Relationship between higher-order wavefront aberrations and natural progression of myopia in schoolchildren.

This study investigated the relationship between higher-order aberrations (HOAs) and myopia progression as well as axial elongation in schoolchildren. We examined cycloplegic refraction, axial length, and wavefront aberrations prospectively in 71 myopic children. Changes in cycloplegic refraction and axial length during a 2-year study period were assessed, and their correlations with HOA components were analyzed. Sixty-four subjects ([mean ± SD] 9.2 ± 1.6 years) completed the 2-year examinations. Cycloplegic refraction was significantly changed after 2 years (P < 0.0001), and the average change (myopia progression) was -1.60 ± 1.04 D. Axial length also increased significantly (P < 0.0001), and the average increase (axial elongation) was 0.77 ± 0.40 mm. Myopia progression and axial elongation showed significant correlations with many components of corneal HOA (P < 0.0001 to P = 0.0270). Multivariate analysis showed that the total HOA of the cornea was the most relevant variable to myopia progression and axial elongation (P < 0.0001). Eyes with larger amounts of corneal HOAs showed less myopia progression and smaller axial elongation, suggesting that corneal HOAs play a role in the refractive and ocular developments in children.

Influence of ocular wavefront aberrations on axial length elongation in myopic children treated with overnight orthokeratology.

PURPOSE: To determine ocular optical parameters that affect axial length elongation in myopic children undergoing overnight orthokeratology. DESIGN: Prospective, noncomparative study. PARTICIPANTS: Fifty-nine subjects who met the inclusion criteria were enrolled in this study. METHODS: Axial length and ocular wavefront aberration were assessed before and 1 year after the start of orthokeratology. Corneal topography was performed, and then corneal multifocality was calculated for a 4-mm pupil. After evaluating simple correlations between axial elongation and optical parameters, multiple linear regression analysis was performed to identify explanatory variables with a statistically significant contribution to axial elongation. MAIN OUTCOME MEASURES: Axial length and ocular wavefront aberration before and 1 year after the start of orthokeratology. RESULTS: Fifty-five subjects completed the 1-year follow-up examinations. At baseline, their age ranged from 7.2 to 12.0 years. The manifest spherical equivalent refractive error ranged from -3.50 to -0.75 diopters. The mean axial length significantly increased from 24.20 mm at baseline to 24.43 mm 1 year after treatment. The axial elongation showed significant simple correlations with the change in C2(0), change in second-order aberration, change in coma-like aberration, change in spherical-like aberration, change in total higher-order aberrations, change in corneal multifocality, baseline age, and baseline spherical equivalent refractive error, but not C4(0). Multiple linear regression analysis showed that the change in coma-like aberration was the most relevant variable. CONCLUSIONS: Asymmetric corneal shapes, rather than concentric and radially symmetric shapes, have a considerable effect on retardation of axial elongation, suggesting that the inhibitory effect of orthokeratology on myopia progression is caused by mechanisms other than the reduction in peripheral hyperopic defocus.

Long-term effect of overnight orthokeratology on axial length elongation in childhood myopia: a 5-year follow-up study.

PURPOSE: Our prospective study was conducted to compare axial length elongation in myopic children receiving long-term overnight orthokeratology (OK) treatment to those wearing spectacles as controls. METHODS: There were 59 subjects enrolled in this study. The OK group comprised 29 subjects who matched the inclusion criteria for OK. The control group comprised 30 subjects who also matched the inclusion criteria for OK, but preferred spectacles for myopia correction. Axial length was measured periodically for 5 years using an IOLMaster device, and the time course of changes was evaluated and compared between the groups. RESULTS: A total of 43 subjects (22 and 21 in the OK and control groups, respectively) completed the 5-year follow-up examinations. At baseline, the mean age ± SD was 10.04 ± 1.43 and 9.95 ± 1.59 years, the spherical equivalent refractive error was -1.89 ± 0.82 and -1.83 ± 1.06 diopters (D), and the axial length was 24.09 ± 0.77 and 24.22 ± 0.71 mm in the OK and control groups, respectively, with no significant differences between the groups. The increase in axial length during the 5-year study period was 0.99 ± 0.47 and 1.41 ± 0.68 mm for the OK and control groups, respectively, and the difference was statistically significant (P = 0.0236, unpaired t-test). The annual increases in axial length were significantly different between the groups for the first (P = 0.0002), second (P = 0.0476), and third years (P = 0.0385), but not for the fourth (P = 0.0938) and fifth (P = 0.8633) years. There were no severe complications throughout the study period. CONCLUSIONS: The current 5-year follow-up study indicated that OK can suppress axial length elongation in childhood myopia.

