Performance of Rigid Gas Permeable (RGP) Scleral Contact Lenses With a Passive Artificial Iris

Summary

Data from 15 healthy subjects will be recorded in two testing sessions spread on two days, using three lens designs (A, B and C). Before the measuring days, each subject will undergo an extra fitting session of a large-diameter scleral contact lens on the dominant eye, assessed by an experienced practitioner. The fitting data will be used to custom-make the three lens designs for each subject, thus ensuring their comfort and safety during the days of the experiments. During the experiment days baseline measurements will be obtained before and after pupil dilation and contact lens wear. During the first testing session data from the lens design A (reference lens without artificial iris) will be recorded. During the second testing session data from the lens designs B and C (lenses with artificial iris with different transmittances) will be recorded. In each testing session, contrast sensitivity and visual acuity will be evaluated and non-invasive imaging measurements will be undertaken (optical coherence tomography and slit lamp). A specific questionnaire will be given to the subject to assess comfort, light sensitivity, the horizontal visual angle and overall experience of the scleral lens and in combination with a pair of sunglasses category 3-4.

Timeline

Start

2019-09-16

Primary completion

2021-06-22

Completion

2021-06-22

Publications

• Background Garcia-Lazaro S, Ferrer-Blasco T, Radhakrishnan H, Cervino A, Charman WN, Montes-Mico R. Visual function through 4 contact lens-based pinhole systems for presbyopia. J Cataract Refract Surg. 2012 May;38(5):858-65. doi: 10.1016/j.jcrs.2011.11.042. Epub 2012 Mar 16.
• Background Pepose JS. Small-aperture contact lenses for presbyopia. J Cataract Refract Surg. 2012 Nov;38(11):2060-1; author reply 2062-4. doi: 10.1016/j.jcrs.2012.08.041. No abstract available.
• Background Xu R, Gil D, Dibas M, Hare W, Bradley A. The Effect of Light Level and Small Pupils on Presbyopic Reading Performance. Invest Ophthalmol Vis Sci. 2016 Oct 1;57(13):5656-5664. doi: 10.1167/iovs.16-20008.
• Background Eyeson-Annan ML, Hirst LW, Battistutta D, Green A. Comparative pupil dilation using phenylephrine alone or in combination with tropicamide. Ophthalmology. 1998 Apr;105(4):726-32. doi: 10.1016/S0161-6420(98)94030-1.
• Background Compan V, Oliveira C, Aguilella-Arzo M, Molla S, Peixoto-de-Matos SC, Gonzalez-Meijome JM. Oxygen diffusion and edema with modern scleral rigid gas permeable contact lenses. Invest Ophthalmol Vis Sci. 2014 Sep 4;55(10):6421-9. doi: 10.1167/iovs.14-14038.
• Background Holden BA, Mertz GW. Critical oxygen levels to avoid corneal edema for daily and extended wear contact lenses. Invest Ophthalmol Vis Sci. 1984 Oct;25(10):1161-7.

Drugs

Indications