Intraocular Scattering after Instillation of Diquafosol Ophthalmic Solution.

PURPOSE: To assess the changes in intraocular scattering before and after instillation of diquafosol ophthalmic solution in patients with short tear breakup time (TBUT) dry eye. METHODS: We prospectively examined 20 eyes of 20 short TBUT dry eye patients (study group) and age-matched 20 eyes of 20 healthy subjects (control group). Intraocular scattering was measured as the objective scattering index (OSI) at 0.5-second intervals over 10 seconds without blinking. Patients were instructed to start topical administration of 3% diquafosol ophthalmic solution six times daily for 4 weeks. RESULTS: The OSI significantly deteriorated after 7.0 seconds compared with the initial value of OSI after the blinking in the study group. The OSI was also significantly higher in the study group than in the control group at 4.5 to 10.0 seconds after the blinking (p < 0.05). We found significant improvements 2 weeks after treatment not only in TBUT (p < 0.001) but also in the mean OSI, the OSI change rate, and the slope of the linear regression line of the OSI within 10 seconds (p < 0.001, p = 0.003, and p = 0.002, respectively). We also found significant improvements 4 weeks after treatment in these variables. CONCLUSIONS: Intraocular scattering deteriorates significantly with time in patients with short TBUT dry eye. Diquafosol ophthalmic solution exhibits an improvement not only in TBUT but also in intraocular scattering, indicating that diquafosol is also effective for improving the optical quality of the eye.

Comparison of astigmatic correction after femtosecond lenticule extraction and wavefront-guided LASIK for myopic astigmatism.

PURPOSE: To compare postoperative astigmatic correction between femtosecond lenticule extraction (FLEx) and wavefront-guided LASIK in eyes with myopic astigmatism. METHODS: Fifty-eight eyes of 41 patients undergoing FLEx and 49 eyes of 29 patients undergoing wavefront-guided LASIK to correct myopic astigmatism were examined. Visual acuity, cylindrical refraction, predictability of the astigmatic correction, and astigmatic vector components were compared between groups 6 months after surgery. RESULTS: There was no statistically significant difference in manifest cylindrical refraction (P = .08) or percentage of eyes within ± 0.50 diopter (D) of its refraction (P = .11) between the surgical procedures. The index of success in FLEx was statistically significantly better than that of wavefront-guided LASIK (P = .02), although there was no significant difference between the groups in other indices (eg, surgically induced astigmatism, target-induced astigmatism, astigmatic correction index, angle of error, difference vector, and flattening index). Subgroup analysis showed that FLEx had a better index of success (P = .02) and difference vector (P = .04) than wavefront-guided LASIK in the low cylinder subgroup; the angle of error in FLEx was significantly smaller than that of wavefront-guided LASIK in the moderate cylinder subgroup (P = .03). CONCLUSIONS: Both FLEx and wavefront-guided LASIK worked well for the correction of myopic astigmatism by the 6-month follow-up visit. Although FLEx had a better index of success than wavefront-guided LASIK when using vector analysis, it appears equivalent to wavefront-guided LASIK in terms of visual acuity and the correction of astigmatism.

[Corneal astigmatism before cataract surgery].

PURPOSE: To investigate the distribution of corneal astigmatism, and the relationship of astigmatism to the patients' age in a large number of pre-cataract surgery patients. MATERIALS AND METHOD: We retrospectively examined 12428 eyes of 7187 patients (5396 eyes of men, 7032 eyes of women) who underwent cataract surgery at Kitasato University Hospital from April, 2002 to September, 2009. The mean patients' age at the time of surgery was 69.9 +/- 12.1 years. We determined corneal astigmatism using an Auto Refract Keratometer ARK-700A, a RKT-7700 (Nidek), a RK-F1 (Canon) and a Retinomax K-plus2(Righton). We carried out these measurements at least three times for each patient, and the average values were used for analysis. RESULTS: The mean corneal astigmatism was 1.02 +/- 0.81 D (0 to 14.75 D). The percentage of 1 D or less of corneal astigmatism was 63.6%, that of more than 1 D and 1.5 D or less was 20.9%, that of more than 1.5 D and 2 D or less was 7.4%, that of more than 2 D and 2.5 D or less was 3.8% and that of more than 2.5 D and 3 D or less was 1.8%. Neither significant laterality nor age difference in corneal astigmatism were found. The prevalence of with-the-rule astigmatism (WTR) was common in young population, whereas the prevalence of against-the-rule astigmatism(ATR) increased in the older population, whereas the prevalence of oblique astigmatism remains unchanged. CONCLUSIONS: Approximately two thirds of the preoperative patients had 1 D or less corneal astigmatism, and the remaining one third had over 1 D corneal astigmatism. The frequency of WTR was greater at a younger age, and that of ATR, at an older age.

