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.

Therapeutic Effect of Corneal Crosslinking on Fungal Keratitis: Efficacy of Corneal Collagen Crosslinking as an Adjuvant Therapy for Fungal Keratitis in a Tertiary Eye Hospital in South India.

PURPOSE: To evaluate the efficacy of CXL in treating fungal keratitis as an adjuvant therapy. METHODS: Detailed clinical examination microbiological investigation was performed. Twenty fungal keratitis patients were recruited and randomized into two groups: group 1 (n= 11, standard antifungal), group 2 (n=9, corneal collagen crosslinking with standard antifungal). Corneal scraping and tear samples collected were subjected to real-time PCR targeting ITS, TLR analysis and cytokine analysis. RESULTS: The mean time for complete resolution of ulcer for group 2 was significantly shorter compared to group 1 and the final mean BCVA was better for group 2. Expression of IL-1ß, IL-8, IFN-γ significantly decreased immediately post CXL in group 2 patients. Significant downregulation of TLR 6, TLR-3, TLR-4 was observed 3-days post CXL compared to group 1 patients. CONCLUSION: Adjuvant effect of CXL was significant in treating fungal keratitis compared to standalone antifungal treatment.

Expression analysis of toll-like receptors of Dengue-infected cornea by real-time polymerase chain reaction.

BACKGROUND: Toll-like receptors (TLRs) play a significant role based on innate immune mechanism during viral infection. TLR signaling mechanism designates to protect the cells from invading viruses. The expression of TLRs during dengue virus (DENV) infection not yet well explained. This study evaluates the TLR gene expression from DENV-infected patient's cornea. METHODS: Reverse transcriptase PCR was performed for the detection and genotyping of viral nucleic acid from corneal grafts and DENV-infected cell suspension. TLR expression studies were done on DENV-infected cornea by real-time RT2 Profiler PCR Array. RESULTS: The reverse transcriptase PCR and genotyping confirmed the presence of DENV-3. TLR expression studies revealed the upregulated expression of TLR4, TLR7, TLR9 and TLR10. CONCLUSION: Molecular testing of DENV reveals that serological positivity induces transmission of the virus through cornea and stimulates the expression of TLR4, TLR7, TLR9 and TLR10, which may lead to up-regulation of innate pro-inflammatory response in the cornea.

Incidence, microbiology, and outcomes of endophthalmitis after 111,876 pars plana vitrectomies at a single, tertiary eye care hospital.

PURPOSE: To describe the incidence, risk factors, clinical presentation, causative organisms, and outcomes in patients with endophthalmitis following pars plana vitrectomy (20G and minimally invasive vitrectomy surgery (MIVS). METHODS: Of 111,876 vitrectomies (70,585 20-G 41,291 MIVS) performed, 45 cases developed acute-onset, postoperative endophthalmitis. RESULTS: The rate of culture positive and culture negative endophthalmitis was 0.021% (2.1/10,000 surgeries) and 0.019% (1.9/10,000 surgeries) overall, 0.031% (3.1/10,000 surgeries) and 0.025% (2.5/10,000 surgeries) in 20G, and 0.005% (0.5/10,000 surgeries) and 0.007% (0.7/10,000 surgeries) in the MIVS group respectively. Potential predisposing factors were as follows: diabetes, 46.7%; vitrectomy for vascular retinopathies, 44.4%; and vitrectomy combined with anterior segment surgeries, 35.5%. The culture proven rates were 53.3% overall, 55.0% for 20G and 40.0% for MIVS. The most common organism was Pseudomonas aeruginosa for 20G. Klebsiella and Staphylococcus aureus were isolated in the two culture positive cases in MIVS group. The follow-up period for the patients with endophthalmitis was 586.14 ± 825.15 days. Seven were lost to follow up beyond one week. Of the remaining 38, 13 (34.2%) cases had a favorable visual outcome (i.e., best-corrected visual acuity [BCVA] > 5/200) and 24 (63.2%) had unfavorable visual outcome (BCVA < 5/200). Group with culture test results negative had significantly better outcomes (P < 0.05) as compared to those with positive. CONCLUSIONS: MIVS does not increase the risk of endophthalmitis. Outcomes are poor despite appropriate treatment, particularly in cases with culture results positive.

