A Single-Site, Double-Blind, Randomized, Cross-Over study to assess the Effects of Pilocarpine Induced Changes to the Anterior Chambers based Upon Concentration
Thirty subjects will be recruited for a two-part crossover, randomized, observer/patient masked design. During the course of the study each patient will be treated with each of the test articles at separate visits.
Visit 1 - Screening Assessment: Following the execution of informed consent, subjects will be carefully screened for ocular signs and symptoms, consistent with the protocol inclusion and exclusion criteria. This includes review of ocular and medical history including use of concomitant and amp; ocular medications and surgeries performed in the past. Researchers will also collect age, ethnicity, demographics, ophthalmic notes and eye exam history. Prospective patients will undergo basic ophthalmic examination of the anterior segment at the slit lamp along with gonioscopy by a third year ophthalmology resident or glaucoma fellow to ensure anatomically open angles and will have a dilated fundoscopic examination of the retina using 1% tropicamide and 2.5% phenylephrine.
Slit Lamp Microscopy: An ocular examination of the external (lids, lashes) along with internal (cornea, lens, retina) structures of the eye can be performed with the aid of a slit lamp.
Gonioscopy: After a drop of topic anesthetic is placed to anesthetize the surface of the eye, a 4-mirror gonio lens is applied to the cornea will the patient is positioned at the slit lamp. This instrument allows indirect visualization of the configuration of the iris, its location of insertion and signs of prior episodes of angle closure.
Upon completion of the screening exam, subjects will be deemed eligible based on study criteria the testing procedures will be performed by the investigators and will be randomized into the cross over project based on the randomization assignment.
Visit 2 - Testing procedures (+1 day): A second examination will be performed at least one day later. Patients will baseline measurements of the anterior chamber using the Visante anterior segment OCT of one eye along with anterior chamber depth measurements using the IOL master performed by a member of the research team. Following imaging studies, each randomized subject will then receive either 1 drop of 1% or 4% pilocarpine twice over a span of 15 minutes following the recommendation of Wills Eye manual1. This drop will be placed by a member of the study team that will not masked to treatment assignment. A repeat scan of the anterior segment using the OCT and IOL master will be performed at 1 hour after instillation as anatomic changes induced from pilocarpine require 30 minutes or greater to reach maximal effect8.
* Visante Anterior Segment OCT: The Visante anterior segment OCT uses 1310 nm wavelength light to provide high-resolution images of the cornea, iris, anterior chamber and lens. It is non-invasive and does not require patient contact for scanning.
* Anterior chamber depth measurements using the IOL master: The IOL master is an optics based machine which takes multiple ocular measurements including anterior chamber depth, axial length and keratometry.
Visit 3 - Testing procedures (+ 8 days): The shallowing effect of pilocarpine is no longer statistically significant after 1 week in patients using for 6 weeks.9 Therefore, the third study visit will be performed no sooner than 7 days after the second visit. The same procedure as described in visit 2 will be repeated but this time with the other concentration of the pilocarpine drop based on the treatment assignment given at
Healthy, non-smoking volunteers.
Patients without diagnosis of Glaucoma, Glaucoma suspect or ocular hypertension with anatomically open angles.
Non-contact lens wearers of any gender and race, ages 18 and up.
Minority representation will be proactively encouraged.
Patients that are willing to review, understand, and sign the written Informed Consent.
Written authorization for use or release of health and research study information.
Patient that is willing and able to cooperate with the Investigator and follow all instructions.