Risk of corneal ulcer in patients with end-stage renal disease: a retrospective large-scale cohort study

Trends in Infectious Keratitis in Taiwan: An Update on Predisposing Factors, Microbiological and Antibiotic Susceptibility Patterns

Infectious keratitis (IK) represents a major cause of corneal blindness. This study aims to investigate the demographics, risk factors, microbiological characteristics and antibiotic susceptibility patterns of IK in Taiwan over the past 15 years. A retrospective population-based study was conducted using the Chang Gung Research Database. Patients with IK were identified by diagnostic codes for corneal ulcer from 2004 to 2019. Of 7807 included subjects, 45.2% of patients had positive corneal cultures. The proportion of contact lens-related IK declined, while that of IK related to systemic diseases grew. The percentage of isolated gram-positive bacteria surpassed that of gram-negative bacteria in the 15-year period. The prevalence of Pseudomonas aeruginosa showed a decreasing trend (p = 0.004), whereas coagulase-negative Staphylococcus (CNS) and Propionibacterium species were increasingly detected (p < 0.001). Overall, the trend of antibiotic susceptibility of both gram-positive and gram-negative bacteria did not change throughout the study period. The susceptibility to the test antibiotics maintained over 90% in gram-negative isolates over 15 years. Vancomycin preserved 100% susceptibility to all gram-positive isolates. Since most tested antibiotics exhibited stable susceptibility over decades, this study reinforced that fluoroquinolones and fortified vancomycin continue to be good empiric therapies for treating bacterial keratitis in Taiwan.

Infectious keratitis: an update on epidemiology, causative microorganisms, risk factors, and antimicrobial resistance

Corneal opacity is the 5th leading cause of blindness and visual impairment globally, affecting ~6 million of the world population. In addition, it is responsible for 1.5-2.0 million new cases of monocular blindness per year, highlighting an ongoing uncurbed burden on human health. Among all aetiologies such as infection, trauma, inflammation, degeneration and nutritional deficiency, infectious keratitis (IK) represents the leading cause of corneal blindness in both developed and developing countries, with an estimated incidence ranging from 2.5 to 799 per 100,000 population-year. IK can be caused by a wide range of microorganisms, including bacteria, fungi, virus, parasites and polymicrobial infection. Subject to the geographical and temporal variations, bacteria and fungi have been shown to be the most common causative microorganisms for corneal infection. Although viral and Acanthamoeba keratitis are less common, they represent important causes for corneal blindness in the developed countries. Contact lens wear, trauma, ocular surface diseases, lid diseases, and post-ocular surgery have been shown to be the major risk factors for IK. Broad-spectrum topical antimicrobial treatment is the current mainstay of treatment for IK, though its effectiveness is being challenged by the emergence of antimicrobial resistance, including multidrug resistance, in some parts of the world. In this review, we aim to provide an updated review on IK, encompassing the epidemiology, causative microorganisms, major risk factors and the impact of antimicrobial resistance.

Epidemiology and the Estimated Burden of Microbial Keratitis on the Health Care System in Taiwan: A 14-Year Population-Based Study

PURPOSE

To investigate the epidemiologic characteristics of microbial keratitis and its overall burden on the health care system in Taiwan.

DESIGN

Retrospective, population-based study.

METHODS

We conducted a study using claims data in the Taiwan National Health Insurance Research Database in 2000-2013, employing diagnoses, drugs, and procedure codes to define diseases and procedures. Participants were classified into groups according to the requirement of hospitalization and surgical intervention. The main outcome measures were incidence, risk factors, predictive factors for hospitalization and surgical intervention, and health care expenditure.

RESULTS

A total of 2,071 patients were included. The overall incidence significantly increased from 8.4 in 2000 to 20.2 per 100,000 person-years in 2013. The peak age range of incidence was between 18 and 40 years, but the peak age group for health care expenditures was those older than 65 years. A total of 704 patients (33.99%) had analyzable risk factors, of which the top 3 were diabetes mellitus (DM, 11.52%), eye trauma (10.55%), and dry eye (8.72%). Older patients, those using steroid and antiglaucoma agents, and those with ocular and systemic diseases were susceptible to further hospitalization and surgical intervention for the treatment of microbial keratitis.

