Biomedical subjects

Naoyuki Maeda

Publications and source records attributed to Naoyuki Maeda.

At least 37 records · Page 2Linked to original sources

PubMed2004

A spectrum of clinical manifestations of gelatinous drop-like corneal dystrophy in japan.

PURPOSE: Typical manifestations of gelatinous drop-like corneal dystrophy (GDLD) have been documented in past studies. In practice, however, we see few typical cases and encounter many with atypical clinical manifestations. Moreover, there have been no detailed reports about the various clinical presentations. The purpose of this study is to describe a clinical subclassification for GDLD. DESIGN: Observational case series. METHODS: A retrospective, observational case series study was conducted at a single institution, Osaka University Hospital. Examined were 18 eyes of ten patients with GDLD with no prior surgery. All were found to have M1S1 mutations. Using slit-lamp examinations we performed a phenotypic classification. RESULTS: We classified GDLD patients into four groups. They included band keratopathy type (seven eyes of four patients), stromal opacity type (five eyes of three patients), kumquat-like type (four eyes of two patients), and typical mulberry type (two eyes of two patients). CONCLUSIONS: Gelatinous drop-like corneal dystrophy is thought to be the result of mutations in M1S1; however, it has various clinical manifestations. To our knowledge, this study is the first to report the range of clinical phenotypes of GDLD in a Japanese population. As most clinicians have no criteria for diagnosing GDLD, many cases are likely to be overlooked or be mistaken for other conditions. We believe that our present classification will be useful for the diagnosis of GDLD.

Adolescent↗

PubMed2004

Age-related changes in ocular and corneal aberrations.

PURPOSE: To compare the ocular and corneal higher-order aberrations (HA) in eyes of different ages. DESIGN: Observational cross-sectional study. METHODS: Sixty-six eyes of 66 normal subjects (age range 4-69 years; average 37.4 +/- 15.4 years) were examined. Wavefront aberrations of the whole eye (ocular) and cornea were measured for the central 4 mm using a Hartmann-Shack aberrometer. RESULTS: Ocular Coma-like aberration (r = 0.270, P =.029), Spherical-like aberration (r = 0.531, P =.001), and total HA(r = 0.431, P =.001) were significantly correlated with age, whereas the corneal aberrations were not significantly correlated. The ocular total HA aberrations increased significantly after age 50 years. CONCLUSIONS: After 50 years of age, ocular aberrations increased abruptly due to the increase of lenticular HA. Customized ablation should be carefully considered, especially in eyes of presbyopic age.

Adolescent↗

PubMed2004

Light scattering and optical aberrations as objective parameters to predict visual deterioration in eyes with cataracts.

PURPOSE: To predict the visual deterioration of eyes with cortical (CC) or nuclear (NC) cataract from objective data on ocular higher-order aberration (HOA) and forward (FLS) and backward light scattering (BLS). SETTING: Osaka University Medical School, Osaka, Japan. METHODS: Twenty-two eyes with mild NC, 41 eyes with mild CC, and 11 normal eyes were examined. Higher-order aberrations were calculated with the Zernike polynomials up to the fourth order from the values obtained by wavefront analysis using the Hartmann-Shack aberrometer. Forward light scattering was calculated from the size of the aberrometer spot images for the central 4 mm, and backward light scattering (BLS) was calculated from the optical density of the Scheimpflug images. The relationship between the area under the log contrast sensitivity function (AULCSF) curve and HOAs, FLS, and BLS was examined. RESULTS: Area under the log contrast sensitivity function was moderately correlated with the HOAs, FLS, and BLS. Multiple linear regression analysis revealed that the AULCSF was predicted by the linear combination of these variables (R(2)=.484, P<.001). Area under the log contrast sensitivity was predicted by BLS and HOA (R(2)=.555) in the NC group and by FLS and HOAs (R(2)=.540) in the CC group. CONCLUSIONS: Loss of contrast sensitivity was predominantly due to BLS and HOA in eyes with NC and FLS and HOA in eyes with CC. Higher-order aberrations, FLS, and BLS, variables that are obtained objectively, can be used to predict quantitatively the visual deterioration in cataractous eyes.

