Effect of Artificial Tears on Ocular Biometry Parameters

Due to the instability of the tear film, the biometry often needs to be done multiple times in a clinical environment. The high variability of both short-term and long-term repeatability in keratometry of dry eyes is well-known. Consequently, enhancing the condition of the eye surface in individuals with dry eyes will result in improved precision when choosing the power of intraocular lenses (IOLs). This prospective and before-and-after self-control study will recruit 100 patients.

Over the past ten years, surgery has progressed from rejuvenation surgery to refractive surgery, which focuses on enhancing both vision and addressing pre-existing issues that impact visual quality. This is why good surgical outcomes involve thorough preoperative assessment and precise intraocular lens(IOL) power determination. To achieve the intended postoperative refractive outcomes, it is essential to perform an accurate calculation of intraocular lens power (i.e., biometry), which may impact the accuracy of the computation.

Damage to the eye's surface from chronic inflammation and induced tear film hyperosmolarity occurs in DED because tear film homeostasis is disrupted. The changes in tear film dynamics and damage to the ocular surface result in mistakes in optical measures, which in turn affect the results of procedures like cataract surgery that heavily rely on these assessments.

Consequently, enhancing the condition of the eye surface in individuals with dry eyes will result in improved precision when choosing the power of intraocular lenses (IOLs).

Eligibility Criteria:
Inclusion Criteria:

(1) age ≥18 years,(2) able and willing to comply with the treatment schedule.

Exclusion Criteria:

1. The eyes cannot fixate on the fixation lamp (such as children, nystagmus diseases, severe low vision, inattention, etc.) and cannot act according to the user's instructions and sit in the front of the equipment (the forehead or lower song is injured so that it cannot be supported on the forehead / lower song bracket)
2. The eyes are cloudy with optical media (such as corneal opacity, central corneal scar, mature cataract, posterior chamber bag opacity, vitreous hemorrhage, etc.).
3. The eyelid is completely closed or too small (drooping, relaxation) resulting in complete or partial occlusion of the cornea
4. Just after contact measurement or examination, use a corneal local anesthesia solution. (IOL Master 700 should avoid using local anesthetic before all contact examinations)
5. Tear film deformation (lack of specular reflection of the cornea during corneal curvature measurement), the severity of grade IV dry eye, and whether eye drops were used 24 hours before the examination.
6. Any corneal lesions (corneal irregularity, corneal scar or corrosive burning, severe irregular astigmatism of cornea)
7. Fundus lesions (changes in the anatomical morphology of retinal macular fovea during axial length measurement, such as retinal detachment, edema, ulcer, etc.)
8. Patients with ocular trauma, surgery, and excessive photosensitivity, such as photodynamic therapy (PDT), were excluded.
9. using eye drops (0.1% Sodium hyaluronate) allergic patients