary pathogens in postoperative endophthalmitis, which is a devastating complication of cataract surgery and often results in irreversible visual loss and even blindness. Meanwhile, it is the most frequently isolated commensal bacterium in the healthy conjunctiva. In this study, we investigated the differentially expressed genes (DEGs) of S. epidermidis isolated from the patients with postoperative endophthalmitis and the healthy conjunctiva to predict their functions and pathways by Illumina high-throughput RNA sequencing. Using genome-wide transcriptional analysis, 281 genes (142 upregulated and 139 downregulated genes) were found to be differentially expressed (fold change ≥ 2, p ≤ 0.05) in the strains from endophthalmitis. Ten randomly selected DEGs were further validated by quantitative reverse transcription polymerase chain reaction (qRT-PCR). GO enrichment analysis suggested that more DEGs were associated with the thioredoxin system and iron ion metabolism. KEGG pathway analysis revealed that more DEGs were associated with the pathways of the two-component system and pyruvate metabolism. Moreover, the gene SE1634 code for staphylococcal toxin was significantly upregulated in S. epidermidis strains of the endophthalmitis, which might be directly responsible for the pathogenesis of endophthalmitis. In conclusion, this research is helpful for further investigations on genes or pathways related with the pathogenesis and therapeutic targets of S. epidermidis 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.

Biofilm forming capacity and antibiotic susceptibility of Staphylococcus spp. with the icaA/icaD/bap genotype isolated from ocular surface of patients with diabetes

Introduction

Bacterial biofilm is an exopolysaccharide matrix that is produced by bacteria while they adhere on abiotic or biotic surfaces. The bacteria living in this matrix are more resistant to antibiotics than planctonic bacteria. The biofilm formation property of the bacteria is determined by genes; and this is related to virulence of the microorganism. In ophthalmology, biofilms form especially on abiotic surfaces such as silicon tubes, contact lenses, intraocular lenses etc.

Aim

Our aim was to investigate genotypic and phenotypic structures of biofilms that are produced by Staphylococcus spp., which was obtained from the eyes of diabetic patients and determine the effect on antibiotic susceptibility.

Methods

The study group was comprised with 83 isolates from diabetic patients and 21 isolates from non-diabetic patients. Presumptive isolates were detected and confirmed by a microbial identification system VITEK II. Automated EcoRI Ribotyping was performed. Biofilm production was detected by Congo Red Agar Plate and Microtiter Plate Assay. Disc diffusion method was used for determination of antibiotic susceptibility of isolates.

Results

Out of the 83 isolates from diabetic patients, 25 were weakly (30%), 20 were moderately (24%), and 25 were strongly (30%) biofilm positive. Seven isolates of S. aureus, 11 isolates of S.epidermidis, 2 isolates of S. warneri, 3 isolates of S.hominis, and 2 isolates of S.lugdunensis were identified as strong biofilm producers. Out of the 83 Staphylococcus isolates, 37 were cefuroxime, 18 ciprofloxacin, 11 vancomycin, 12 gatifloxacin, and 18 moxifloxacin resistant. In total, 37 strains were resistant to three or more antibiotics. There was a statistically significant relation between biofilm formation and multidrug resistance (against three or more antibiotics, p<0.001). In nondiabetic patients, 15(71%) isolates were non adherent or weakly adherent, and 2(10%) were strongly adherent biofilm positive.

Conclusion

In conclusion, bacterial conjunctival flora of patients with diabetes is likely to produce biofilm. Biofilm formation is associated with multidrug rsistance in patients with diabetes.

Moxifloxacin superior to cefuroxime in reducing bacterial adhesion of Staphylococcus epidermidis on hydrophobic intraocular lenses

PURPOSE

To compare the anti-adhesive effect of cefuroxime and moxifloxacin on the primary attachment phase of Staphylococcus epidermidis on hydrophobic acrylic intraocular lenses (IOLs).

METHODS

Forty hydrophobic acrylic IOLs were used. Two groups of IOLs were soaked in a moxifloxacin (Mox-T1: 0.5 mg/0.1 ml) or a cefuroxime (Cef-T1: cefuroxime 1 mg/0.1 ml) solution before incubation in a S. epidermidis bacterial suspension. Two other groups were incubated in the bacterial suspension before antibiotics (Cef-T2 and Mox-T2) were added. The control group (Ctrl) consisted of IOLs incubated in the bacterial suspension. After incubation, IOLs were sonicated and vortexed. The resultant suspension was spread over a nutritive agar plate. Bacterial colonies were counted after 24 hr of incubation.

