Embracing technology in cataract surgical training � The way forward

While ophthalmology as a surgical branch itself has evolved technologically with newer instruments, techniques and procedures; ophthalmic surgical training appears to have stagnated in terms of how it is delivered and how trainees� learning and performance are assessed. This collaborative editorial attempts to identify the lacunae in ophthalmic residency training and highlight how technological tools such as surgical simulators can be incorporated into ophthalmic training even in limited-resource settings with good results

Efficacy of voriconazole and amphotericin B in corneal preservative media

Purpose: To evaluate the efficacy of voriconazole and amphotericin B in McCarey–Kaufman (MK) media. Methods: MK media vials were supplemented with either voriconazole at 1, 2, 20, 50, 100 ?g/mL or amphotericin B at 0.5, 1, 2, 10, 20 ?g/mL. The standard inoculum of the American Type Culture Collection (ATCC) strain of Candida albicans, Aspergillus flavus, and Fusarium keratinoplasticum was added to the set of vials. The efficacy outcomes were calculated as ‘viable fungal colony counts’ determined from the samples taken on Days 0 and 4. MK media containing fungal inoculum but without antifungal supplements were used as control. Results: In the voriconazole arm, on Day 4, a reduction in the colony count was observed for Candida albicans (1 ?g/mL, 36%; 100 ?g/mL, 100%), Aspergillus flavus (1 ?g/mL, 53.8%; 100 ?g/mL, 80.4%), and Fusarium keratinoplasticum (1 ?g/mL, 39.0%; 100 ?g/mL, 72.2%). Similarly, in the amphotericin B arm, on Day 4, a reduction in the colony count was observed for Candida albicans (0.5 ?g/mL; 99.9%; 20 ?g/mL, 100%), Aspergillus flavus (0.5 ?g/mL, 65.2%; 20 ?g/mL, 84.8%), and Fusarium keratinoplasticum (0.5 ?g/mL, 90.1%; 20 ?g/mL, 100%). Conclusion: Compared to voriconazole, the addition of amphotericin B significantly reduces fungal contamination in MK media.

Outcome of transplanted donor corneas with more than 6 h of death‑to‑preservation time.

Purpose: In tropical countries, physicians are skeptic in using corneas with death‑to‑preservation time (DTPT) >6 h, concerns being endothelial cell viability and microbial contamination on prolonged DTPT. The objective of the study was to investigate these concerns by analyzing the outcomes of corneal transplants performed using donor corneas with DTPT >6 h. Materials and Methods: The study was a retrospective case series of 65 transplants performed in 2013 with donor corneas that had DTPT >6 h (range, 6.1–9.8 h). The information on donor cornea tissues and the recipient details were collected from the eye bank and the medical records department of our tertiary eye care center. The main outcome measures were slit lamp assessment of the donor corneas, primary graft failure, graft survival, and postoperative adverse reactions, especially infections, if any. Results: Median DTPT was 7 h. Forty‑four (67.7%) corneas were evaluated as optical grade and 21 (32.3%) were deemed as therapeutic grade; 36 (55.4%) were used for optical indications. There was no relationship between DTPT and the tissue grading of corneas or endothelial cell density. Of the 23 keratoplasties for purely optical indications with a minimum follow‑up of 3 months, 15 (65.2%) remained clear whereas 7 (30.4%) failed (mean follow‑up 15.1 ± 6.7 months). The causes of failure were primary graft failure (n = 1) and secondary graft failure (n = 6). Conclusion: The donor corneas with DTPT 6 h to 10 h can be utilized for optical indications provided that they meet the criteria of tissue acceptance for optical use.

Natamycin in the treatment of keratomycosis: Correlation of treatment outcome and in vitro susceptibility of fungal isolates.

In this study, 60 fungal isolates from 60 patients with fungal keratitis were tested in vitro for their susceptibility to natamycin and the mean minimum inhibitory concentrations of natamycin (MICn) were correlated with clinical outcome. The mean MICn for various groups of fungi from patients with either early (<10 days) or late (≥10 days) presentation was correlated with the outcome. Aspergillus flavus showed resistance to natamycin with a high mean MICn (>16 μg/ml). While the clinical response in all patients with early A. flavus keratitis was good it was poor in late cases (5/8 patients, 62.5%). Fusarium species, Acremonium species and dematiaceous fungi were sensitive with low mean MICn (Fusarium: 5.7-7.2 μg/ml, Acremonium: 5.7-6.8 μg/ml, dematiaceous: (1.6-4 μg/ml). However, 46.6% (7/15) patients in Fusarium and 57.1% (4/7) in Acremonium group needed keratoplasty. We conclude that despite susceptibility of most fungal species causing keratitis to natamycin, the treatment outcome is poor in advanced fungal keratitis.

