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

Efficacy of Trial Fitting and Software Fitting for Orthokeratology Lens: One-Year Follow-Up Study

OBJECTIVE

To observe and compare the clinical efficacy of 1-year trial fitting and software fitting orthokeratology lenses.

METHODS

One hundred myopes who received vision correction with the use of orthokeratology lenses form July 2016 to September 2017 were included in this study. Subjects were assigned randomly into the two groups: the trial fitting group (group A) and the software fitting group (group B). For the right eye of each subject, measurements, such as uncorrected visual acuity (UCVA, logarithm of minimal angle of resolution), refractive error, corneal topography, ocular health status, and the fitting situation, were obtained at baseline, 1 week, 1 month, 3 months, 6 months, and 12 months after lens wear. Axial length and corneal endothelium cells (CECs) were also measured at baseline and 12 months after wearing the lens.

RESULTS

Compared with the baseline, the spherical equivalent refraction, UCVA, and central corneal curvature changed significantly after orthokeratology (OK) lens wear (all P<0.05). Between groups A and B, the parameters aforementioned were insignificant at each time point (all P>0.05). Axial length and CECs showed no significant changes during the first year of OK treatment (all P>0.05). Rate of corneal staining between two groups revealed no difference during 1-year visit (P<0.05).

CONCLUSION

Both the trial lens fitting and software fitting approaches were effective in temporarily reducing myopia, providing good UCVA and delaying the elongation of axial length for moderate and high myopic adolescents. Both the two approaches can be combined in OK lens fitting.

Accommodation function comparison following use of contact lens for orthokeratology and spectacle use in myopic children: a prospective controlled trial

AIM

To study effects of orthokeratology (Ortho-k) on accommodation function in myopic children.

METHODS

A prospective, non-randomized, case-control study was performed from September to October 2016. Eighty-three children with myopia were divided into two groups. One group was treated with the rigid contact lens for overnight Ortho-k, and the other was treated with single-vision spectacle lens (SVL). Accommodation function were assessed by accommodative amplitude (AA), accommodative sensitivity (AS), accommodative lag (Lag), negative relative accommodation (NRA), and positive relative accommodation (PRA) before and 1, 3, 6 and 12mo after treated.

RESULTS

Totally 72 myopic children were finished the follow-up: 37 in Ortho-k group and 35 in SVL group. Wearing time had a significant effect on AA, AS, Lag, and NRA of myopic children in two groups (all P<0.05). Meanwhile, there was an interaction effect between wearing time and wearing types (F_AA=5.3, F_AS=45.5, F_Lag=7.0, F_NRA=3.7, all P<0.05). However, the between-group difference of AA (F=0.1), AS (F=3.2), Lag (F=1.1), NRA (F=0.3), and PRA (F=0.1) showed no significance. AA, AS, NRA, Lag and PRA were improved significantly in Ortho-k group within 1 to 6mo after wearing.

CONCLUSION

Wearing Ortho-k can improve the accommodation function of myopic children, which might be one of the mechanisms for myopia control.

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.

Factors Determining Effective Orthokeratology Treatment for Controlling Juvenile Myopia Progression

BACKGROUND

We aimed to identify factors influencing the therapeutic outcome of orthokeratology on controlling juvenile myopia progression, and the risk factors for complications.

METHODS

Myopic patients (n=724) in Shenzhen Second Hospital from Jan 2011 to Jan 2016 fitted with orthokeratology lenses and followed-up for 6-65 months were reviewed retrospectively. Univariate and multivariate logistic regression analyses were used to screen for the factors that can improve treatment outcome and prevent the development of complications.

RESULTS

Patients where the orthokeratology treatment was effective displayed a shorter myopia time, smaller diopter and corneal curvature, larger corneal endothelium density, high proportion of overnight wear and longer wearing times compared with patients whose treatments were ineffective. Additionally, wearing Ortho-k for 6 or 12 months yielded improved corrective effect and achieved higher comfort level. Logistic regression analyses showed that myopia time, diopter, corneal curvature e value, corneal endothelium density, time with Ortho-k and corrective effect after wearing Ortho-k for 6 or 12 months were all independent factors influencing the treatment effects. Results showed corneal curvature, anterior chamber depth and central corneal thickness were independent risk factors.

CONCLUSION

This study systematically identified the factors leading to effective treatments, and those carrying a risk for complications, to provide guidance for the prescription and follow-up of orthokeratology in the treatment of juvenile myopia.

Orthokeratology: clinical utility and patient perspectives

Orthokeratology (ortho-k) is a special rigid contact lens worn at night to achieve myopic reduction and control. This review provides an overview on prescribing ortho-k, including clinical consideration on patient aspect and lens design; its clinical outcomes; and clinical efficacy and safety. Patient satisfaction was summarized. In order to achieve long-term healthy ortho-k treatment, it requires both patient and practitioners' care and rapport to maintain good ocular health and lens conditions.