Adult↗

PubMed2004

Wavefront analysis of an eye with monocular triplopia and nuclear cataract.

PURPOSE: To determine whether higher-order aberrations explain patient-reported monocular triplopia. DESIGN: Observational case report. METHOD: A patient complaining of monocular triplopia was examined with a Hartmann-Shack aberrometer to determine whether higher-order wavefront aberrations could account for the triplopia. The patient had a mild nuclear cataract; measurements were made before and after lensectomy. The retinal image was simulated using the Zernike polynomials. RESULT: Spherical aberration (-0.18 microm, 4 mm pupil) and trefoil aberration (-0.16 microm) were increased. The simulated retinal image had a triple configuration similar to the subjective image reported by the patient. After cataract surgery, the subjective triplopia disappeared; spherical, and trefoil aberrations were markedly decreased. CONCLUSION: The monocular triplopia probably stemmed from combined effects of spherical and trefoil aberrations caused by the nuclear cataract.

Adult↗

PubMed2003

Sclerotic scattering illumination during phototherapeutic keratectomy for better visualization of corneal opacities.

PURPOSE: To report on a simple method to obtain a better view of corneal opacities during excimer laser phototherapeutic keratectomy (PTK). DESIGN: An interventional case report. METHODS: Phototherapeutic keratectomy was performed under sclerotic scattering illumination with a vitrectomy-endoilluminator at the limbus. RESULTS: During conventional PTK with diffuse illumination, the intraoperative observations of corneal opacities are not as good as that with a slit lamp. Conversely, subtle corneal opacities can be easily seen with sclerotic scattering illumination even under a surgical microscope. CONCLUSIONS: The use of sclerotic scattering illumination during PTK is valuable, because it provides a better view of opacified tissues and avoids excessive ablation.

Corneal Opacity↗

PubMed2003

Diagnosing dry eye using a blue-free barrier filter.

PURPOSE: To investigate the benefit of the blue-free barrier filter (BF filter) in diagnosing dry eye. DESIGN: Nonrandomized clinical comparison. METHODS: Fifty-three eyes with Sjögren syndrome (n = 42) or keratoconjunctivitis sicca (n = 11) were enrolled. Fluorescein staining was performed in temporal and nasal conjunctiva, and staining was scored with (BF score) and without the filter (FL score) from 0 to 3. Rose bengal staining was also scored (RB score) similarly. RESULTS: With FL scores of 0, 1, or 2, the BF score was significantly higher: 0.85 +/- 0.37 (P =.031), 1.74 +/- 0.65 (P =.001), and 2.65 +/- 0.48 (P =.001), respectively; with a FL score of 3, the BF score was 3 at all sites. The BF score was superior to the FL score in 66.6% of cases when the FL score was 0 and 1 and in 65.2% when the FL score was 2, but not when the FL score was 3. When the RB score was 0, 1, or 2, the BF score was higher: 1.88 +/- 0.92, 1.78 +/- 0.79, and 2.57 +/- 0.50, respectively (P =.001 for all); when the RB score was 3, the BF score was 2.97 +/- 0.16. The BF score was superior to the RB score in 75.5% of cases when the RB score was 0 and 1 and in 57.8% when the FL score was 2, but not in cases with a RB score of 3. CONCLUSIONS: The BF filter detects damaged conjunctival epithelium stained with fluorescein. Using the filter was beneficial in mild-to-moderate cases, not in severe cases. The BF filter allows diagnosis of dry eye even at the initial stage that is undetectable by conventional observation.

Adult↗

PubMed2003

Wavefront analysis in eyes with accommodative spasm.

PURPOSE: To investigate changes of spherical aberration in eyes with accommodative spasm. DESIGN: Case reports. METHODS: Four eyes of two patients with accommodative spasm were studied. Ocular spherical aberration was measured with a Hartmann-Shack wavefront aberrometer for the central 4-mm zone. RESULTS: The root mean square values of spherical aberration were negative (-0.086 +/- 0.026 microm root mean square). However, when the spasm of accommodation was cured or treated with a cycloplegic agent, the value shifted toward positivity (0.025 +/- 0.004 microm root mean square). CONCLUSIONS: Excessive accommodative tone is manifested objectively by negative spherical aberration in eyes with accommodative spasm.

