Taraprasad Das

Microbiologic spectrum and susceptibility of isolates

PURPOSE To present the microbial spectrum and susceptibilities of isolates in postoperative endophthalmitis. METHOD Isolates from 206 eyes of 206 patients who underwent vitrectomy for postoperative endophthalmitis were examined. RESULTS One-hundred twelve (54.4%) of 206 vitreous samples were culture positive and 14 (12.5%) of 112 culture-positive cases were polymicrobial, yielding a total of 126 isolates. Isolates included 59 (46.8%) gram-positive cocci, eight (6.3%) gram-positive bacilli, 33 (26.2%) gram-negative organisms, five (4.0%) Actino-mycetes-related organisms, and 21 (16.7%) fungi. Susceptibilities to amikacin, ceftazidime, chloramphenicol, cefazolin, ciprofloxacin, gentamicin, and vancomycin are reported. CONCLUSIONS This is the largest, single-center, prospective series on microbial susceptibilities in postoperative endophthalmitis. We report a high prevalence of gram-negative species and fungi, suggesting that empiric therapy should include coverage for gram-negative pathogens and for fungal pathogens in appropriate settings.

Microbiologic spectrum and susceptibility of isolates: Part II. Posttraumatic endophthalmitis

PURPOSE To present the microbial spectrum and susceptibilities of isolates in posttraumatic endophthalmitis. METHOD Isolates from 182 eyes of 182 patients who underwent vitrectomy for posttraumatic endophthalmitis were examined. RESULTS One hundred thirteen (62.1%) of 182 vitreous samples were culture-positive, and 23 (20.4%) of 113 culture-positive cases were polymicrobial, including three (2.7%) trimicrobial cases, yielding a total of 139 isolates. Isolates included 63 (45.3%) gram-positive cocci, 24 (17.3%) gram-positive bacilli, 25 (18.0%) gram-negative organisms, seven (5.0%) Actinomycetes-related organisms, and 20 (14.4%) fungi. Susceptibilities to amikacin, ceftazidime, chloramphenicol, cefazolin, ciprofloxacin, gentamicin, and vancomycin are reported. CONCLUSIONS This study represents a large series on microbial spectrum and susceptibilities in posttraumatic endophthalmitis. We report a high prevalence of gram-positive bacilli species and polymicrobial infections containing gram-negative species, underscoring the importance of broad-spectrum, combination antibiotics in the empiric treatment of posttraumatic endophthalmitis.

Intravitreal dexamethasone in exogenous bacterial endophthalmitis: results of a prospective randomised study

AIM To evaluate the efficacy of intravitreal dexamethasone co-administered with intravitreal antibiotics along with vitrectomy in the management of exogenous bacterial endophthalmitis. METHODS In a prospective randomised clinical trial, 63 patients (63 eyes) with suspected bacterial endophthalmitis (postoperative and post-traumatic) were treated with vitrectomy and intravitreal antibiotics and randomised to intravitreal dexamethasone (IOAB with = 29 eyes) and no dexamethasone (IOAB without = 34 eyes). Inflammation score (IS) and visual acuity were measured by two masked observers before surgery, and at 1, 4, and 12 weeks after surgery in both the groups. RESULTS There was significant reduction (p <0.0001) in IS at 1, 4, and 12 weeks after the surgery in the “IOAB with” group; there was temporary but significant increase (p <0.01) in IS at 1 week in the “IOAB without” group, before decline (p <0.001) of IS at 4 and 12 weeks. The magnitude and relative percentage change in IS between the two groups were found to be significant at 1 (p <0.0001), and 4 (p <0.01) weeks, and not at 12 weeks. The visual acuity at 12 weeks was comparable in both the IOAB with and IOAB without groups. CONCLUSION Intravitreal dexamethasone helps in early reduction of inflammation in exogenous bacterial endophthalmitis, but has no independent influence on the visual outcome. In selected patients with endophthalmitis where oral corticosteroids cannot be given for medical reasons intravitreal corticosteroids could be beneficial; in other situations they could be complementary to oral corticosteroid therapy.

