Hidenaga Kobashi

Visual and refractive outcomes of femtosecond lenticule extraction and small-incision lenticule extraction for myopia.

PURPOSE To compare the visual and refractive outcomes of femtosecond lenticule extraction (FLEx) and small-incision lenticule extraction (SMILE) in eyes with myopia. DESIGN Prospective, randomized, masked clinical trial with intraindividual comparison. METHODS This study evaluated 52 eyes of 26 consecutive patients with spherical equivalents of -4.19 ± 1.65 diopters (D) (mean ± standard deviation) who underwent FLEx in 1 eye and SMILE in the other eye by randomized assignment. Before surgery, and 1 week and 1, 3, and 6 months after surgery, we assessed safety, efficacy, predictability, stability, and adverse events of the 2 surgical techniques. RESULTS LogMAR uncorrected and corrected distance visual acuity was, respectively, -0.17 ± 0.10, -0.20 ± 0.07 in the FLEx group and -0.15 ± 0.10, -0.19 ± 0.07 in the SMILE group 6 months postoperatively. In the FLEx and SMILE groups 6 months postoperatively, 96% and 100% of eyes, respectively, were within 0.5 D of the targeted spherical equivalent correction. Changes of -0.02 ± 0.39 D and 0.00 ± 0.30 D occurred in manifest refraction from 1 week to 6 months in the FLEx and SMILE groups, respectively. No clinically significant complications occurred in the FLEx or the SMILE group. CONCLUSIONS Both FLEx and SMILE performed well in the correction of myopia throughout the 6-month observation period. FLEx may be essentially equivalent to SMILE in terms of safety, efficacy, predictability, and stability, suggesting that the presence or absence of lifting the flap does not significantly affect these visual and refractive outcomes.

Clinical evaluation of the additive effect of diquafosol tetrasodium on sodium hyaluronate monotherapy in patients with dry eye syndrome: a prospective, randomized, multicenter study.

PurposeTo assess the additive effect of diquafosol tetrasodium on sodium hyaluronate monotherapy in patients with dry eye syndrome.MethodsThis study evaluated 64 eyes of 32 patients (age: 62.6±12.8 years (mean±SD)) in whom treatment with 0.1% sodium hyaluronate was insufficiently responsive. The eyes were randomly assigned to one of the two regimens in each patient: topical administration of sodium hyaluronate and diquafosol tetrasodium in one eye, and that of sodium hyaluronate in the other. Before treatment, and 2 and 4 weeks after treatment, we determined tear volume, tear film break-up time (BUT), fluorescein and rose bengal vital staining scores, subjective symptoms, and adverse events.ResultsWe found a significant improvement in BUT (P=0.049, Dunnett test), fluorescein and rose bengal staining scores (P=0.02), and in subjective symptoms (P=0.004 for dry eye sensation, P=0.02 for pain, and P=0.02 for foreign body sensation) 4 weeks after treatment in the diquafosol eyes. On the other hand, we found no significant change in these parameters after treatment in the control eyes.ConclusionsIn dry eyes, where sodium hyaluronate monotherapy was insufficient, diquafosol tetrasodium was effective in improving objective and subjective symptoms, suggesting its viability as an option for the additive treatment of such eyes.

Comparison of visual acuity, higher-order aberrations and corneal asphericity after refractive lenticule extraction and wavefront-guided laser-assisted in situ keratomileusis for myopia

Aim To compare postoperative visual acuity, higher-order aberrations (HOAs) and corneal asphericity after femtosecond lenticule extraction (FLEx) and after wavefront-guided laser-assisted in situ keratomileusis (wfg-LASIK) in myopic eyes. Methods We examined 43 eyes of 23 patients undergoing FLEx and 34 eyes of 19 patients undergoing wfg-LASIK to correct myopia. Ocular HOAs were measured by Hartmann-Shack aberrometry and corneal asphericity was measured by a rotating Scheimpflug imaging system before and 3 months after surgery. Results There was no statistically significant difference in uncorrected (p=0.66 Mann–Whitney U-test) or corrected distance visual acuity (p=0.14) after two surgical procedures. For a 6-mm pupil, the changes in fourth-order aberrations after FLEx were statistically significantly less than those after wfg-LASIK (p<0.001). On the other hand, there were no statistically significant differences in the changes in third-order aberrations (p=0.24) and total HOAs (p=0.13). Similar results were obtained for a 4-mm pupil. The positive changes in the Q value after FLEx were statistically significantly less than those after wfg-LASIK (p=0.001). Conclusions In myopic eyes, FLEx induces significantly fewer ocular fourth-order aberrations than wfg-LASIK, possibly because it causes less oblation in the corneal shape, but there was no statistically significant difference in visual acuity or in the induction of third-order aberrations and total HOAs. It is suggested that FLEx is essentially equivalent to wfg-LASIK in terms of visual acuity and total HOA induction, although the characteristics of HOA induction are different.