Accommodation, Ocular↗

PubMed2003

Electron microscopy of the epithelial flap created by ethanol treatment in the rabbit corneal epithelium.

PURPOSE: To assess the effect of corneal debridement with 25% ethanol on rabbit corneal epithelium by electron microscopy. SETTING: Department of Ophthalmology, Osaka University School of Medicine, Osaka, Japan. METHODS: Rabbit corneas were deepithelialized by applying 25% ethanol for 3 minutes, and a hinged epithelial flap was created and repositioned. Ten corneas were evaluated immediately after the epithelial debridement procedure and at 1, 3, and 7 days. Histological changes were evaluated using scanning and transmission electron microscopy. RESULTS: Corneas treated with ethanol showed a decrease in microvilli, breaks in intercellular junctions, epithelial cell edema, and damage in basement membrane hemidesmosomes. These toxic changes recovered to an almost normal appearance after 24 hours and rapidly improved over the following week. An increase in desquamated cells was observed after debridement; this returned to normal after 1 week according to the normal cellular cycle. Wing cells showed no damage at any stage. CONCLUSIONS: Although ethanol appeared to have a toxic effect on rabbit epithelial cells, the effect did not persist over time. The first signs of recovery were observed 24 hours after debridement, and full recovery was observed over the following week. The ethanol path to the central basement membrane appeared to be centripetally from a round cut through the basement membrane, leaving the wing cells intact.

Animals↗

PubMed2003

Fourier analysis of corneal astigmatic changes following photorefractive keratectomy.

The purpose of this study was to evaluate the corneal irregular astigmatism following photorefractive keratectomy (PRK) for myopia. The corneal topography of 30 eyes of 26 patients was measured with the TMS-1 videokeratoscope before and 1 month after PRK. Axial dioptric data were decomposed into four components; A0 (Sphericity), C1 x 2 (Asymmetry), C2 x 2 (Regular astigmatism), and C3 (higher-order irregularity) for the central 3 and 6 mm zone by Fourier series harmonic analysis. Post-operative topographies were divided into those with an irregular and those with a homogeneous pattern, and the Fourier components were compared. In the 6 mm zone, A0 was significantly decreased (P < 0.001), and C1 x 2, C2 x 2, and C3 were significantly increased (P = 0.001, 0.005, 0.002, respectively). In the 3 mm zone, A0 decreased (P < 0.001) and C1 x 2 increased (P < 0.001) significantly. C1 x 2 was correlated with the post-operative corrected visual acuity (P < 0.001, r = 0.647). The irregular pattern group had a larger C1 x 2 component (P < 0.001). The treatment displacement was not correlated with any component. In conclusion, irregular topography due to intraoperative drift or asymmetrical wound healing may play a more important role in the post-operative corneal optical property than mild treatment displacement.

Adult↗

PubMed2003

Comparison of ocular higher-order aberrations and visual performance between photorefractive keratectomy and laser in situ keratomileusis for myopia.

The purpose was to compare the ocular higher-order aberrations and the visual performance between photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK). Ocular aberrations and visual performance were measured after PRK in 26 eyes, after LASIK in 39 eyes, and in 29 normal myopic control eyes. Ocular aberrations were measured with a Hartmann-Shack aberrometer. Visual performance was evaluated with grating contrast sensitivity, high and low contrast visual acuity, and letter contrast sensitivity under full correction with spectacles. The results were that the root mean square (RMS) values of ocular higher-order aberrations after PRK or LASIK were significantly greater than that of normal controls for both 4-mm and 6-mm zones (PRK; 0.22 +/- 0.09 and 0.85 +/- 0.24 microm, LASIK; 0.20 +/- 0.06 and 0.82 +/- 0.24 microm, normal; 0.10 +/- 0.03 and 0.33 +/- 0.11 microm. P < 0.05 between PRK and normal, LASIK and normal, One Way ANOVA on Ranks). There were no significant differences between PRK and LASIK. The ocular higher-order aberrations increased in proportion with the attempted refractive correction by PRK and LASIK. The ocular higher-order aberrations correlated better with grating contrast sensitivity, low contrast visual acuity, and letter contrast sensitivity than with high contrast visual acuity. There was no difference among normal, PRK and LASIK in all the visual function tests, except between normal and PRK, or between normal and LASIK with letter contrast sensitivity. In conclusion, there was no difference in both ocular higher-order aberrations and visual performance between PRK and LASIK. The result suggests that surgeons can choose refractive procedures according to the corneal conditions or daily activities of patients.