The Transplantation of Human Fetal Neuroretinal Cells in Advanced Retinitis Pigmentosa Patients: Results of a Long-Term Safety Study ☆

The purpose of this study was to determine the long-term safety of transplanting human fetal neuroretinal cells (14 to 18 week gestational age) into a series of patients with advanced retinitis pigmentosa (RP). After obtaining informed consent, both hosts and mothers of donors were screened for transmissible diseases. Pre- and postoperative clinical exams, visual acuity, electroretinograms, and fluorescein angiograms were performed and visual field testing was attempted in each case. Surgically, an anterior approach through pars plana ciliaris was used. A retinotomy was performed in the paramacular area and a two-function cannula was introduced into the subretinal space to deliver a suspension of donor cells. The cell suspension carried approximately 4000 cells/microl; the volume injected did not exceed 150 microl. The patients were examined for periods ranging from 12 to 40 months posttransplantation. To date, no evidence of inflammation, infection, or overt rejection of the graft was noted in the host eye, neither was any change observed in the contralateral, unoperated eye. In conclusion, neuroretinal cells were injected into the subretinal space of 14 patients with advanced RP with no clinical appearance of detrimental effects at the time of surgery or up to 40 months postinjection except in 1 patient who developed retinal detachment. This sets the stage for a phase II clinical trial to determine the possible beneficial effects of this procedure in patients blinded by degenerative retinal disease.

Sensitivity And Predictability Of Vitreous Cytology, Biopsy, And Membrane Filter Culture In Endophthalmitis

Purpose Forty-seven consecutive patients with endophthalmitis were prospectively studied to: 1) compare the undiluted vitreous biopsy culture and membrane filter culture of vitrectomy cassette fluid; 2) determine the sensitivity and specificity of initial smear examinations in relation to final culture; and 3) characterize vitreous cytology in culture positive and negative endophthalmitis. Methods Examinations included smears (Gram stains, Diff Quik [Bacto Laboratories Pvt. Ltd., Liverpool, Australia] and unstained) and aerobic/anaerobic culture of undiluted vitreous biopsy specimens and diluted vitreous collected in the cassette. The cassette fluid was passed through 5-jum polycarbonate filter for cytology and a 0.22-μm polyvinylidene difluoride millipore filter for culture. Results By either method culture results were positive in 27 (57.4%) patients. Culture positivity of the vitreous biopsy alone was 44.6% and cassette fluid alone was 49% (P > 0.05). In the initial smear examination the sensitivity and specificity of the Gram stain were 66.6% and 84.2%, respectively. Comparatively, Diff Quik provided lower sensitivity and specificity at 40.7% and 80.9% respectively. Examination of wet film of vitreous samples did not provide any useful information. Although polymorphs were seen in large numbers in all cultures that yielded positive results on examination, they also were seen in 80% of the sterile samples. There was no significant difference in the quantity of macrophages observed in infected and noninfected samples. Conclusions Initial smear examination and cytology have limited roles in the diagnosis of infectious endophthalmitis. Obtaining cultures of both an undiluted vitreous biopsy sample and the vitrectomy cassette fluid has a significant advantage compared with culture of only one sample.

Activity of newer fluoroquinolones against gram-positive and gram-negative bacteria isolated from ocular infections: An in vitro comparison

