effect of cequa treatment on accuracy of pre-operative biometry & higher order aberrations in dry eye patients undergoing cataract surgery

Conditions: Dry Eye Syndromes

Summary: the purpose of this study is to examine the effect of cequa treatment on the accuracy of pre-operative biometry and on corneal higher-order aberrations (hoas) in cataract patients who have signs of dry eye disease.

hypothesis: in patients with dry eye, defined as corneal staining and a reduced tear breakup time, the accuracy of pre-operative biometry and corneal surface hoas will improve significantly after four weeks of cequa treatment. primary outcome measure: spherical equivalent prediction error of pre-cequa vs post-cequa ocular biometry performed for cataract surgery. secondary outcome measures: the impact of cequa treatment on corneal higher order aberrations measured in the central 6 mm of the cornea. the difference in speed questionnaire scores before and 4 weeks after cequa treatment. the difference in corneal staining and tear breakup time (tbut) before and after treatment with cequa.

Eligibility criteria:
inclusion criteria: * patients with planned cataract surgery, * the presence of central or inferior corneal fluorescein staining defined by the oxford scale * reduced tear break up time (tbut) ≤ 10 seconds. * able to comprehend and sign a statement of informed consent. * willing and able to complete all required postoperative visits. exclusion criteria: * ocular surgery (e.g., intraocular, oculoplastic, corneal or refractive surgical procedure) performed within the last 3 months or at any time that in the investigator's clinical judgment if it would interfere with the outcome measures of this study. * clinically significant ocular trauma. * active ocular herpes simplex or herpes zoster infection * ocular inflammation (uveitis, iritis, scleritis, episcleritis, keratitis, conjunctivitis) at the discretion of the investigator. * ocular infection (e.g., viral, bacterial, mycobacterial, protozoan or fungal infection or the cornea, conjunctiva, lacrimal gland, lacrimal sac or eyelids including hordeolum/stye). * active, systemic or local disease condition that causes clinically significant ocular surface irritation such that it could interfere with the study findings. * moderate to severe (grade 2-4) allergic, vernal or giant papillary conjunctivitis. * severe (grade 3 or 4) inflammation of the eyelid (e.g., blepharochalasis, staphylococcal blepharitis or seborrheic blepharitis) * eyelid abnormalities that significantly affect the lid function (e.g., entropion, ectropion, tumor, edema, blepharospasm, lagophthalmos, severe trichiasis, severe ptosis). * ocular surface abnormality that may compromise the corneal integrity (e.g., prior chemical burn, recurrent corneal erosion, corneal epithelial defect, grade 3 corneal fluorescein staining, map dot fingerprint dystrophy, or the effect of any other ophthalmic medication that might in the opinion of the investigator compromise the ocular surface integrity). * participation in this trial in the same patient's fellow eye * patients who are under age 18, pregnant or breastfeeding, or who may become pregnant during participation in the study.