Shizuka Koh

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.

Serial Measurements of Higher-Order Aberrations after Blinking in Patients with Dry Eye

PURPOSE To study the sequential postblink changes in ocular higher-order aberrations (HOAs) in patients with dry eye. METHODS A wavefront sensor was used to measure HOAs sequentially for 30 seconds in 20 eyes of 20 patients with dry eye. The 20 eyes were classified into two groups, with or without superficial punctate keratopathy (SPK) in the central cornea. During the measurement, subjects were required to blink every 10 seconds. The aberration data were analyzed in the central 4-mm diameter for coma-like, spherical-like, and total HOAs up to sixth-order Zernike polynomials. Total HOAs, as well as fluctuation index (FI) and stability index (SI) of the total HOAs over time were compared between the two groups. The sequential changes in coma-like aberration, spherical-like aberration, and total HOAs were also investigated. RESULTS The total ocular HOAs were significantly (P = 0.001) greater in dry eyes with central SPK than in dry eyes without central SPK. The sequential pattern of the total ocular HOAs had higher initial and consistently higher values in dry eyes with central SPK, whereas that of dry eyes without central SPK showed consistently lower total HOAs that were similar to the pattern of normal eyes. CONCLUSIONS Increased HOAs in dry eye at least partially result from SPK above the optical zone. The low tear volume in dry eye may not cause sequential increases in HOAs after blinking. Sequential measurement of HOAs may be useful for evaluating the sequential changes in optical quality in patients with dry eye.

Effects of suppression of blinking on quality of vision in borderline cases of evaporative dry eye.

Purpose: To study the effects of suppression of blinking on quality of vision in borderline cases of evaporative dry eye. Methods: Ocular higher-order aberrations (HOAs) were measured sequentially for 30 seconds in 10 eyes with a short tear film breakup time (TBUT; 3.0 ± 0.6 seconds) without ocular surface staining or tear deficiency. During measurements, the subjects suppressed blinking to every 10 seconds, which is more than double the TBUT. The aberration data were analyzed for comalike and spherical-like aberrations and total HOAs to the sixth-order Zernike polynomials. Results: Sequential changes in total HOAs in subjects with a short TBUT showed a sawtooth pattern with a marked upward curve that increased after blinking. From 5 to 9 seconds after blinking, the total HOAs were significantly higher than immediately after blinking (P < 0.001). Conclusions: Serial HOA measurements showed that optical quality might deteriorate in subjects with a short TBUT by suppressed blinking, such as when gazing at a video display terminal, even with sufficient tear volume.

Characteristic higher-order aberrations of the anterior and posterior corneal surfaces in 3 corneal transplantation techniques.

PURPOSE To investigate the corneal higher-order aberrations (HOAs) of the anterior and posterior corneal surfaces in eyes that underwent penetrating keratoplasty (PK), deep anterior lamellar keratoplasty (DALK), and Descemet stripping automated endothelial keratoplasty (DSAEK). DESIGN Retrospective, case-control study. METHODS study population: Twenty-four eyes underwent PK, 28 eyes underwent DALK, and 19 eyes underwent DSAEK; 29 normal eyes served as controls. observation procedures: The anterior and posterior corneal heights and pachymetric data were obtained with a Scheimpflug-based corneal topographer. Corneal HOAs for 4-mm pupils were calculated from the height data and were expanded with normalized Zernike polynomials. The HOAs resulting from the anterior and posterior corneal surfaces were compared among the procedures. main outcome measures: Anterior and posterior corneal HOAs (root mean square). RESULTS Control eyes had significantly lower total HOAs and Zernike vector terms of the anterior and posterior surfaces than the other groups, except for spherical aberration. The mean anterior corneal surface total HOAs in the PK, DALK, DSAEK, and control groups were 1.38 ± 0.67 μm, 1.19 ± 0.57 μm, 0.61 ± 0.33 μm, and 0.21 ± 0.07 μm, respectively. The anterior corneal HOAs in the DSAEK group were significantly less than those in the PK group (P < .001) and DALK group (P < .001). The mean posterior corneal surface total HOAs were, respectively, 0.20 ± 0.09 μm, 0.24 ± 0.11 μm, 0.27 ± 0.15 μm, and 0.07 ± 0.02 μm. There were no significant differences in the posterior corneal HOAs among the treatment groups. CONCLUSIONS Because the refractive indices between the anterior and the posterior surfaces differed greatly, eyes that undergo DSAEK have lower anterior corneal HOAs compared with PK or DALK eyes. However, the anterior and posterior corneal HOAs in DSAEK eyes still were greater than those in control eyes.

