Patient Satisfaction and Clinical Outcomes After Overnight Orthokeratology

The History and Impact of Prescribing Orthokeratology for Slowing Myopia Progression

ABSTRACT

This paper discusses the history and impact of orthokeratology on slowing the progression of myopia. It discusses the origins and evolution of orthokeratology from polymethymethaccrylate lenses worn during the day to its current prescribing of highly permeable, innovative reverse-geometry designs worn only while sleeping. Technological advances in corneal topography, lens design, lens materials, and manufacturing have facilitated growth of orthokeratology to a precise and predictable procedure. More recently, significant interest in orthokeratology has been stimulated by its efficacy in slowing axial elongation in myopic children. Safety of children wearing contact lenses while sleeping has been an ongoing concern. The potential of serious complications exists, but long-term studies and clinical experience have shown that risks of those events can be minimized with strict compliance with lens cleaning, disinfection, and hand hygiene. Because no correction is required during waking hours, patients using orthokeratology report higher vision-related quality of life, less activity restrictions, and more comfortable eyes compared with spectacles or contact lenses worn during the day. The future growth of orthokeratology will be fueled by the prescribing of orthokeratology as a modality to slow axial elongation and an alternative modality to spectacles, traditional contact lenses, and refractive surgery to correct refractive error.

Patient and parent perceptions of myopia modalities

PURPOSE

This study compared quality of life (QoL) of myopic adults and children who were established spectacle, soft contact lens (SCL), or orthokeratology (OK) wearers as well as parent/child responses using Pediatric Refractive Error Profile 2 (PREP2).

METHODS

Forty-eight adults (aged 18-26 years), 49 children (aged 9-17 years), and the children's parent, completed PREP2, with 7 subscales (symptoms, vision, activities, appearance, peer perception, handling, and overall). Adults and children must have worn their correction for at least three years. Parents were asked to answer how they thought their child would answer. Scores were compared between age groups, among correction groups, and between children and their parents using non-parametric ANOVA, Mann-Whitney U and Wilcoxon Signed-Rank tests, as appropriate. Post-hoc pairwise comparisons among correction groups were conducted with Bonferroni adjustment.

RESULTS

Average age of adults was 22 ± 2 and children was 14 ± 2 years, and duration of correction use was 8 ± 3 for adults and 5 ± 2 years for children (both p < 0.01). Adult OK wearers were more satisfied with vision (p = 0.04), activities (p < 0.001) and overall (p = 0.03) compared to spectacle wearers. Children OK wearers reported higher scores for activities than SCL (p = 0.048) and spectacle wearers (p < 0.001). Parents of contact lens wearers reported higher perceived QoL for activities (OK p < 0.001; SCL p = 0.02), handling (OK p = 0.02; SCL p < 0.001), appearance (SCL p = 0.001), and overall (OK p = 0.001; SCL p < 0.001) subscales than parents of child spectacle wearers.

CONCLUSION

Activity-driven children and adults perceive significant benefits from OK over spectacles. Parents' perceptions did not align with their children's perceptions of their correction.

Changes in Shape Discrimination Sensitivity Under Glare Conditions After Orthokeratology in Myopic Children: A Prospective Study

Purpose

To investigate changes in shape discrimination under mesopic conditions with and without glare after orthokeratology in myopic children.

Methods

This prospective study included 79 eyes of 79 myopic children (ages: 8-16 years). Shape discrimination thresholds (SDTs) were measured using radial frequency patterns, with a radial frequency of 4 cycles/360°, a peak spatial frequency of 3 cycles per degree, a contrast of 20%, and a mean radius of 1.5 degrees. SDT under mesopic conditions with and without glare was measured before orthokeratology and again at 1 week and 1 month after orthokeratology. Changes in the SDTs and their relationships to baseline ocular parameters were analyzed.

Results

SDTs with glare decreased significantly at 1 week (-0.08 ± 0.15 log(arcsec), P < 0.001) and 1 month (-0.09 ± 0.15 log(arcsec), P < 0.001) after orthokeratology. SDTs without glare remained stable (P = 0.81 and P = 1.00, respectively). The difference between SDTs with and without glare also decreased significantly at 1 week (-0.10 ± 0.17 log(arcsec), P < 0.001) and at 1 month (-0.08 ± 0.18 log(arcsec), P = 0.001) after orthokeratology. Based on a multivariate analysis, the greater decrease in SDT with glare after 1 month of orthokeratology was associated with a higher baseline spherical equivalent refraction.