Adult↗

PubMed2003

Efficacy of CS-758, a novel triazole, against experimental fluconazole-resistant oropharyngeal candidiasis in mice.

The therapeutic efficacy of CS-758, a novel triazole, was evaluated against experimental murine oropharyngeal candidiasis induced by Candida albicans with various susceptibilities to fluconazole. Against infections induced by strains with various susceptibilities to fluconazole, the efficacy of fluconazole was strongly correlated with the MIC of fluconazole, as measured by the NCCLS method, and agreed with the NCCLS interpretive breakpoints, suggesting that the efficacies of new drugs could be predicted by using this model. The results of the fungal burden study corresponded with the results of the histopathological study. CS-758 exhibited potent in vitro activity (MICs, 0.004 to 0.06 micro g/ml) against the strains used in this murine model including fluconazole-susceptible dose-dependent and fluconazole-resistant strains (fluconazole MICs, 16 to 64 micro g/ml). CS-758 exhibited excellent efficacy against the infections induced by all the strains including a fluconazole-resistant strain, and the reductions in viable cell counts were significant at 10 and 50 mg/kg of body weight/dose. Fluconazole was not effective even at 50 mg/kg/dose against infections induced by a fluconazole-resistant strain (fluconazole MIC, 64 micro g/ml). These results suggest that CS-758 is a promising compound for the treatment of oropharyngeal candidiasis including fluconazole-refractory infections.

Animals↗

PubMed2002

Wavefront analysis in eyes with nuclear or cortical cataract.

PURPOSE: To compare the higher-order aberrations of the oculus (whole eye) and cornea in eyes with mild cortical or nuclear cataract and to estimate the effect of ocular higher-order aberrations on the loss of contrast sensitivity using wavefront analysis. DESIGN: Observational case series. METHODS: Six eyes of four patients with mild nuclear cataract, 18 eyes of 14 patients with mild cortical cataract, and nine eyes of nine normal patients were examined. Wavefront aberrations of the oculus and cornea for central 6 mm diameter were measured using the Hartmann-Shack (HS) aberrometer. Higher-order aberrations were calculated with Zernike polynomials up to sixth order. The relationship between average lens density (ALD) measured by the Scheimpflug camera and the ocular total higher-order aberration (OTHA) was investigated. The relationship between contrast sensitivity (CS) and the OTHA or ALD was also examined. RESULTS: The OTHA was significantly larger in cataracts compared with normal subjects, while corneal total higher-order aberration did not differ between cataracts and normal subjects. The polarity of spherical aberration was negative in all eyes with nuclear cataract while positive in all eyes with cortical cataract. The correlation between ALD and OTHA was not significant in eyes with cataracts. The CS highly correlated with OTHA while it moderately correlated with ALD. CONCLUSIONS: The HS aberrometer is useful to objectively evaluate the deterioration of images in eyes with mild cataract and it revealed that the polarity of spherical aberration was different between nuclear and cortical cataract. It was also suggested that in mild nuclear or cortical cataract, not only light scattering, but also optical aberration of the lens contributes to the loss of contrast sensitivity.

Adult↗

PubMed2002

Effect of tear film break-up on higher-order aberrations measured with wavefront sensor.

