Abstract
Purpose: :
to compare between Pigment Dispersion Syndrome (PDS)/Pigmentary Glaucoma (PG) subjects and healthy volunteers by mean of ultrasound biomicroscopy (UBM)
Methods: :
consecutive patients referring to our Glaucoma Service between Jan 2005 and Dec 2007, receiving a first diagnosis of PDS or PG. A baseline complete ophthalmologic evaluation was performed. Control group consisted of of healthy volunteers matched for sex, age and SEq. UBM examination was performed by a 50 MHz transducer probe. All the examinations were made by the same trained examiner (PM). We considered for the study the radial perpendicular image taken on the horizontal temporal meridian of the sole right eye, first in an unsolicited accommodative state (patient looked with the fellow eye a target at about 3m), then in accommodative state (the images were frozen 10 sec after the patient was fixating a star-shaped target of 6 mm presented at 40 cm to the fellow eye). UBM-evaluated parameters were: Anterior Chamber Depth in far vision (ACDfv), Iris-Lense Contact in far vision (ILCfv), Iris-Lense Contact in near vision (ILCnv), Irido-Corneal Angle in far vision (ICAfv), Irido-Corneal Angle in near vision (ICAnv), Iris Concavity in far vision (Icfv), Iris Concavity in near vision (Icnv)
Results: :
24 patients entered the study in the case group. Mean age was 39 years; mean Seq was -2.51±3.81 D and the mean IOP at baseline was 19±7 mmHg. 4 eyes had PG and 20 eyes had PDS. After the baseline evaluations, all the eyes with PG were treated. 25 subjects formed the control group. The two groups were statistically similar except for the baseline IOP which was significantly higher in the case group (p=.0001). The comparison between the two groups by Student’s T-test yelded significant results for all seven considered parameters. The analysis of the same parameters by mean of Receiver Operating Characteristic (ROC) analysis equally provided highly significant values for all parameters. The better values for Areas under the ROC Curves (AUCs) of were obtained, in decreasing significance, for ICAnv, Icnv, Icfv, ICAfv
Conclusions: :
All UBM parameters tested in this study were significantly different between the two groups, both in accomodative and non-accomodative state, thus well discriminatig normal subjects and people with PDS or PG. Seeing that the maximal predictivity of each parameter was observed upon accomodation, involment of peripheral iris seems relevant in the pathophysiology of pigment dispersion syndrome and pigmentary glaucoma
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • accomodation • anterior segment