Comparative evaluation of intraoperative aberrometry and Barrett’s toric calculator in toric intraocular lens implantation

Purpose: Barrett toric calculator (BTC) is known for its accuracy in toric IOL (tIOL) calculation over standard calculators; however, there is no study in literature to compare it with real?time intraoperative aberrometry (IA). The aim was to compare the accuracy of BTC and IA in predicting refractive outcomes in tIOL implantation. Methods: This was an institution?based prospective, observational study. Patients undergoing routine phacoemulsification with tIOL implantation were enrolled. Biometry was obtained from Lenstar?LS 900 and IOL power calculated using online BTC; however, IOL was implanted as per IA (Optiwave Refractive Analysis, ORA, Alcon) recommendation. Postoperative refractive astigmatism (RA) and spherical equivalent (SE) were recorded at one month, and respective prediction errors (PEs) were calculated using predicted refractive outcomes for both methods. The primary outcome measure was a comparison between mean PE with IA and BTC, and secondary outcome measures were uncorrected distance visual acuity (UCDVA), postoperative RA, and SE at one month. SPSS Version?21 was used; P < 0.05 considered significant. Results: Thirty eyes of 29 patients were included. Mean arithmetic and mean absolute PEs for RA were comparable between BTC (?0.70 ± 0.35D; 0.70 ± 0.34D) and IA (0.77 ± 0.32D; 0.80 ± 0.39D) (P = 0.09 and 0.09, respectively). Mean arithmetic PE for residual SE was significantly lower for BTC (?0.14 ± 0.32D) than IA (0.001 ± 0.33D) (?0.14 ± 0.32D; P = 0.002); however, there was no difference between respective mean absolute PEs (0.27 ± 0.21 D; 0.27 ± 0.18; P = 0.80). At one?month, mean UCDVA, RA, and SE were 0.09 ± 0.10D, ?0.57 ± 0.26D, and ?0.18 ± 0.27D, respectively. Conclusion: Both IA and BTC give reliable and comparable refractive results for tIOL implantation.

Ocular conjunctival microbiome profiling in dry eye disease: A case control pilot study

Purpose: Keratoconjunctivitis sicca (KCS) or dry eye disease (DED) is a multifactorial disease that results in discomfort, visual disturbance, and tear film instability with potential damage to the ocular surface. A pilot study was undertaken to determine if there were any major substantial differences in the ocular microbiome in DED patients versus healthy controls. Methods: The bacterial communities residing in the conjunctiva of patients with DED (n = 4) and healthy controls (n = 4) were assessed by 16S ribosomal RNA (rRNA) gene sequencing of the V4–V5 region. Results: The phyla Proteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes were most dominant and accounted for 97% and 94.5% of all bacterial sequences in patients and controls, respectively. At the genus level, 27 bacterial genera were found with more than two?fold difference between patients and controls. Four of these – Acinetobacter, Corynebacterium, Lactobacillus, and Pseudomonas spp. – dominated the ocular microbiome of all subjects, but were proportionately lower in DED (16.5%) compared to controls (37.7%). Several bacterial genera were found to be unique in DED (34) and controls (24). Conclusion: This pilot study is an attempt to profile the ocular microbiome in patients with DED that demonstrated a higher concentration of microbial DNA compared to controls, with Firmicutes phyla dominating the bacterial population in patients with DED.

Evaluation of liposomal amphotericin B for the treatment of fungal keratitis in a tertiary eye care hospital