Risk Factors for Endophthalmitis after Pars Plana Vitrectomies in a Tertiary Eye Institute in India.

PURPOSE: To identify the risk factors associated with endophthalmitis after pars plana vitrectomy (PPV). DESIGN: Retrospective case-control study. PARTICIPANTS: All eyes that presented with endophthalmitis after PPV within 6 weeks in a tertiary eye care center were evaluated. There were 36 cases with endophthalmitis and 93 controls without endophthalmitis. METHODS: Other patients undergoing operation by the same surgeon on the same date and in the same operating room were included as controls. Univariate and multivariate regression analyses were performed to evaluate the risk factors. MAIN OUTCOME MEASURES: Incidence and risk factors for endophthalmitis after PPV. RESULTS: In this study, 36 cases and 93 controls met the inclusion criteria. For endophthalmitis, 3 independent risk factors were identified: systemic immunosuppression (odds ratio [OR], 10.673; 95% confidence interval [CI], 1.114-102.292; P = 0.04), balanced salt solution (BSS) or Ringer's lactate (RL) as vitreous substitute (OR, 5.288; 95% CI, 1.769-15.813; P = 0.003), and surgery performed in the second half of the day (OR, 0.016; 95% CI, 1.266-10.398; P = 0.016). Operating on phakic patients compared with pseudophakic or aphakic patients (OR, 0.962; 95% CI, 5.049-57.644; P < 0.001) and the use of endotamponade (OR, 5.288; 95% CI, 1.769-15.813; P = 0.003) were associated with a reduced risk for endophthalmitis. In culture-positive endophthalmitis, the presence of diabetes (OR, 4.61; 95% CI, 1.15-18.39; P = 0.03), vitreous substitute (BSS or RL) (OR, 6.08, 95% CI, 1.47-25.10, P = 0.012), and pseudophakia (OR, 5.68; 95% CI, 1.37-23.47; P = 0.016) were significant risk factors. CONCLUSIONS: Patients who are immunocompromised, pseudophakic, or aphakic are at a higher risk of endophthalmitis after PPV. Endotamponade significantly mitigates the risk of infection after vitrectomy surgery.

Incidence, management, and visual outcomes in pediatric endophthalmitis following cataract surgery by a single surgeon.

PURPOSE: To report the incidence of endophthalmitis following cataract surgery by a single surgeon in children and to describe its microbiological profile, management, and visual outcomes. METHODS: The medical records of patients who underwent cataract surgery performed by a single surgeon between January 2000 and December 2012 were retrospectively reviewed to identify those with postoperative endophthalmitis. The primary goals of the study were to describe the incidence of endophthalmitis, microbiological profile, and measure visual acuity after management. RESULTS: A total of 2,390 cataract surgeries were performed during the study period. The overall endophthalmitis rate during the study period was 0.376% (95% CI, 0.357-0.395). Of the 9 cases of postoperative endophthalmitis identified, 8 had a median duration of 2.5 days between time of surgery and diagnosis. The common presenting symptoms were pain and redness. Of the 5 cases in which early vitrectomy was performed, 4 showed good visual recovery at final follow-up visit. Both Gram-positive and Gram-negative organisms were seen equally. Culture-positive results were seen in 4 patients, the majority of which showed Acinetobacter calcoaceticus. Most of the organisms were resistant to ceftazidime. CONCLUSIONS: Endophthalmitis following pediatric cataract surgery is rare but occurs rapidly and can cause severe loss of vision. Early recognition and treatment can help in salvaging the vision.

Characterization of Antibiotic Resistance Profiles of Ocular Enterobacteriaceae Isolates.

Emergence of extended-spectrum ß-lactamase (ESBL) and fluoroquinolone resistance among ocular Enterobacteriaceae is increasing in higher frequency. Therefore, studies are being carried out to understand their multidrug resistance pattern. A total of 101 Enterobacteriaceae isolates recovered from various ocular diseases in a tertiary eye care center at Chennai, India during the period of January 2011 to June 2014 were studied. Forty one randomly chosen isolates were subjected to antibiotic susceptibility by minimum inhibitory concentration (MIC) and genotypic analysis. Of them, 16 were ESBL producers, one was carbapenemase producer and four were resistant to ertapenem which could be due to porin loss associated with AmpC production, and 17 were resistant to fluoroquinolones. Sixteen isolates harbored ESBL genes in which 14 had more than one gene and none of them were positive for blaNDM-1 gene. QNR genes were detected in 18 isolates. ESBL producers were predominantly isolated from conjunctiva. A high degree of ESBL production and fluoroquinolone resistance is seen among the genus Klebsiella sp. Hence, monitoring the rate of ESBL prevalence plays a vital role in the administration of appropriate intravitreal antibiotics to save the vision and also to reduce the development of drug resistance in ocular pathogens.

