Purpose:
To evaluate and quantify changes in the anterior chamber morphologyafter small incision cataract extraction and intraocular lens(IOL) placement using anterior segment optical coherence tomography(ASOCT)
Design:
Prospective comparative observational case series.
Methods:
We examined the anterior chamber configuration of 32 eyes of32 patients before and after small incision cataract extractionand posterior chamber IOL implantation by means of ASOCT. Centralanterior chamber depth (ACD) was measured, along with severalangle parameters: angle opening distance at 500 µm fromscleral spur (AOD 500) and trabecular-iris space at 500 µmand 750 µm (TISA 500 and 750). Pre-operatively lens thickness(LT) and lens position (LP) defined as ACD + ½ LT were calculated
Results:
Preoperative ACD and LT were highly correlated (r = -0.46, P= 0.0083) as were ACD and TISA 500 (r = 0.63, P = 0.0001). LPwas highly correlated with TISA 500 (r=0.52, P=0.0001). However,LT did not correlate with TISA 500 (r = -0.11, P= 0.74). Themean ACD, AOD 500, TISA 500 and TISA 750 all increased significantlyafter cataract extraction (p<0.001), Table, Figure. The degreeof angle widening was not correlated with preoperative angleor lens parameters.
Conclusions:
Preoperative lens thickness affects central anterior chamberdepth, but does not seem to significantly affect angle opening.The position of the lens may have a greater influence on anglewidth. Regardless of preoperative anatomy, cataract extractionsignificantly deepens the anterior chamber and widens the angle.These changes can be objectively quantified by anterior segmentOCT.
Keywords: anterior segment • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)