Effect of Defocus in Soft Contact Lenses on Internal Retinal Vascularization

Condition(s) studied

Investigational drug(s) / intervention(s)

Experimental: Myopic defocus soft lens design (MDSL): An optical device designed to provide a myopic defocus to control myopia progression

Active Comparator: Single vision soft lens design (SVSL: An optical device designed to correct refractive error like myopia

Study summary

The purpose of this study is to gain a better understanding of the retinal vascular changes that occur in response to the optical effect of a myopic defocus daily disposable soft contact lens (MDSL) in a group of healthy young myopic adults (18-35 years; myopia -1.00D to -4.00D; all genders). It will also learn about the acceptance of this visual correction modality compared to regular contact lenses.

The main questions to be answered are:

* To evaluate changes in retinal blood flow by visualizing retinal vascular density in the superficial and deep plexus after one week of MDSL wear.
* To evaluate changes in choroidal thickness at the macular level after one week of MDSL wear.
* To evaluate the visual comfort provided by this MDSL design using a questionnaire.

Researchers will compare the MDSL to a daily disposable single vision soft lens (SVSL) used to correct myopia to determine if the addition of a defocus area makes a difference in the retinal response to the visual signal.

Participants will be required to

* Wear both MDSL and SVSL for one week each, in a random order.
* Read letters to measure visual acuity
* Have a deep scan of their retina with an optical coherence tomography (OCT) device
* Rate the comfort and vision provided by both devices using a questionnaire.

Eligibility

Primary outcome measure(s)

• Measurement of Retinal blood vessel density measured by Triton OCT-A — Measurement done at baseline and after 1 week of contact lens wear
  The TRITON angiographic optical coherence tomograph will be used in this research project. OCT-A is a non-invasive angiography that enables changes in retinal vascularization to be observed. This is achieved by analyzing the movement of erythrocytes in blood vessels using a series of B-scans. Retinal vessel density will be measured at the macular area and at the optic nerve head. (2 scans)

Trial sites (1)

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