Study on polymethylmethacrylate ring in protecting limbal stem cells during collagen cross-linking.

OBJECTIVE: The UV rays used in the collagen cross-linking (CXL) procedure seem to cause potential damage to the limbal stem cells. This study was designed to evaluate the ability of polymethylmethacrylate (PMMA) hemiannulus as an alternative to protect corneal limbal stem cells during CXL. METHODS: Ten freshly enucleated human cadaveric eyeballs were subjected to the corneal CXL procedure. The cadaveric eye ball was divided into 2 sectors: A and B. Sector A was left unprotected, while sector B was covered by a PMMA shield. Limbal biopsies from both sectors before and after the procedure were analyzed. Each limbal tissue was placed on human amniotic membrane (HAM) to check the cultivability and was subjected to marker studies using reverse transcriptase PCR. RESULTS: Before CXL, biopsies from both sectors showed growth on HAM. After CXL, biopsies from sector A showed no growth on HAM while 2 out of the 10 from sector B covered with the PMMA ring did show growth on HAM. The putative stem-cell marker ABCG2 was negative in all the samples from sector A after CXL and was positive in 2 out of the 10 samples from sector B. CONCLUSION: Covering the limbal region with PMMA offers partial protection of the limbus from the UV rays during the CXL procedure.

Acute postoperative Bacillus cereus endophthalmitis mimicking toxic anterior segment syndrome.

OBJECTIVE: To study the clinicomicrobiologic characteristics and treatment outcomes in eyes with acute postoperative endophthalmitis (APE) owing to Bacillus cereus from a tertiary eye-care center. DESIGN: Retrospective, interventional case series. PARTICIPANTS: Case records of all eyes with culture-proven APE attributable to B cereus from January 2000 to May 2011 were identified from a computerized database and evaluated. METHODS: Clinical features at time of presentation, microbiological characteristics, and treatment measures were recorded. A thorough literature search using PubMed and the Cochrane Library databases was done to identify all cases of APE owing to Bacillus species reported to date and clinical characteristics of these eyes was compared with our series. MAIN OUTCOME MEASURES: Structural (globe salvage) and functional (visual rehabilitation) outcomes at last follow-up visit. RESULTS: We found 6 sporadic cases that experienced APE during the study period. All eyes had a fulminant onset within the first 24 hours of cataract surgery with extremely high intraocular pressure (IOP) and corneal edema similar to toxic anterior segment syndrome (TASS). However, these eyes progressed rapidly to develop corneal infiltrates, scleral and uveal tissue necrosis with hyphema, brownish exudates in anterior chamber and necrotizing retinitis within hours despite immediate initiation of intravitreal pharmacotherapy and vitrectomy. All eyes demonstrated gram-positive bacilli from the aqueous and B cereus was isolated, which was sensitive to conventional antibiotics except penicillin. Two eyes required therapeutic keratoplasty, combined with a scleral patch graft in 1 eye, 1 eye was eviscerated after 48 hours of onset of symptoms, and 2 eyes experienced phthisical changes within 10 days of onset. CONCLUSIONS: We found that APE owing to B cereus has an onset within 12 to 24 hours of intraocular surgery and simulates TASS in the first few hours. The clinical course is marked by rapidly worsening necrotizing infection, leading to very poor outcomes despite early institution of appropriate therapy. One must closely observe every case of TASS that presents with intense pain and extremely high IOP and rule out APE owing to B cereus with microbiologic testing. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any of the materials discussed in this article.

The effect of riboflavin-UV-A treatment on corneal limbal epithelial cells--a study on human cadaver eyes.

