Surgically Induced Posterior Corneal Astigmatism in 2.2 mm Microcoaxial Cataract Surgery Versus 2.85 mm Coaxial Conventional Cataract Surgery

PURPOSE: To compare the surgically induced posterior astigmatism of microcoaxial cataract surgery using a 2.2 mm incision and conventional cataract surgery using a 2.85 mm incision. METHODS: This study included 56 eyes that underwent phacoemulsification and intraocular lens insertion. Subjects were divided into 2 groups: 26 eyes receiving a microcoaxial cataract surgery using a 2.2 mm incision (MCCS group) and 30 eyes receiving a conventional cataract surgery using a 2.85 mm incision (CCS group). Anterior, posterior and total corneal astigmatism was measured. The surgically induced anterior astigmatism, surgically induced posterior astigmatism and surgically induced total astigmatism were compared between MCCS and CCS groups. Corneal astigmatism was measured using a Pentacam(R) device (Oculus, Wetzlar, Germany), uncorrected visual acuity, best corrected visual acuity and corneal aberrations of front and rear side was measured preoperatively and at 1 day, 1 month and 2 months postoperatively. RESULTS: There was no difference in surgically induced posterior astigmatism between CCS and MCCS groups, however, surgically induced anterior astigmatism and surgically induced total astigmatism were significantly lower in the MCCS group than in the CCS group (p = 0.005 and, p = 0.036, respectively). There was a significant positive linear correlation between surgically induced posterior astigmatism and surgically induced total astigmatism in the CCS group (p = 0.01, r = 0.563). There was also a significant positive linear correlation between surgically induced anterior astigmatism and surgically induced total astigmatism in both CCS and MCCS groups (CCS group: p = 0.00, r = 0.855; MCCS group: p = 0.039, r = 0.407). CONCLUSIONS: There was no significant difference in the surgically induced posterior astigmatism between the MCCS and CCS groups. However, surgically induced posterior astigmatism significantly affected surgically induced total astigmatism in the CCS group but not in the MCCS group. Considering both anterior and posterior astigmatism of the cornea, microcoaxial cataract surgery using a 2.2 mm incision affects surgically induced total astigmatism less than conventional cataract surgery.

Changes of Higher-Order Aberrations after Microcoaxial Cataract Surgery According to Pupil Size

PURPOSE: To analyze changes of higher-order aberrations (HOAs) after micro-coaxial cataract surgery according to pupil size and to evaluate systemic factors affecting these changes. METHODS: Forty-two patients (42 eyes) who had undergone micro-coaxial cataract surgery were followed-up in the present study. HOAs (total RMS, coma, trefoil and spherical aberration) were measured at 1 week, 1 month, 3 months and 6 months post surgery. Differences of HOAs according to pupil size and systemic factors affecting changes of HOAs were analyzed. RESULTS: Total RMS (1.08 +/- 0.89 microm) and spherical aberration (0.03 +/- 0.13 microm) were lower in the group with a pupil size between 5.6 and 6.4 mm at 1 month after surgery compared with the group with pupil size lower than 5.5 mm (1.69 +/- 0.97 microm, 0.09 +/- 0.11 microm) or the group with pupil size larger than 6.5 mm (1.75 +/- 0.87 microm, 0.12 +/- 0.18 microm), which remained low at 6 months after surgery. Coma and trefoil showed a similar tendency. Patients with diabetes mellitus had smaller pupil size and higher total RMS, coma, trefoil and spherical aberration values at 1 month after surgery compared with patients without diabetes. CONCLUSIONS: HOAs were lowest in patients with pupil size between 5.6 and 6.4 mm after micro-coaxial cataract surgery. Patients with diabetes mellitus tend to have smaller pupil size after micro-coaxial cataract surgery and show higher postoperative HOAs.