BACKGROUND To determine the antibacterial activity of newer fluoroquinolones and compare their activity between ciprofloxacin-susceptible and resistant bacterial isolates from patients with keratitis and endophthalmitis. MATERIALS AND METHODS The minimum inhibitory concentration (MIC) of ciprofloxacin, ofloxacin, levofloxacin, gatifloxacin and moxifloxacin was determined for 123 bacterial isolates, using E test. Among the 123 isolates, 68 were gram-positive (Staphylococcus spp, Streptococcus spp, Corynebacterium spp, Bacillus spp.) and 55 were gram-negative (Pseudomonas aeruginosa). The bacterial isolates were divided into three groups: susceptible/intermediate/resistant to ciprofloxacin. The MIC values for various fluoroquinolones were compared between the three groups and between gram-positive and gram-negative bacteria. RESULTS For gram-positive isolates, median MICs of fourth generation fluoroquinolones were lower than second generation. The median MIC was lowest for gatifloxacin and moxifloxacin (0.094 mg/ml) in ciprofloxacin-susceptible isolates of gram-positive bacteria. For ciprofloxacin-susceptible gram-negative bacteria, the median MIC of ciprofloxacin (0.19 mg/ml) was significantly lower than ofloxacin, levofloxacin, gatifloxacin and moxifloxacin (1.5, 0.5, 0.5 and 2 mg/ml respectively). Ciprofloxacin-resistant isolates of gram-positive bacteria showed higher MIC of levofloxacin, moxifloxacin and gatifloxacin though they remained susceptible to them. None of the fluoroquinolones were effective against ciprofloxacin-resistant gram-negative bacteria. Overall, for gram-positive bacteria, median MICs of levofloxacin, moxifloxacin and gatifloxacin were below ciprofloxacin, the MIC of gatifloxacin and moxifloxacin was equal for gram-positive bacteria. CONCLUSIONS Levofloxacin, gatifloxacin and moxifloxacin are statistically more effective against gram-positive bacteria, the latter two being equally effective. Ciprofloxacin remains the most effective fluoroquinolone against gram-negative bacteria.

A randomised, double-masked, controlled study of the efficacy and safety of intravitreal bevacizumab versus ranibizumab in the treatment of macular oedema due to branch retinal vein occlusion: MARVEL Report No. 1

Purpose To assess the efficacy and safety of intravitreal bevacizumab (IVB) compared with ranibizumab (IVR) in the treatment of macular oedema due to branch retinal vein occlusion (BRVO). Methods In this prospective, randomised, non-inferiority trial, 75 participants with macular oedema due to BRVO received intravitreal injections of ranibizumab or bevacizumab after 1:1 block randomisation. The primary outcome measure was the difference in mean changes in best-corrected visual acuity (BCVA) at 6 months. Secondary outcome measures included mean change in central retinal thickness (CRT), the proportion of patients improving by >15 letters and the proportion of patients developing neovascularisation. Results Participants received either IVR (n=37) or IVB (n=38). The mean BCVA at baseline was 52.8±14.4 letters (20/80) and 56.1±10.0 letters (20/80) (p=0.24) in the ranibizumab and bevacizumab groups, respectively. At 6 months, the mean gains in BCVA were +18.1 letters (p<0.0001; 95% CI, +12.8 to +22.6) in the ranibizumab group and +15.6 letters (p<0.0001; 95% CI +12.0 to +20.5) in the bevacizumab group. The difference between the mean visual gains of the treated groups (bevacizumab–ranibizumab) was −2.5 letters (95% CI −8.0 to +5.0; p=0.74). Mean reductions in CRT at 6 months were 177.1±122.3 µm in the ranibizumab group (p<0.0001) and 201.7±166.2 µm in the bevacizumab group (p<0.0001), with no significant difference between the two groups (p=0.48). The mean numbers of ranibizumab and bevacizumab injections were 3.2±1.5 and 3.0±1.4, respectively (p=0.55). Two serious adverse events occurred in the ranibizumab group and one in the bevacizumab group but both were unrelated to intravitreal injections. Conclusions This study demonstrated significant gain in visual acuity in eyes with BRVO treated with either bevacizumab or ranibizumab. Pro-re-nata strategy was effective in maintaining the visual gain. Trial registration number http://www.ctri.nic.in/ CTRI/2012/01/003120.

Clinical profile and outcome in Bacillus endophthalmitis

OBJECTIVE To study the clinical presentation, microscopic and organismal culture correlation of vitreous, and species-specific outcome in Bacillus endophthalmitis DESIGN Retrospective noncomparative case series. INTERVENTION Thirty-one culture proven Bacillus endophthalmitis patients between January 1991 and February 1998 underwent vitrectomy and intravitreal antibiotic injection. Lensectomy was combined when considered essential, and on a few occasions intravitreal dexamethasone was added. The patients also received topical and systemic antibiotics. The undiluted vitreous biopsy was the source for microbiologic evaluation (microscopy and culture sensitivity). MAIN OUTCOME MEASURES The duration of symptoms, the presenting visual acuity, and influence of intravitreal dexamethasone with intravitreal antibiotics were examined for any statistical correlation with the final visual acuity. RESULTS Trauma was the major cause of infection. Vitreous biopsy microscopy demonstrated gram-positive bacillus in 28 of 31 cases, and polymicrobial infection was seen in 12 instances. All Bacillus species were sensitive to gentamicin, followed by vancomycin and ciprofloxacin. Clinical treatment within 7 days of symptoms, use of intravitreal vancomycin, and absence of polymicrobial infection were associated with better visual outcome. CONCLUSIONS With appropriate treatment that essentially consists of vitrectomy and intravitreal antibiotics, patients with Bacillus endophthalmitis are likely to benefit in many instances. Gram-positive bacilli detected on vitreous microscopy should be empirically treated as Bacillus species unless otherwise proved.

