Today, cataract surgery has become one of the safest and most effective eye surgical procedures performed on many people through the development and development of surgical techniques and instruments. However, a significant number of patients who underwent cataract surgery still complain about postoperative symptoms, such as irritation, pain, dryness, burning sensation, and foreign body sensation. The reasons of dry eye (DE) development after cataract surgery include thermal and light toxicity from the microscope, corneal epithelial damage, and frequent irrigation of ocular surface during operation, sterilization of conjunctival sac and eyelid with chemicals, transection of the corneal nerves by corneal incision, use of topical anesthetics, and preservatives in topical eye drops. In this era of high expectation of patients and premium intraocular lenses, the postoperative discomforts cannot be accepted to many patients. Several studies have recently reported that the common cause of postoperative symptoms of the patients is DE. Furthermore, if the ocular surface is deformed due to DE syndrome after surgery, the optical quality is greatly affected which results in a decrease of the quality of vision. If the tear film becomes irregular, the higher-order aberration can change due to local irregular total radius of curvature of ocular surface and result in decreased visual acuity.

There have been many attempts to treat DE syndrome after cataract surgery. Artificial tears are commonly used for the first line treatment of postoperative DE and several studies revealed its effectiveness on management of DE symptoms and signs. The postoperative use of cyclosporine 0.05 % topical eye drop improved DE symptoms and visual quality after cataract surgery. Recently, diquafosol sodium ophthalmic solution has been used for the management of DE after cataract. Diquafosol is a dinucleotide derivative and functions as agonist to the purinergic P2Y2 receptor. Diquafosol is known to stimulate not only the mucin secretion from the goblet cells but also water secretion from conjunctival epithelial cells and accessory lacrimal glands. According to previous studies, diquafosol has been found to be very effective in treating DE after cataract and to alleviate symptoms of DE syndrome. Furthermore, several studies have shown that topical diquafosol has a better efficacy in managing DE after cataract surgery than artificial tears. The preservative free diquafosol ophthalmic solution has been released recently. The use of eye drops without preservatives has also been shown to play an important role in the treatment of DE after cataract surgery. Until now, there is no study that evaluated the effect of preservative free diquafosol ophthalmic solution. Thus the investigators try to investigate the efficacy of preservative free diquafosol ophthalmic solution compared to preservative containing diquafosol ophthalmic solution and sodium hyaluronate ophthalmic solution, which are widely used in patients with DE after cataract surgery.

Enrollment period : 24 months after IRB approval Participants : The subjects over 20 years old, who visited Severance hospital for cataract surgery and has dry eye. The participants who satisfies criteria, and who can be monitored at all times during each period of observation after surgery are included in the study.

Methods: The subjects are randomly divided into three groups. Group 1 will use preservative diquafosol ophthalmic solution, Group 2 will use preservative containing diquafosol ophthalmic solution, and Group 3 will use preservative free sodium hyaluronate after cataract surgery. Before surgery, all patients underwent a detailed ophthalmological examination that included evaluation of logarithm of the minimum angle of resolution (logMAR) uncorrected-distance visual acuity (UDVA) and CDVA, manifest refraction, slit-lamp examination (Haag-Streit, Köniz, Switzerland), and dry eye parameters including tear breakup time, schirmer test, OSDI, and MGD staging. All examinations were repeated at 1, and 3 months after surgery.

Inclusion Criteria:

1. Cataract
2. age of 20 years or older
3. dry eye patient

Exclusion Criteria:

1. previous use of eye drops, except artificial tears within 3 months before cataract surgery,
2. presence of severe ocular surface diseases,
3. corneal epithelial pathologies except DE syndrome
4. a history of previous ocular surgery or trauma,

4. presence of ocular comorbidities such as glaucoma, uveitis, cystoid macular edema, 5. any surgical complications including rupture of the posterior capsule during cataract surgery.