Tomoaki Nakamura

Social Insurance Chukyo Hospital, Nagoya, Aichi, Japan

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Publications (11)27.76 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: To evaluate the correlation between postoperative rotation of the toric Implantable Collamer Lens phakic intraocular lens (pIOL) and associated factors. Nagoya Eye Clinic, Nagoya, Japan. Case series. The toric pIOL axis was analyzed by calculating the ocular internal cylinder power and axis from the total refractive cylinder and corneal astigmatism using vector analysis (Jaffe and Clayman method). The correlation between the toric pIOL rotation over 6 months postoperatively and the associated factors (ie, age, preoperative manifest refractive sphere, preoperative manifest spherical equivalent, mean keratometric power, axial length, toric pIOL intraoperative fixation angle, postoperative toric pIOL vault [distance between toric pIOL and anterior surface of crystalline lens], toric pIOL spherical power) were evaluated. The mean age of the 34 patients (58 eyes) was 35.7 years ± 6.5 (SD). The mean rotation 6 months postoperatively was 4.82 ± 6.98 degrees (range 0.0 to 47.2 degrees). The intraoperative toric pIOL fixation angle and postoperative toric pIOL rotation were significantly correlated (Spearman rank correlation: P=.0096 and R(2) = 0.1140; multiple logistic regression analysis: P=.009). In the 1 eye with significant rotation (47.2 degrees), the toric pIOL was exchanged for a larger toric pIOL. A small toric pIOL rotation occurred during the 6-month follow-up. One cause of rotation could be the intraoperative fixation angle of the toric pIOL. A toric pIOL with a minimum intraoperative fixation angle should be used to prevent postoperative rotation.
    Journal of Cataract and Refractive Surgery 02/2012; 38(4):568-73. · 2.75 Impact Factor
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    ABSTRACT: To compare the stability and predictability of astigmatism correction between toric phakic intraocular lens (pIOL) implantation and laser in situ keratomileusis (LASIK). Nagoya Eye Clinic, Nagoya, Japan. Comparative case series. Consecutive patients who had Implantable Collamer Lens pIOL implantation or LASIK were divided into 3 subgroups according to the amount of refractive cylinder correction (low, 0.00 to 1.25 diopters [D]; moderate, 1.50 to 2.75 D; high, ≥ 3.00 D). Manifest refraction was measured preoperatively and 1, 3, 6, and 12 months postoperatively. Based on these data, the predictability and stability of the refractive cylinder correction, error of the refractive cylinder correction, and error of the refractive cylinder correction axis were evaluated. The study comprised 338 eyes (196 patients) in the toric pIOL group and 351 eyes (202 patients) in the LASIK group. In the moderate cylinder subgroup, more eyes were corrected within ± 0.50 D of the postoperative refractive cylinder in the LASIK group (132 eyes [91%]) than in the toric pIOL group (111 eyes [79%]). In the high refractive cylinder subgroup, the error of the refractive cylinder correction in the LASIK group was significantly higher than in the toric pIOL group (P=.032). The postoperative manifest refractive cylinder did not change in either group during the follow-up period. The stability of the refractive cylinder after toric pIOL implantation was as high as after LASIK. Although predictability in the LASIK group was higher than in the toric pIOL group in eyes with moderate refractive cylinder, the toric pIOL group had higher predictability than the LASIK group in eyes with high refractive cylinder.
    Journal of Cataract and Refractive Surgery 02/2012; 38(4):574-81. · 2.75 Impact Factor
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    ABSTRACT: To develop and evaluate a new implantable collamer lens (ICL) sizing method that uses high-frequency ultrasound biomicroscopy (UBM). Interventional case series. ICL were implanted in 47 eyes of 25 patients (8 male, 17 female, mean age 34.7±6.8 years). At 3 months after ICL surgery, the vault (distance between ICL and crystalline lens) was measured using anterior optical coherence tomography (OCT). Stepwise multiple regression analysis was performed in order to determine the optimal ICL size that will be expected to achieve a 0.5-mm vault, and the regression equation was calculated. Mean keratometric power, axial length, anterior chamber depth, sulcus-to-sulcus (STS) diameter, and distance between STS plane and crystalline lens were applied as candidates for explanatory variables. Subsequently, the equation was applied to a new group of patients (81 eyes of 43 patients, 20 male and 23 female, mean age 35.6±7.2 years) in order to decide the ICL size. Postoperative vault was evaluated at 3 months after surgery. Main outcome measures were mean postoperative vault and percentages of eyes that achieved moderate vault. The regression equation was determined using 3 explanatory variables: anterior chamber depth (ACD), STS diameter, and distance between STS plane and anterior crystalline lens surface (STSL). The mean vault error (postoperative vault-predicted vault) was -0.06±0.29 mm. Of the total number of eyes, 88.9% had a vault between 0.15 and 1.0 mm. None of the eyes had a low vault (<0.15 mm). Nine eyes (11.1%) had a high vault (>1.0 mm). A novel ICL sizing equation was developed and shown to be an effective method for calculation of the optimal ICL size in order to achieve an appropriate vault.