Conclusions

Orthokeratology resulted in improved shape discrimination in myopic children under mesopic conditions but only when measured in the presence of glare.

The effect of orthokeratology lenses on optical quality and visual function in children

Purpose

To assess changes in optical quality and visual function in children after 3 months of wearing orthokeratology (OK) lenses.

Methods

A total of 25 myopic children aged 8-12 years were recruited and completed the follow-up study. Optical quality, visual function and corneal morphology were assessed at baseline and at follow-ups 1 and 3 months after wearing OK lenses. Optical quality parameters mainly included the modulation transfer function (MTF) cutoff, objective scattering index (OSI), Strehl ratio (SR) and the predicted visual acuities (PVAs). Visual function was assessed by visual acuity, monocular contrast sensitivity function (CSF) across five spatial frequencies and the area under the log contrast sensitivity function (AULCSF) that was also computed as an index for overall CSF.

Results

The MTF cutoff and SR values both increased after 1 month of wearing the OK lenses (baseline vs. 1 month: P _MTF = 0.008 and P _SR = 0.049); this improvement plateaued after 3 months of lens wear (1 month vs. 3 months: P _MTF = 0.626, P _SR = 0.428). The corneal morphology also showed the similar change trend. The OSI showed the opposite change trend (baseline vs. 1 month: P _OSI < 0.001; 1 month vs. 3 months: P _OSI = 0.720). The mean CSF at 1.5 cpd decreased significantly after 1 month of wearing the lenses (baseline vs. 1 month: p = 0.001) and recovered after 3 months of lens wear (baseline vs. 3 months: p = 0.076). CSF at spatial frequencies of 3, 6, 12 and 18 cpd as well as the AULCSF did not significantly differ between any two timepoints (all Ps > 0.05).

Conclusion

After 3 months of wearing OK lenses, the subjects exhibited a decrease in optical quality, similar to corneal morphology, whereas their visual function remained largely unchanged. Thus, the optical quality was more susceptible to OK lenses than visual function in children. The initial month of OK treatment of children is a key period to be paid close attention to deterioration of optical quality and visual function.

Assessment of Satisfaction, Compliance and Side Effects among Long-Term Orthokeratology Wearers

Purpose: This study aims to assess the satisfaction, compliance, and side effects among the long-term orthokeratology (Ortho-K) users in a tertiary hospital in Taiwan and analyze the side effects and related risk factors. Methods: Children and their guardians were assessed using a structured and validated questionnaire inquiring about background information, wear and care behaviors, daily activities, satisfaction, and related concerns. Clinical information, including refractive data and side effects, was obtained through patient medical files. Results: Three hundred and five school-aged patients were enrolled, and the average age was 13.13 ± 3.39 years, with an average wearing period of 17.1 ± 8.1 months. Over 83% of the subjects had clear daytime vision all day, around 88% felt satisfied or very satisfied with the results, and 98% exhibited a willingness to continue wearing the Ortho-K lenses. Most guardians (83%) were pleased with the controlling effect of myopic progression. Initial spherical equivalent and regular cleaning of the lens protein significantly correlated with clear day vision. Wearing >6 days/week correlated with less risk of lens binding. Based on the questionnaire, the main reasons for using Ortho-K were effectiveness, safety, and practicality, while the major concerns were discomfort, harmful to the eyes, and no effect. Conclusion: With a comprehensive care program from practitioners and good compliance of users, Ortho-K could be the most effective and satisfactory option for myopic children in Taiwan.

The Role of Orthokeratology in Myopia Management

ABSTRACT

Intervention to slow axial elongation and progressing degree of myopia has become an important public health issue. Although orthokeratology (OrthoK) has been prescribed to temporarily reduce or eliminate refractive error, myopic children undergoing OrthoK have shown significant slowing of axial elongation and myopic progression. This review presents data on the efficacy, benefits, and risks of the use of OrthoK to slow axial elongation in myopic children. It also discusses how OrthoK fits into an overall strategy of myopia management in practice compared with alternative prescribed interventions to slow myopic progression. Other factors discussed are patient candidacy, impact on vision-related quality of life, and use of OrthoK in combination with pharmaceutical agents. With precise fitting, careful follow-up, and patient compliance with recommended lens cleaning and disinfection, OrthoK is a safe and effective method to slow axial elongation in children.

