Corneal ulceration in pediatric patients: a brief overview of progress in topical treatment

α-Cyclodextrins Polyrotaxane Loading Silver Sulfadiazine

As a drug carrier, polyrotaxane (PR) has been used for targeted delivery and sustained release of drugs, whereas silver sulfadiazine (SD-Ag) is an emerging antibiotic agent. PR was synthesized by the use of α-cyclodextrin (CD) and poly(ethylene glycol) (PEG), and a specific antibacterial material (PR-(SD-Ag)) was then prepared by loading SD-Ag onto PR with different mass ratios. The loading capacity and the encapsulation efficiency were 90% at a mass ratio of 1:1 of PR and SD-Ag. SD-Ag was released stably and slowly within 6 d in vitro, and its cumulative release reached more than 85%. The mechanism of PR loading SD-Ag might be that SD-Ag attached to the edge of α-CD through hydrogen bonding. PR-(SD-Ag) showed a higher light stability than SD-Ag and held excellent antibacterial properties against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus).

Infectious Ulcerative Keratitis Following Retinopathy of Prematurity Treatment

PURPOSE

To report the complication of infectious ulcerative keratitis after laser photocoagulation and pars plana vitrectomy (PPV) for retinopathy of prematurity (ROP).

METHODS

A retrospective chart review of infants treated for ROP with plus disease between 2004 and 2013 at University Hospital, Newark, New Jersey.

RESULTS

Of the 110 eyes (55 patients) that underwent treatment for ROP, 8 (7.27%) eyes were noted to develop infectious ulcerative keratitis in 4 neonates (4 eyes after laser photocoagulation and 4 eyes after PPV). All 8 eyes that developed ulcerative keratitis had a preceding corneal epithelial defect followed by corneal stromal haze. Seven of 8 eyes developed epithelial defect within 8 days of the procedure. All epithelial defects progressed to ulcerative keratitis within 7 days. A total of 10 (9.1%) eyes developed postoperative epithelial defects, and 8 (80%) of these eyes were ultimately diagnosed as having ulcerative keratitis. Four (4.08%) of 98 eyes treated with laser photocoagulation alone developed infective ulcerative keratitis, compared to 4 (33.33%) of 12 eyes treated with PPV. Because keratitis healed, corneal opacification ensued and covered 10% to 90% of the corneal surface area. Five of the 8 eyes had positive culture of corneal scrapings: 2 grew coagulase-negative Staphylococcus and Stenotrophamonas; 1 grew coagulase-negative Staphylococcus; 1 grew Streptococcus viridans, and 1 grew Staphylococcus hominis, Streptococcus mitis, and Streptococcus viridans. All 8 eyes were treated with antibiotic eye drops.

CONCLUSIONS

Infectious ulcerative keratitis developed in a small, but significant, percentage of patients undergoing treatment for ROP. Postoperative corneal epithelial defects with subsequent corneal haze appear to be involved in the progression to ulcerative keratitis.

Paediatric bacterial keratitis cases in Shanghai: microbiological profile, antibiotic susceptibility and visual outcomes

PURPOSE

The purpose of this study was to review the microbiological profile, in vitro antibiotic susceptibility and visual outcomes of paediatric microbial keratitis in Shanghai, China over the past 6 years.

METHODS

Medical records of patients aged ≤16 years were reviewed, who were diagnosed as having bacterial keratitis between 1 January 2005 and 31 December 2010. Bacterial culture results and in vitro antibiotic susceptibility were analysed. A logistic regression analysis was conducted to evaluate the relationship between visual impairment and possible risk factors.

RESULTS

Eighty consecutive cases of paediatric bacterial keratitis cases were included, among which 59 were identified as having positive culture. Staphylococcus epidermidis was the most commonly isolated organism (n=23; 39.0%), followed by Streptococcus pneumoniae (n=11; 18.6%) and Pseudomonas aeruginosa (n=6; 10.2%). Antibiotic sensitivities revealed that tested bacteria had low resistance rates to fluoroquinolones and aminoglycosides (8.3-18.4% and 12.5-24.4%, respectively). Multivariate logistic regression analysis proved that visual impairment was significantly associated with Gram-negative bacterial infection (odds ratio (OR)=7.626; P=0.043) and an increasing number of resistant antibiotics (OR=0.385; P=0.040).