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.

Increased Tear Fluid Production as a Compensatory Response to Meibomian Gland Loss: A Multicenter Cross-sectional Study

PURPOSE To compare tear film parameters as well as meibomian gland morphologic features and function among patients with meibomian gland dysfunction (MGD), those with non-Sjögren syndrome aqueous-deficient dry eye (non-SS ADDE), those with non-SS ADDE and MGD, and normal subjects. DESIGN Multicenter, cross-sectional, observational case series. PARTICIPANTS Forty-one eyes of 41 patients (all women; mean age ± standard deviation, 62.1±9.9 years) with non-SS ADDE, 70 eyes of 70 patients (all women; 66.0±8.7 years) with MGD, 17 eyes of 17 patients (all women; 72.4±7.8 years) with non-SS ADDE and MGD, and 70 eyes of 70 normal control subjects (all women; 65.0±7.1 years). METHODS Ocular symptoms were scored from 0 to 14 and lid margin abnormalities from 0 to 4 according to their respective number. Meibomian gland changes were scored from 0 to 6 (meiboscore) on the basis of noncontact meibography findings, and meibum was graded from 0 to 3 depending on its volume and quality. Conjunctival and corneal epithelial damage were scored from 0 to 9 (fluorescein score). Tear film break-up time (TBUT) was measured as an index of tear film stability, and tear fluid production was evaluated with Schirmers test. MAIN OUTCOME MEASURES Ocular symptom score, lid margin abnormality score, meiboscore, meibum grade, fluorescein score, TBUT, and Schirmers test value. RESULTS The ocular symptom score did not differ significantly between the MGD and non-SS ADDE groups (P = 0.762). The lid margin abnormality score, meiboscore, and meibum grade were significantly higher in the MGD group than in the non-SS ADDE group (P = 0.0012, P < 0.0001, and P < 0.0001, respectively). The fluorescein score, TBUT, and Schirmers test value were significantly worse in the non-SS ADDE group than in the MGD group (P < 0.0001, P = 0.0061, and P < 0.0001, respectively). The meiboscore correlated significantly with Schirmers test value only in the MGD group (ρ = 0.508, P = 8.3×10(-6)). CONCLUSIONS An increase in tear fluid production likely compensates for loss of meibomian glands in individuals with MGD.

Quality of vision in eyes after selective lamellar keratoplasty.

Abstract: With the increasing popularity of selective lamellar keratoplasty procedures, it is important to characterize the optical differences among penetrating keratoplasty (PK), deep anterior lamellar keratoplasty (DALK), and Descemet stripping automated endothelial keratoplasty (DSAEK). The impact of optical differences on the visual acuity (VA) in eyes after keratoplasty is significant. Quantitative evaluation of corneal higher-order aberrations (HOAs) of anterior and posterior surfaces using a rotating Scheimpflug-based corneal topographer, showed that eyes that undergo DSAEK have lower anterior corneal HOAs compared with eyes subjected to PK or DALK. In DSAEK, the anterior corneal surfaces are not replaced, which is in contrast to PK or DALK, where they are replaced. Through evaluation of corneal scatter with a densitometry program associated with the rotating Scheimpflug-based corneal topographer, 3 characteristic patterns of corneal scatter were found in eyes that had undergone keratoplasty. Investigation of the impact of corneal HOAs and corneal scatter on VA after keratoplasty showed that the VA was correlated significantly with corneal scatter.