Relationship between Clinical Presentation and Visual Outcome in Postoperative and Posttraumatic Endophthalmitis in South Central India

PURPOSE To determine risk factors for poor visual outcome in postoperative and posttraumatic endophthalmitis in a large referral center in south central India. METHODS In this prospective observational series the authors examined 388 patients of postoperative (n= 206) and posttraumatic (n= 182) endophthalmitis at the L V Prasad Eye Institute in Hyderabad, India between 1991 and 1997. The analysis was confined to 236 patients-128 (62.1%) postoperative and 108 (59.3%) posttraumatic patients who were followed for a minimum period of 3 months. A detailed protocol was followed. Chi-square and logistic regression analysis were used to determine risk factors for visual outcome worse than 6/18 and worse than 6/120. RESULTS Postoperative endophthalmitis: In univariate analysis the features associated with poor visual acuity (grouped as < 6/18 and < 6/120) included intracapsular cataract surgery, poor presenting visual acuity, presence of vitreous cells, inability to visualise the optic disc on indirect ophthalmoscopy, presence of vitreous membranes on ultrasonography, and a culture-positive vitreous biopsy. In the multivariate analysis, visual acuity of less or equal light perception (LP) at presentation was associated with a 3-month postoperative visual acuity of < 6/18, with an odds ratio of 5.85 [1.25 - 27.42, 95% CI], and vitreous membranes seen on ultrasonography was associated with a final visual acuity of < 6/120, with an odds ratio of 2.47 [1.05 - 5.83, 95% CI]. Posttraumatic endophthalmitis: In univariate analysis the features associated with poor visual acuity (grouped as < 6/18 and < 6/120) included a retained intraocular foreign body (IOFB), trauma by needle (hypodermic or sewing), poor presenting visual acuity, inability to visualise the optic disc on indirect ophthalmoscopy, presence of vitreous membranes on ultrasonography, and a culture-positive vitreous biopsy. In multivariate analysis, IOFB was associated with a 3-month follow-up visual acuity of < 6/18, with an odds ratio of 5.90 [1.85 - 18.78, 95% CI], and trauma by a needle (hypodermic or sewing) and retained IOFB was associated with a final visual acuity of < 6/120, with an odds ratio of 4.47 [1.22 - 16.38, 95%CI] and 3.76 [1.36 - 10.37, 95% CI] respectively. CONCLUSION This is the largest, single-centre, prospective study on risk factors for poor visual outcome in postoperative and posttraumatic endophthalmitis. The independent risk factor for 3-month follow-up visual acuity of < 6/18 was the presenting visual acuity of < or =LP in postoperative endophthalmitis and a retained IOFB in posttraumatic endophthalmitis. The independent risk factor for 3-month visual acuity of < 6/120 was the presence of vitreous membranes on ultrasonography in postoperative endophthalmitis, and trauma by a needle (hypodermic/ sewing) and retained IOFB in posttraumatic endophthalmitis.

Eales’ disease: diagnosis and management

Eales’ disease is an idiopathic inflammatory venous occlusive disease. It primarily affects young adults and is often bilateral. It is characterized by three overlapping stages of venous inflammation (vasculitis), occlusion, and retinal neovascularization. Diagnosis is mostly clinical and requires exclusion of other systemic or ocular conditions that could present with similar retinal features. Recurrent vitreous haemorrhage is the hall mark of Eales’ disease. Treatment is usually corticosteroids in the inflammation stage and photocoagulation in the proliferative stage of the disease. Visual prognosis is good if treated early in the course of the disease.