Changes in astigmatism and corneal higher-order aberrations after phacoemulsification with toric intraocular lens implantation for mild keratoconus with cataract.

PURPOSE: To assess the changes in astigmatism and higher-order aberrations (HOAs) after toric intraocular lens (IOL) implantation for mild non-progressive keratoconus with cataract. METHODS: We prospectively examined 19 eyes of 19 consecutive keratoconic patients (mean age ± standard deviation, 63.1 ± 9.1 years) who underwent phacoemulsification with toric IOL implantation. We determined uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refractive astigmatism, corneal astigmatism, corneal HOAs and astigmatic axis rotation both preoperatively and 3 months postoperatively. RESULTS: Logarithm of the minimal angle of resolution (logMAR) UDVA was significantly improved from 1.14 ± 0.50 preoperatively to 0.46 ± 0.33 postoperatively (Wilcoxon signed-rank test, p < 0.001). LogMAR CDVA was also significantly improved from 0.27 ± 0.45 preoperatively to -0.01 ± 0.09 postoperatively (p < 0.001). In 5 of 6 eyes in which the target refraction was emmetropia, postoperative UDVA was better than 20/32. The achieved spherical equivalent correction was within ±0.5 diopters (D) of the targeted correction in 13 (68 %) eyes and 1.0 in 18 (95 %) eyes. The refractive astigmatism was significantly decreased from -1.92 ± 1.73 D preoperatively to -0.70 ± 0.60 D postoperatively (p = 0.006). The corneal astigmatism changed from 2.89 ± 1.30 D preoperatively to 2.98 ± 1.09 D postoperatively (p = 0.492), which was not statistically significant. The corneal HOAs for a 4-mm pupil was changed from 0.47 ± 0.23 µm preoperatively to 0.52 ± 0.26 µm postoperatively (p = 0.211), which was not statistically significant. CONCLUSIONS: According to our experience, toric IOL implantation for mild keratoconic patients having rigid gas-permeable lens intolerance appears to be effective for reducing refractive astigmatism without a significant induction of corneal HOAs.

Distribution of posterior corneal astigmatism according to axis orientation of anterior corneal astigmatism.

PURPOSE: To investigate the distribution of posterior corneal astigmatism in eyes with with-the-rule (WTR) and against-the-rule (ATR) anterior corneal astigmatism. METHODS: We retrospectively examined six hundred eight eyes of 608 healthy subjects (275 men and 333 women; mean age ± standard deviation, 55.3 ± 20.2 years). The magnitude and axis orientation of anterior and posterior corneal astigmatism were determined with a rotating Scheimpflug system (Pentacam HR, Oculus) when we divided the subjects into WTR and ATR anterior corneal astigmatism groups. RESULTS: The mean magnitudes of anterior and posterior corneal astigmatism were 1.14 ± 0.76 diopters (D), and 0.37 ± 0.19 D, respectively. We found a significant correlation between the magnitudes of anterior and posterior corneal astigmatism (Pearson correlation coefficient r = 0.4739, P<0.001). In the WTR anterior astigmatism group, we found ATR astigmatism of the posterior corneal surface in 402 eyes (96.6%). In the ATR anterior astigmatism group, we found ATR posterior corneal astigmatism in 82 eyes (73.9%). Especially in eyes with ATR anterior corneal astigmatism of 1 D or more and 1.5 D or more, ATR posterior corneal astigmatism was found in 28 eyes (59.6%) and 9 eyes (42.9%), respectively. CONCLUSIONS: WTR anterior astigmatism and ATR posterior astigmatism were found in approximately 68% and 91% of eyes, respectively. The magnitude and the axis orientation of posterior corneal astigmatism were not constant, especially in eyes having high ATR anterior corneal astigmatism, as is often the case in patients who have undergone toric IOL implantation.

