Eyeworld

EW CATARACT 34 June 2017 Presentation spotlight by Stefanie Petrou Binder, MD, EyeWorld Contributing Writer the study eyes demonstrated PCW. While PCW in eyes with the Tecnis IOL is explained largely by haptic location, in AcrySof eyes, PCW is associated with other factors as well. "In eyes with the AcrySof IOL, PCW may be attributed to the sticky posterior surface of the IOL, which contributes to wrinkle formation between the posterior capsule and lens optic and haptics, causing the malposition of the IOL. On the other hand, the higher prevalence of PCW in AcrySof IOLs may indicate firm fixation in the capsular bag," he said. The study showed a significant difference between IOL tilt (P<0.01) and decentration (P<0.05) in AcrySof eyes with and without PCW. The AcrySof IOL has a platform structure. Dr. Sasaki explained that since various parts of both the optic and haptics were in physical contact with the posterior capsule, and due to the cohesive nature of the lens material, the position of PCW could be uneven. Wrinkle formation with these IOLs could therefore lead to lens malpositioning. However, as PCW caused by the AcrySof IOL is likely to result from the firm con- tact between the IOL and the lens capsule, this IOL may offer the advantage of less risk of rotation in toric lenses. Dr. Sasaki's study corroborates an earlier, unrelated study that investigated the mechanisms of capsular wrinkles following cata- ract surgery. 1 The study compared a one-piece IOL with a three-piece IOL and showed that wrinkle incidence differed depending on IOL shape, and was associated with IOLs with high compressive strength. Short axial length and eyes with small lens capsules were more likely to develop PCW, as was shown in the present study. EW Reference 1. Nagata M, et al. Posterior capsule wrinkle after cataract surgery. Poster presented at the European Society of Cataract and Refractive Surgeons Congress, London, England, 2014. Editors' note: Dr. Sasaki has no finan- cial interests related to his comments. Contact information Sasaki: mogu@kanazawa-med.ac.jp with a WTW measuring greater than or equal to 11.9 mm. The PCW in the Tecnis IOL was more localized, while in the AcrySof IOL, PCW was much more scattered. The distribution of PCW in the Tecnis group was 62.0 degrees ± 1.3 degrees, while in the AcrySof group it was 76.3 degrees ± 29.7 degrees. Tecnis According to the study outcomes, the Tecnis IOL could be stably fixat- ed in small lens capsular diameters of roughly 10.0 mm because of the large area of contact between the haptics and lens capsule. In cap- sular bags with an average size of 10.5 mm, the haptic had contact with the lens capsule at a position between 48 degrees and 72 degrees, allowing the edge of the haptic to apply force at a position about 60 degrees above the center in the lens capsule, which may account for the presence of PCW at around 60 degrees. When using the Tecnis IOL, PCW may be an indicator for stable fixation due to haptic contact, Dr. Sasaki explained. The construction of the Tecnis allows a good understanding of why wrinkles form at certain locations of the capsule. "The haptics of the Tecnis IOL are offset from the optic. Only the peripheral parts of the optic have contact with the poste- rior capsule. Also, both sides of the haptics are fixed in the lens capsule, allowing PCW to form around the edges, making stable central fixation of the IOL possible," he said. AcrySof The construction of the AcrySof IOL explains why nearly 70% of as 0 degrees. Postoperatively, the IOLMaster (Carl Zeiss Meditec, Jena, Germany) was used to measure the lens capsular diameter, axial length, corneal horizontal diameter (WTW: white-to-white), and corneal curva- ture radius. The EAS-1000 was used to measure IOL malposition, such as tilt and decentration. "The mechanism of PCW formation differs by IOL. There was PCW in 32.3% of Tecnis patients (50 eyes), and no PCW in 67.7% (105 eyes). In the AcrySof patients, 69% demonstrated PCW (40 eyes) and 31% did not demonstrate PCW (18 eyes). PCW in eyes with the Tecnis IOL may denote good fixation of the IOL in the capsular bag. In eyes with the AcrySof IOL, PCW may desig- nate a risk of IOL malposition due to the firm contact caused by adhesion between both the IOL and its hap- tics with the posterior capsule," Dr. Sasaki said. There was a significant correla- tion between the axial length of eyes that developed PCW in both the Tecnis and AcrySof groups (P<0.05). The WTW measurement was also significant in Tecnis eyes in the for- mation of PCW (P<0.05), while the corneal curvature was not a signifi- cant factor in PCW formation. In the Tecnis group, PCW devel- oped in 44.4% of eyes with a WTW measurement smaller than 11.5 mm, in 30% of those with WTW between 11.5 mm and 11.9 mm, and in 12.9% of eyes with a WTW measure- ment greater than or equal to 11.9 mm. In the AcrySof group, PCW was seen in 64.7% of eyes with a WTW smaller than 11.5 mm, in 77.8% of eyes with a WTW between 11.5 mm and 11.9 mm, and in 60% of those Study compares posterior capsular wrinkle in two commonly used IOLs P osterior capsular wrinkle (PCW) occurs as a result of traction between IOLs and the posterior capsule and may depend on different factors, such as the shape of the implanted artificial lens, the size of an individual's capsular bag, the position of the lens haptics, and the tactile characteristics of the lens material. Understanding the effects of PCW on optimal visual outcomes and knowing more about which IOLs cause PCW can help cataract and refractive surgeons achieve bet- ter, more satisfactory visual results for their patients. Tecnis versus AcrySof In a study presented at the 2016 ESCRS Congress by Hiroshi Sasaki, MD, Department of Ophthalmology, Kanazawa Medical University, Japan, the incidence of PCW was evaluated in eyes receiving one of two differ- ent one-piece IOLs, the Tecnis IOL (Johnson & Johnson Vision, Santa Ana, California) and the AcrySof IOL (Alcon, Fort Worth, Texas). The investigation also studied the relationship between PCW and lens capsular diameter, the position of PCW, the relationship between PCW and malpositioned IOLs, and the re- lationship between lens capsular bag diameters ranging from 10.0 mm to 11.5 mm and haptic fit within the bag. The study included 213 eyes of patients who underwent phacoemul- sification and implantation of a one-piece IOL at Kanazawa Medical University Hospital and Anamizu General Hospital, Kanazawa, Japan. The Tecnis group was comprised of 155 eyes in patients with a mean age of 71.0 ± 9.6 years, and the AcrySof group had 58 eyes in individuals with a mean age of 75.0 ± 8.8 years. In the study, Dr. Sasaki evaluat- ed PCW within the 3-mm diameter of the central pupil 1 month post- operatively using retroillumination images with the EAS-1000 (Nidek, Aichi, Japan). The PCW position was measured counterclockwise, taking the central line of the optic/ haptic junction, or the toric mark, Different lens, different wrinkles Understanding the effects of PCW on optimal visual outcomes and knowing more about which IOLs cause PCW can help cataract and refractive surgeons achieve better, more satisfactory visual results for their patients.

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