    American journal of ophthalmology 01/2012; 153(4):632-7, 637.e1. · 3.83 Impact Factor
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    ABSTRACT: To evaluate the effect of preoperative punctal plug treatment on early postoperative visual function and wound healing after laser epithelial keratomileusis (LASEK). Punctal plugs were implanted in 188 eyes from 95 patients (plug group; 41 men, 54 women; mean age 30.8 ± 6.6 years) before undergoing LASEK. Punctal plugs were inserted into both the superior and inferior puncta. Wound healing, visual acuity, and haze score after surgery were compared in 175 eyes of 88 age- and sex-matched control patients without punctal plug treatment (non-plug group; 43 men, 45 women; mean age 30.3 ± 8.0 years). One week after LASEK, the mean fluorescein score in the plug group was significantly lower than the non-plug group (P<.0001). One week after surgery, uncorrected distance visual acuity (UDVA) of 20/20 or better was achieved in 82% and 53% of plug and non-plug patients, respectively. Compared with the non-plug group, better mean UDVA was seen in the plug group 7 days after surgery (non-plug group, 0.02 ± 0.17; plug group, -0.06 ± 0.13; P<.0001). Incidence of haze after LASEK was higher in the non-plug group (7.4%) compared with the plug group (1.6%) (P=.014). Preoperative punctal plug treatment prior to LASEK promoted corneal epithelial wound healing and was associated with better visual acuity in the early postoperative period.
    Journal of refractive surgery (Thorofare, N.J.: 1995) 08/2011; 27(12):894-8. · 2.47 Impact Factor
  • Source
    Takashi Kojima, Tomoaki Nakamura, Kazuo Ichikawa
    Albrecht von Graæes Archiv für Ophthalmologie 07/2011; 250(10):1555. · 1.93 Impact Factor
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    ABSTRACT: To evaluate the interexaminer and intraexaminer variance in ciliary sulcus-to-sulcus (STS) diameter measurements using wide-scanning-field ultrasound biomicroscopy (UBM) (Vumax II). Nagoya Eye Clinic, Nagoya, Japan. Evaluation of diagnostic test or technology. Two examiners measured the STS diameter 10 times in each subject. Intraexaminer and interexaminer variances were calculated. To determine interexaminer variance at each UBM measurement step, the examiner was changed every 2 steps when the STS diameter was measured. The Bland-Altman plot test was used to analyze each step of measurement variance. Thirty eyes of 15 volunteers (9 men, 6 women; mean age 29.6 years ± 6.2 [SD]) were enrolled. The mean coefficient of variation was 0.62% ± 0.20% for intraexaminer measurements and 3.4% ± 2.4% for interexaminer measurements. There were statistically significant differences between the 2 examiners in the step of extracting images and determining and measuring the STS diameter (P=.02). The 95% confidence intervals in all steps were relatively high (recordings, -1.02 to 1.08 mm; extracting images and determining and measuring STS; -0.79 to 1.25 mm). Interexaminer variance in STS measurement should be considered if the STS diameter is used for selecting the size of posterior chamber phakic intraocular lenses.
    Journal of Cataract and Refractive Surgery 07/2011; 37(7):1251-6. · 2.75 Impact Factor
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    ABSTRACT: To evaluate night vision disturbance and investigate correlations between pre- and post-treatment parameters and glare scores in orthokeratology patients. Twenty-eight right eyes of 28 patients were enrolled in this study. Corneal topography and a night vision test (NVT) to evaluate the extent of glare were performed after orthokeratology. From the corneal topography, two indices [surface regularity index (SRI) and surface asymmetry index (SAI)] were calculated. Fourier analysis was performed on the topographic data from the central 6 mm, and data were decomposed into asymmetric and higher order components for analysis. There was no correlation between the glare score and pre-treatment keratometric value, pre-treatment cylinder, post-treatment sphere, and post-treatment cylinder. However, there was a statistically significant correlation between pre-treatment sphere and glare score (Pearson correlation coefficient, r = -0.54, p < 0.01). SRI and SAI significantly correlated with glare score (SRI: r = 0.52, p < 0.01, SAI: r = 0.41, p < 0.05). Higher order and asymmetric components were also significantly correlated with glare score (asymmetry: r = 0.61, p < 0.01, higher order: r = 0.67, p < 0.001). The glare score was significantly correlated with corneal irregularity, and appeared to be a beneficial parameter for assessment of night vision performance in patients receiving orthokeratology.
    Albrecht von Graæes Archiv für Ophthalmologie 05/2011; 249(10):1519-26. · 1.93 Impact Factor