Effect of axis orientation on visual performance in astigmatic eyes

PURPOSE: To determine the effect of axis orientation on visual performance in astigmatic eyes. SETTING: Department of Ophthalmology, Kitasato University, Kanagawa, Japan. DESIGN: Investigational simulation. METHODS: Healthy volunteers with no ophthalmic disease other than refractive errors were enrolled. After cycloplegic refraction was fully corrected with a 3.0 mm artificial pupil, with‐the‐rule (WTR), against‐the‐rule (ATR), and oblique (OBL) astigmatism of 1.0 diopter (D), 2.0 D, and 3.0 D were produced using trial lenses in each subject. Distance visual acuity and reading performance with uncorrected astigmatism imposed by the trial lenses under cycloplegia were assessed. Reading performance was determined from reading acuity and maximum reading speed using the Japanese version of the Minnesota Low Vision Reading Test acuity charts. RESULTS: Distance visual acuity and reading performance in the 38 volunteers decreased significantly with increasing astigmatism (P<.001, analysis of variance). Distance visual acuity, reading acuity, and maximum reading speed with uncorrected astigmatism were significantly affected by axis orientation at each diopter of astigmatism (P<.05, 1.0 D and 2.0 D; P<.001, 3.0 D). All parameters showed significantly better values in eyes with WTR or ATR astigmatism than in eyes with OBL astigmatism at each diopter (P<.05); there were no significant differences between eyes with WTR astigmatism and eyes with ATR astigmatism. CONCLUSIONS: Eyes with OBL astigmatism had significantly lower visual performance than eyes with WTR or ATR astigmatism. Correcting the preexisting astigmatism to acquire excellent visual outcomes may be necessary, especially in eyes with OBL astigmatism. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Comparison of corneal power, corneal astigmatism, and axis location in normal eyes obtained from an autokeratometer and a corneal topographer.

PURPOSE: To assess the repeatability and agreement of corneal power, corneal astigmatism, axis location, and astigmatic vector component measurements using an autokeratometer and a corneal topographer in healthy subjects. SETTING: Department of Ophthalmology, Kitasato University, Kanagawa, Japan. DESIGN: Evaluation of diagnostic test or technology. METHODS: Keratometric readings were obtained with an ARK‐700A autokeratometer and an Atlas corneal topographer. Measurement repeatability and agreement in corneal power (flattest and steepest meridians), mean corneal power, corneal astigmatism, axis location, and astigmatic vector components (Jackson cross‐cylinders J0, J45) between the devices were evaluated. RESULTS: The repeatability of both devices in the flattest and steepest meridians, mean corneal power, corneal astigmatism, axis location, J0, and J45 was high. The 95% limits of agreement between the 2 devices were from −0.51 to 0.48 diopters (D) for the flattest meridian, from −0.74 to 0.71 D for the steepest meridian, from −0.56 to 0.53 D for the mean corneal power, from −0.58 to 0.58 D for corneal astigmatism, from −15.3 to 17.5 degrees for axis location, from −0.32 to 0.30 D for J0, and from −0.22 to 0.20 D for J45. In eyes with a small amount of astigmatism, there was wider disagreement in axis location between the 2 devices. CONCLUSIONS: Both devices provided excellent repeatability and comparability of corneal powers and corneal astigmatism, suggesting they can be used interchangeably for measurement of these corneal variables in healthy eyes. However, disagreement in axis location between the 2 devices was not negligible in some eyes, especially in those with low astigmatism. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Intraindividual comparison of changes in corneal biomechanical parameters after femtosecond lenticule extraction and small-incision lenticule extraction