RESULTS

Mean number of colony-forming units per IOL was Cef-T1: 184 × 10(3) (SE: 5.24; SD: 28.21), Cef-T2: 117 × 10(3) (SE: 5.74; SD: 30.37), Mox-T1: 1.27 × 10(3) (SE: 0.12; SD: 0.61), Mox-T2: 25 × 10(3) (SE:1.98; SD: 9.72) and Ctrl: 361 × 10(3) (SE: 26.9; SD: 107.6). The number of adhering bacteria did not vary whether cefuroxime was added before or after IOL incubation in the bacterial suspension (p = 0.132). Moxifloxacin was more effective in reducing the number of adhering bacteria when used before IOL incubation (p < 0.001). Overall for T1 and T2, moxifloxacin was more effective than cefuroxime in reducing bacterial adhesion on IOLs (p < 0.001).

CONCLUSION

Moxifloxacin and cefuroxime significantly reduced S. epidermidis adhesion on hydrophobic acrylic IOLs. The anti-adhesive effect was superior with moxifloxacin.

Biofilms in infections of the eye

The ability to form biofilms in a variety of environments is a common trait of bacteria, and may represent one of the earliest defenses against predation. Biofilms are multicellular communities usually held together by a polymeric matrix, ranging from capsular material to cell lysate. In a structure that imposes diffusion limits, environmental microgradients arise to which individual bacteria adapt their physiologies, resulting in the gamut of physiological diversity. Additionally, the proximity of cells within the biofilm creates the opportunity for coordinated behaviors through cell–cell communication using diffusible signals, the most well documented being quorum sensing. Biofilms form on abiotic or biotic surfaces, and because of that are associated with a large proportion of human infections. Biofilm formation imposes a limitation on the uses and design of ocular devices, such as intraocular lenses, posterior contact lenses, scleral buckles, conjunctival plugs, lacrimal intubation devices and orbital implants. In the absence of abiotic materials, biofilms have been observed on the capsule, and in the corneal stroma. As the evidence for the involvement of microbial biofilms in many ocular infections has become compelling, developing new strategies to prevent their formation or to eradicate them at the site of infection, has become a priority.

Evaluation of bacterial contamination rate of the anterior chamber during phacoemulsification surgery using an automated microbial detection system

AIM

To assess the incidence of anterior chamber bacterial contamination during phacoemulsification surgery using an automated microbial detection system (BacT/Alert).

METHODS

Sixty-nine eyes of 60 patients who had uneventful phacoemulsification surgery, enrolled in this prospective study. No prophylactic topical or systemic antibiotics were used before surgery. After antisepsis with povidone-iodine, two intraoperative anterior chamber aqueous samples were obtained, the first whilst entering anterior chamber, and the second at the end of surgery. BacT/Alert culture system was used to detect bacterial contamination in the aqueous samples.

RESULTS

Neither aqueous samples obtained at the beginning nor conclusion of the surgery was positive for microorganisms on BacT/Alert culture system. The rate of bacterial contamination during surgery was 0%. None of the eyes developed acute-onset endophthalmitis after surgery.

CONCLUSION

In this study, no bacterial contamination of anterior chamber was observed during cataract surgery. This result shows that meticulous surgical preparation and technique can prevent anterior chamber contamination during phacoemulsification cataract surgery.

Evaluation of the vitreous microbial contamination rate in office-based three-port microincision vitrectomy surgery using Retrector technology

Background

To perform a microbiological contamination analysis of the vitreous during office-based micro-incision vitrectomy surgery (MIVS) assessing whether the bacteria detected correlated with patient's ocular conjunctival flora.

Methods

This is a prospective, interventional, nonrandomized case series of patients undergoing office-based MIVS, anti-VEGF, and dexamethasone intravitreal injections (triple therapy) for the treatment of wet age-related macular degeneration (AMD) and diabetic macular edema (DME).

All patients were operated at a small procedure room in an ambulatory clinic of the Department of Ophthalmology, University of Montreal, Quebec, Canada. Conjunctival samples were done before placing the sclerotomies. The MIVS was done with a 23-gauge retractable vitrector, a 27-gauge infusion line, and a 29-gauge chandelier. Undiluted and diluted vitreous were collected for aerobic, anaerobic and fungal cultures. Outcomes measured were bacterial species identification within samples collected from the conjunctiva and the vitreous.

Results

Thirty-seven patients (37 eyes) were recruited and completed over 17 months of follow-up. Twenty-eight had wet AMD and nine had DME. There were 13 men and 24 women, with a mean age of 78 years. Eighteen patients (46%) had culture positive conjunctival flora. Twenty-six bacterial colonies were tabulated in total from the conjunctival swabs. All bacteria detected were gram-positive bacteria (100%), most commonly: Staphylococcus epidermitis in 11 (42%) and Corynebacterium sp. in 6 (23%). Only 1/18 patients had more than 3 species isolated, 6/18 patients had 2 species and 11/18 patients had 1 species identified on the conjunctival swab. Only 1 of the 37 undiluted midvitreous samples was culture positive, equating to a contamination rate of 2.7%. None of the diluted vitreous samples were culture positive. All cultures were negative for fungus. No serious postoperative complications occurred, including bacterial endophthalmitis, choroidal detachment, and retinal detachment.