Purpose: To evaluate the efficacy of liposomal amphotericin B (L?AMB) for the treatment of fungal keratitis. Methods: Patients with fungal keratitis confirmed by potassium hydroxide (KOH) smear and/ or confocal microscopy were administered topical L?AMB and randomized into three groups treated with three different formulations. The medication was administered two hourly till clinical improvement was achieved, followed by six hourly till complete resolution. The outcome measures were time to clinical improvement, resolution of epithelial defect, stromal infiltrate, hypopyon, extent and density of corneal opacity, neovascularization, and best corrected visual acuity (BCVA) at 3 months. Results: Mean age of the patients was 46.6 ± 14.8 years, and trauma with vegetative matter was the most common predisposing factor. Aspergillus flavus (36%) was the most common fungus cultured, followed by Fusarium (23%). Mean time to clinical improvement, time to resolution of epithelial defect, mean time to resolution of infiltrate, and time to resolution of hypopyon were 3.45 ± 1.38, 25.35 ± 8.46, 37.97 ± 9.94, and 13.33 ± 4.90 days, respectively, and they were comparable among the three groups. There was a significant difference between treatment failure and success cases in terms of days of presentation (P < 0.01), size of the epithelial defect (P?value 0.04), and infiltrate size at presentation (P?value 0.04). At 3 months follow?up, no statistically significant difference was noted in BCVA and mean scar size among groups. Conclusion: L?AMB in a gel form is an effective antifungal agent that promotes the healing of fungal ulcers with notably least vascularization and better tolerance.

Prevalence and causes of low vision in a population-based study on childhood visual impairment in North India (CHVI 4)

Purpose: The present study was a population?based study to determine the prevalence and causes of low vision in children less than 16 years in North India. Methods: This cross?sectional study was conducted in 40 clusters of urban Delhi. Children aged less than 16 years underwent visual acuity screening using age?appropriate visual acuity charts. All children with visual acuity of <6/12 in any eye in the age group between 3 and 15 years and inability to follow the light in age less than 3 years were referred for detailed ophthalmic examination in a centrally based clinic. Cycloplegic examination and best?corrected visual acuity (BCVA) were assessed. They were examined by an ophthalmologist to determine the prevalence and causes of functional low vision (FLV). The prevalence of FLV was compared with other population?based studies across India and other parts of the world. Results: Amongst 20,955 children examined for visual acuity, 789 children were referred to the central clinic for detailed ophthalmic examination. The overall prevalence of low vision was 0.62 per 1,000 children (95% confidence interval [CI] 0.12–1.90). The main anatomical cause of low vision was retinal abnormalities. Conclusion: Although the prevalence of children with low vision decreased as compared to previous population?based studies. There is an important need to create awareness among parents on appropriate and timely usage of low?vision devices (LVDs) at an affordable cost to improve the visual quality in children with low vision.

Evaluation of antifungal susceptibility and clinical characteristics in fungal keratitis in a tertiary care center in North India

