Glaucoma - Modesto, Stockton, Merced, Tracy, Manteca
Narrow Angle & Pupil Size
Pupil Size and the Narrow Angles
The pupil is the black hole in center of the colored part of the eye (the iris). This pupil is just simply and area devoid of iris. The pupil is influenced by many factors including light. When light shines on the pupil, it causes the pupil to constrict.
The angles are classically assessed by performing gonioscopy. The Gonioscope is a piece of contact glass or plastic lens that is placed on the eye and allows the angles to be visualizes under direct observation. The biggest flaw with this system is the fact that light has to be used in order to see the angles... and light causes the constriction of the pupil. Additionally, this system is purely a subjective evaluation and depends on the expertise of the doctor performing the test.
Light has enormous effect on the angle size. See the images below:
It can be noted in the image above with plain view and with angle tools below that at angle size of 2.20mm the pupil is open to 21.7 degrees, but in the natural state of pupil at 3.85mm, the angle virtually closed at 2.9 degrees.
The Visante Anterior Segment OCT has brought the capability of objectively documenting and understanding of the angle. Since the Visante OCT's 1310nm light beam is outside of the visible range, it has no effect on the pupil size and as compare to gonioscopy, it does not cause an artificial opening of the angle.
Page last edited 08/23/09
Dr. Ash is a highly experienced ophthalmologist specializing in glaucoma surgery, laser eye surgery and treatment of cataracts. At his laser eye surgery Stockton / Modesto offices, patients are offered customized, highly precise procedures that deliver excellent vision correction results. Similarly, Dr. Ash performs advanced techniques of cataract surgery to help all of his Stockton and Modesto cataract surgery patients achieve clear vision while reducing their dependence on glasses.
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