Investigating the conjunctival and limbal vessels in patients who use contact lenses is important for clinicians, as certain findings may indicate inﬂammation. A study based in Turkey investigated the vasculature of the perilimbal conjunctiva of overnight contact lens wearers using OCT angiography (OCT-A) and found that vessel density at the superﬁcial layer is signiﬁcantly higher in this demographic than in healthy individuals.
The researchers conducted OCT-A imaging in the temporal quadrant of the perilimbal region with the Triton DRI (Topcon) on 22 individuals who had been wearing SiHy senofilcon-A overnight lenses with a base curve of 8.4mm and a total diameter of 14.0mm for at least three months and 20 healthy controls. The team assessed from the conjunctival epithelium to a scleral depth of 200μm and the scleral depth between 200µm and 1,000μm.
While the vessel density at the superficial layer was significantly higher in the lens group compared with the control group, the study found that vessel diameter index, vessel length density and fractal dimension at the superficial layer did not differ between the groups.
The researchers did note that their study results may be different for other SiHy and non-SiHy lens materials because Dk and tissue compatibility can vary, and all these factors might be exaggerated in patients who are using overnight lenses.
The investigators also found that perilimbal injection in overnight lens wearers can be indicative of inﬂammation and may cause adverse effects in those patients. However, the degree of hyperemia in high Dk lens wearers is rarely excessive, usually ranging from wellness to mild compromise.
Nevertheless, the researchers believe, “The grading scales used by practitioners should be more sensitive to document those ﬁndings and changes in limbal vasculature.” They concluded that their study demonstrated that OCT-A imaging can be used to objectively detect initial limbal vasculature changes.
Ceran BB, Ozates S, Arifoglu HB, et al. Changes in limbal optical coherence topography angiography outcomes in patients with overnight contact lens wear. Eye Contact Lens. July 5, 2021. [Epub ahead of print].