Tear osmolarity and ocular surface disease in keratoconjunctivitis sicca

Area of Science:

• Ophthalmology
• Ocular Surface Disease
• Tear Film Research

Background:

• Dry eye disease, or keratoconjunctivitis sicca (KCS), is a common condition characterized by ocular discomfort and visual disturbance.
• Tear film abnormalities, including increased tear osmolarity, are implicated in the pathogenesis of KCS.
• Rose Bengal staining is a clinical measure of ocular surface damage.

Purpose of the Study:

• To evaluate the efficacy of isotonic and one-half isotonic saline solutions in treating KCS.
• To determine if tear film osmolarity can be correlated with the severity of ocular surface disease in KCS patients.
• To compare patient preference between isotonic and hypotonic saline treatments.

Main Methods:

• A group of 20 KCS patients received isotonic saline drops every three hours for one week.
• Tear osmolarity and Rose Bengal staining scores were measured before and after treatment.
• A double-masked comparison was conducted between isotonic and one-half isotonic saline solutions.

Main Results:

• Treatment with isotonic saline significantly reduced average tear osmolarity (365 to 329 mOsm/L) and Rose Bengal staining scores (4.1 to 3.6).
• No significant objective difference was observed between isotonic and one-half isotonic saline treatments.
• Four out of five patients with significant Rose Bengal staining preferred the one-half isotonic solution.
• A significant positive correlation was found between tear film osmolarity and Rose Bengal staining scores.

Conclusions:

• Saline treatment, particularly isotonic solutions, can improve tear film parameters and reduce ocular surface damage in KCS.
• While objective measures showed no difference, hypotonic saline may offer subjective relief for some KCS patients.
• Tear film osmolarity serves as a valuable indicator of ocular surface disease severity in keratoconjunctivitis sicca.