PURPOSE: To investigate whether optical wavefront aberrations vary with tear film break-up. DESIGN: Observational case series. METHODS: Higher-order aberrations were examined for 20 eyes of 20 normal subjects with a Hartmann-Shack wavefront sensor before and after tear film break-up. RESULTS: Higher-order aberrations for photopic vision (central 4 mm diameter) after tear film break-up increased 1.44 fold compared to higher-order aberrations before tear film break-up (P =.001, paired t-test). Higher-order aberrations after tear film break-up for scotopic vision (central 6 mm diameter) were also 1.23 times higher than those before break-up (P =.005, paired t-test). CONCLUSION: Wavefront sensing enabled us to evaluate the induced irregular astigmatism caused by tear film break-up quantitatively. Wavefront aberrations should be measured carefully to avoid the effects of tear film break-up, especially in wavefront-guided refractive surgery.

Adult↗

PubMed2002

Changes of ocular aberration with accommodation.

PURPOSE: To study the effect of accommodation on ocular aberrations. DESIGN: Observational case series. METHODS: The ocular aberrations in 33 eyes of 33 young adults were measured with a Hartmann-Shack wavefront aberrometer before and during 3 diopters of accommodation. RESULTS: The root mean square values of wavefront error did not change for a 4-mm and a 6-mm zone; however, spherical aberration changed significantly toward negativity for both the 4-mm zone (P <.001) and 6-mm zone (P =.022). CONCLUSIONS: During accommodation, the significant change in spherical aberration occurs without a change of image quality. Therefore, for customized aberration, it may not be advantageous to eliminate the physiologic spherical aberration for far vision.

Accommodation, Ocular↗

PubMed2002

Higher order wavefront aberrations of cornea and magnitude of refractive correction in laser in situ keratomileusis.

OBJECTIVE: To assess the relation between magnitude of refractive correction and changes in higher order wavefront aberrations of the cornea after laser in situ keratomileusis. DESIGN: Prospective, consecutive, nonrandomized comparative trial (self-controlled). PARTICIPANTS: One hundred eyes of 53 patients with myopia (-2.0 to -13.0 diopters) were included. INTERVENTION: Laser in situ keratomileusis was performed. Videokeratography measurements were conducted before and 1 month after surgery. MAIN OUTCOME MEASURES: The videokeratography data were used to calculate the higher order wavefront aberrations of the cornea for both small (3 mm) and large (6 mm) pupils. RESULTS: For a 3-mm pupil, the surgery significantly increased coma-like (2.4 +/- 1.3-fold, P < 0.001, paired t test) and spherical-like (1.8 +/- 0.9-fold, P < 0.001) aberrations. For a 6-mm pupil, both coma-like (4.4 +/- 3.3-fold, P < 0.001) and spherical-like (9.4 +/- 5.2-fold, P < 0.001) aberrations were significantly increased by surgery. The amount of achieved correction showed significant correlations with the changes in coma-like (Pearson correlation coefficient r = 0.446, P < 0.001) and spherical-like (r = 0.348, P < 0.001) aberrations for a 3-mm pupil, and coma-like (r = 0.566, P < 0.001) and spherical-like (r = 0.693, P < 0.001) aberrations for a 6-mm pupil. The eyes that lost 2 or more lines of baseline spectacle-corrected visual acuity showed significantly larger induced increases in coma-like (P = 0.003, Mann-Whitney U test) and spherical-like (P = 0.009) aberrations for a 3-mm pupil than those that either improved or remained within 1 line of spectacle-corrected visual acuity CONCLUSIONS: Laser in situ keratomileusis, performed using the current algorithms, increases higher order wavefront aberrations of the cornea, dependent on the amount of refractive correction.

Adult↗

PubMed2002

Standardized color-coded scales for anterior and posterior elevation maps of scanning slit corneal topography.

