Subhadra Jalali

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.

NMNAT1 mutations cause Leber congenital amaurosis.

Leber congenital amaurosis (LCA) is an infantile-onset form of inherited retinal degeneration characterized by severe vision loss. Two-thirds of LCA cases are caused by mutations in 17 known disease-associated genes (Retinal Information Network (RetNet)). Using exome sequencing we identified a homozygous missense mutation (c.25G>A, p.Val9Met) in NMNAT1 that is likely to be disease causing in two siblings of a consanguineous Pakistani kindred affected by LCA. This mutation segregated with disease in the kindred, including in three other children with LCA. NMNAT1 resides in the previously identified LCA9 locus and encodes the nuclear isoform of nicotinamide mononucleotide adenylyltransferase, a rate-limiting enzyme in nicotinamide adenine dinucleotide (NAD+) biosynthesis. Functional studies showed that the p.Val9Met alteration decreased NMNAT1 enzyme activity. Sequencing NMNAT1 in 284 unrelated families with LCA identified 14 rare mutations in 13 additional affected individuals. These results are the first to link an NMNAT isoform to disease in humans and indicate that NMNAT1 mutations cause LCA.

Premature Truncation of a Novel Protein, RD3, Exhibiting Subnuclear Localization Is Associated with Retinal Degeneration

The rd3 mouse is one of the oldest identified models of early-onset retinal degeneration. Using the positional candidate approach, we have identified a C-->T substitution in a novel gene, Rd3, that encodes an evolutionarily conserved protein of 195 amino acids. The rd3 mutation results in a predicted stop codon after residue 106. This change is observed in four rd3 lines derived from the original collected mice but not in the nine wild-type mouse strains that were examined. Rd3 is preferentially expressed in the retina and exhibits increasing expression through early postnatal development. In transiently transfected COS-1 cells, the RD3-fusion protein shows subnuclear localization adjacent to promyelocytic leukemia-gene-product bodies. The truncated mutant RD3 protein is detectable in COS-1 cells but appears to get degraded rapidly. To explore potential association of the human RD3 gene at chromosome 1q32 with retinopathies, we performed a mutation screen of 881 probands from North America, India, and Europe. In addition to several alterations of uncertain significance, we identified a homozygous alteration in the invariant G nucleotide of the RD3 exon 2 donor splice site in two siblings with Leber congenital amaurosis. This mutation is predicted to result in premature truncation of the RD3 protein, segregates with the disease, and is not detected in 121 ethnically matched control individuals. We suggest that the retinopathy-associated RD3 protein is part of subnuclear protein complexes involved in diverse processes, such as transcription and splicing.

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.

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.

Outcomes of a Protocol-Based Management for Zone 1 Retinopathy of Prematurity: The Indian Twin Cities ROP Screening Program Report Number 2

PURPOSE To report the outcomes of zone 1 aggressive posterior retinopathy of prematurity (ROP) treated with aggressive laser photocoagulation by a protocol-based approach over a 10-year period. DESIGN Prospective, interventional case series. METHODS SETTING Tertiary eye institute and neonatal intensive care units in the twin cities of Hyderabad and Secunderabad in South India. STUDY POPULATION Babies screened under the Indian Twin Cities Retinopathy of Prematurity Screening (ITCROPS) program between January 1, 1997 and March 31, 2007. INTERVENTION Multiple sessions of laser photocoagulation at any sign of plus disease with abnormal shunt vessels with or without neovascularization in zone 1. OUTCOME MEASURE Based on the anatomic status of the retina at the final follow-up, the outcome was classified into good (completely regressed with no vitreoretinal changes), fair (regression with vitreoretinal distortion), or poor (progression into partial or total retinal detachment involving macula). Descriptive statistics (mean and range) were used for gestational age at birth, birth weight, and post-conceptional age at first presentation and at the first intervention. Trends in incidence of zone 1 ROP over 1 decade were analyzed. Outcomes were expressed in terms of proportions and 95% confidence interval (CI). RESULTS Of the 3654 babies screened, 227 eyes of 115 babies were detected to have zone 1 aggressive disease, defined as zone 1 retinal vessels having abnormal closed-loop shunts, dilation and tortuosity, flat new vessels, or rapid progression. Laser was performed in 169 eyes. Disease regressed with good outcome in 142 eyes (84%) (95% CI, 77.6-89.2) and progressed to poor outcome in 13 eyes (7.69%) (95% CI, 4.1-12.8), while fair outcome was seen in 6 eyes (3.55%) (95% CI, 1.3-7.5). Thus 148 babies (87.5%) (95% CI, 81.6-92.14) had a favorable outcome. The outcomes in 8 treated eyes (4.7%) lost to follow-up were unknown. CONCLUSIONS Zone 1 aggressive ROP has a good outcome if the screening is done early; intervention is prompt and adequate, with frequent follow-up until complete regression is achieved.

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.