Alcohol epitheliectomy with mechanical debridement in a case of granular corneal dystrophy with r555w homozygous mutation of TGF B1 gene.

An eight-year-old girl, an offspring of a consanguineous marriage presented with multiple anterior stromal geographic corneal opacities in both eyes. She was diagnosed to have superficial variant of granular dystrophy based on the family history, clinical features and mutation of TGF B1 gene. She was treated by alcohol-assisted removal of epithelium followed by mechanical debridement of abnormal deposits. Postoperatively, the cornea in both eyes was clear with no trace of opacity and the patient had an unaided visual acuity of 20/20 partial.

Review of epidemiological features, microbiological diagnosis and treatment outcome of microbial keratitis: Experience of over a decade.

Purpose: To review the epidemiological characteristics, microbiological profile, and treatment outcome of patients with suspected microbial keratitis. Materials and Methods: Retrospective analysis of a non-comparative series from the database was done. All the patients presenting with corneal stromal infiltrate underwent standard microbiologic evaluation of their corneal scrapings, and smear and culture-guided antimicrobial therapy. Results: Out of 5897 suspected cases of microbial keratitis 3563 (60.4%) were culture-proven (bacterial – 1849, 51.9%; fungal – 1360, 38.2%; Acanthamoeba – 86, 2.4%; mixed – 268, 7.5%). Patients with agriculture-based activities were at 1.33 times (CI 1.16–1.51) greater risk of developing microbial keratitis and patients with ocular trauma were 5.33 times (CI 6.41–6.44) more likely to develop microbial keratitis. Potassium hydroxide with calcofluor white was most sensitive for detecting fungi (90.6%) and Acanthamoeba (84.0%) in corneal scrapings, however, Gram stain had a low sensitivity of 56.6% in detection of bacteria. Majority of the bacterial infections were caused by Staphylococcus epidermidis (42.3%) and Fusarium species (36.6%) was the leading cause of fungal infections. A significantly larger number of patients (691/1360, 50.8%) with fungal keratitis required surgical intervention compared to bacterial (799/1849, 43.2%) and Acanthamoeba (15/86, 17.4%) keratitis. Corneal healed scar was achieved in 75.5%, 64.8%, and 90.0% of patients with bacterial, fungal, and Acanthamoeba keratitis respectively. Conclusions: While diagnostic and treatment modalities are well in place the final outcome is suboptimal in fungal keratitis. With more effective treatment available for bacterial and Acanthamoeba keratitis, the treatment of fungal keratitis is truly a challenge.

Voriconazole for the treatment of refractory Aspergillus fumigatus keratitis.

We report a case of Aspergillus fumigatus keratitis in a 53-year-old, well-controlled diabetic female who did not respond to standard antifungal treatment. She was started on topical natamycin eye drops, but the infiltrate continued to progress. Topical amphotericin B and systemic ketoconazole was added, however, there was no response and the infiltrate increased further. She was then switched to topical and systemic voriconazole. Steady resolution of the infiltrate was noted within 2 weeks of therapy.

Nocardia infection following phacoemulsification.

Infection of a self-sealing tunnel incision is a rare but vision-threatening complication of cataract surgery. We describe two cases of side port infection following an uneventful phacoemulsification. Nocardia was isolated in one case. Both the cases were worsening on medical treatment and were successfully treated by therapeutic keratoplasty.

Comparison of clinical and microbiological profiles in smear-positive and smear-negative cases of suspected microbial keratitis.

PURPOSE: To examine the hypothesis that initial smear examination results have a significant bearing on the management and outcome of suspected microbial keratitis. MATERIALS AND METHODS: One hundred and seventy consecutive patients with suspected microbial keratitis were included in a prospective nonrandomized comparative study and their detailed clinical and microbiological data (smears and cultures of corneal scrapings) were captured on a predesigned corneal ulcer database. Patients were divided into two groups: Group 1 included 68 patients with corneal scrapings negative in smears while Group 2 included 102 patients with corneal scrapings positive in smears. The two groups were compared for their clinico-microbiological profile, management and clinical outcome. The outcome was noted at three months. Fisher's exact test was applied for statistical analysis. RESULTS: Cultures were sterile in 57.3% of patients in Group 1 compared to 17.6% in Group 2. Scrapings that grew S. pneumoniae, gram-negative organisms, fungi and Acanthamoeba were more often positive in smears (18.6%, 11.8%, 19.6% and 2.9% respectively). While data on duration of prior treatment was not available, prior medication made no significant difference to smear results. More (79.3%) patients of Group 1 had small infiltrate size (CONCLUSIONS: Initial smear examination helps in instituting specific therapy thereby improving the outcome in cases of microbial keratitis. Positive smears indicate greater severity of disease and prior medication may not be a significant cause of smear negativity.

