Ultrasound biomicroscopic morphometry of the anterior eye segment before and after one drop of pilocarpine.
OBJECTIVE
To measure anterior eye-segment morphometric data using ultrasound biomicroscopy. This is a new high-frequency, high-resolution ultrasound method enabling the visualisation of the anterior segment of the living eye with magnification similar to a light microscope.


METHODS
Thirteen morphometric parameters of the anterior eye segment were measured before and after the application of one drop of pilocarpine in 10 eyes of 5 persons, using a Zeiss-Humphrey Ultrasound Biomicroscope at a frequency of 50 MHz. In each session, 3 morphometric parameters in the central images (corneal thickness, anterior chamber depth, pupillary diameter) were measured 4 times, and 10 parameters in the radial images (scleral thickness, angle-opening distance, trabecular-iris angle, trabecular-ciliary process distance [TCPD], iris thickness, 1, 2 and 3, iris-ciliary process distance, iris-lens contact distance [ILCD], iris elevation) were measured on the 3, 6 and 9 o'clock meridians three times each.


RESULTS
Statistically significant changes were noted in the following parameters: pupillary diameter, iris thickness 1 and 2, and TCPD were decreased, while ILCD was increased after pilocarpine. Wide chamber angles showed a tendency to become narrower and narrow ones to become wider after pilocarpine.


CONCLUSIONS
One drop of pilocarpine caused significant changes in the anterior eye segment morphology. Not only the pupillary diameter decreased but iris thickness and trabecular-ciliary process distance were also decreased simultaneously. At the same time the contact surface between the lens and iris increased significantly. Ultrasound biomicroscopy gives new morphometric image information about the anterior eye segment which is not available using conventional gonioscopy or ophthalmic echography.
Németh
J
J
1st Department of Ophthalmology, Semmelweis Medical University, Budapest, Hungary.
Csákány
B
B
Pregun
T
T
D000287:Administration, Topical; D000869:Anterior Eye Segment / Q000000981:diagnostic imaging* / Q000187:drug effects; D002924:Ciliary Body / Q000000981:diagnostic imaging / Q000187:drug effects; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007498:Iris / Q000000981:diagnostic imaging / Q000187:drug effects; D008297:Male; D008853:Microscopy / Q000379:methods; D008875:Middle Aged; D008916:Miotics / Q000008:administration & dosage*; D015588:Observer Variation; D009883:Ophthalmic Solutions; D010862:Pilocarpine / Q000008:administration & dosage*; D011680:Pupil / Q000187:drug effects; D015203:Reproducibility of Results; D012590:Sclera / Q000000981:diagnostic imaging / Q000187:drug effects; D014463:Ultrasonography
D008916:Miotics; D009883:Ophthalmic Solutions; D010862:Pilocarpine