Evaluate the short-term corneal response of oxygen deprivation when using toric contact
      lenses. The response will be noted by endothelial bleb formation in both open eye and closed
      eye state.

Endothelial Bleb Response With Toric Lenses

Ametropia

Interested subjects who meet the entry criteria for the study will be scheduled for four
      sessions of approximately 30 minutes duration each. Informed consent obtained. Baseline
      measurements of visual acuity and corneal and conjunctival physiology will be recorded. An
      examination of the endothelium of the corneas will be conducted using the specular
      microscope, readings obtained at 5 locations on each cornea: one in the centre and one in
      each of the superior, inferior, nasal and temporal peripheral regions, approximately 2mm from
      the limbal margin. The assigned lenses will be inserted according to a fixed-allocation
      randomization schedule, where each session follows an optimized 2- period simultaneous
      crossover design, which specifies lenses to be used in each of the four sessions. Lenses will
      be worn for 20 minutes and then removed. Endothelial specular microscopy will be conducted at
      20 minutes with the lenses on. A final evaluation of corneal and conjunctival physiology will
      be performed prior to subject clearance from the study.

alphafilcon A toric

lotrafilcon B toric

senofilcon A toric

Evaluation of the Short-Term Corneal Endothelial Response to Wear of Toric Soft Contact Lenses in Asian Eyes

Mean area of endothelial blebs in the following corneal locations: Central, Nasal, Temporal, Inferior, Superior. A masked observer performed the analysis by subjectively selecting a region in a given image that provided an optimal balance of maximum area and clarity of cell outlines. Blebs were then outlined manually and the software calculated the area of blebs. The different sessions are reported showing results for each lens according to the lens worn in the contralateral (contra) eye.Open eye sessions simulated the subjects normal ocular behavior during waking hours; closed eye sessions simulated ocular activity during duration of closed eye activity, such as sleeping. Results are reported as the mean percent difference between the stated test (senofilcon A) and the control lens (alphafilcon A, lotrafilcon B), after 20 minutes of wear, for each testing scenario.

Subjects were first randomized to a session and then randomized to receive one of four lens sequences for that session. Each subject participated in all four sessions. Session A only contains senofilcon A toric and alphafilcon A toric lenses.

Subjects were first randomized to a session and then randomized to receive one of four lens sequences for that session. Each subject participated in all four sessions. Session B only contains senofilcon A toric and alphafilcon A toric lenses.

Subjects were first randomized to a session and then randomized to receive one of four lens sequences for that session. Each subject participated in all four sessions. Session C only contains senofilcon A toric and lotrafilcon B toric lenses.

Subjects were first randomized to a session and then randomized to receive one of four lens sequences for that session. Each subject participated in all four sessions. Session D only contains senofilcon A toric and lotrafilcon B toric lenses.

Endothelial Bleb Response With Toric Lenses

About this trial

Study ID

Status

Type

Phase

Placebo

Accepting

Trial Timing

What is this trial about?

What are the participation requirements?