Understanding the Burden of Contact Lens-Associated Keratitis (CLAK)
Contact lens wear has become increasingly prevalent worldwide, with an estimated 140 million contact lens wearers globally. While contact lenses provide significant benefits in vision correction and cosmetic enhancement, they also carry the risk of developing sight-threatening complications, such as contact lens-associated keratitis (CLAK). CLAK is a form of microbial keratitis (MK) that specifically arises from contact lens use and accounts for up to 50% of all MK cases.
The global incidence of CLAK has been estimated to range from 2 to 20 cases per 10,000 contact lens wearers annually. This presents a substantial burden on both individual patients and healthcare systems, as CLAK can lead to corneal scarring, vision loss, and even blindness if not managed promptly and effectively. In the United Kingdom (UK), CLAK contributes to approximately 18% of all emergency eye care visits each year, further straining the resources of the National Health Service.
Identifying Key Risk Factors for CLAK
Understanding the risk factors associated with CLAK is crucial for developing targeted prevention and management strategies. The most significant risk factors identified in the literature include:
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Extended-wear Contact Lenses: The use of extended-wear contact lenses, such as two-weekly, monthly, and rigid gas-permeable lenses, was the most common risk factor in our study, accounting for over 50% of the cases.
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Poor Hygiene and Prolonged Wear Duration: Improper contact lens hygiene, including showering or swimming while wearing lenses, as well as prolonged wear duration (over 10 hours per day) were other major risk factors.
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Ocular Surface Conditions: Preexisting ocular surface disorders, such as dry eye and blepharitis, were also associated with an increased risk of CLAK.
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Previous CLAK History: Patients with a history of prior CLAK episodes were more susceptible to developing recurrent infections.
Identifying these risk factors allows healthcare providers to implement targeted interventions, such as improved patient education on proper contact lens care, and to closely monitor high-risk individuals for early signs of CLAK.
Categorizing CLAK Using a Novel Grading System
In our study, we employed a novel grading system to categorize CLAK cases based on the size of the epithelial defect (ED) or infiltrate, whichever was larger. This classification system comprised three grades:
- Grade 1: ED or infiltrate ≤2.0 mm
- Grade 2: ED or infiltrate 2.1-4.0 mm
- Grade 3: ED or infiltrate >4.0 mm
This grading system allowed us to analyze the outcomes and management approaches for different severities of CLAK, providing an evidence-based framework to guide clinical decision-making.
Outcomes and Management of CLAK
Our retrospective analysis of 161 eyes from 153 patients with CLAK revealed several key findings:
- Excellent Outcomes for Grades 1 and 2 CLAK:
- The majority of Grade 1 (96%) and Grade 2 (94.1%) CLAK cases were successfully discharged within 48 hours and 2 weeks, respectively, following an empirical treatment regimen with topical moxifloxacin.
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These patients exhibited favorable visual acuity outcomes, with a mean best-corrected visual acuity (BCVA) of 0.15 logMAR and 0.29 logMAR for Grades 1 and 2, respectively.
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Prolonged Treatment for Grade 3 CLAK:
- Grade 3 CLAK cases, characterized by larger epithelial defects or infiltrates, required a more prolonged treatment course, with an average weaning period of 38.88 days.
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These patients also had poorer visual outcomes, with a mean BCVA of 1.14 logMAR.
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Importance of Atypical Features:
- Patients with atypical CLAK features, such as anterior chamber activity, hypopyon, ring infiltrates, or sloughing epithelium, required closer monitoring, further diagnostics, and often more intensive treatment.
These findings suggest that a risk-adjusted management approach can be implemented, where typical Grade 1 and 2 CLAK cases can be safely discharged with empirical fluoroquinolone therapy, while Grade 3 and atypical CLAK cases warrant closer follow-up and potential escalation of treatment.
Optimizing Resource Allocation in Eye Care Services
The current management protocols for CLAK in the UK often necessitate a review for every patient within 48 hours, regardless of the severity of the condition. This approach places a significant burden on resource-limited healthcare services, particularly in urban settings with a high demand for emergency eye care.
Our study provides an evidence-based framework to optimize the management of CLAK and reduce unnecessary patient visits. By safely discharging typical Grade 1 and 2 CLAK cases with empirical treatment, healthcare providers can focus their resources on patients with more severe or atypical presentations, who require closer monitoring and potentially more intensive interventions.
This approach not only benefits the patients by ensuring timely and appropriate care but also helps alleviate the strain on the National Health Service, allowing for more efficient resource allocation and improved access to specialized eye care services.
Conclusion
Contact lens-associated keratitis (CLAK) is a significant public health concern, posing a threat to vision and placing a substantial burden on healthcare systems. By identifying key risk factors, developing a novel grading system, and analyzing the outcomes of different CLAK severities, our study provides valuable insights to guide the management of this condition.
The findings suggest that a risk-adjusted approach, where typical Grade 1 and 2 CLAK cases are safely discharged with empirical fluoroquinolone therapy, can optimize resource allocation and improve access to specialized eye care services. This evidence-based approach can be implemented in the UK and potentially replicated in other developed countries facing similar challenges in managing CLAK.
Continued research, improved patient education, and the implementation of evidence-based management protocols are crucial steps in addressing the growing burden of CLAK and ensuring the long-term eye health of contact lens wearers.