Assessment of Anterior, Posterior, and Total Central Corneal Astigmatism in Eyes With Keratoconus.

PURPOSE: To investigate the magnitudes and the axis orientations of anterior, posterior, and total central corneal astigmatism in eyes with keratoconus. DESIGN: Retrospective case series. METHODS: This study comprised 137 eyes of 137 keratoconic patients (97 men and 40 women; mean age ± standard deviation, 36.9 ± 12.2 years). The magnitude and the axis orientation of each corneal astigmatism were determined with a rotating Scheimpflug system. RESULTS: The mean magnitudes of anterior, posterior, and total central corneal astigmatism were 3.93 ± 2.74 diopters (D), 0.93 ± 0.64 D, and 3.90 ± 2.75 D, respectively. With-the-rule (WTR), against-the-rule (ATR), and oblique astigmatism of the anterior corneal surface was found in 90 eyes (65.7%), 33 eyes (24.1%), and 14 eyes (10.2%), respectively, whereas the corresponding astigmatism of the posterior corneal surface was found in 14 eyes (10.2%), 15 eyes (10.9%), and 108 eyes (78.8%), respectively. We found a significant correlation between the magnitudes of anterior and posterior corneal astigmatism (Pearson correlation coefficient r = 0.769, P < .001). CONCLUSIONS: The mean magnitudes of anterior and posterior corneal astigmatism were approximately 4 D and 1 D, respectively, in eyes with keratoconus. Approximately 65% and 80% of eyes showed that WTR anterior astigmatism and ATR posterior astigmatism, respectively. The presence of posterior corneal astigmatism is not necessarily negligible for the accurate astigmatic correction of toric intraocular lens implantation or rigid gas-permeable contact lens wear for keratoconus.

Long-term clinical outcomes of toric intraocular lens implantation in cataract cases with preexisting astigmatism.

PURPOSE: To evaluate the long-term clinical outcomes and rotational stability of toric intraocular lenses (IOLs) to correct preexisting astigmatism in cataract patients. SETTING: Kitasato University Hospital, Kanagawa, Japan. DESIGN: Prospective observational study. METHODS: Phacoemulsification with implantation of a toric IOL (Acrysof IQ toric SN6AT) was performed in cataract patients with corneal astigmatism. The postoperative follow-up was up to 2 years. RESULTS: This study enrolled 378 eyes of 302 patients with a mean age of 63.4 years ± 16.9 (SD). The corrected distance visual acuity 3 months postoperatively was 20/25 or better in 94.7% of eyes. The mean refractive cylinder was -1.92 ± 1.45 diopters (D) preoperatively, -0.59 ± 0.62 D 3 months postoperatively (322 eyes), and -0.67 ± 0.90 D at 2 years (73 eyes). There were statistically significant differences between the preoperative and 3-month postoperative measurements (P<.001, Wilcoxon signed-rank test). The mean IOL misalignment was 4.1 ± 3.0 degrees 2 years postoperatively. The mean IOL rotation was 4.5 ± 4.9 degrees within 1 day postoperatively. The rotation was more than 20 degrees in 6 eyes, all of which had an axial length (AL) of more than 25.0 mm. All rotations occurred within 10 days postoperatively. CONCLUSIONS: Toric IOLs were effective in reducing preexisting corneal astigmatism and had overall good rotational stability. A large degree of IOL rotation might occur in eyes with a relatively long AL, especially during the early postoperative period. The 6 rotated IOLs were implanted to correct with-the-rule astigmatism. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.