Purpose: To study the antifungal susceptibility of common corneal pathogenic fungi to antifungal agents in the North Indian population. Methods: Prospective study of the antifungal sensitivity testing (natamycin, amphotericin B, voriconazole, itraconazole, fluconazole, posaconazole, caspofungin, micafungin) of fungal isolates from 50 cases of culture positive fungal keratitis by using E test method. Details noted included demographic data, visual acuity, clinical details, grade of keratitis, healing time, and success in medical management. Results: Of 50 patients with fungal keratitis (mean age: 40.28 ± 16.77 years), 12 eyes healed within 3 weeks, 14 had a delayed healing response, and 24 had chronic keratitis. Among the 15 cases of Fusarium isolates, 93.3% were sensitive to natamycin, while 40% to amphotericin B; 66.6% to voriconazole, 13.4% to itraconazole and fluconazole each. 80% of Fusarium cases (n = 12) showed susceptibility to posaconazole. Among Aspergillus flavus isolates, 53.4% (n = 8) were sensitive to natamycin, with only 40% (n = 7) showing sensitivity to amphotericin B and good susceptibility to azoles. MIC against susceptible Fusarium spp. for natamycin was 3–16 ?g/mL, amphotericin B: 1–8 ?g/mL, voriconazole: 0.5–1.5 ?g/ mL, itraconazole: 0.5–12 ?g/mL, posaconazole: 0.094–1.5 ?g/mL. MIC against Aspergillus flavus was natamycin: 8–32 ?g/mL, amphotericin B: 0.5–16 ?g/mL, voriconazole: 0.025–4 ?g/mL, itraconazole: 0.125–8 ?g/mL, posaconazole: 0.047–0.25 ?g/mL; against Aspergillus niger isolates, to natamycin was 6 ?g/mL (n=1), amphotericin B 8–12 ?g/mL (n = 3), voriconazole: 0.125–0.19 ?g/mL (n = 3), itraconazole: 0.38–0.75 ?g/mL, posaconazole: 0.064–0.19 ?g/mL and against Aspergillus fumigatus (n = 1), was natamycin4 ?g/ mL, amphotericin B ? 8 ?g/mL, voriconazole 0.25 ?g/mL, itraconazole 1 ?g/mL, and posaconazole 0.19 ?g/mL. MIC against susceptible Acremonium spp. for natamycin was 1.5–16 ?g/mL, amphotericin B: 0.5–8 ?g/mL, voriconazole: 0.19–3 ?g/mL, itraconazole: 0.125 ?g/mL, posaconazole: 0.125–0.5 ?g/mL and against susceptible Curvularia was natamycin 0.75–4 ?g/mL, amphotericin B 0.5–1 ?g/mL, voriconazole 0.125–0.19 ?g/mL, itraconazole 0.047–0.094 ?g/mL, posaconazole 0.047–0.094 ?g/mL. MIC against Mucor spp.+ Rhizopus spp. (n = 1) was natamycin: 8 ?g/mL, amphotericin B: 0.75 ?g/mL, posaconazole: 1.5 ?g/ mL. MIC against of Alternaria (n = 1) was voriconazole: 0.19 ?g/mL, posaconazole: 0.094 ?g/mL. MIC against Penicillium (n=1) was natamycin: 8 ?g/mL, voriconazole: 0.25 ?g/mL, itraconazole: 0.5 ?g/mL, and Posaconazole: 0.125 ?g/mL. Conclusion: Our observations highlight the variations in susceptibility to antifungal agents. Posaconazole seems to be effective with low MIC against common corneal pathogenic fungal isolates

Spectrum of bacterial keratitis in North India: A retrospective analysis of six years at a tertiary care eye center

Purpose: To analyze the pattern of bacterial pathogens causing infective keratitis and their resistance to the recommended antibiotics over six years. Methods: It was a retrospective study of 9,357 cases of bacterial keratitis from January 2015 to December 2020, at a tertiary care ophthalmic center. A total of 9,547 corneal specimens were obtained from the study subjects. Demographic details of the patients, pathogenic bacteria isolated, and their antimicrobial susceptibility were noted and analyzed. Results: Bacterial pathogens were identified in 23.52% of the specimens. The most common isolates were coagulase?negative Staphylococci (60.75%), followed by Pseudomonas aeruginosa (14.23%), Staphylococcus aureus (13.92%), gram negative bacilli of the family Enterobacterales (8.64%), Streptococcus spp. (1.72%), Acinetobacter spp. (0.13%), and other non?fermenting gram?negative bacilli (0.57%). In Staphylococci, 55–80% of isolates were resistant to erythromycin, and 40–70% to fluoroquinolones, while no resistance was observed against vancomycin. 40–60% of isolates of P. aeruginosa were resistant to cephalosporins, 40–55% to fluoroquinolones, and 30–60% to aminoglycosides. Also, 40–80% of isolates of Enterobacterales were resistant to cephalosporins, and 50–60% to fluoroquinolones. Most gram?negative isolates were susceptible to carbapenems and polymyxin B. Conclusion: To the best of our knowledge, our study is the largest compilation of microbiological profile of bacterial keratitis from North India. It highlights the current trend of the bacterial pathogens that cause infectious keratitis. Staphylococci and Pseudomonas were found to be the most common pathogens. Increased resistance was seen against some of the commonly prescribed empirical antibiotics. Such evidence is useful for restructuring the empirical prescription practices from time to time.