Conclusion

This preliminary study of office-based MIVS gives us insights on the ocular surface microbial profile and vitreous contamination rate of performing such procedures outside the OR-controlled environment. Our initial results seem to indicate that there is little risk of bacterial translocation and contamination from the conjunctiva into the vitreous. Therefore, if endophthalmitis occurs post-operatively, the source may likely arise after the procedure. Larger studies are needed to confirm our data.

Anterior chamber bacterial contamination in cataract surgery

Background

The incidence of postoperative endophthalmitis has reduced during last several years to <0.01%; however, its associated complications continue to be devastating. Several sources of infection, including contamination by air, solutions, surgical instruments, intraocular lens, and wound leakage have been identified. The objective of this study was to evaluate the surgical technique, antibiotics, and asepsis that are used to reduce the risk of infection during cataract surgery.

Methods

This was a transversal prospective study, in which 64 cataract surgeries were evaluated from 32 patients, with 1 month recovery time; and cultures from preoperative and postoperative aspirates were analyzed. Two groups were established based on whether preoperative antibiotics were given or not. The analysis employed descriptive statistics.

Results

Of the 32 patients whose aspirates were obtained, three (9.37%) and 10 (31.25%) yielded positive cultures preoperative and postoperatively respectively. Staphylococcus species was the most common contaminating bacteria. The isolation of Staphylococcus species may indicate its potential as exogenous contaminant at time of wound closure. The cultures obtained from patients using preoperative antibiotics were positive for S. aureus in 10% (n = 2) of cases, and positive in 8.33% (n = 1) of cases not using antibiotics. The mean transoperative time with positive growth was 67 ± 17.8 minutes, and with negative growth was 76.3 ± 25.2 minutes. Two surgical techniques were evaluated: phacoemulsification and extracapsular extraction. The extracapsular technique showed a contamination rate of 33.33% (n = 8) compared to phacoemulsification with a rate of 25% (n = 2) (RR = 1.33).

Conclusions

Common contaminating microorganisms included the Staphylococcus species, which was isolated from the eyelids and ocular annexes at the time of wound closure. The isolation of microorganisms postoperatively could have been influenced by the surgical technique used, the surgical time, and the use of antibiotics.

Ophthalmic viscosurgical device backflow into cartridge during intraocular lens insertion using injectors

Background

The purpose of this study was to assess the risk of intraocular contamination caused by intraocular lens (IOL) insertion with injectors by observing the dynamics of an ophthalmic viscosurgical device (OVD).

Methods

Each type of injector was equipped with a colored OVD and IOL, and a 2 mm length from the tip of the cartridge was replaced with a colored OVD. The various combinations of IOLs and injectors used were: a three-piece shaped IOL, VA60BBR + TypeE1 (HOYA incision size 2.5 mm; group A, n=5); a single-piece IOL, 251+ iSert micro, preloaded (HOYA, incision size 2.2 mm; group G, n=5); and a single-piece IOL, SN6CWS preloaded (Alcon, incision size 2.7 mm; group C, n=5).

Results

In group A, the intraocular OVD instantly flowed backward into the injector, whereas the colored OVD was pushed backward deep inside the cartridge without flowing into the eye. In group B, the backflow of the intraocular OVD into the injector was limited, resulting in the influx of a large amount of the colored OVD into the eye along with the IOL. In group C, as in group A, a large amount of the intraocular OVD flowed backward into the injector. Consequently, a small amount of the colored OVD flowed into the eye.

Conclusion

The tip of the injector and OVD could be contaminated because the surgical field cannot be completely sterile, even after preoperative disinfection. Our experiments revealed that OVD backflow into the injector cavity occurs during IOL insertion, and this phenomenon may have minimized intraocular contamination. However, small-diameter cartridges along with plate-type haptics allow insufficient OVD backflow, resulting in intraocular influx of the contaminated OVD. Surgeons have to be notified that intraoperative bacterial contamination can occur even after IOL insertion using injectors.