PURPOSE: To determine the effect of riboflavin-UV-A treatment on the corneal limbal epithelial cells during a corneal collagen cross-linking (CXL) procedure. METHODS: Thirty freshly enucleated human cadaveric eyeballs were subjected to a CXL procedure, mimicking the clinical protocol. During the UV-A exposure, one half of the limbus (sector A) was left unprotected, whereas the other half (sector B) was covered by a metal shield. Limbal biopsies from both sectors before and after the procedure were analyzed. Each strip of tissue was divided into 3 segments, for cell count of viable cells, for cultivation on human amniotic membrane (HAM), and for stem cell and differentiated corneal epithelial cell marker studies using reverse transcriptase-polymerase chain reaction. RESULTS: Compared with the cell count before CXL, there was a statistically significant drop in the mean number of viable cells after CXL in sector A but not in sector B. Biopsies from both sectors before CXL and from sector B after CXL showed good growth on HAM. Biopsies from sector A after CXL showed no growth on HAM. The putative stem cell marker ABCG2 was absent in all samples and p63 was absent in 3 of 10 samples taken from sector A after CXL. All markers were present in all samples from sector B after CXL. CONCLUSIONS: Riboflavin-UV-A treatment can result in damage to limbal epithelial cells, particularly the stem cells. Covering the limbal region with a metal shield effectively prevents this damage.

Phylogenetic comparison of exonic US4, US7 and UL44 regions of clinical herpes simplex virus type 1 isolates showed lack of association between their anatomic sites of infection and genotypic/sub genotypic classification.

BACKGROUND: HSV-1 genome is a mosaic of recombinants. Clinical Herpes simplex virus -1 (HSV1) isolates were already genotyped as A, B and C types based on nucleotide variations at Unique Short (US) 4 (gG) and US 7 (gI) regions through phylogeny. Analysis of Glycoprotein C (gC) exon present on the Unique Long (UL) region had also revealed the existence of different genotypes. Glycoprotein C is mainly involved in initial viral attachment to heparan sulphate on host cell surface facilitating the virus's binding and penetration into cell. As the amount of heparan sulphate on the host cell surface varies according to the cell type, it is plausible that different genotypes bind differentially to cell types. Hence, this study was framed to determine the existence of novel genotypes/sub genotypes in the US or UL regions which could associate with clinical entities. RESULTS: All the twenty five isolates analyzed in this study were of genotype A as per their gG gene sequences. In case of gI gene, 16 out of 25 were found to be type A and the remaining nine were type B putative intergenic recombinants. Intragenic recombinations were also encountered in both the US genes, with gG possessing novel subgenotypes, arbitrarily designated A1 and A2. The 9 type B isolates of gI genes also branched out into 2 clades due to genetic variations. Glycoprotein C of UL region had two distinct genotypic clades α and ß, whose topological distribution was significantly different from that of the US region. Neither the US nor UL regions, however, showed any preference among the genotypes to a specific anatomic site of infection. Even the non synonymous variations identified in the functional domain of gC, were not confined to a particular genotype/clinical entity. CONCLUSION: The analyses of the US and UL regions of the HSV-1 genome showed the existence of variegated genotypes in these two regions. In contrary to the documented literature, in which Asian strains were concluded as more conserved than European ones, our study showed the existence of a higher degree of variability among Indian strains. However, the identified novel genotypes and subgenotypes were not found associated with clinical entities.

A study on isolation rate and prevalence of drug resistance among microorganisms isolated from multiorgan donor and donor corneal rim along with a report on existence of bla NDM-1 among Indian population.

PURPOSE: To study the rate of isolation and prevalence of drug resistance among bacteria isolated from conjunctival swabs collected from multiorgan donor and Donor corneal rim specimens obtained from a tertiary eye hospital in South India. METHODS: Donor corneal rims (DCR) and conjunctival swabs from multiorgan donors collected over a period of 6 months were screened for the prevalent species of bacteria and drug resistance associated with them against the first line of antibiotics by phenotypic methods and multidrug resistant isolates were further subjected for genotypic analysis. RESULTS: Seventy-six DCR specimens were screened out of which 46 (60.5%) specimens showed bacterial growth, the predominant isolate being Coagulase negative Staphylococci, the rest 30 (39.5%) did not show any culture growth. All 42 (100%) conjunctival swabs collected from multiorgan donors were positive for bacterial culture, the prevalent species once again, being Coagulase negative Staphylococci. Among the other gram positive bacterial genus encountered were Streptococci, Bacillus, Diphtheroids and the gram negatives were Enterobacteriaceae and nonfermentors. Antibiotic resistance was significantly high among gram positive group. Seven (29.1%) gram negative isolates were positive for Extended Spectrum Beta Lactamases (ESBL's) by conventional and molecular method. A blaNDM -1 carrying Acinetobacter baumannii was isolated from a multiorgan donor. CONCLUSION: Preexcision culture in multiorgan donor is necessary to prevent postoperative endophthalmitis. Preexcision culture and antibiotic susceptibility testing of bacterial isolates of DCR will aid in understanding antibiotic pattern as institution of correct antibiotic will prevent the emergence of postoperative endophthalmitis. Molecular methods help in reducing the turn-around time for understanding the drug resistance genotypes.