One-Year Outcome of Microcoaxial Cataract Surgery Using 1.8 mm and 2.2 mm Incisions Versus that of Conventional Cataract Surgery

PURPOSE: To compare the 1-year outcome of 1.8 mm and 2.2 mm microcoaxial cataract surgery (MCCS) versus 2.75 mm conventional cataract surgery (CCS). METHODS: The present study evaluated 120 eyes (40 eyes in each group). The mean ultrasound power, ultrasound time (UST), and cumulative dissipated energy (CDE) were measured preoperatively and at 1 day, 1, 2, 6 months, and 1 year postoperative. Visual acuity, number of corneal endothelial cells, and surgically induced astigmatism (SIA) were compared. RESULTS: In LOCS III NO4, 1.8 mm MCCS showed a statistically higher ultrasound time (p-value = 0.031) and CDE (p-value = 0.029), and the day 1 corneal thickness increase was relatively higher in 1.8 mm MCCS (p-value = 0.043) than other two groups. There were no differences in postoperative 1 year visual acuity or number of corneal endothelial cells among the groups. SIA was significantly lower in 1.8 mm and 2.2 mm MCCS compared to that of the conventional treatment (p-value = 0.046). CONCLUSIONS: There were no differences in postoperative 1 year mean endothelial cell density or corrected visual acuity between 1.8 and 2.2 mm MCCS and CCS at all cataract densities. The 1.8 mm and 2.2 mm MCCS techniques were as safe and effective as CCS, and SIA in 1.8 mm and 2.2 mm MCCS was significantly lower than that of CCS.

Steep Axis Incision Versus Temporal Incision in Microcoaxial Cataract Surgery

PURPOSE: To determine if a difference exists in surgically-induced astigmatism (SIA) and the mean change in keratometric astigmatism in patients who underwent microcoaxial cataract surgery (MCCS). METHODS: A prospective study including 193 eyes with astigmatism of greater than 0.5 diopters was performed. The eyes were randomized into two groups: (1) 95 eyes with steep axis incision, and (2) 98 eyes with temporal incision. A 2.2-mm microcoaxial phacoemulsification was performed. The UCVA, BCVA and corneal topography (Orbscan II, Bausch & Lomb) were measured preoperatively and three months postoperatively. Surgically induced astigmatism was calculated via vector analysis, and the mean change in keratometric astigmatism was also calculated. RESULTS: There were no significant differences in UCVA or BCVA between the two groups three months postoperative. The mean SIA was 0.45 +/- 0.27 diopters in the steep axis incision group and 0.30 +/- 0.17 diopters in the temporal incision group. In the steep axis incision group, the mean keratometric astigmatism showed a mean reduction of 0.31 +/- 0.37 diopter (WTR: 0.37 D; oblique: 0.35D; ATR: 0.16 D), while the mean keratometric astigmatism showed a mean increase of 0.06 +/- 0.29 diopters (WTR: 0.15 D increased; oblique: 0.11 D increased; ATR: 0.13 D reduced) in the temporal incision group. There were statistically significant differences in SIA and change in astigmatism between the two groups (p = 0.002, p = 0.000). CONCLUSIONS: In MCCS, steep axis incision achieved superior astigmatism correction in patients having with-the-rule or oblique astigmatism of greater than 0.5 diopters.

Comparison of Visual Function Between Two Aspheric Intraocular Lenses After Microcoaxial Cataract Surgery

PURPOSE: To compare the visual function and postoperative refraction between two aspheric intraocular lenses (IOLs) after microcoaxial cataract surgery. METHODS: A prospective analysis of 60 eyes of 58 patients who had undergone microcoaxial phacoemulsification and implantation of aspheric IOLs (AcrySof IQ, 30 eyes; Akreos MI60, 30 eyes) was performed. The best corrected visual acuity (BCVA), spherical equivalent, intraocular pressure (IOP), corneal thickness, endothelial cell density (ECD), predictability of postoperative spherical equivalent, higher order aberrations, contrast sensitivity test, satisfaction, and glare were evaluated during the follow-up period of three months. RESULTS: There were no significant differences in BCVA, spherical equivalent, IOP, corneal thickness, or ECD (p>0.05). The predictability of the postoperative spherical equivalent in the AcrySof IQ and Akreos MI60 IOL groups was not significantly different (p=0.59), and the two groups showed good anterior-posterior stability during the postoperative three months. There were no significant differences in higher order aberrations, contrast sensitivity test, satisfaction or glare (p>0.05). CONCLUSIONS: Both AcrySof IQ and Akreos MI60 implantation groups showed similar visual functions and postoperative spherical equivalents after microcoaxial cataract surgery.