Bacteriologic Profile of the Conjunctiva in the Patients with Dry Eye

PURPOSE To assess the conjunctival bacterial profiles in dry eye and their fluoroquinolone susceptibility patterns. DESIGN Prospective, observational study. METHODS Sixty-seven female patients with dry eye (29 with Sjögren syndrome and 38 without Sjögren syndrome) who received artificial tears were enrolled at Osaka University Hospital in Japan. Twenty-three patients received additional topical steroids. Twenty-six puncta were occluded with plugs. Cultures were obtained with conjunctival swabs at the right eye of the subjects. The minimum inhibitory concentrations of isolated strains were determined for the fluoroquinolones (levofloxacin and gatifloxacin). The profiles of conjunctival bacteria of patients with dry eye were compared with those obtained before surgery from 56 female control patients. RESULTS Eighty-eight strains were isolated (48 strains of Propionibacterium acnes, 26 coagulase-negative Staphylococcus [CNS] species, six Staphylococcus aureus strains, and eight others). Of the 26 CNS strains, 17 (65.4%) were fluoroquinolone resistant, including four (33.3%) of 12 methicillin-sensitive CNS and 13 (92.9%) of 14 methicillin-resistant CNS. All methicillin-sensitive S. aureus strains and P. acnes strains were sensitive to fluoroquinolones; one methicillin-resistant S. aureus strain was resistant. There was no significant difference in the conjunctival isolation rates between patients with dry eye and controls. However, the dry eye group had a significantly higher incidence of fluoroquinolone-resistant methicillin-sensitive CNS and of fluoroquinolone-resistant methicillin-resistant CNS than controls (P = .018 and P = .024, respectively). There were no significant differences in bacteria isolated between subgroups with or without punctal plugs and with or without topical steroids. CONCLUSIONS Patients with dry eye are more likely to have fluoroquinolone-resistant conjunctival bacteria than controls. These results may help prevent infectious keratoconjunctivitis in patients with dry eye.

Tear Film Break-up Time Evaluated by Real-Time Hartmann-Shack Wavefront Sensing

PurposeTo develop a novel method for measuring tear break-up time (BUT) by continuously measuring higher order wavefront aberrations using a Hartmann-Shack (H-S) aberrometer.MethodsWavefront aberrations up to the sixth order for a 4-mm pupil were measured in six eyes of six normal subjects using an H-S aberrometer. The aberrometry was performed once every second for up to 50 s under topical anesthesia. The sequence of the points was divided into two stages, and the BUT was defined as the wavefront border of the stages (WFBUT). The WFBUT was compared with the BUT by the conventional fluorescein method (FLBUT) or by the disruption of placid-ring images (PLBUT).ResultsIn three eyes, the WFBUT (average, 10.9 ± 1.1 s) was shorter than the PLBUT (average, 17.5 ± 2.5 s), while in the other three eyes the WFBUT (average, 21.5 ± 2.2 s) was longer than PLBUT (average, 8.1 ± 2.2 s). The FLBUT was shorter than WFBUT or PLBUT in most cases.ConclusionsThe tear break-up time measured by H-S aberrometer may be used as a practical measure of tear break-up. Jpn J Ophthalmol 2006;50:85–89

Effect of rebamipide ophthalmic suspension on optical quality in the short break-up time type of dry eye.

Purpose: To determine the effect of rebamipide ophthalmic suspension on optical quality in patients with dry eye with short break-up time (BUT) of the tear film. Methods: Twenty-six eyes of 16 patients with the short BUT type of dry eye were enrolled and treated with 2% rebamipide ophthalmic suspension. At baseline and at 2 and 4 weeks after initiating the treatment, the serial corneal higher-order aberrations (HOAs), BUT, fluorescein staining, and Schirmer test were measured. Patients were asked to complete questionnaires about the changes in dry eye–related ocular symptoms after the treatment. Results: Before the treatment, the pattern of postblink corneal HOAs for 10 seconds showed a sawtooth pattern, with a marked upward curve that increased after blinking. Treatment with rebamipide for 4 weeks significantly (P < 0.05) improved the postblink corneal HOAs and stabilized the pattern of the corneal HOAs. Significant increases in the tear film BUT were seen 2 and 4 weeks after the treatment (P < 0.001 for both comparisons). Conclusions: Rebamipide administered to treat the short BUT type of dry eye significantly improved optical quality because of the improvement in tear stability.