Clinical Report: Managing Complex Scleral Lens Challenges in Megalocornea

Overview

Specialized scleral lens fitting is evolving to address unique challenges such as megalocornea, characterized by a large corneal diameter exceeding 13 mm. Successful management requires larger lens diameters and chamber sizes to ensure proper vault and alignment, emphasizing a return to fundamental fitting principles.

Background

Megalocornea presents a rare and atypical ocular anatomy with a horizontal visible iris diameter greater than 13 mm, normal pachymetry, and deep anterior chambers. These features complicate traditional scleral lens fitting, often rendering standard lens sizes insufficient. Clinicians face challenges in achieving lens stability and comfort due to inadequate sagittal depth and landing zone alignment with conventional designs. Advanced imaging may assist but has limitations in atypical eyes, making diagnostic fitting sets essential for real-world assessment.

Data Highlights

Megalocornea is defined by a horizontal visible iris diameter >13 mm, often accompanied by a deep anterior chamber and normal intraocular pressure. Standard scleral lens diameters may not provide adequate sagittal depth or landing zone alignment, necessitating increased lens diameter and chamber size to achieve proper vault and scleral alignment.

Key Findings

• Megalocornea requires scleral lenses with larger diameters to accommodate the increased corneal size.
• Proper vault and scleral alignment are critical to lens stability and patient comfort.
• Deep anterior chambers necessitate careful consideration of lens depth during fitting.
• Advanced imaging tools have limited accuracy in atypical ocular shapes, highlighting the importance of diagnostic fitting sets.
• Successful fitting depends on clinician confidence, flexibility, and adherence to fundamental scleral lens principles.
• Collaborative case discussions, such as those in the "Call-In Conundrums" podcast, provide valuable insights for managing complex cases.

Clinical Implications

Clinicians should anticipate the need for larger scleral lens diameters and increased chamber depths when fitting patients with megalocornea. Reliance on diagnostic fitting sets remains crucial to evaluate lens behavior on atypical eyes, as imaging alone may be insufficient. Embracing a flexible, principle-based approach can improve outcomes in challenging specialty lens cases.

Conclusion

Addressing complex scleral lens challenges in megalocornea requires a thoughtful return to fundamental fitting strategies, emphasizing larger lens sizes and real-world assessment. Through experience and collaboration, clinicians can successfully manage these uncommon presentations.

References

1. Jedlicka & Messer 2026 -- Call-In Conundrums: Tackling Complex Scleral Lens Challenges