Influence of overnight orthokeratology on axial elongation in childhood myopia.

PURPOSE: This prospective study was conducted to assess the influence of overnight orthokeratology (OK) on axial elongation in children, with those wearing spectacles as controls. METHODS: One hundred five subjects (210 eyes) were enrolled in the study. The OK group comprised 45 patients (90 eyes, age 12.1 ± 2.5 years, mean ± SD; OK group) who matched the inclusion criteria for OK. The control group comprised 60 patients (120 eyes, 11.9 ± 2.0 years) who also matched the inclusion criteria for OK but preferred spectacles for myopia correction. Axial length was measured at baseline and after 2 years using ocular biometry, and the changes were evaluated and compared between the groups. RESULTS: Ninety-two subjects (42 and 50 in the OK and control groups, respectively) completed the 2-year follow-up examinations. At baseline, the spherical equivalent refractive error was -2.55 ± 1.82 and -2.59 ± 1.66 D, and the axial length was 24.66 ± 1.11 and 24.79 ± 0.80 mm in the OK and control groups, respectively, with no significant differences between the groups. The increase in axial length during the 2-year study period was 0.39 ± 0.27 and 0.61 ± 0.24 mm, respectively, and the difference was significant (P < 0.0001, unpaired t-test). CONCLUSIONS: OK suppressed axial elongation in myopic children, suggesting that this treatment can slow the progression of myopia to a certain extent.

Patient satisfaction and clinical outcomes after overnight orthokeratology.

PURPOSE: To assess patient satisfaction following overnight orthokeratology using a visual analogue scale and to find clinical factors that influence patient satisfaction. METHODS: In this prospective study, subjective patient satisfaction with visual outcomes was measured using a visual analogue scale, ranging from 0 (very dissatisfied) to 10 (very satisfied) in 17 patients who completed 1-year follow-up examinations after commencement of orthokeratology. Spherical equivalent refraction at baseline was 2.17 +/- 0.84 diopter (mean +/- SD). Various clinical parameters including refraction, visual acuity, ocular higher-order aberrations, and photopic and mesopic contrast sensitivity function were examined before and after the procedure. The influence of these parameters on patient satisfaction was evaluated using Spearman rank correlation test. RESULTS: The overall satisfaction with visual outcomes was scored 7.8 +/- 1.8 (range, 3.5 to 10). The level of satisfaction showed significant correlation (Spearman rank correlation coefficient; r = -0.599, p = 0.017) with posttreatment uncorrected visual acuity and pretreatment myopic error (r = 0.500, p = 0.045). CONCLUSIONS: This study demonstrated a relatively high level of patient satisfaction following overnight orthokeratology. Posttreatment uncorrected visual acuity is associated with patient satisfaction, and patients with higher myopia are predisposed to lower levels of subjective satisfaction.

Time course of changes in ocular higher-order aberrations and contrast sensitivity after overnight orthokeratology.

