Clinical Review of Fenestrated Scleral Lenses: Benefits and Considerations

Overview

Fenestrated scleral lenses, historically used to reduce corneal edema and improve comfort, have seen decreased use with modern GP materials but remain relevant in specific clinical scenarios. Recent studies show fenestrations may reduce corneal edema in compromised corneas and alleviate lens suction and midday fogging, though their impact on intraocular pressure (IOP) remains inconclusive.

Background

Scleral lenses were initially made from glass and PMMA, with fenestrations introduced in the 1940s to reduce corneal hypoxia and edema. While fenestrations were common in early scleral lens designs, their use declined with the advent of high-Dk GP materials. Modern clinical practice considers fenestrations primarily to manage corneal edema, lens suction, and tear reservoir debris, especially in patients with compromised corneas or endothelial dysfunction. The effect of fenestrations on IOP is still debated, with conflicting study results.

Data Highlights

Key Findings

• Fenestrations in scleral lenses reduce corneal edema, particularly in compromised corneas such as post-penetrating keratoplasty.
• Fenestrated lenses may relieve lens suction, facilitating easier removal and preventing adhesion.
• Fenestrations can reduce midday fogging by decreasing conjunctival pressure and limiting debris accumulation in the tear reservoir.
• Optimal fenestration fitting includes a 0.5 to 1.0 mm fenestration in the limbal curve with appropriate vault clearance to avoid visual axis interference and discomfort.
• The impact of fenestrations on intraocular pressure is unclear, with some studies showing no significant change and others indicating a small increase.
• Comfort issues related to fenestrations can be minimized by rounding and polishing fenestration edges and optimizing lens fit.

Clinical Implications

Clinicians should consider fenestrated scleral lenses for patients with compromised corneas or those experiencing lens suction and midday fogging. Proper fenestration sizing and placement are critical to maximize benefits while minimizing discomfort and visual disturbances. Given the uncertain effects on intraocular pressure, careful monitoring is advised when fitting fenestrated lenses, especially in glaucoma-susceptible patients.

Conclusion

Fenestrated scleral lenses offer potential advantages in managing corneal edema, lens suction, and fogging, particularly in compromised eyes, though their influence on intraocular pressure remains to be fully elucidated. Optimized fitting techniques can enhance patient comfort and lens performance.

References

1. Bowden and Barnett, 2017 -- History of Scleral Lenses
2. Fisher et al, 2022 -- Corneal oedema during open-eye fenestrated scleral lens wear
3. Harris et al, 1977 -- The effect of peripherally fenestrated contact lenses on corneal edema
4. Cheung et al, 2020 -- The impact of short-term fenestrated scleral lens wear on intraocular pressure
5. Fadel and Ezekiel, 2020 -- Fenestrated scleral lenses and lens suction
6. Schornack et al, 2023 -- Anatomical and physiological considerations in scleral lens wear: Intraocular pressure