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    ABSTRACT: To assess the early clinical outcomes of toric implantable collamer lenses (toric ICL™, STAAR Surgical) for the correction of high myopic astigmatism with keratoconus. This study evaluated 27 eyes of 14 patients with spherical equivalents of -10.11 ± 2.46 D (mean ± standard deviation) and astigmatism of -3.03 ± 1.58 D who underwent toric ICL implantation for mild keratoconus. Before, and 1, 3 and 6 months after surgery, we assessed the safety, efficacy, predictability, stability, and adverse events of the surgery. LogMAR uncorrected visual acuity (UCVA) and LogMAR best spectacle-corrected visual acuity (BSCVA) were -0.09 ± 0.16 and -0.15 ± 0.09 respectively, 6 months after surgery. The safety and efficacy indices were 1.12 ± 0.18 and 1.01 ± 0.25. At 6 months, 85% and 96% of the eyes were within ±0.5 and ±1.0 D respectively of the targeted correction. Manifest refraction changes of 0.00 ± 0.35 D occurred from 1 week to 6 months. No vision-threatening complications occurred during the observation period. Toric ICL implantation was good in all measures of safety, efficacy, predictability, and stability for the correction of spherical and cylindrical errors in eyes with early keratoconus throughout the 6-month follow-up period, suggesting its viability as a surgical option for the treatment of such eyes.
    Albrecht von Graæes Archiv für Ophthalmologie 10/2010; 249(7):1073-80. · 1.93 Impact Factor
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    ABSTRACT: To evaluate the feasibility of piggyback insertion with a toric Implantable Collamer Lens (ICL, STAAR Surgical). This study investigated eight pseudophakic eyes of five patients who underwent piggyback insertion of a toric ICL to correct residual refractive error. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and manifest refractive sphere and astigmatism were measured before and 6 months after surgery. Pre- and 6-month postoperative logMAR UDVA were 0.759±0.430 and 0.201±0.458, respectively. All eyes were corrected within ±0.50 diopters (D) of intended spherical equivalent refraction. The manifest refractive astigmatism was within ±0.50 D in five (62.5%) eyes and ±1.00 D in seven (87.5%) eyes. No eyes lost more than one line of CDVA. Pupillary block occurred in one eye on postoperative day 1. Piggyback insertion of a toric ICL appears to be effective and predictable in correcting refractive error in pseudophakic eyes.
    Journal of refractive surgery (Thorofare, N.J.: 1995) 10/2010; 26(10):766-9. · 2.47 Impact Factor
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    ABSTRACT: To evaluate the changes in vault over time after Implantable Collamer Lens (ICL; STAAR Surgical) posterior chamber phakic intraocular lens implantation. A total of 36 eyes of 19 patients who underwent ICL implantation were enrolled in the study. Vault (the distance between the back surface of the ICL and the front surface of the crystalline lens) was measured postoperatively using anterior optical coherence tomography. Patients were divided into three groups based on vault (low < or =0.25 mm, moderate >0.25 to <0.75 mm, or high > or =0.75 mm). Mean vault at 1 year postoperative was 0.53+/-0.25 mm. The percentages of eyes in the low, moderate, and high vault groups were 13.9%, 72.2%, and 13.9%, respectively. A significant decrease in vault was noted up to 1 month, after which the value stabilized (P<.0001). High vault showed a gradual decrease up to 3 months (P<.0001), after which the value stabilized. A statistically significant correlation was present between the change noted for vault values during the 1-year follow-up period and those measured for the initial vault on postoperative day 1 (P<.0001, r(2)=0.6393). Although values for low and moderate vault exhibited little change after ICL implantation, high vault tended to decrease over time and became stable at 3 months after surgery.
    Journal of refractive surgery (Thorofare, N.J.: 1995) 05/2010; 26(5):327-32. · 2.47 Impact Factor
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    ABSTRACT: To determine whether topography-guided custom ablation produces acceptable outcomes in the treatment of irregular corneal astigmatism caused by previous corneal surgery or corneal disease. Thirteen eyes of nine patients who had irregular corneal astigmatism from previous corneal surgery or corneal disease were treated with customized aspheric treatment zone (CATz) ablations using the NIDEK Advanced Vision Excimer Laser System (NAVEX). Changes in corneal surface regularity index, surface asymmetry index, asymmetry component, corneal and ocular higher order aberrations, uncorrected visual acuity, and best spectacle-corrected visual acuity (BSCVA) were analyzed using Wilcoxon and paired t tests. A P value < .05 was considered statistically significant. After CATz treatment, 62% of eyes (8 of 13) showed an increase in BSCVA. Improvements in both the surface asymmetry index and asymmetry components were statistically significant after CATz treatment (P < .05). Topography-guided custom ablation can be safe and effective in the management of irregular corneal astigmatism due to previous corneal surgery or corneal disease.
    Journal of refractive surgery (Thorofare, N.J.: 1995) 01/2008; 24(1):24-32. · 2.47 Impact Factor

Publication Stats

30 Citations
27.76 Total Impact Points

Institutions

  • 2010–2012
    • Social Insurance Chukyo Hospital
      Nagoya, Aichi, Japan
    • Kitasato University
      • Department of Ophthalmology
      Edo, Tōkyō, Japan
  • 2011
    • Keio University
      • Department of Ophthalmology
      Tokyo, Tokyo-to, Japan