Tear film lipid layer thickness measurement from Ocular Surface Analyzer as a marker to monitor treatment of meibomian gland dysfunction in a study comparing physiological detergent-free eyelid wipes with conventional therapy: A randomized trial

Purpose: To compare the efficacy of physiological, non?detergent eyelid wipes with conventional lid hygiene in patients with meibomian gland dysfunction (MGD). Methods: Fifty participants with MGD were recruited and randomized into two groups. Participants in group I used Evolve Pure? Eyewipes twice a day to clean the eyelid debris along with standard therapy (antibiotic and lubricants) and participants in group II followed lid hygiene with warm compresses along with standard therapy. Symptoms, ocular surface assessment (lipid layer thickness, tear meniscus height, non?invasive tear film breakup time, and meibography), slit?lamp biomicroscopy (eyelash contamination, meibomian gland blockage, meibomian gland secretion, and meibomian gland telangiectasia) and tear film osmolarity were noted at baseline and 90 days after therapy. Results: Significant improvement in symptoms and signs of MGD was observed in both groups after treatment (P < 0.001); however, the clinical improvement was better with the use of eyelid wipes. Lipid layer thickness increased significantly in group I (P = 0.0006) and group II (P = 0.0002), which was maintained even after adjusting for sociodemographic variables such as age, sex, and severity score of symptoms and signs. Conclusion: Lipid layer thickness of the tear film is a sensitive marker in monitoring response to treatment in patients with MGD. The use of physiological detergent?free eyelid wipes is non?inferior to lid hygiene and warm compresses, which remains the mainstay for treatment of MGD; the clinical improvement with eyelid wipes was noted to be better

Noninvasive ocular surface analyzer as an adjunct in diagnosis and estimating prevalence of meibomian gland dysfunction: Hospital-based comparative study

Purpose: To assess the role of noninvasive ocular surface analyzer (OSA) in workup of meibomian gland dysfunction (MGD) and to estimate hospital?based prevalence of MGD using this objective device. Methods: The study recruited 113 consecutive participants attending the ophthalmology outpatient department of a tertiary care hospital. All participants were administered a symptom questionnaire. Participants underwent a comprehensive ocular examination, including slit?lamp biomicroscopy and meibomian gland expression. Lipid layer thickness (LLT), noninvasive tear breakup time (NIBUT), tear meniscus height (TMH), and meibomian gland loss (MGL) were assessed using OSA. The presence of either or both reduced/absent meibum secretion and cloudy to toothpaste?like secretion was diagnosed as MGD. Results: Prevalence of total MGD was 57.52% (95% confidence interval [95% CI]: 48.3%–66.8%) and that of symptomatic MGD was 42.5% (95% CI: 33.2%–51.7%). Prevalence of total and symptomatic MGD was highest in those aged ?50 years (P < 0.001 and P = 0.004, respectively). Computer vision syndrome increased the odds of symptomatic MGD (odds ratio [OR]: 4.3). NIBUT and MGL significantly differed in MGD and non?MGD groups (P = 0.023 and P < 0.001, respectively). LLT significantly differed between asymptomatic and symptomatic cases (P = 0.033). MGL >25% increased the odds of having MGD (OR: 19.1). Significant negative correlations were observed between MGL and NIBUT (P = 0.04) and between MGL and LLT (P = 0.02). MGL demonstrated the highest diagnostic accuracy for MGD (AUC = 0.827, sensitivity = 75.4%, specificity = 85.4%, cut?off value: ?26%). Conclusion: MGD is a common disorder in adults attending the ophthalmology outpatient services of a tertiary eye care hospital. Incorporating noninvasive OSA in clinical practice can aid in rapid and reliable measurements of MGD?related parameters

Myopia prevalence in a population-based childhood visual impairment study in North India – CHVI-2

Purpose: The aim of the study was to determine the prevalence of myopia at the community level. Methods: A population?based, cross?sectional study was planned in 40 clusters among children identified with subnormal vision in the urban community of Delhi. House?to?house visits were conducted for visual acuity screening of 20,000 children aged 0–15 years using age appropriate visual acuity charts. All the children with visual acuity of < 6/12 in any eye in the age group between 3 and 15 years and inability to follow light in age group 0–3 years were referred for detailed ophthalmic examination. Results: A total of 13,572 (64.7%) children belonged to the age group of 6–15 years. Of these, a total of 507 (3.7%) were found to be having myopia (spherical equivalent of ?0.50 DS or worse in one or both eyes) with positive association with higher age groups. Conclusion: The estimated prevalence of myopia is 3.7%; the proportion of uncorrected myopia was 45%, which reflects that refractive error services need to be improved further.