PURPOSE: To investigate prospectively the time course of changes in ocular higher-order aberration and contrast sensitivity after overnight orthokeratology. METHODS: Data from 34 eyes of 17 patients who completed 1-year follow-up examinations were analyzed. The manifest refraction was -2.17 +/- 0.86 D at baseline. Ocular higher-order aberrations for a 4-mm pupil were measured, and the root-mean-square (RMS) of the third-, fourth-, and total higher-order aberrations were determined. Contrast sensitivity was assessed at four spatial frequencies, and the area under the log contrast sensitivity function (AULCSF) was calculated. These examinations were performed before and 1, 2, 3, 6, and 12 months after commencement of the procedure. RESULTS: The treatment significantly increased third-, fourth-, and total higher-order RMS (all P < 0.0001, paired t-test). Log contrast sensitivity significantly decreased at all four spatial frequencies, and AULCSF was also significantly reduced after the treatment (P < 0.0001). To assess the time course of changes in these parameters, posttreatment data were analyzed by using repeated-measures analysis of variance. There were no significant fluctuations in manifest refraction; uncorrected visual acuity; third-, fourth-, and total higher-order RMS; and AULCSF (all P > 0.05). In addition, there was no significant variance in log contrast sensitivity at each spatial frequency during the 1-year follow-up period (all P > 0.05). CONCLUSIONS: The initial reduction in optical quality of the eye and quality of vision after the procedure is stable during the treatment period of at least 1 year, and the reduction does not worsen further after 1 month. Orthokeratology candidates should be fully informed of these changes.

Mesopic contrast sensitivity and ocular higher-order aberrations after overnight orthokeratology.

PURPOSE: To investigate mesopic contrast sensitivity and night driving ability in eyes undergoing overnight orthokeratology, and to analyze the relationship among mesopic contrast sensitivity, ocular higher-order aberrations, and myopic correction. DESIGN: Prospective, noncomparative, consecutive case series. METHODS: In 44 eyes of 22 subjects (mean age +/- standard deviation [SD], 24.0 +/- 3.2 years) with orthokeratology, ocular aberrations and mesopic contrast sensitivity were determined before and three months after commencement of the procedure. Mean spherical equivalent refraction +/- SD was -2.34 +/- 0.99 diopters at baseline. Mesopic contrast sensitivity with and without glare was assessed using the Mesotest II (Oculus, Wetzlar, Germany). RESULTS: Orthokeratology significantly reduced the log mesopic contrast sensitivity from 0.25 +/- 0.08 to 0.08 +/- 0.10 without glare (P < .0001, Wilcoxon) and from 0.21 +/- 0.11 to 0.07 +/- 0.10 with glare (P < .0001). The proportion of eyes that fulfilled the German standard recommendation level for night driving was 36%. The induced changes in log mesopic contrast sensitivity showed significant negative correlation with the changes in third-order (r = -0.490, P = .0013 without glare; r = -0.362, P = .0177 with glare; Spearman rank correlation coefficient) and fourth-order root mean square (r = -0.586, P = .0001 and r = -0.306, P = .0450, respectively). Furthermore, significant correlation was found between the amount of myopic correction and the induced changes in log mesopic contrast sensitivity (r = -0.442, P = .0038 without glare; r = -0.464, P = .0024 with glare). The induced changes in higher-order aberrations significantly correlated with the amount of myopic correction (P < .0001, Pearson correlation coefficient). CONCLUSIONS: Mesopic contrast sensitivity after overnight orthokeratology is deteriorated significantly as ocular higher-order aberrations increase, and these changes depend on the amount of myopic correction.

Contrast sensitivity function and ocular higher-order aberrations following overnight orthokeratology.

