C. Okamoto

Influence of tilt and decentration of scleral-sutured intraocular lens on ocular higher-order wavefront aberration

Aim: To investigate the influence of tilt and decentration of scleral-sutured intraocular lenses (IOLs) on ocular higher-order wavefront aberrations. Methods: In 45 eyes of 36 patients who had undergone scleral suture fixation of posterior chamber IOL, tilt and decentration of IOLs were determined by Scheimpflug videophotography, and higher-order aberration for a 4-mm pupil was measured using the Hartmann–Shack aberrometer. In another 100 eyes of 100 patients after standard cataract surgery with posterior chamber IOL implantation, ocular higher-order aberration was measured. Results: In eyes with scleral-sutured IOL, the mean (SD) tilt angle and decentration were 4.43° (3.02°) and 0.279 (0.162) mm, respectively. Ocular coma-like aberration in the sutured IOL group was 0.324 (0.170) µm, which was significantly greater than that of the standard cataract surgery group (0.169 (0.061) µm, p<0.001, Student’s t test). No significant difference was found in ocular spherical-like aberration between the sutured IOL group (0.142 (0.065) µm) and standard surgery group (0.126 (0.033) µm; p = 0.254). In the sutured IOL group, IOL tilt significantly correlated with ocular coma-like aberration (Pearson’s correlation coefficient r = 0.628, p<0.001), but no significant correlation was found between IOL tilt and ocular spherical-like aberration (r = 0.222, p = 0.175). The IOL tilt did not correlate with corneal coma-like (r = 0.289, p = 0.171) and spherical-like (r = 0.150, p = 0.356) aberrations. The IOL decentration did not correlate with any higher-order aberrations. Conclusion: In eyes with scleral-sutured posterior chamber IOL, tilting of the lens induces considerable amount of ocular coma-like aberrations.

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.

Influence of induced decentered orthokeratology lens on ocular higher-order wavefront aberrations and contrast sensitivity function.

PURPOSE: To quantitatively evaluate the effect of overnight orthokeratology lenses intentionally left decentered after 3 months of wear and assess the influence on clinical outcomes such as ocular higher‐order wavefront aberrations and contrast sensitivity function. SETTING: Department of Ophthalmology, Tsukuba University Hospital, Ibaraki, Japan. METHODS: This prospective study assessed refraction, visual acuity, corneal topography, wavefront aberration, and contrast sensitivity function before and 3 months after overnight orthokeratology treatment. Decentration of the treatment zone from the center of the entrance pupil was determined using computerized videokeratography (TMS‐4) and data‐analysis software (MatLab). The relationship between decentration and the clinical parameters was analyzed. RESULTS: The mean age of the 23 patients (46 eyes) was 24.2 years±3.3 (SD) and the mean spherical equivalent refraction before treatment, −2.38±0.98 diopters. The mean magnitude of decentration (0.85±0.51 mm) was statistically significantly correlated with the amount of myopic correction (P<.05), increases in coma‐like aberration (P<.01), increases in spherical‐like aberration (P<.01), and reductions in contrast sensitivity function (P<.0001). Changes in contrast sensitivity function were also statistically significantly correlated with the amount of myopic correction (P<.05), changes in coma‐like aberration (P<.01), and changes in spherical‐like aberration (P<.01). Stepwise multiple regression analysis showed that the magnitude of decentration was the only explanatory variable related to contrast sensitivity function (P<.0001). CONCLUSION: Decentered treatment of orthokeratology resulted in decreased contrast sensitivity after treatment, showing that centration of the procedure is crucial to good outcomes.

Recovery of corneal irregular astigmatism, ocular higher-order aberrations, and contrast sensitivity after discontinuation of overnight orthokeratology

Aims: To examine prospectively the recovery of various parameters after discontinuation of overnight orthokeratology. Methods: Seventeen subjects undergoing orthokeratology for 12 months were examined. Refraction, corneal topography, wavefront aberrometry, a visual acuity test and a contrast sensitivity test were performed at baseline, 12 months after commencement of the procedure, and 1 week and 1 month after discontinuation of the treatment. Asymmetry and higher-order irregularity components were calculated using a Fourier analysis of the corneal topography data. Contrast sensitivity was assessed at four spatial frequencies, and the area under the log contrast sensitivity function (AULCSF) was calculated. Results: Orthokeratology significantly reduced manifest refraction (p<0.0001, Dunnett test) and significantly improved uncorrected visual acuity (UCVA) at 12 months after commencement of the procedure (p<0.0001). Asymmetry and higher-order irregularity components increased significantly (p<0.0001, p = 0.0032, respectively), and third- and fourth-order aberrations also increased significantly (p<0.0001). The treatment resulted in significant decreases in AULCSF (p = 0.0004). After discontinuing lens wear, all parameters, such as refraction, UCVA, asymmetry, higher-order irregularity, third-order aberration, fourth-order aberration and AULCSF, returned to the baseline level at 1 week. Conclusion: This study confirmed that the effect of orthokeratology is completely reversible in light of optical quality of the eye and quality of vision as well as refraction and visual acuity.

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.

Mesopic contrast sensitivity and ocular higher-order aberrations in eyes with conventional spherical intraocular lenses.

PURPOSE To investigate relationship between mesopic contrast sensitivity (CS) function and ocular higher-order aberrations in eyes implanted with conventional spherical intraocular lenses (IOL). DESIGN Prospective, nonrandomized case series. METHODS Sixty-eight eyes of 48 patients who attained best spectacle-corrected visual acuity (BSCVA) of 20/20 or better after phacoemulsification and spherical IOL implantation were included in the study. At 2 months postoperatively, mesopic CS was measured with the Mesotest II (Oculus; Wetsler, Germany), and ocular higher-order aberrations for a 4-mm pupil were measured with the Hartmann-Shack aberrometer. CS and letter CS under photopic conditions were recorded with the CSV-1000 charts (Vector Vision Co, Greenville, Ohio, USA). RESULTS There was significant correlation between mesopic CS and ocular fourth-order root mean square (RMS) of wavefront aberration (Spearman r(s) = -0.293; P = .017), but no correlation was found between mesopic CS and ocular third-order RMS (r(s) = 0.196; P = .189). Ocular third- and fourth-order RMS did not correlate with other parameters, including BSCVA, and CS and letter CS under photopic conditions. CONCLUSIONS Mesopic CS is significantly associated with ocular fourth-order RMS of wavefront aberrations in eyes implanted with conventional spherical IOLs.