Clinical profile and treatment outcomes of Fusarium keratitis

Purpose: To determine the seasonality, clinical profile, and treatment outcome of Fusarium keratitis. Methods: A retrospective medical chart review of 97 patients with culture?proven Fusarium keratitis at a tertiary eye care institution from January 2018 to December 2019. Results: The median (SD) age at enrollment was 44.6 (16) years; 75 (79.8%) of them were male. Presence of infiltrate less than 4 mm2 at baseline indicated 4.4 times the odds of achieving final BCVA more than 20/60 (95% CI: 1.4–13.3; P = 0.008). The absence of surgical management indicated 8.1 times the odds of achieving final BCVA of more than 20/60 (95% CI: 0.9–71.5; P = 0.06). The visual acuity at presentation, duration between symptoms and presentation, history of ocular trauma, previous use of topical medications, and presence of hypopyon were not identified as significant predictors of final BCVA in the multivariable regression analysis. Conclusion: Smaller infiltrate size and absence of surgical management are the significant predictors of good visual outcome. Visual outcome of Fusarium keratitis is poor, and a significant number of patients did not respond to anti?fungal therapy and had to undergo surgeries. To the best of our knowledge, this is the largest case series on Fusarium keratitis to date

Delayed onset of congenital hereditary endothelial dystrophy due to compound heterozygous SLC4A11 mutations.

Background: Congenital hereditary endothelial dystrophy (CHED) is an autosomal recessive disorder characterized by bilateral, symmetrical, noninflammatory corneal clouding (edema) present at birth or shortly thereafter. This study reports on an unusual delayed presentation of CHED with compound heterozygous SLC4A11 mutations. Materials and Methods: A 45‑year‑old female, presenting with bilateral decreased vision since childhood that deteriorated in the last 5 years, was evaluated to rule out trauma, viral illness, chemical injury, glaucoma, and corneal endothelial dystrophies. Tear sample was sent for herpes simplex viral (HSV) antigen testing. Genomic DNA from peripheral blood was screened for mutations in all exons of SLC4A11 by direct sequencing. Full‑thickness penetrating keratoplasty was done and corneal button was sent for histopathological examination. Results: Slit‑lamp findings revealed bilateral diffuse corneal edema and left eye spheroidal degeneration with scarring. Increased corneal thickness (762 μm and 854 μm in the right and left eyes, respectively), normal intraocular pressure (12 mmHg and 16 mmHg in the right and left eyes, respectively), inconclusive confocal scan, and specular microscopy, near normal tear film parameters, were the other clinical features. HSV‑polymerase chain reaction was negative. Histopathological examination revealed markedly thickened Descemet’s membrane with subepithelial spheroidal degeneration. SLC4A11 screening showed a novel variant p.Ser415Asn, reported mutation p.Cys386Arg and two polymorphisms, all in the heterozygous state and not identified in 100 controls. Conclusions: The study shows, for the first time, compound heterozygous SLC4A11 mutations impair protein function leading to delayed onset of the disease.

Ocular graft versus host disease in allogenic haematopoetic stem cell transplantation in a tertiary care centre in India.