Opportunities and threats to contact lens practice: A global survey perspective

AIM

To understand the views of contact lens (CL) practitioners across the globe regarding what they perceive as opportunities and threats in CL practice.

METHODS

A self-administered anonymised questionnaire, constructed in English and translated in six more languages, was distributed through reputed international professional bodies and academic institutions worldwide. The questionnaire included items on demographic characteristics, type of practice, and questions designed to explore practitioners' perspective on the future of their CL practice over the next five years.

RESULTS

A total of 2408 valid responses were analysed. Multifocal CLs for presbyopia, CLs for myopia control, use of daily disposable (DD) CLs for occasional wear, and biocompatible materials to improve comfort were identified as promising areas of opportunities by practitioners (all 8/10). Respondents from North America, and Europe valued DDCLs for occasional wear moderately more favourable (Median: 9/10 for all) as compared to colleagues in Asia (Median: 8/10, p < 0.001), South America (Median: 8/10, p < 0.01), and Africa (Median: 8/10p < 0.01). Multifocal CLs for presbyopia was perceived as a better opportunity by practitioners in North America and Europe (Median: 9/10 for both), as well as in Australasia (Median: 8/10), in comparison to Asia, Africa, and Middle East (for all Median: 6/10, p < 0.001). Practitioners expressed concerns about the availability of CLs and CL prescriptions online without direct professional involvement (both 9/10).

CONCLUSIONS

Overall, the most appealing opportunities for CL practice growth were identified in occasional use of DD CLs, biocompatible materials to reduce CL discomfort, multifocal CLs for presbyopia correction and management of myopia control with CLs. Lack of regulation in CL sales, especially online, seemed to be a constant threat. The insights from this study can be used to design targeted strategies to enhance CL practice across the globe and in specific geographical areas.

Effect of Orthokeratology Lens on Contrast Sensitivity Function and High-Order Aberrations in Children and Adults

OBJECTIVES

Overnight orthokeratology (OOK) lenses are used to temporarily decrease myopic refractive error and improve uncorrected vision. Overnight orthokeratology lenses significantly increase ocular and corneal high-order aberrations (HOAs) and compromise contrast sensitivity function (CSF) to a degree correlated with myopic correction achieved. In Taiwan, OOK lenses are mainly used in children for myopia control. However, information regarding its effects in this population remains limited. This study discusses the change in HOAs and CSF after 28 nights of OOK lens use in children compared with that in adults.

METHODS

In total, 46 children (9-18 years) and 26 adults (>18 years) who visited Ophthalmology Department of Mackay Memorial Hospital from October to December 2013 were enrolled. Contrast sensitivity and ocular/corneal total high-order, coma, and spherical aberrations (SA) were tested before OOK treatment. After 28 days of overnight use, CSF and topography were reexamined, and data were collected and analyzed using t test and Pearson correlation coefficients.

RESULTS

In total, 23 eyes of 23 children and 14 eyes of 14 adults were evaluated. The treatment resulted in a significant increase in ocular total HOA, coma, and SA in both groups. However, CSF declined more in adults than children.

CONCLUSION

Our study revealed that OOK lenses decrease CSF to a greater extent in adults than that in children despite no significant differences in the change of ocular HOAs between both subject groups. We proposed children may have better neural adaptation to compensate for optical aberrations induced by OOK lens use.

Practice of orthokeratology in Algeria: a retrospective study

PURPOSE

To report the practice of orthokeratology (OK) in Algeria and to investigate the visual outcomes, safety and subjective responses with this technique in myopes.

METHODS

A retrospective chart review of 48 participants using OK lenses since January 2010 were included in the study. Lenses were selected and fitted according to the manufacturer's recommendations using their respective software and the number of lenses required for a successful fit was recorded. Visual acuity (VA) in logMAR units and biomicroscopic findings were recorded for each visit. Subjective ratings was determined with analogue rating scale was filled in by the investigator, the participants were divided into Group 1 (> 4.00D) and Group 2 (< 3.75D) myopic groups for analysis.