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.

Clinical resistance of Staphylococcus keratitis to ciprofloxacin monotherapy.

PURPOSE: To review the in vitro susceptibility and the clinical response to 0.3% ciprofloxacin in Staphylococcus aureus keratitis. METHODS: This is a non-comparative case series derived from a prospectively collected database and analysed retrospectively. One hundred and twenty one patients presenting in the cornea service of LV Prasad Eye Institute, Hyderabad, India, between January 1993 and December 2000, and identified to have S. aureus keratitis were included in the study. All patients had received slitlamp evaluation of the cornea and diagnostic microbiologic workup. They were treated with topical antimicrobial therapy based on smear and culture results. All S. aureus isolates were tested for antibiotic susceptibility by disk diffusion and those resistant to ciprofloxacin were confirmed by testing for minimum inhibitory concentration. The patients' clinical response to the antimicrobial therapy was noted. RESULTS: Twenty-five (20.6%) of 121 isolates resistant to ciprofloxacin on in vitro susceptibility testing were further analysed in this study. Fifteen of these 25 (60%) patients were initially treated with topical ciprofloxacin. Twelve of 15 (80%) patients showed no clinical improvement (3-8 days). Based on antibiotic susceptibility results, the antibiotic therapy was modified to fortified cefazolin and gentamicin in seven (58.3%), to vancomycin in one and to chloramphenicol in four cases. The corneal infiltrate resolved in 11 (73.3%) of 15 cases. Two patients required penetrating keratoplasty (PK), one required evisceration, and one patient was lost to follow up. Nine of 25 patients were initially started on fortified cefazolin and gentamicin therapy based on smear positive for gram-positive cocci; this resulted in resolution of infiltrate in 44.4% (4/9) while three required change of antibiotics (vancomycin-2, chloramphenicol-1), one required PK and one patient was lost to follow up. One of 25 patients started and continued on chloramphenicol, showed no response and required PK. CONCLUSIONS: This study shows a significant resistance of S. aureus to many antibiotics including ciprofloxacin and highlights the need for an alternative to ciprofloxacin monotherapy for the treatment of staphylococcal keratitis.

Recurrent shield ulcer following penetrating keratoplasty for keratoconus associated with vernal keratoconjunctivitis.

Though penetrating keratoplasty for keratoconus secondary to vernal keratoconjunctivitis (VKC) invariably carries a good prognosis, the postoperative course may be complicated by recurrent epitheliopathy. Despite good medical control of VKC shield ulcer is still a possibility.

Ophthalmic complications and management of Stevens-Johnson syndrome at a tertiary eye care centre in south India.

PURPOSE: To review the possible aetiological factors, ocular complications and their management in patients of Stevens-Johnson syndrome with ocular involvement, seen at a tertiary eye care centre. METHODS: We retrospectively reviewed the medical records of patients with Stevens-Johnson syndrome seen between 1987-1998 at L V Prasad Eye Institute. The demographic and possible aetiological factors data causing Stevens-Johnson syndrome were collected. The details of the ocular examination and treatment were collected and examined to determine the pattern of presentation, complications, treatment response and outcome. RESULTS: A total of 95 patients, 40 males (42.10%) and 55 females (57.89%), were identified during the 11-year period. A majority of the patients (n = 53; 55.78%) were between 20 and 40 years of age. All patients had bilateral involvement and most (n = 93; 97.89%) had bilateral symmetrical presentation. The duration from the onset of symptoms to the time of presentation at the institute varied from 6 days to 18 years with most patients presenting after one year (n = 39; 41.05%). The most commonly identified possible causative factor was drugs (n = 55; 51.89%). No definitive cause was identified in 37 (38.94%) patients, and 3 (3.15%) patients had a history of viral fever preceding the onset of Stevens-Johnson syndrome. The best corrected visual acuity at initial presentation was 6/12 or better in 32 (33.68%) patients. Lid abnormalities were observed in 87 (91.51%) patients, conjunctival abnormalities in 92 (96.84%) and corneal complications in 93 (97.89%). All patients were managed medically and 26 (27.36%) patients underwent surgery. CONCLUSION: Stevens-Johnson syndrome remains an important cause of severe visual loss and ocular morbidity, both of which significantly affect the quality of life. Not many medical or surgical options are available even in tertiary eye-care centres. Future advances in immune modulation techniques may prevent many of the sequelae that continue to occur despite the best possible medical care.

"String of pearls" following Nd:YAG laser posterior capsulotomy.

Posterior capsular re-opacification can occur following Nd-YAG capsulotomy. This necessitates multiple capsulotomies with its potential complications. We report one such case and discuss possible predisposing factors and preventive measures for this condition.