Background & objectives: This study was aimed to report the occurrence of ocular graft versus host disease (oGVHD) in allogeneic haematopoietic stem cell transplantation (allo-HSCT) patients in a tertiary care hospital setting. Methods: A cross-sectional study of ocular surface of allo-HSCT patients was done. Slit lamp biomicroscopy, symptom score, tear meniscus height, fluorescein tear break-up time, Schirmer’s test I, ocular surface staining, dry eye severity, ocular surface disease index score were done. Indications for allo-HSCT, human leukocyte antigen (HLA) matching, GVHD risk factor, systemic manifestation and treatment were also noted. Results: GVHD occurred in 44.4 per cent of 54 allo-HSCT patients (mean age 26.7 ± 12 yr) included in the study. GVHD risk factors identified included female gender, relapse, older age of donor, cytomagelo virus (CMV) reactivation, and multiparous female donors. oGVHD was noted in 31.5 per cent with mean time to occurrence being 17.8 ± 21.9 months after the allo-HSCT and was observed in 89.5 per cent of chronic GVHD cases. Acute GVHD (oral and dermatological) involvement showed a significant association with GVHD in our patients (P< 0.001, 0R 23.0, CI 6.4-82.1). Chronic GVHD was observed to be associated with the occurrence of oGVHD (dry eye) (P<0.001, OR = 24.0, CI 0.02 - 0.29). Of the 34 eyes with oGHVD, dry eye of level 3 severity was seen in 16, level 2 in six, level 1 in 12 eyes. Interpretation & conclusions: GVHD occurred in 44.4 per cent of the patients studied in the present study. Acute and chronic GVHD showed a strong association with oGVHD. Dry eye disease due to chronic oGVHD was observed in 17 (31.5%) of 54 allo-HSCT patient with chronic oGVHD occurring in 17 (89.4%) of chronic GVHD cases in allo-HSCT patients. Our study on oGVHD in post allo-HSCT patients in tertiary care centre points towards the fact that ocular morbidity due to dry eye disease as a result of oGVHD is a cause for concern in these patients.

Changing pattern of utilization of human donor cornea in India.

Purpose: To review the changing pattern of donor, corneal utilization in an eye bank at a Tertiary Care Center in Northern India by analyzing the trend in the years 2003, 2008, and 2011. Methods: A retrospective review of eye bank records for 3 years (2003, 2008, and 2011) was performed at the National Eye Bank. Details including a clinical grade of donor cornea, indication of corneal transplantation (therapeutic or optical), type of procedure (penetrating or lamellar keratoplasty [LK]), and clinical diagnosis of the graft recipients were recorded. Primary outcome measure was to observe any preference toward LK, judicious usage of donor corneal tissue, and impact of lamellar corneal transplant in the usage of donor corneas. Secondary outcomes included overall utilization rate and change in trend of indication for keratoplasty. Results: A total of 673, 745, and 864 corneas were retrieved in the years 2003, 2008, and 2011, respectively. The percentage of donor corneal utilization increased significantly over time with the rate being 65.08%, 70.06%, and 68.29%, respectively, in the years 2003, 2008, and 2011 (P = 0.014); however, this change was reflected only in the usage of nonoptical grade corneas and not for the optical grade corneas. There was an overall increase in lamellar corneal procedures for any clinical grade of cornea (P = 0.0019); number of Descemet’s stripping automated endothelial keratoplasty (DSAEK) procedures increased significantly (P < 0.001), particularly for pseudophakic corneal edema (PCE) (P = 0.0085) and failed graft (P = 0.002). Significant increase in the utilization of nonoptical grade corneas was observed over the years (P = 0.005), though the utilization did not increase significantly for optical purposes viz., LK (P = 0.08). Conclusions: Utilization rate of donor corneas increased over the years, primarily due to increase in usage of nonoptical grade corneas for therapeutic purposes. There was a procedural shift toward DSAEK for PCE and failed graft. However, an increase in usage of nonoptical grade corneas for LK, a single donor corneal tissue for two recipients, and retrieval or utilization of optical grade cornea was not observed.

Ocular Chlamydia trachomatis infections in patients attending a tertiary eye care hospital in north India A twelve year study.