CONCLUSIONS

In Taiwan, DM, eye trauma, and dry eye were key predisposing factors for microbial keratitis. Older patients (>40 years) accounted for approximately 80% of health care expenditure for the management of infectious keratitis. Special care may be required for older patients with medication-related risk factors and ocular and systemic comorbidities because they are likely to have severe diseases leading to hospitalization and surgical interventions.

Association between atopic keratoconjunctivitis and the risk of corneal ulcer

AIMS

To investigate the risk of corneal ulcer in patients with atopic keratoconjunctivitis (AKC).

METHODS

The nationwide, population-based, retrospective, matched cohort study included 171 019 newly diagnosed patients with AKC who were identified by the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM), code 372.05, and selected from the Taiwan National Health Insurance Research Database. The age-, sex- and potential comorbidities-matched control group included 171 019 patients with non-AKC selected from the Taiwan Longitudinal Health Insurance Database 2000. Patient information was collected between 1 January 2004 and 31 December 2011, and both groups of patients were tracked from the index date until December 2013. The incidence and risk of corneal ulcer (ICD-9-CM code 370.0 except for 370.07) was compared between the groups. A Cox proportional hazard regression analysis was performed to obtain the adjusted HR for corneal ulcer. The cumulative corneal ulcer incidence rate was calculated with the Kaplan-Meier analysis.

RESULTS

In total, 2018 patients with AKC and 1481 controls developed a corneal ulcer during the follow-up period. The incidence rate of corneal ulcer was 1.42 times (95% CI1.33 to 1.52; p<0.0001) higher in patients with AKC than in controls. After adjusting for potential confounders, including diabetes mellitus, chronic renal disease, topical steroid ophthalmic agent use, lid margin disease, keratoconjunctivitis sicca, ocular blunt trauma and post-corneal transplantation, patients with AKC were 1.26 times more likely to develop a corneal ulcer than controls (adjusted HR, 1.26; 95% CI 1.14 to 1.39; p<0.05).

CONCLUSIONS

Patients with AKC had an increased risk of developing a corneal ulcer and should be advised of this risk.

Outcomes of therapeutic keratoplasty for severe infectious keratitis in Chongqing, a 16-year experience

Purpose

This study aimed to evaluate the outcomes of therapeutic keratoplasty for severe infectious keratitis in Chongqing (Southwest China).

Patients and methods

The records of 561 eyes that underwent therapeutic keratoplasty for refractory microbial keratitis from 2001 to 2016 were analyzed in this retrospective study. Data included demographic information, microbiological investigations, associated factors, graft size, preoperative status, postoperative complications, and final anatomical outcomes.

Results

Trauma was the most common cause (267, 47.6%) for corneal ulcers leading to therapeutic keratoplasty. The etiological diagnosis included bacterial keratitis (80 eyes, 14.3%), fungal keratitis (317 eyes, 56.5%), acanthamoeba keratitis (3 eyes, 0.5%), and mixed bacteria/fungal infection (15 eyes, 2.7%). Anatomical success was achieved for 492 eyes (87.7%), with bacterial keratitis having a better outcome than fungal and mixed infections. Diabetes and preoperative time ≥30 days were significantly associated with anatomical failure in the multivariate logistic regression (P=0.028 and P=0.022, respectively). Patients with hypopyon, corneal perforation, surgical delay, and/or large graft size had a higher incidence of postoperative complications (reinfection, cataract, glaucoma, hyphema, or graft rejection) (P<0.05).

Conclusion

Therapeutic keratoplasty was an effective procedure in managing refractory infectious keratitis. Prompt and appropriate surgery would result in fewer complications and better outcomes.