"pp65 antigenemia and real time polymerase chain reaction (PCR) based-study to determine the prevalence of human cytomegalovirus (HCMV) in kidney donors and recipients with follow-up studies".

BACKGROUND: The present study was undertaken to determine the rate of occurrence of Human cytomegalovirus (HCMV) among kidney transplant recipients and donors by application of direct detection methods and to understand HCMV infection/disease development among transplanted patients as a prospective study. RESULTS: Peripheral blood samples collected from 76 kidney donors and 76 recipients from September 2007 to August 2009 were subjected to pp65 antigenemia and Quantitative real-time PCR (qRT-PCR) assays. Data were analyzed under Group A, B and C. Group A was further divided into sub-groups I, II, III, IV, and V for better understanding. Three, one and two donors in sub-group I, III, IV of Group A tested positive for real time PCR respectively. One recipient from group III tested positive for HCMV by qRT- PCR prior transplantation and remained positive one month post-transplantation. Three other recipients, tested negative prior to transplantation became positive a month after transplantation. Group B consisted of 18 donor-recipient pairs and one of the donor tested positive for HCMV by qRT-PCR. Eight recipients tested positive for HCMV one month after transplantation. The pp65 positivity and HCMV DNA load was high among group C recipients who mostly had symptoms of active disease. Significantly high values of pp65 antigenemia were observed among recipients of sub-group II (non-parametric chi-square test p = 0.007). Positive correlation between pp65 antigenemia and qRT-PCR value was observed. Thirty three of the recipients with disease treated with Valgancyclovir showed improved clinical outcome. CONCLUSION: Our study showed that a significant proportion of kidney recipients develop HCMV infection following renal transplantation in spite of the absence of HCMV among donors. pp65 antigenemia assay and qRT- PCR methods can be applied to detect HCMV among kidney donors and recipients to monitor development of disease and these assays were predicative of HCMV infection among them. Clinical resistant to valganciclovir was not observed.

A study on the incidence, microbiological analysis and investigations on the source of infection of postoperative infectious endophthalmitis in a tertiary care ophthalmic hospital: an 8-year study.

BACKGROUND: The objective of the study was the determination of the incidence of culture-proven postoperative endophthalmitis and probable sources of infection. MATERIALS AND METHODS: It was a prospective study on the microbiology, incidence and probable sources of infection in patients with postoperative infectious endophthalmitis carried out in a tertiary care eye hospital. Consecutive patients diagnosed with postoperative infectious endophthalmitis during the years 2000-2007 were investigated for the causative infective agent and possible sources of infection. The surgical data and microbiological data including the investigations performed to trace the source were recorded in a specific formatted form and were gathered and compiled for analysis. RESULTS: Data of analysis showed that 98 (0.042%) out of 2,31,259 patients who underwent intra-ocular surgery developed infectious endophthalmitis. Among these, 70 (0.053%) occurred after cataract, 10 (0.5%) after penetrating keratoplasty (PK) and 18 (0.018%) following other types of intra-ocular surgeries. The predominant infectious agents isolated were bacteria (89.7%), with equal proportions of gram-positive and gram-negative bacteria. Polymicrobial infection was noted in four and fungi in seven patients. Occurrence of postoperative endophthalmitis was sporadic and not related to any specific part of period in a year. Sources of infection were donor corneal rim in six post-PK patients and phaco probe in one who had postphacoemulsification endophthalmitis CONCLUSIONS: Overall incidence of postoperative endophthalmitis over an 8-year period was quite low. The sources of infection could be established in six post-PK endophthalmitis patients and in a postcataract surgery.