Purpose To compare the biomechanical changes after femtosecond lenticule extraction and small‐incision lenticule extraction for myopia. Setting Department of Ophthalmology, Kitasato University, Kanagawa, Japan. Design Comparative case series. Methods In eyes of consecutive patients, femtosecond lenticule extraction was performed in 1 eye and small‐incision lenticule extraction in the other eye (both Visumax laser) by random assignment. Corneal hysteresis (CH) and the corneal resistance factor (CRF) were quantitatively assessed using a dynamic bidirectional applanation device (Ocular Response Analyzer) in relation to the amount of myopic correction preoperatively and 1 week and 1 and 3 months postoperatively. Results This study comprised 48 eyes (24 patients). The decrease in CH and the CRF was statistically significant 1 week after both lenticule extraction procedures; however, the changes subsequently stabilized with no further deterioration (P<.001). There were no statistically significant differences between the biomechanical changes in the 2 procedures at any time; however, a significant correlation was found between the changes and the myopic correction 3 months after femtosecond lenticule extraction (r = 0.41, P=.046, CH; r = 0.41, P=.045, CRF) and after small‐incision lenticule extraction (r = 0.62, P=.001, CH; r = 0.67, P<.001, CRF). Conclusions The greatest changes in biomechanical parameters occurred within 1 week after femtosecond lenticule extraction and small‐incision lenticule extraction; the changes were then nearly stable in relation to the amount of myopic correction. This suggests that the presence or absence of flap lifting does not significantly affect biomechanical parameters. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Comparison of Optical Quality and Intraocular Scattering after Posterior Chamber Phakic Intraocular Lens with and without a Central Hole (Hole ICL and Conventional ICL) Implantation Using the Double-Pass Instrument

Purpose To objectively compare the optical quality and the intraocular scattering after implantation of the posterior chamber phakic implantable collamer lens (Visian ICL™, STAAR Surgical) with and without a central artificial hole for moderate to high ametropia. Methods This retrospective study comprised 28 eyes of 28 consecutive patients undergoing Hole ICL implantation (mean age ± standard deviation, 30.3±5.8 years), and 24 age-matched eyes of 24 patients undergoing conventional ICL implantation (age, 30.4±6.1 years). We quantitatively assessed the postoperative values of MTF cutoff frequency, Strehl ratio, objective scattering index (OSI), and OQAS values (OVs), using an Optical Quality Analysis System™. We compared these postoperative variables between the two groups. Results The mean MTF cutoff frequency, Strehl ratio, OSI, OV100%, OV 20%, and OV9%, were 26.21±8.32 cycles/degree, 0.16±0.04, 1.16±0.57, 0.87±0.28, 0.80±0.35, and 0.80±0.33, respectively, 3 months after Hole ICL implantation. We found no significant differences in the MTF cutoff frequency (Mann Whitney U test, p = 0.59), the Strehl ratio (p = 0.82), the OSI (p = 0.63), or the OVs at contrasts of 100% (p = 0.58), 20% (p = 0.40), and 9% (p = 0.87), between the two groups. Conclusions Both Hole ICL and conventional ICL implantation provides an excellent optical performance including intraocular scattering. Newly developed Hole ICL implantation appears to be essentially equivalent in the optical quality variables to conventional ICL implantation, suggesting that the presence of the central artificial hole does not significantly affect the optical quality and the intraocular scattering after surgery.

Clinical evaluation of optical quality and intraocular scattering after posterior chamber phakic intraocular lens implantation.

