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

This study has been completed.
Information provided by:
University of Parma Identifier:
First received: January 20, 2010
Last updated: January 21, 2010
Last verified: January 2003


  1. To determine the 10-year conversion rate from pigment dispersion syndrome (PDS) to pigmentary glaucoma (PG)
  2. To evaluate the possible protective effect of a Yag-laser iridotomy

Condition Intervention
Pigment Dispersion Syndrome Procedure: Yag laser iridotomy

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single (Investigator)
Primary Purpose: Prevention
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

Resource links provided by NLM:

Further study details as provided by University of Parma:

Primary Outcome Measures:
  • > 5 mmHg IOP increase vs baseline (average 2 highest readings, 8 am - 6 pm phasing, 6 readings) [ Time Frame: 10 years ]

Enrollment: 72
Study Start Date: January 1993
Study Completion Date: December 2003
Primary Completion Date: April 2003 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
No Intervention: observation
Experimental: Yag laser iridotomy
the enrolled eyes will undergo an iridotomy performed by using a Yag-laser
Procedure: Yag laser iridotomy
the procedure will be performed by using a Yag laser. Single spot, 1 mJ power, beam aimed to an existing iris crypt
Other Name: iridectomy

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.


Ages Eligible for Study:   Child, Adult, Senior
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

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)
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Please refer to this study by its identifier: NCT01053416

Sezione Di Oftalmologia, Universita' Di Parma
Parma, Italy, 43100
Sponsors and Collaborators
University of Parma
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Other Study ID Numbers: PARMAPIGMO
Study First Received: January 20, 2010
Last Updated: January 21, 2010

Keywords provided by University of Parma:
pigmentary glaucoma
laser iridotomy

Additional relevant MeSH terms:
Glaucoma, Open-Angle
Pathologic Processes
Ocular Hypertension
Eye Diseases processed this record on September 21, 2017