RESULTS

First lens fitting success rate of 64.58%. There was also a significant difference between the BCVA at baseline and VA at Day 1 (P < 0.05), and no significant difference at Day 7, Day 30 and the final visit (P = 0.51, P = 0.93, P = 0.62, respectively), for Group 2. There was a significant difference between the BCVA at baseline and VA at Day 1, 7, 30 and the final visit (P < 0.05), for Group 1. the patients of the second group were happier but the results from the survey were not statistically significant (P = 0.10), no serious complication was reported.

CONCLUSION

the technique was efficient and safe as we didn't have any serious complication, with a high success rate for first lens fitting.

Blur Detection Sensitivity Increases in Children Using Orthokeratology

Purpose

To investigate changes in blur detection sensitivity in children using orthokeratology (Ortho-K) and explore the relationships between blur detection thresholds (BDTs) and aberrations and accommodative function.

Methods

Thirty-two children aged 8–14 years old who underwent Ortho-K treatment participated in and completed this study. Their BDTs, aberrations, and accommodative responses (ARs) were measured before and after a month of Ortho-K treatment. A two forced-choice double-staircase procedure with varying extents of blur in three images (Tumbling Es, Lena, and Street View) was used to measure the BDTs. The participants were required to judge whether the images looked blurry. The BDT of each of the images (BDT_Es, BDT_Lena, and BDT_Street) was the average value of the last three reversals. The accommodative lag was quantified by the difference between the AR and the accommodative demand (AD). Changes in the BDTs, aberrations, and accommodative lags and their relationships were analyzed.

Results

After a month of wearing Ortho-K lenses, the children’s BDT_Es and BDT_Lena values decreased, the aberrations increased significantly (for all, P ≤0.050), and the accommodative lag decreased to a certain extent [T(31) = 2.029, P = 0.051]. Before Ortho-K treatment, higher-order aberrations (HOAs) were related to BDT_Lena (r = 0.463, P = 0.008) and the accommodative lag was related to BDT_Es (r = −0.356, P = −0.046). After one month, no significant correlations were found between the BDTs and aberrations or accommodative lags, as well as between the variations of them (for all, P ≥ 0.069).

Conclusion

Ortho-K treatment increased the children’s level of blur detection sensitivity, which may have contributed to their good visual acuity.

The influence of orthokeratology compression factor on ocular higher-order aberrations

BACKGROUND

To investigate the influence of compression factor upon changes in ocular higher-order aberrations (HOAs) in young myopic children undergoing orthokeratology treatment.

METHODS

Subjects aged between six and < 11 years, with low myopia (0.50-4.00 D inclusive), low astigmatism (≤ 1.25 D), and anisometropia (≤ 1.00 D), were randomly assigned to wear orthokeratology lenses of different compression factors in each eye (one eye 0.75 D and the fellow eye 1.75 D). HOAs were measured weekly over one month of lens wear. Wavefront analysis was conducted over a 5-mm pupil using a sixth order Zernike polynomial expansion. Linear mixed models were used to examine the individual Zernike co-efficients and specific root-mean-square (RMS) error (spherical, comatic, total HOAs) metrics and their changes between the two eyes during the study period.

RESULTS

Twenty-eight myopic (mean manifest spherical equivalent refraction: -2.10 ± 0.58 D) children (median [range] age: 9.3 [7.8-11.0] years) were analysed. Significant interocular differences in HOAs at baseline were observed for Z 6 - 6 and Z 6 - 4 only (both p < 0.05). During the lens wear period, eyes fitted with the increased compression factor showed greater changes in primary spherical aberration ( Z 4 0 , p = 0.04) and RMS values for spherical and total HOAs (both p < 0.01). Considering data from both eyes together, after adjusting for the paired nature of the data, some other Zernike terms ( Z 3 1 and Z 6 0 , both p < 0.01) and the RMS value of comatic aberrations (p < 0.001) significantly increased after one month of orthokeratology treatment. The increase in primary spherical aberration ( Z 4 0 ) was positively correlated with the reduction in spherical equivalent refractive error, but only in eyes fitted with the increased compression factor (r = 0.69, p < 0.001).

CONCLUSIONS

Increasing the orthokeratology compression factor by 1.00 D significantly altered some HOAs, particularly spherical aberration. Given the association between positive spherical aberration and eye growth in children, further research investigating the influence of orthokeratology compression factor on axial eye growth is warranted.

