Abstract
Purpose: :
To compare the visual quality in eyes undergoing primary posterior capsulorhexis (PPC) to prevent posterior capsular opacity, versus YAG laser procedure treatment.
Methods: :
A prospective, longitudinal, interventional and comparative study is made. Two groups of eyes were evaluated: Group one underwent PPC and group two a procedure for Yag laser in the presence of posterior capsular opacity (PCO). Both procedures were always performed in the same patient. All patients were implanted a hydrophobic acrylic monofocal lens. PPC was performed before the lOL implantation and after phacoemulsification and aspiration of cortical remnants filling the capsular bag with viscoelastic. Then, a small central incision towards the periphery was performed .The cutting was done in a circular form always being smaller than the size of the anterior capsulorhexis. Capsulotomy was used for the device 3000LE Alcon Neodymium: YAG laser. A circle with the shooting around the central area of the lens of an average size of 3.0 to 4.5 mm eccentricity was made. The number of shots averaged 20.0 ± 5 per session and the maximum energy used was 1.84 ± 0.3 mJ. Both groups were tested for visual quality using: LogMAR test of visual acuity, LogMAR test of best corrected visual acuity, Sine Wave Contrast Test of contrast sensitivity and Farnsworth-Munsell D-15 test of color vision. The tests were performed one month after surgery for eyes with PPC and one week after the YAG laser-treated eyes. The results were analyzed using SPSS for Windows. A P value less than 0.05 was considered statistically significant.
Results: :
The study enrolled 20 eyes of 10 patients (6 women, 4 men; 20 eyes) with a mean age of 62.7 years (range 47 to 85 years). The average visual acuity in eyes with PPC was 0.248 logMAR (range 0.17 to 0.3 ) and in the eyes with YAG laser was 0.24 logMAR (range 0.09 to 0.47 ) (P = 0.852). The average of best corrected visual acuity in eyes with PPC was 0.061 logMAR (range 0.0 to 0.17) and in the eyes with YAG laser was 0.46 logMAR (range 0.0 to 0.17 ) (P = 0.65). The average contrast sensitivity was 5, 4.2 and 1.4 respectively for low, medium and high frequencies in PPC eyes. YAG laser treatment eyes had a average of 5.6, 4.4 and 2.2 respectively for low, medium and high frequencies. For low frequencies the P = 0.037, for the midrange was P = 0.641 and high frequencies was P = 0.288. No alteration was found in color tests.
Conclusions: :
Although there is a difference in contrast sensitivity for low frequencies using YAG laser treatment for capsular opacity, there were no differences in visual quality between these procedures.
Clinical Trial: :
HOL, 15
Keywords: cataract • laser • visual acuity