Effects of Cyclotorsion Orientation and Magnitude in Eyes with Compound Myopic Astigmatism on the Compensation Capacity of WaveLight EX500 Photorefractive Keratectomy

PURPOSE: To investigate the clinical effects of different orientation and magnitude of cyclotorsion on the compensation capacity of the WaveLight EX500 photorefractive keratectomy (PRK) platform. METHODS: This retrospective study comprised 400 eyes of 200 patients who underwent bilateral simultaneous PRK due to compound myopic astigmatism. The subjects were separated according to the orientation of cyclotorsion into incyclotorsion and excyclotorsion groups, and by the magnitude of cyclotorsion into group 1 (0.50 to 2.50 degrees), group 2 (3.00 to 5.00 degrees), group 3 (5.50 to 7.50 degrees), and group 4 (8.00 to 9.50 degrees). RESULTS: The mean magnitude of cyclotorsion was 3.50 ± 2.4 degrees (0.50 to 9.50 degrees) in the incyclotorsion group and 3.32 ± 2.3 degrees (0.50 to 9.50 degrees) in the excyclotorsion group (p = 0.617). The postoperative refractive outcomes of the incyclotorsion and excyclotorsion groups were similar (p > 0.05 for all). The postoperative mean cylindrical refractive error was −0.32 ± 0.3 diopters (D, −1.25 to 0.00 D) in group 1, −0.47 ± 0.2 D (−2.00 to 0.00 D) in group 2, −0.62 ± 0.2 D (−1.00 to −0.25 D) in group 3, and −0.91 ± 0.2 D (−1.50 to −0.50 D) in group 4 (p < 0.001). Preoperative cylindrical refractive error was positively correlated with magnitude of cyclotorsion (r = 0.125 and p = 0.013), which was also positively correlated with postoperative cylindrical refractive error (r = 0.600 and p < 0.001). CONCLUSIONS: Incyclotorsion and excyclotorsion can be equally compensable in the WaveLight EX500 PRK platform for compound myopic astigmatism. A value of ≤2.50 degrees cyclotorsion magnitude was observed to be more compensable than higher degrees of cyclotorsion magnitude. Preoperative high astigmatism was associated with high cyclotorsion magnitude, which was also associated with a high degree of postoperative astigmatism.

Intravitreal Dexamethasone Implantation in Intravitreal Bevacizumab Treatment-resistant Pseudophakic Cystoid Macular Edema

PURPOSE: To evaluate the changes in visual acuity (VA) and central macular thickness (CMT) after intravitreal dexamethasone (IVD) implantation in intravitreal bevacizumab (IVB) treatment-resistant cases with pseudophakic cystoid macular edema (PCME). METHODS: This study included 10 PCME cases who underwent uneventful phacoemulsification and intraocular lens implantation with similar methods and six PCME cases referred to our hospital for treatment of low VA after cataract surgery. Due to the persistence of PCME, both topical steroid and anti-inflammatory medication were administered first, followed by IVB injection. IVD implantation was performed for all IVB treatment-resistant cases. VA and CMT values were compared before and at three months after the first IVD implantation. RESULTS: The mean VA values before and at 3 months after the first IVD implantation were 0.69 ± 0.19 logarithm of the minimum angle of resolution (logMAR) (1.50 to 0.10 logMAR) and 0.26 ± 0.07 logMAR (1.00 to 0.00 logMAR), respectively (p < 0.001). The mean CMT was 476.13 ± 135.13 mm (314 to 750 mm) and 294.06 ± 15.26 mm (222 to 480 mm), respectively (p < 0.001). The mean number of implanted IVD was 1.44 ± 0.89 (1 to 4) and the mean follow-up time was 7.4 ± 4.6 months (6 to 24 months). After IVD implantation therapy, the mean VA and CMT values were 0.19 ± 0.05 logMAR (0.70 to 0.00 logMAR) and 268.38 ± 31.35 mm (217 to 351 mm), respectively. CONCLUSIONS: To the best of our knowledge, this is the first report to show the efficacy of IVD implantation even after repeated IVB injections in treatment-resistant PCME. IVD implantation is both a safe and effective method for decreasing PCME after both uneventful and complicated cataract surgery.