THE BENEFITS of toric landing zones have transformed modern scleral lens fitting. Scleral profilometry studies have demonstrated that the majority of eyes exhibit clinically significant scleral toricity at typical lens diameters (Kojima et al, 2020). Scleral lenses that mimic scleral toricity can effect better ocular health outcomes due to less conjunctival blanching and a better overall fit.
Today, most diagnostic fitting sets include a wide range of toric landing options. Scleral profilometry can measure scleral shape at the selected lens diameter, which can be used for initial lens selection. In the absence of imaging, practitioners can follow brand-specific fitting guides to select toric diagnostic lenses and use fluorescein to view alignment of the landing zone after lens settling.
A recent study challenged the previous assumptions that increased haptic alignment limits tear exchange (Iqbal et al, 2026). The researchers investigated the question: Does landing zone toricity influence tear exchange within the scleral lens fluid reservoir?
Using a corneoscleral profilometer, fluorescence intensity in the scleral lens fluid reservoir was analyzed at set time intervals after sodium fluorescein was applied onto the lower bulbar conjunctiva. The toric landing zone design demonstrated greater fluorescence intensity than the spherical design at 0, 60, and 100 minutes of wear. Fluorescein was observed centrally and peripherally in the toric lens during the first 30 minutes, followed by a gradual decline. In contrast, the fluorescein level in the spherical design stabilized after 5 to 10 minutes, suggesting limited tear exchange.
In this study, the lenses with toric landing zones demonstrated greater inflow of tears compared to the lenses with a spherical landing zone. The authors suggest that the use of toric haptics may help aid tear exchange, in addition to modifications including fenestrations and channels that are typically used to increase tear exchange.
Scleral lenses are thought to exhibit minimal tear exchange. Tear exchange can increase inflow of debris into the fluid reservoir, which could lead to visual disturbances. Conversely, tear exchange can help patients with excessive debris trapped in the fluid reservoir.
It can be helpful to observe the tear exchange in each patient to determine what changes could help to maintain optical clarity and minimize excessive debris accumulation.
The study described above demonstrates that toric haptics not only improve fit stability but also may influence ocular health beneath the lens. Specifically, toric landings can be used for patients at risk of hypoxia-induced corneal edema, such as those having undergone eye surgery.
As our understanding of scleral shape and lens fluid dynamics evolves, prescribing toric landing zones should be viewed not as an advanced option, but as a standard consideration in modern scleral lens practice.
References
1. Kojima RCP, Kinoshita B, Lampa M, Andre M, Fujimoto M. How toric should scleral lenses be for most patients? Poster presented at the 2020 Global Specialty Lens Symposium. January 2020, Las Vegas.
2. Iqbal A, Fisher D, Alonso-Caneiro D, Collins MJ, Vincent SJ. Scleral lens landing zone toricity and tear exchange. Cont Lens Anterior Eye. 2026;49(1):102571. doi: 10.1016/j.clae.2025.102571