Effect of Artificial Tears on the Parameters of the Eye and Its Impact on IOL Power Calculation for Cataract Surgery

Effect of Artificial Tears on the Parameters of the Eye in Normal and Dry Eyes and Its Impact on IOL Power Calculation for Cataract Surgery

First, preoperative biometry of the eye at the IOL Master® will be performed. Then, corneal topography will be measured at the Oculus pentacam®. Afterwards, one of two eye drops are instilled in the eye, and biometry and corneal topography will be repeated after 5 minutes.

For all patients, the Barrett Universal II formula will be used for calculation of IOL power. Predicted refraction outcome will be referred to as SEQ. The chief surgeon will perform the uneventful standard cataract operation with in-the-bag implantation of a HOYA IOL (Model 251) through a 2.4-mm corneal incision.

A Subjective Refraction using plus principle will be performed one month after the operation, and ETDRS visual acuity charts will be used to measure best-corrected visual acuity. Refraction will be described as SR (postoperative SEQ) and will be calculated as:

SR = sphere + (0.5*cylinder)

First, preoperative biometry of the eye at the IOL Master® will be performed. Then, corneal topography will be measured at the Oculus pentacam®. Patients will be classified as dry eye or normal eye based on BUT. The tear film breakup (BUT) time of less than 5 seconds will be diagnosed as dry eyes.Afterwards, one of two eye drops are instilled in the eye, and biometry and corneal topography will be repeated after 5 minutes.

For all patients, the Barrett Universal II formula will be used for calculation of IOL power. Predicted refraction outcome will be referred to as SEQ. The chief surgeon will perform the uneventful standard cataract operation with in-the-bag implantation of a HOYA IOL (Model 251) through a 2.4-mm corneal incision.

A Subjective Refraction using plus principle will be performed one month after the operation, and ETDRS visual acuity charts will be used to measure best-corrected visual acuity. Refraction will be described as SR (postoperative SEQ) and will be calculated as:

SR = sphere + (0.5*cylinder)

Inclusion Criteria:

• A patient diagnosed with age related cataract
• 30 to 95 years old
• Medical history and physical examination should be normal.

Exclusion Criteria:

• • Abnormality of the cornea (scaring of the cornea)

  • If any topical therapy (i.e. glaucoma) of the eye is needed
  • Active allergy of eye or nose
  • Any conjunctivitis or keratitis
  • If nasolacrimal drainage apparatus is abnormal
  • severity level 4 of dry eye (constant discomfort in the eye accompanied with visual symptoms, filamentary keratitis, , keratinization, severe conjunctival injection, ulceration clumping of mucus glands, tear debris, , trichiasis, symblepharon)
  • deformities of lid
  • Preceding eye trauma or surgery
  • Any Uncontrolled ocular disease or systemic disease
  • Lactation
  • Pregnancy