CONCLUSIONS

S. epidermidis was the most common isolated organism in Shanghai paediatric keratitis. The fluoroquinolones and aminoglycosides remained good choices for treating these patients. Gram-negative bacterial infection and an increasing number of resistant antibiotics were associated with worse visual prognoses in paediatric keratitis.

Immunization and nutritional profile of cases with atraumatic microbial keratitis in preschool age group

PURPOSE

To evaluate the role of protein energy malnutrition and immunization profile in cases of atraumatic microbial keratitis in preschool children.

DESIGN

Retrospective case analysis.

METHODS

Case records of all children 5 years of age and younger with atraumatic microbial keratitis treated at the Dr Rajendra Prasad Centre for Ophthalmic Sciences, New Delhi, India, between January and December 2006 were reviewed retrospectively. Main parameters evaluated were age, degree of protein-energy malnutrition, immunization profile, microbiologic profile, and final outcome.

RESULTS

Fifty-four consecutive children were enrolled during the study period. The mean age was 33.69 ± 21.91 months (range, 3 to 60 months). Mean weight on presentation was 10.57 ± 3.87 kg (range, 4 to 17 kg), with an average protein-energy malnutrition grade of 1.77 ± 0.74. The immunization for age was complete in 43 (80%) children. Severe protein-energy malnutrition was associated with the occurrence of bilateral keratitis (P < .001) and incomplete immunization (P < .001). Positive bacterial culture results were obtained in 44 (82%) cases, with Staphylococcus species being the most prevalent isolate (33/44; 75%). Cases requiring emergency corneal transplantation (24%) were associated with severe protein-energy malnutrition (P < .00) and bilaterality (P < .00). In multivariate analyses, cases without severe protein-energy malnutrition were 36% less likely to undergo any kind of surgical intervention (odds ratio, 0.64; 95% confidence interval, 0.04 to 0.91).

CONCLUSIONS

Our study highlights the association of protein-energy malnutrition and immunization profile with the occurrence of atraumatic microbial keratitis in preschool children. Most of these cases required corneal transplantation surgery to preserve the ocular integrity and to restore vision.

Pediatric Metarrhizium anisopliae keratitis

Metarrhizium anisopliae (M. anisopliae) is an entomopathogenic fungus used as an agricultural pesticide in many countries, including the United States. M. anisopliae grows optimally at 25°C and is therefore considered safe to humans. We report a case of a 12-year-old girl who is a soft contact lens wearer with M. anisopliae corneal ulcer who was treated effectively with topical natamycin after identification of the organism by corneal culture. Topical amphotericin B was not effective.

Étude de l’effet des oligomères procyanidoliques sur la fibrillogénèse de la cornée

PURPOSE

We showed in a previous study that procyanidolic oligomers (PCOs) from grape seeds effectively protect corneal stroma against degradation by bacterial collagenase. Here we report the study of the effect of PCOs on protein and collagen composition of cornea and on the biosynthesis of corneal collagens.

METHODS

Bovine corneas were used in explant cultures. We quantitatively determined total proteins and collagen as well as the incorporation of 3H-proline in separated collagen types. Collagens type I, V, and VI were separated and quantitated. In order to understand some of the results obtained, we studied the interaction of PCO with collagen type I separately.

RESULTS

In the absence of PCOs, collagen typing and 3H-proline incorporation yielded the expected results for a normal cornea, with the usual proportion of the three major types of collagens. In presence of PCOs at 1 mg/ml and after 24 h incubation, total proteins and collagens decreased, as did papain-extractable collagens. Proteins in the final residue solubilized in 1 M KOH-80% v/v aqueous ethanol increased. The proportion of the three principal collagens was also modified: type I became preponderant, and the proportions of the two others (type V and VI) decreased. The study of the interaction of collagen type I with PCOs showed that 30% of total PCOs do not interact with collagen, 20% interact reversibly, and 50% of PCOs are strongly and irreversibly fixed. This strongly fixed fraction could not be separated from collagen by either column chromatography or collagenase or KOH in aqueous ethanol.

CONCLUSIONS

Bovine corneas in explant cultures in presence of PCOs undergo a modification of their protein and collagen content, with a concurrent modification of the proportion of collagens types I, V, and VI. Collagen type I predominates, and the two other types decrease. Study of the collagen type I-PCO interaction showed that roughly 50% of PCOs become irreversibly fixed to collagen, resisting collagenase or other methods of separation. This strong PCO-collagen type I interaction explains the decrease in solubility.