The effects of implantable collamer lens implantation on higher order aberrations

AIM: To evaluate the changes in higher order aberrations(HOAs) after implantable collamer lens(ICL;Staar Surgical, Nidau, Switzerland) implantation. METHODS: Totally 30 eyes of 18 patients with myopia were included in this study with an average age of 25.77y(min: 21, max: 40). Refraction, uncorrected distance visual acuity(UDVA), corrected distance visual acuity(CDVA), HOAs(entire, corneal and internal) were evaluated preoperatively and three months postoperatively. Ocular aberrations were measured by using iT race(Tracey Technology, Houston, Texas, USA). SPSS(IBM Corp. Released 2013. IBM SPSS Statistics for Windows, Version 22.0. Armonk, NY: IBM Corp) was used for the statistical analysis and the interpretation of the data. P values of less than 0.05 were considered statistically significant. RESULTS: The preoperative mean spherical power was -9.01 D(min:-5.00, max:-13.00) and the mean cylindrical error was -2.40 D(min:-0.50, max:-4.75). The postoperative mean residual spherical power was -0.73 D(min:-0.20, max:-1.75) and the mean cylindrical error was -0.89 D(min:-0.18, max:-2.09). Analyses were made on root mean square(RMS) values of total HOAs(tH OAs), spherical aberration, coma and trefoil as entire, corneal and internal components. The differences in entire t HOAs and in internal t HOAs were significant. There was no significant change found in spherical aberrations. The differences in entire coma and in internal coma were significant. There was no significant change found in corneal coma. With respect to trefoil, the only significant difference was in internal trefoil. CONCLUSION: The ICL implantation corrects the refractive error successfully and changes entire and internal HOAs of the eye.

年龄相关性黄斑变性患者的眼球壁硬度

PURPOSE: To compare the ocular rigidity in vivo measurements of patients with age-related macular degeneration (AMD) and control subjects. DESIGN: Prospective comparative clinical study. METHODS: The pressure-volume relation and the ocular rigidity coefficient were compared among 32 patients with AMD (AMD group: 16 with neovascular and 16 with nonneovascular AMD) and 44 age-matched control patients (control group) who underwent operation for cataract. This was achieved by an injection of 200 μ l of a balanced salt solution (in steps of 4.5 μ l) through the limbus in the anterior chamber, while the intraocular pressure was monitored continually with a transducer, up to the limit of 30 mm Hg. RESULTS: The mean age (AMD group: 69.89± 15.92 years vs control group: 65.28± 12.34 years; P=.195), gender (AMD group: 13 female vs control group: 17 female; P=.513), eye’s axial length (AMD group: 23.14± 0.75 mm vs control group: 23.04± 1.16 mm; P=.725) of patients with AMD and the healthy control subjects were comparable. No statistically significant difference in ocular rigidity measurements between patients with AMD and control subjects (AMD group: 0.0142 ± 0.0077 μ l- 1 vs control group: 0.0125± 0.0049 μ l- 1; P= .255) was found. When we examined separately the two subgroups of patients with AMD (neovascular and nonneovascular AMD), the average ocular rigidity measurements were higher in patients with neovascular AMD vs both control subjects and patients with nonneovascular AMD (neovascular AMD group: 0.0186± 0.0078 μ l- 1 vs control group: 0.0125± 0.0048 μ l- 1 [P =.014] vs nonneovascular AMD group: 0.0104± 0.0053 μ l- 1 [P=.004]). CONCLUSIONS:Despite the limitations placed by the small sample of the examined cases, patients with neovascular AMD who are treated (with photodynamic therapy) have increased ocular rigidity measurements compared with patients with nonneovascular AMD and control patients.