Background & objectives: Ocular infection with Chlamydia trachomatis is a major public health problem in densely populated countries like India. The true prevalence of such infections is uncertain due to insufficient data available from India. The aim of this study was to do a retrospective analysis of C. trachomatis eye infections in patients attending the outpatient department of Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, over a period of 12 years. Methods: From 1997 to 2008, the Chlamydia laboratory received conjunctival swabs from 1281 consecutive patients for C. trachomatis detection after thorough clinical examination. Specimens were subjected to direct fluorescent antigen detection assay using monoclonal antibody based commercial kit to detect the presence of C. trachomatis antigen. Results: Antigen positivity varied between 22-28 per cent. Children below 11 yr and people above the age of 60 yr showed comparatively higher antigen positivity (25.7 and 27.8%, respectively). As compared to males significantly (P<0.05) higher number of females in the age group of 31-60 yr were positive for C. trachomatis antigen. Patients with the clinical diagnosis of follicular/allergic conjunctivitis and trachoma showed higher rate of antigen positivity. Interpretation & conclusions: Northern India having dry and arid climatic conditions in most parts of the year was considered in the past as one of the trachoma hyper-endemic foci. The study indicated that laboratory proven C. trachomatis eye infection still persisted in this part of the country throughout the study period of 12 years.

Post-operative endophthalmitis: Antibiogram & genetic relatedness between Pseudomonas aeruginosa isolates from patients & phacoemulsifiers.

Background & objectives: Though not frequently but there are reports showing phacoemulsifiers as a potent source of infection in post-operative cases of endophthalmitis. This study was carried out to find antibiogram and genetic relatedness between Pseudomonas aeruginosa isolates from a post-cataract surgery endophthalmitis outbreak (3 patients) and internal tubings of 5 phacoemulsifiers. Methods: In vitro antimicrobial sensitivity patterns of the 8 bacterial isolates were observed. Genetic analysis of the bacterial isolates was done using random amplification of polymorphic DNA (RAPD) assay and PCR ribotyping. The resulting DNA band patterns were examined visually and by computer assisted analysis using unweighted pair group method. Results: The three P. aeruginosa patient isolates were found to be different from the five phacoemulsifier isolates in sensitivity towards 3 antibiotics and by genetic analysis (33 and 44% homology by RAPD assay and PCR ribotyping). Two of the patient isolates shared 100 per cent genetic homology by RAPD assay and another pair shared 100 per cent homology by PCR ribotyping. The five isolates from phacoemulsifiers did not share significant genetic homology. There was significant genetic variation between bacterial isolates from patients and phaco emulsifiers. Interpretation & conclusion: Though the three P. aeruginosa isolates obtained from the patients were phenotypically similar and genetically close, they differed from the phaco-machine isolates both genetically, and in their antibiogram profile. However, the five phacoemulsifier isolates were genetically diverse though they shared the same antibiogram profile. Therefore the Ringer’s lactate from phacomachines could not be conclusively proven to be the source of infection.

Investigative modalities in infectious keratitis.

Standard recommended guidelines for diagnosis of infectious keratitis do exist. Based on an extensive Medline literature search, the various investigative modalities available for aiding the diagnosis of microbial keratitis have been reviewed and described briefly. Preferred practice patterns have been outlined and the importance of routine pre-treatment cultures in the primary management of infectious keratitis has been highlighted. Corneal scraping, tear samples and corneal biopsy are few of the specimens needed to carry out the investigative procedures for diagnosis and for initiating therapy in cases of microbial keratitis. In bacterial, fungal and amoebic keratitis, microscopic examination of smears is essential for rapid diagnosis. Potassium hydroxide (KOH) wet mount, Gram's stain and Giemsa stain are widely used and are important for clinicians to start empirical therapy before microbial culture results are available. The usefulness of performing corneal cultures in all cases of suspected infectious keratitis has been well established. In cases of suspected viral keratitis, therapy can be initiated on clinical judgment alone. If a viral culture is needed, scrapings should directly be inoculated into the viral transport media. In vivo confocal microscopy is a useful adjunct to slit lamp bio-microscopy for supplementing diagnosis in most cases and establishing early diagnosis in many cases of non-responding fungal and amoebic keratitis. This is a non-invasive, high resolution technique which allows rapid detection of Acanthamoeba cysts and trophozoites and fungal hyphae in the cornea long before laboratory cultures give conclusive results. Other new modalities for detection of microbial keratitis include molecular diagnostic techniques like polymerase chain reaction, and genetic finger printing by pulsed field gel electrophoresis.

Visual outcome after intravenous dexamethasone therapy for idiopathic optic neuritis in an Indian population: a clinical case series.