PURPOSE We assessed the optical quality and intraocular scattering after posterior chamber phakic intraocular lens implantation. METHODS We examined prospectively 38 eyes of 19 consecutive patients undergoing implantable contact lens (ICL) implantation (mean age ± SD 36.3 ± 5.7 years), and 38 age-matched normal eyes of 19 healthy volunteers (mean age 36.4 ± 4.9 years). We assessed quantitatively the values of modulation transfer function (MTF) cutoff frequency, Strehl ratio, objective scattering index (OSI), and the Optical Quality Analysis System (OQAS) values (OVs). We compared these variables in eyes undergoing ICL implantation to those in healthy eyes. RESULTS The mean MTF cutoff frequency, Strehl ratio, OSI, OV 100%, OV 20%, and OV 9% were 28.69 ± 8.59 cycles/degree, 0.17 ± 0.04, 1.06 ± 0.48, 0.96 ± 0.29, 0.83 ± 0.31, and 0.83 ± 0.32, respectively, 3 months after ICL implantation. We found no significant differences in the MTF cutoff frequency (Mann Whitney U test, P = 0.31), Strehl ratio (P = 0.46), OSI (P = 0.30), or OVs at contrasts of 100% (P = 0.51), 20% (P = 0.46), and 9% (P = 0.36), between the ICL and control groups. CONCLUSIONS The optical quality parameters, such as the MTF cutoff frequency, Strehl ratio, OSI, or OVs in the ICL group, were not significantly different from those in the control group, suggesting that the optical quality and intraocular scattering of eyes undergoing ICL implantation essentially was equivalent to those of healthy eyes.

Three-year follow-up of posterior chamber toric phakic intraocular lens implantation for the correction of high myopic astigmatism in eyes with keratoconus

Aim To assess the clinical outcomes following the use of toric implantable collamer lenses (toric ICL, STAAR Surgical) for the correction of high myopic astigmatism with keratoconus. Methods This retrospective study evaluated 21 eyes of 11 patients with spherical equivalents of −9.70±2.33 D (mean±SD) and astigmatism of −3.21±1.56 D who underwent toric ICL implantation for keratoconus. Preoperatively, and at 1, 3 and 6 months and 1, 2 and 3 years postoperatively, we assessed the safety, efficacy, predictability, stability and adverse events of the surgery. Results The logarithm of the minimum angle of resolution (logMAR) uncorrected distance visual acuity (UDVA) and the logMAR corrected distance visual acuity (CDVA) were −0.06±0.11 and −0.12±0.09, respectively, at 3 years postoperatively. At 3 years, 67% and 86% of the eyes were within ±0.5 and ±1.0 D, respectively, of the targeted correction. Manifest refraction changes of 0.04±0.33 D occurred from 1 month to 3 years postoperatively. No significant change in manifest refraction (analysis of variance, p=0.989) or keratometry (p=0.951), or vision-threatening complications occurred during the observation period. Conclusions Toric ICL implantation is beneficial according to measures of safety, efficacy, predictability and stability for the correction of refractive errors for keratoconus during a 3-year observation period. The disease did not progress even in the late-postoperative period, suggesting the viability of this procedure as a surgical option for the treatment of such eyes.

Effect of pupil size on uncorrected visual acuity in astigmatic eyes

Aim To determine the effects of pupil size on uncorrected visual acuity (UCVA) in astigmatic eyes. Methods The authors examined 20 normal eyes of 20 healthy volunteers (age 26.7±4.9 years (mean±SD); 8 men, 12 women). After fully correcting cycloplegic refraction, the authors created with-the-rule and against-the-rule astigmatism of 1, 2, and 3 dioptres (D) in each eye, and then assessed UCVA using artificial pupils (1 to 5 mm) in these astigmatic eyes. Measurements were performed three times, and the mean value was used for statistical analysis. Results In eyes with with-the-rule astigmatism of 1, 2 and 3 D, logMAR UCVA was 0.04±0.08, 0.09±0.09 and 0.16±0.16 for 1 mm pupils, −0.01±0.09, 0.12±0.15 and 0.33±0.24 for 2 mm pupils, 0.02±0.09, 0.20±0.19 and 0.46±0.30 for 3 mm pupils, 0.02±0.08, 0.24±0.20 and 0.48±0.21 for 4 mm pupils, and 0.08±0.10, 0.33±0.18 and 0.53±0.22 for 5 mm pupils, respectively. The variance of the data was statistically significant (p=0.03 for 1 D, p<0.001 for 2 D, p<0.001 for 3 D, analysis of variance). Similar results were obtained in eyes with against-the-rule astigmatism. Conclusions Both the amount of astigmatism and the pupil size can affect UCVA in astigmatic eyes. It is suggested that not only the amount of astigmatism but also the pupil size should be taken into consideration for acquiring better visual performance in astigmatic eyes.