About this trial
This prospective single-center study evaluates the effect of dry eye disease and short-term ocular surface treatment on the agreement and repeatability of corneal astigmatism measurements in patients with age-related cataract. Participants undergoing preoperative cataract evaluation are classified into a control group or a dry eye disease group according to ocular surface symptoms and objective tear film findings.
All participants undergo ocular surface assessment and repeated corneal measurements using three commonly used devices: IOLMaster 700, Pentacam AXL, and iTrace Prime. Measurements include keratometric corneal astigmatism, total corneal astigmatism, and vector components of astigmatism. Patients with dry eye disease receive 0.3% sodium hyaluronate eye drops four times daily for 2 weeks, after which ocular surface assessment and device measurements are repeated.
The primary objective is to determine whether dry eye disease reduces interdevice agreement and test-retest repeatability of corneal astigmatism measurements, and whether short-term ocular surface treatment improves measurement stability. Interdevice agreement is assessed using Bland-Altman analysis, and repeatability is evaluated using within-subject standard deviation, test-retest repeatability, and intraclass correlation coefficient.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
Patients with age-related cataract undergoing preoperative ocular examination.
Ability to complete ocular surface evaluation, including the Ocular Surface
Disease Index questionnaire, non-invasive tear film break-up time, tear meniscus height, Schirmer test, and ocular surface staining.
Ability to complete repeated corneal astigmatism measurements using IOLMaster 700, Pentacam AXL, and iTrace Prime.
Disqualifiers
Previous ocular surgery or ocular trauma.
Corneal degeneration, corneal dystrophy, or other corneal diseases that could affect corneal measurements.
Active corneal or conjunctival infection.
Uveitis.
Trial design
Parallel
Treatments tested in this trial
Sodium Hyaluronate Eye Drops
Drug0.3% sodium hyaluronate eye drops administered four times daily for 2 weeks in participants with dry eye disease.
Treatment groups
Trial outcomes
Primary outcomes
Interdevice Agreement of Corneal Astigmatism Measurements
Interdevice agreement of corneal astigmatism measurements among IOLMaster 700, Pentacam AXL, and iTrace Prime will be assessed using Bland-Altman analysis. Pairwise comparisons will be performed for IOLMaster 700 versus Pentacam AXL, IOLMaster 700 versus iTrace Prime, and Pentacam AXL versus iTrace Prime. The main parameters include keratometric corneal astigmatism, total corneal astigmatism, and their vector components J0 and J45. The mean difference and 95% limits of agreement will be calculated.
Test-Retest Repeatability of Corneal Astigmatism Measurements
Test-retest repeatability of corneal astigmatism measurements obtained using IOLMaster 700, Pentacam AXL, and iTrace Prime will be evaluated using three consecutive valid measurements from each device. The main parameters include keratometric corneal astigmatism, total corneal astigmatism, and their vector components J0 and J45. Repeatability will be assessed using within-subject standard deviation, test-retest repeatability calculated as 2.77 times the within-subject standard deviation, and intraclass correlation coefficient with 95% confidence intervals.
Sponsors and contacts
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Jin Yang
Lead sponsor
Eye & ENT Hospital of Fudan University
Sponsor institution