Session Title: Cataract II
Session Date/Time: Saturday 16/02/2013 | 08:30-11:00
Paper Time: 10:21
Venue: Hall 1
First Author: : M.Yugay RUSSIA
Co Author(s): : A. Ryabtzeva N. Nikitina
Purpose:
The effect of phacoemulcification on intraocular pressure (IOP) was discussed repeatedly. Majority of publications report decrease of IOP by 2-4 mm after cataract surgery. Probably, it can affect tactics choice in cases of cataract complicated with glaucoma. Ultrasound biomicroscopy (UBM) provides obtaining in vivo images of anterior segment of the eye. Our purpose was to study anatomical prerequisites for IOP reduction after phacoemulsification using UBM.
Setting:
Moscow Region Scientific Investigation Clinical Institute, Moscow, Russia
Methods:
The study included 24 patients (24 eyes) with cataract ranged in age from 56 to 82 years (mean age 71,2±2,6 years). All patients underwent uneventful ultrasound phacoemulsification with implantation of foldable intraocular lens. Standard examination included noncontact ophthalmotonometry. Configuration of anterior chamber was examined using UBM «Aviso» (Quantel Medical France), sensor frequency 50 MHz, scan area 16 mm, focus 9 to 11 mm, maximum resolution 35 microns, lateral resolution 60 microns. By UBM imaging the following parameters were measured one day before and 1-4 days after surgery: anterior chamber depth, angle opening distance at 500 µm from the scleral spur, trabecular-ciliary processes distance, thickness of iris root, iris profile, maximum thickness of ciliary body, and its thickness of 1 and 2 mm from the scleral spur, anterior chamber angle measurement. Data are expressed as mean values with standard deviation of the mean.
Results:
Anterior chamber depth significantly increased after surgery. The average depth of anterior chamber was 2,67±0,06 mm before surgery and 4,17±0,07 mm postoperatively. Trabecular-ciliary processes distance decreased insignificantly (1,50±0,06 mm before surgery and 1,46±0,07 mm after phacoemulsification). Iris profile from convex became more flat. We registered decrease in the thickness of iris root from 0,37±0,01 mm to 0,32±0,02 mm. The average value of anterior chamber angle increased by over a third from 31,99 ± 2,58° to 44,84 ± 2,33°. According to our data, maximum thickness of ciliary body after phacoemulsification increased somewhat from 0,61±0,02 mm to 0,65±0,03 mm and thickness in 1mm from the scleral spur was almost unchanged (0,59±0,03 mm preoperatively and 0,60±0,02 mm after surgery). Thickness of ciliary body in 2 mm from the scleral spur also remained unchanged (0,48±0,02 mm and up to 0,49±0,02 mm after surgery). Intraocular pressure decreased from 17,69±1,55 mm Hg to 11,57±2,34 mm Hg.
Conclusions:
Ultrasound biomicroscopy in vivo provides high-resolution images of anterior segment structures and possibility of their mathematical evaluation. Performing cataract phacoemulsification with implantation of a foldable intraocular lens increases depth of the anterior chamber, expansion of the entrance to the anterior chamber angle and degree of its opening. Apparently, these factors create favorable anatomic and topographic conditions for amplification of trabecular outflow of intraocular fluid and subsequent decrease of intraocular pressure.
Financial Disclosure:
None
