Pigment Dispersion Syndrome: Natural History and Possible Protective Effect of a YAG Laser Iridotomy

Study Overview
=================
Brief Summary
-----------------
STUDY AIMS To determine the 10-year conversion rate from pigment dispersion syndrome (PDS) to pigmentary glaucoma (PG) To evaluate the possible protective effect of a Yag-laser iridotomy

Detailed Description
-----------------
1154 workers in the Parma area will be screened for eligibility to long-term use of video-monitors. Those referred to the Glaucoma Clinic for suspected PDS will be enrolled in the study. In a prospective study on the natural history of PDS and PG, Richter et al. (Arch Ophtal 104:211-5, 1986) found an association between active pigment dispersion and elevated IOP. Therefore, in order to evaluate the stability of the pigment, a phenylephrine test will be performed following the method reported by Epstein et al (1978) AJO 85:43-50. The test will be performed by one investigator (SAG)and was considered positive if > grade 1+ (i.e. at least 10 particles in a single light beam). Eyes showing a positive test will be considered as high-risk for conversion to PG. Yag laser iridotomy will be performed in patients showing both eyes at high risk. One eye only (randomly chosen) will be treated. the fellow eye will be left untreated and considered as internal control. Low risk eyes will be followed without any intervention.

Official Title
-----------------
10-year Follow up of Patients With Pigment Dispersion Syndrome: Risk Factors for Conversion to Pigmentary Glaucoma and Potential Protective Effect of a Yag-laser Iridotomy in High Risk Eye

Conditions
-----------------
Pigment Dispersion Syndrome

Intervention / Treatment
-----------------
* Procedure: Yag laser iridotomy


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Krukenberg spindle Slit-like mid peripheral iris defect Pigment in > 270° of AC angle Exclusion Criteria: IOP > 18 mmHg PEX (full mydriasis) w/w field defect (Octopus G1 program)
Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: observation<br> | |
| Experimental: Yag laser iridotomy<br>the enrolled eyes will undergo an iridotomy performed by using a Yag-laser | Procedure: Yag laser iridotomy<br>* the procedure will be performed by using a Yag laser. Single spot, 1 mJ power, beam aimed to an existing iris crypt<br>* Other names: iridectomy;|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| > 5 mmHg IOP increase vs baseline (average 2 highest readings, 8 am - 6 pm phasing, 6 readings) |  | 10 years | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
glaucoma, pigmentary glaucoma, laser iridotomy