PURPOSE: To evaluate relationships among contrast sensitivity function, ocular higher-order aberration, and myopic correction in eyes undergoing overnight orthokeratology for myopia. METHODS: A prospective study was conducted in 46 eyes of 23 patients undergoing orthokeratology. Inclusion criteria were spherical equivalent refraction between -1.00 and -4.00 diopters (D), refractive astigmatism up to 1.00 D, and best-corrected visual acuity of 20/20 or better. Ocular higher-order aberrations and contrast sensitivity function were determined before and 3 months after initiation of the procedure. We measured three indices of contrast sensitivity function: contrast sensitivity, low-contrast visual acuity, and letter contrast sensitivity with the CSV-1000 charts (Vector Vision Co., Greenville, OH). Area under the log contrast sensitivity function (AULCSF) was calculated from the contrast sensitivity data. RESULTS: Orthokeratology significantly improved logMAR uncorrected visual acuity (P < 0.0001; paired t-test) but significantly increased ocular higher-order aberrations (P < 0.0001) and decreased contrast sensitivity function, including AULCSF (P < 0.0001), low-contrast visual acuity (P = 0.0025), and letter contrast sensitivity (P < 0.0001; Wilcoxon signed-rank test). The induced changes in AULCSF, low-contrast visual acuity, and letter contrast sensitivity by orthokeratology showed significant correlation with changes in third-order (Pearson r = -0.430, P = 0.0026; r = 0.423, P = 0.0031; and Spearman r(s) = -0.351, P = 0.0186, respectively), fourth-order (r = -0.418, P = 0.0035; r = 0.425, P = 0.0029; and r(s) = -0.566, P = 0.0001, respectively), and total higher-order (r = -0.460, P = 0.0011; r = 0.471, P = 0.0008; and r(s) = -0.434, P = 0.0036, respectively) aberrations. The induced changes in contrast sensitivity function and higher-order aberrations significantly correlated with the amount of myopic correction (P < 0.01). CONCLUSIONS: Orthokeratology significantly increases ocular higher-order aberrations and compromises contrast sensitivity function, depending on the amount of myopic correction.

Rapid and sensitive diagnosis of adenoviral keratoconjunctivitis by loop-mediated isothermal amplification (LAMP) method.

PURPOSE: To develop a new method to detect and type adenoviruses directly from conjunctival scrapings using loop-mediated isothermal amplification (LAMP) with adenovirus (ad) type specific primer. METHODS: Using primers specific for the gene of ad1, ad3, ad4, ad8, ad19 and ad37, heat denatured adenovirus DNA was amplified by the LAMP and polymerase chain reaction (PCR). Alkaline lysed adenovirus prototype and conjunctival scrapings were also used directly as templates. RESULTS: Type specific primers amplified ad genes of the corresponding ad prototype specifically. The specific amplification was observed in both heat denatured and alkaline lysed samples. The amplified product was first detected within 45 min. Ad genotypes of clinical samples determined by the LAMP method were almost identical to those determined using the PCR-sequencing method. CONCLUSIONS: LAMP based isothermal amplification of adenovirus genome for detection and typing of adenoviruses is faster than PCR based methods. This new method will be useful for rapid diagnosis and typing of adenoviral conjunctivitis.

Rapid and sensitive diagnosis of adenoviral keratoconjunctivitis by loop-mediated isothermal amplification (LAMP) method.

PURPOSE: To develop a new method to detect and type adenoviruses directly from conjunctival scrapings using loop-mediated isothermal amplification (LAMP) with adenovirus (ad) type specific primer. METHODS: Using primers specific for the gene of ad1, ad3, ad4, ad8, ad19 and ad37, heat denatured adenovirus DNA was amplified by the LAMP and polymerase chain reaction (PCR). Alkaline lysed adenovirus prototype and conjunctival scrapings were also used directly as templates. RESULTS: Type specific primers amplified ad genes of the corresponding ad prototype specifically. The specific amplification was observed in both heat denatured and alkaline lysed samples. The amplified product was first detected within 45 min. Ad genotypes of clinical samples determined by the LAMP method were almost identical to those determined using the PCR-sequencing method. CONCLUSIONS: LAMP based isothermal amplification of adenovirus genome for detection and typing of adenoviruses is faster than PCR based methods. This new method will be useful for rapid diagnosis and typing of adenoviral conjunctivitis.

Corneal iron ring formation associated with overnight orthokeratology.