Aspergillus tubingenesis endophthalmitis after cataract surgery with implantation of preloaded intraocular lens

Abstract An 88-year-old man underwent uneventful phacoemulsification and aspiration with an implantation of a preloaded acrylic intraocular lens. Six months later, he developed endophthalmitis with negative aqueous cultures, and the inflammation was refractory to conventional antibacterial therapies. He was treated successfully with vitrectomy and removal of the IOL and the entire lens capsule. A combination of intravitreal voriconazole and systemic micafungin were prescribed, and the inflammation was resolved. As best we know, this is the first case of Aspergillus tubingenesis endophthalmitis that followed the implantation of a preloaded intraocular lens.

A Case of Delayed-Onset Propionibacterium acnes Endophthalmitis after Cataract Surgery with Implantation of a Preloaded Intraocular Lens

Purpose

To report a case of delayed-onset endophthalmitis after implantation of a preloaded intraocular lens (IOL) and examine the surgically removed IOL by scanning electron microscopy (SEM).

Case

A 77-year-old female underwent uneventful phacoemulsification and aspiration with preloaded silicone IOL implantation. Since intraocular inflammation unexpectedly worsened 1 month after the surgery, she was referred to our hospital. Her visual acuity was hand motion in the left eye. Hypopyon and fibrin formation were observed in the anterior chamber. A diagnosis of postoperative delayed-onset endophthalmitis was made, and vitrectomy with anterior chamber wash-out was performed. As intraocular inflammation remained unchanged postoperatively, an additional surgery with IOL removal was performed. We cultivated the surgically removed samples of aqueous humor and vitreous fluid under both aerobic and anaerobic conditions, performed 16S rDNA clone library analysis of these clinical samples, and examined the removed IOL by SEM.

Result

Inflammation subsided after the re-operation. Although cultures of aqueous and vitreous samples were negative, DNA of Propionibacterium acnes was detected in the aqueous humor. The SEM images showed that the rod bacteria and biofilm-like material formed on the tip of the IOL haptic.

Conclusion

Delayed-onset endophthalmitis may occur after uneventful implantation of a preloaded IOL. The SEM findings suggested that the tip of the preloaded IOL haptic might scratch bacteria which adhered to the tip of the injector nozzle when the IOL was inserted into the anterior chamber. In some cases with delayed-onset endophthalmitis, IOL removal is needed to eliminate the bacteria which adhere to the tip of the IOL haptic.

Bacterial endophthalmitis in the age of outpatient intravitreal therapies and cataract surgeries: host-microbe interactions in intraocular infection

Bacterial endophthalmitis is a sight threatening infection of the interior structures of the eye. Incidence in the US has increased in recent years, which appears to be related to procedures being performed on an aging population. The advent of outpatient intravitreal therapy for management of age-related macular degeneration raises yet additional risks. Compounding the problem is the continuing progression of antibiotic resistance. Visual prognosis for endophthalmitis depends on the virulence of the causative organism, the severity of intraocular inflammation, and the timeliness of effective therapy. We review the current understanding of the pathogenesis of bacterial endophthalmitis, highlighting opportunities for the development of improved therapeutics and preventive strategies.

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.

Real-time polymerase chain reaction test to discriminate between contamination and intraocular infection after cataract surgery

PURPOSE

To determine the usefulness of real-time polymerase chain reaction (PCR) assays in the diagnosis of postoperative bacterial endophthalmitis in clinically diagnosed infectious cases and to test for bacterial DNA in control samples collected from noninfected eyes.

SETTING

Federal University of São Paulo, Brazil.

DESIGN

Evaluation of diagnostic test or technology.

METHODS

This study comprised patients with clinically diagnosed infectious endophthalmitis after cataract surgery and vitreous samples (from noninflamed eyes obtained through vitrectomy) and aqueous samples (at end of phacoemulsification) from control patients at a single university setting. Universal and gram-specific real-time PCR, Gram staining, and culture were performed. Sensitivity and cycle thresholds were determined. Clinical and microbiologic data were also assessed.

RESULTS

The study evaluated 11 patients with infectious endophthalmitis (9 vitreous and 7 aqueous samples), 12 control vitreous samples, and 50 control aqueous samples. Gram and culture identified 80% and 75%, respectively, of patients with infectious endophthalmitis. Real-time PCR assays were positive in 91% of patients with a clinical diagnosis of endophthalmitis using aqueous samples, vitreous samples, or both. None of the 12 vitreous controls were positive by PCR. Two aqueous control samples were positive by real-time PCR. The cycle threshold cutoff value was 36 for universal PCR (sensitivity 93.8%; specificity 100%) and 38 for gram-specific PCR (sensitivity 93.8%; specificity 100%). Gram-positive microorganisms prevailed, and visual acuity varied according to the causative bacteria.

CONCLUSIONS

Real-time PCR provided fast and accurate diagnosis of bacterial endophthalmitis. As a quantitative technique, it may be useful in distinguishing between contamination and infection based on the cycle thresholds value.

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.