PURPOSE: To evaluate the clinical profile, response to dexamethasone treatment and visual function outcome in Indian patients with acute optic neuritis. MATERIALS AND METHODS: We conducted an observational study of patients with acute optic neuritis who were treated with intravenous dexamethasone (100 mg in 250 ml of 5% dextrose over 1-2 hours daily, for three consecutive days) and had completed at least two years of follow-up. Parameters assessed included visual acuity, contrast sensitivity, color vision, visual fields, relative afferent pupillary defect (RAPD) and visually evoked potentials. Out of 40 patients studied, 26 patients (33 eyes) had all visual function parameters assessed. Twenty three patients (28 eyes) had completed two years of follow-up and were included for statistical analysis. RESULTS: Improvement in visual acuity was statistically significant for distance after 24 hours of the first dose (P = < 0.001) and for near vision after 24 hours of the second dose (P = 0.006); improvement in color and contrast sensitivity was statistically significant 24 hours after the third dose (P = < 0.001 for color vision and P = 0.013 for contrast sensitivity). Significant improvement in RAPD and visual fields were seen by 1 month (P = 0.005). Recurrence was seen in 4 eyes of 4 patients. No serious side effects were observed. At two years, 82.14% (23 out of 28) eyes had visual acuity > 20/40. CONCLUSION: Treatment with intravenous pulsed dexamethasone led to rapid recovery of vision in acute optic neuritis, without any serious side effects.

Recurrent Salzmann's nodular degeneration: report of two cases and review of literature.

Recurrence of Salzmann's nodular degeneration following corneal transplantation is uncommon. The earlier reports of recurrence of Salzmann's degeneration were based on clinical evidence. We report two histopathologically proven cases of recurrence of Salzmann's nodular degeneration following keratoplasty; one recurring after lamellar keratoplasty and the other following penetrating keratoplasty. Two male patients (40 yrs and 24 yrs) presented to us with a clinical picture of Salzmann's nodular degeneration. One patient had undergone lamellar keratoplasty in both eyes for Salzmann's degeneration, 22 years ago. A repeat lamellar keratoplasty was performed in the right eye (7.5 mm/8 mm). In the other patient, penetrating keratoplasty was performed in the left eye, 6 years ago for the same. Lamellar keratoplasty was performed in the left eye (8 mm/8 mm). The histopathologic evaluation of the host button in both the cases, showed features very much suggestive of a recurrence of Salzmann's nodular degeneration.

Need for optical and low vision services for children in schools for the blind in North India.

CONTEXT: Children admitted in blind schools need low vision assessment for improving functional vision (useful residual vision). AIM: To ascertain the need for spectacles and magnifiers as low vision devices (LVD) in children with useful residual vision, attending blind schools. SETTING AND DESIGN: Cross-sectional study conducted in 13 blind schools in Delhi, North India. MATERIALS AND METHODS: Of a total of 703 children (less than 16 years of age) examined, 133 (18.91%) with useful residual vision were refracted and analyzed. High addition plus lenses (range 5-30 diopters) were used as spectacle magnifiers for near LVD assessment. "World health organization (WHO)/ prevention of blindness (PBL) eye examination record for children with blindness and low vision", was used to collect data. SPSS (statistical package for the social science), version 10.0 was used for analysis. RESULTS: Based on the vision of 133 children at initial examination, 70.7% children were blind and 12.0% were severely visually impaired (SVI). 20.3% children improved by at least one WHO category of blindness after refraction. With best correction, 50.4% children were still blind and 13.5% were SVI. Visual acuity in the better eye after refraction in 47 children (35.3%), improved with spectacles. Children with aphakia (17), coloboma (5), refractive error (5) and microphthalmos (4) benefited from spectacles. Of 124 children with low vision but having useful residual vision, 51 (41.1%) were able to read N-10 unaided or with distance spectacles and 30 children (22.6%) improved to N-10 with spectacle magnifiers and were prescribed the same. CONCLUSION: Visually impaired children with aphakia and congenital anomalies of the eye benefit from refraction and low vision services.