PURPOSE: To describe a case of iron deposition in both eyes after overnight orthokeratology. METHODS: This is a case report of a 31-year-old man who underwent overnight orthokeratology. The subject was fitted with rigid gas-permeable contact lenses of reverse-geometry design to correct myopia. RESULTS: The prefitting manifest refraction was -4.75 -0.25 x 175 in the right eye and -4.50 -0.25 x 175 in the left eye. There was no corneal abnormality until 9 months after treatment, but development of corneal arcuate lines in both eyes was observed at the 1-year follow-up visit. Visual acuity was not affected. The deposition pattern corresponded to the outside border of central flatter zone, as shown on the corneal topography map. CONCLUSION: The current findings suggest that tear pooling between the corneal surface and the back surface of the contact lens plays a role in the development of corneal iron ring after orthokeratology with reverse-geometry contact lenses.

Influence of overnight orthokeratology on corneal endothelium.

PURPOSE: To evaluate the influence of overnight orthokeratology on the corneal endothelium. METHODS: Fifty-two eyes of 31 patients undergoing overnight orthokeratology for myopia were examined. They wore the lens every night and were followed up for at least 1 year. The corneal endothelium was examined with specular microscopy to calculate mean endothelial cell density, coefficient of variation of cell area, and percentage of hexagonal cells. Data obtained at 1-year follow-up examinations were compared with those at the baseline examinations using a paired t test. RESULTS: Orthokeratology significantly reduced manifest refraction from -2.32 +/- 1.18 D (mean +/- standard deviation) to -0.16 +/- 0.33 D (P < 0.0001) and improved uncorrected visual acuity from 0.77 +/- 0.29 to -0.07 +/- 0.10 logMAR (P < 0.0001). The endothelial cell density did not change significantly (2879 +/- 231 cells/mm before and 2864 +/- 260 cells/mm after treatment, P = 0.252). The coefficient of variation of cell area was 22.3 +/- 2.7 at baseline and 22.1 +/- 2.4 at 1-year posttreatment, which did not change significantly (P = 0.537). The percentage of hexagonal cells was 72.8 +/- 10.2% pretreatment and 72.5 +/- 10.9% posttreatment (P = 0.800). CONCLUSIONS: Overnight orthokeratology for 1 year did not influence the density or morphology of corneal endothelial cells.

Quantitative evaluation of regular and irregular corneal astigmatism in patients having overnight orthokeratology.

PURPOSE: To quantitatively assess changes in regular and irregular corneal astigmatism in patients having overnight orthokeratology. SETTING: Matsumoto Eye Clinic, Ibaraki, Japan. METHODS: A prospective study was conducted of 64 eyes of 39 patients having overnight orthokeratology for myopia. Inclusion criteria were an uncorrected visual acuity (UCVA) of 20/20 or better after treatment and a minimum follow-up of 3 months. Using Fourier series harmonic analysis, videokeratography data were decomposed into spherical component, regular astigmatism, asymmetry (tilt or decentration), and higher-order irregularity. RESULTS: Orthokeratology significantly reduced the manifest refraction from -2.60 diopters (D) +/- 1.13 (SD) to -0.17 +/- 0.31 D (P<.0001, paired t test) and improved the UCVA from 0.82 +/- 0.30 to -0.11 +/- 0.06 logMAR (P<.0001). Regular astigmatism increased significantly from 0.53 +/- 0.23 D preoperatively to 0.63 +/- 0.40 D postoperatively (P =.0206). The asymmetry component increased significantly from 0.35 +/- 0.22 D to 0.64 +/- 0.40 D (P<.0001). Higher-order irregularity did not change significantly: 0.14 +/- 0.11 D before treatment and 0.17 +/- 0.20 D after treatment (P =.2166). The amount of myopic correction correlated significantly with the increase in the asymmetry component (Pearson correlation coefficient, R = 0.40, P =.0009) but not with the increase in regular astigmatism (R = 0.24, P =.055). CONCLUSIONS: Irregular corneal astigmatism significantly increased, even in clinically successful orthokeratology cases. The effect of the changes on visual function should be studied further.