Vision Improvement and Compliance With the Use of Orthokeratology Lenses in School Children: A Sample From Five Primary Schools in Northern Taiwan

PURPOSE

To assess the visual acuity and compliance with the use of orthokeratology lenses (OrthoK) in school children.

METHODS

A retrospective study was conducted to determine the education-related factors influencing the improvement in visual acuity in myopic students using OrthoK in five primary schools in Taiwan.

RESULTS

Of the 5,173 eligible students from five primary schools, 1906 (36.8%) students were diagnosed with myopia. Among 201 (10.6%) students wearing OrthoK, 69.7% had used them for at least 1 year, 53.2% achieved visual acuity greater than 0.8 (6/7.5, log of minimal angle of resolution 0.1) in school, and 49.8% had received health education related to OrthoK care. Multiple logistic regression analysis showed that a higher possibility to achieve visual acuity greater than 0.8 was associated with more than 1-year use of OrthoK, good compliance, and receiving health education from an ophthalmologist.

CONCLUSION

It is important that children wearing OrthoK receive education and comply with the use of OrthoK for visual acuity improvement.

Utility of orthokeratology contact lenses; efficacy of myopia correction and level of patient satisfaction in Iranian myopic/myope-astigmatic patients

Purpose

To investigate the medical profiles of patients referred to Iran Lens Clinic with myopic/myope-astigmatic refractive errors.

Methods

Medical records of 182 patients (364 eyes) with myopic/myope-astigmatic refractive errors that underwent orthokeratology contact lens wear and fulfilled a 6-month period of follow-up were recruited. Efficacy and safety of these contact lenses in improving the visual acuity and correction of the refractive errors were investigated. Time needed to achieve final targeted visual acuity and association of various factors in this time course and level of acuity were investigated. Complications related to these lenses that were recorded in the medical profiles were studied.

Results

In manifest refraction, the amount of spherical equivalent and myopia decreased significantly after orthokeratology contact lens wear (P < 0.001). A significant negative association was found between amount of mean baseline spherical equivalent and final achieved mean uncorrected visual acuity (P < 0.001). None of the parameters of age, gender, and keratometric findings influenced the outcomes significantly (P > 0.1).

Conclusion

Patients with myopic refractive error lower than −5.0 Diopters achieved higher final visual acuities rather than patients with higher amounts of myopic refractive errors.

Peripheral optics with bifocal soft and corneal reshaping contact lenses

PURPOSE

To determine whether bifocal soft contact lenses with a distance center design provide myopic defocus to the peripheral retina similar to corneal reshaping contact lenses.

METHODS

Myopic subjects underwent five cycloplegic autorefraction readings centrally and at 10, 20, and 30 degrees temporally, nasally, superiorly, and inferiorly while wearing Proclear Multifocal "D" contact lenses with a +2.00-diopter add power (CooperVision, Fairport, NY) and after wearing Corneal Refractive Therapy (Paragon Vision Sciences, Mesa, AZ) contact lenses for 2 weeks.

RESULTS

Fourteen subjects completed the study. Nine (64%) were female, and 12 (86%) were white. The average (± SD) spherical equivalent noncycloplegic manifest refraction for the right eye was -2.84 ± 1.29 diopters. The average logMAR best-corrected, binocular, high-contrast visual acuity was -0.17 ± 0.15 while wearing the bifocal soft contact lenses and -0.09 ± 0.16 after corneal reshaping contact lens wear (analysis of variance, p = 0.27). The orthokeratology contact lens yielded a more myopic peripheral optical profile than the soft bifocal contact lens at 20 and 30 degrees eccentricity (except inferior at 20 degrees); the two modalities were similar at 10 degrees eccentricity.

CONCLUSIONS

Our data suggest that the two modalities are dissimilar despite the statistical similarities. The corneal reshaping contact lens shows an increase in relative peripheral myopic refraction, a pattern achieved by other studies, but the bifocal lens does not exhibit such a pattern. The low statistical power of the study could be a reason for lack of providing statistical difference in other positions of gaze, but the graphical representation of the data shows a marked difference in the peripheral optical profile between the two modalities. More sophisticated methods of measuring the peripheral optical profile may be necessary to accurately compare the two modalities and to determine the true optical effect of the bifocal soft contact lens on the peripheral retina.