Purpose:
To determine the anterior segment parameters that may influencesuccess of laser peripheral iridotomy (PI) in Caucasians withangle closure
Methods:
Retrospective case series of Caucasian angle closure patientsundergoing laser PI from November 2007 to November 2009. Exclusioncriteria for the study included previous intraocular surgery,laser PI and laser iridoplasty. Slit lamp optical coherencetomography (SL-OCT) images before and after laser PI were evaluated.Images from the right eye were used for analysis if both eyeswere eligible. Temporal SL-OCT angle measurements (Figure 1)and corneal parameters were compared for risk of failure, definedas persistent iridocorneal touch in two or more quadrants inlight or dark.
Results:
Data from 70 eyes of 70 Caucasian patients were obtained. Themean duration from laser PI to follow-up SL-OCT scan was sevenweeks (SD 6.8). The results are summarized in Table 1.
Conclusions:
These results suggest that a less successful outcome after laserPI is associated with greater angle closure in light and dark(increased TICL in light and dark, reduced TIA 500 in light,reduced AOD 500 in light, reduced TISA750 in dark), less pupillaryblock in light (reduced MIBH in light), and greater basal iristhickness in light (increased PIT 500 in light). Eyes with increasedTICL (>0.30 mm) in light had the greatest risk of failure(odds ratio 5.97; 95% confidence interval 1.84 - 19.34).
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)