PURPOSE: To find the most appropriate color-coded scales for the anterior and posterior elevation maps of scanning slit topography in the screening of abnormal corneas such as keratoconus. DESIGN: Retrospective case-control study. PARTICIPANTS: Eighty eyes of 40 normal subjects and 175 eyes of 95 patients with keratoconus. INTERVENTION: Anterior and posterior corneal elevations were assessed using Orbscan 2. Best-fit sphere maps were drawn with several color-coded scales: 2-, 5-, 10-, and 20-microm height per each color interval. MAIN OUTCOME MEASURES: The maps were judged to be abnormal when more than three colors (discriminant number) were found within the central 3-mm area. For each color-coded scale, sensitivity, specificity, positive predictive value, negative predictive value, and sensitivity + specificity were calculated. After determining the most appropriate color-coded scales for the anterior and posterior elevation maps, validity of the discriminant number was assessed. By varying the discriminant number from two to eight, receiver operator characteristic (ROC) curves were created using the sensitivity and specificity for each threshold number. RESULTS: The highest sensitivity + specificity values and highly balanced predictive values were obtained with the 10- and 20-microm scales for the anterior and posterior elevation maps, respectively. The ROC curve analyses showed that the best discriminant color number is three, indicating that maps with four or more colors within the central 3-mm area are judged abnormal in screening. CONCLUSIONS: The 10- and 20-microm interval color scales are most appropriate for the anterior and posterior elevation maps of the scanning slit topography, respectively.

Adolescent↗

PubMed2002

Wavefront aberrations measured with Hartmann-Shack sensor in patients with keratoconus.

OBJECTIVE: To compare the ocular wavefront aberrations of normal and keratoconic eyes and to describe the characteristics of the higher-order aberrations in eyes with keratoconus. DESIGN: Prospective case control and observational study. PARTICIPANTS: Thirty-five keratoconic eyes and thirty-eight normal controls. METHODS: Higher-order aberrations in refraction were measured with a wavefront sensor, and those aberrations resulting from the cornea were evaluated by videokeratographic data. MAIN OUTCOME MEASURES: Coma-like (S(3 + 5)), spherical-like (S(4 + 6)), and total (S(3 + 4 + 5 + 6)) higher-order aberrations in both refraction and the cornea. RESULTS: The mean +/- standard deviation of S(3 + 5) (1.88 +/- 1.16), S(4 + 6) (0.70 +/- 0.55), and S(3 + 4 + 5 + 6) (2.03 +/- 1.23) in refraction (6-mm diameter, root mean square, micro m) were significantly higher in the keratoconic eyes than in normal controls (0.26 +/- 0.10, 0.19 +/- 0.10, 0.34 +/- 0.11, respectively; Mann-Whitney U test, P = 0.001). Coma-like aberrations were 2.32 times larger than spherical-like aberrations in keratoconic eyes. CONCLUSIONS: The increase of ocular higher-order aberrations in keratoconic eyes results from an increase of corneal higher-order aberrations. Coma-like aberrations were dominant compared with spherical-like aberrations in keratoconic eyes. Wavefront sensing will enable us not only to evaluate the quality of vision but also to differentiate keratoconic eyes from normal eyes by analyzing the characteristics of the higher-order aberrations.

Adult↗

PubMed2002

Wavefront analysis of higher-order aberrations in patients with cataract.

PURPOSE: To determine local refractive changes and higher-order aberrations in patients with nuclear or cortical cataract. SETTING: Osaka University Medical School, Osaka, Japan. METHODS: Wavefront analysis of both ocular and corneal aberrations was performed with the Hartmann-Shack aberrometer in 2 patients, a 22-year-old woman with bilateral developmental nuclear cataract and a 68-year-old woman with mild bilateral cortical cataract. RESULTS: Case 1 showed a delay in the wavefront that caused a myopic shift in the central pupillary area in both eyes, associated with the nuclear cataract. The spherical-like aberration (right eye, 36%; left eye, 21%) was greater than the coma-like aberration in both eyes. Case 2 showed an advancement of the wavefront that caused a hyperopic shift, especially in the lower temporal pupillary area, that was associated with the cortical cataract. The coma-like aberration (right eye, 63%; left eye, 52%) was greater than the spherical-like aberration in both eyes. The polarity of the third-order spherical aberration was negative in Case 1 and positive in Case 2. Corneal higher-order aberrations were small and had a different distribution than ocular higher-order aberrations in both patients. CONCLUSIONS: The Hartmann-Shack aberrometer was useful in detecting local refractive changes and higher-order aberrations in patients with mild cataract. The polarity and the absolute value of ocular higher-order aberrations may be useful parameters to characterize eyes with cataract.

Adult↗