Comparison of Clinical Results Between Two Spherical Aberraion-Free Intraocular Lenses

PURPOSE: To compare the postoperative outcomes between Akreos MI60 and Akreos AO intraocular lens (IOLs) after cataract surgery. METHODS: A prospective analysis among 55 eyes of 55 patients who had undergone microcoaxial phacoemulsification and implantation of aspheric IOLs (Akreos MI60, 30 eyes; Akreos Adapt-AO, 25 eyes) was performed. The best corrected visual acuity (BCVA), spherical equivalent, intraocular pressure (IOP), corneal thickness, endothelial cell density (ECD), surgically induced astigmatism (SIA), predictability of postoperative spherical equivalent, higher order aberrations, and contrast sensitivity test were evaluated during the follow-up period of 3 months. RESULTS: There were no significant differences in BCVA, spherical equivalent, IOP, corneal thickness, ECD, SIA, higher order aberrations and contrast sensitivity test (p>0.05). The predictability of postoperative spherical equivalent in the Akreos Adapt-AO (-0.57+/-0.22D) represented statistically significant myopic shift compared with the Akreos MI60 group (-0.05+/-0.69D) (p=0.02). CONCLUSIONS: Both the Akreos MI60 and the Akreos Adapt-AO implantation groups performed similiarly, following cataract surgery, showed similar visual function.

Comparative Study of Microcoaxial Cataract Surgery and Conventional Cataract Surgery

PURPOSE: To compare the postoperative results of 2.2 mm microcoaxial cataract surgery (MCCS) and conventional 3.0 mm cataract surgery (CCS). METHODS: This study included 30 patients (40 eyes): 17 patients (21 eyes) had microcoaxial cataract surgery using a 2.2 mm microcorneal incision, and 13 patients (19 eyes) had conventional cataract surgery using a 3.0 mm corneal incision. In these two groups, we measured phacoemulsification time, total phacoemulsification percentage, and effective phacoemulsification time (EPT) during cataract surgery. We compared corneal thickness, endothelial cell count, uncorrected visual acuity, best corrected visual acuity, and surgically, induced astigmatism (SIA) by corneal topography between the two groups preoperatively and at 1 day, 1 week, 1 month, and 2 months postoperatively. RESULTS: There were significantly lower SIA (p=0.025) at postoperative day 1 in MCCS, and there was no significant difference after that. No difference in phacoemulsification time, total phacoemulsification percentage, EPT, corneal thickness, postoperative uncorrected visual acuity or corrected visual acuity was noted between MCCS and CCS. CONCLUSIONS: MCCS using a 2.2 mm small corneal incision appears to be a safe and advanced procedure with a smaller amount of surgically-induced astigmatism during the early postoperative period.

Surgically Induced Astigmatism and Corneal Higher Order Aberrations in Microcoaxial and Conventional Cataract Surgery

PURPOSE: To compare surgically induced astigmatism (SIA) and some corneal higher order aberrations in patients who underwent microcoaxial cataract surgery (MCCS) or conventional cataract surgery. METHODS: A prospective randomized study included 60 eyes of 55 patients. Thirty eyes received MCCS using a 2.2mm clear corneal incision (group 1), and 30 eyes received conventional cataract surgery using a 2.8 mm clear corneal incision (group 2). SIA and corneal higher order aberrations were measured with a Keratometer (Humphrey, Zeiss) and i-Trace (Tracey Technologies) preoperatively, and at 1 and 3 months after cataract surgery. SIA was analyzed vectorially using the Alpins method. RESULTS: There was no significant difference in preoperative UCVA or BCVA between the two groups. At 1 month and 3 months after surgery, SIA in group 1 was less than that in group 2, but this difference was not significant. There was no statistically significant difference in postoperative change of corneal higher order aberrations in each group at 1 month or 3 months after surgery, and there was no statistically significant difference in corneal higher order aberrations between the two groups preoperatively, at 1 month, or 3 months after surgery. CONCLUSIONS: There was no significant difference in SIA and corneal higher order aberrations between the two groups.