Myopia control with orthokeratology contact lenses in Spain (MCOS):study design and general baseline characteristics

Purpose: Although previous studies suggest that orthokeratology contact lens wear slows eye growth in children with progressing myopia, some limitations in the methodology employed have become evident. Furthermore, the safety of this modality of visual correction has not been assessed. The study "Myopia Control with Orthokeratology Contact Lenses in Spain" (MCOS) is being conducted to compare axial length growth between white European myopic children wearing orthokeratology contact lenses (OK) and wearing distance single-vision spectacles (SV). Additionally, the incidence of adverse events and discontinuations is also recorded. We outline the methodology and baseline data adopted. Methods: Subjects aged 6 to 12, with myopia ranging from 0.75 to 4.00 D and astigmatism ≤1.00 D were prospectively allocated OK or SV correction. Measurements of axial length, anterior chamber depth, corneal topography, cycloplegic autorefraction, visual acuity and corneal staining are performed at 6-month intervals. The incidence of adverse events and discontinuations are also recorded. Results: Thirty one children were fitted with OK and 31 with SV correction. Eight subjects did not meet the refraction-related inclusion criteria for enrollment. No significant differences were found in baseline mean age and refractive and biometric data between the two groups (P>0.05). No adverse events were found in any of the two groups at baseline. Conclusion: To the authors' knowledge, MCOS is the first prospective clinical trial to assess the safety and efficacy of orthokeratology contact lens wear to slow myopia progression vs. single-vision spectacle wear. The MCOS offers a number of notable features: prospective design; well-matched samples and high-resolution ocular biometry measures, which should collectively elucidate whether orthokeratology contact lens wear is a feasible and safe method for myopia-progression control

Myopia control with orthokeratology contact lenses in Spain (MCOS):refractive and biometric changes

PURPOSE. To compare axial length growth between white children with myopia wearing orthokeratology contact lenses (OK) and distance single-vision spectacles (SV) over a 2-year period. METHODS. Subjects 6 to 12 years of age with myopia -0.75 to -4.00 diopters of sphere (DS) and astigmatism ≤1.00 diopters of cylinder (DC) were prospectively allocated OK or SV correction. Measurements of axial length (Zeiss IOLMaster), corneal topography, and cycloplegic refraction were taken at 6-month intervals. RESULTS. Thirty-one children were fitted with OK and 30 with SV. Following 24 months, axial length increased significantly over time for both the OK group (0.47 mm) and SV group (0.69 mm; P 0.05). Significantly greater corneal flattening was evident in the OK group for the flatter and steeper corneal powers and for corneal shape factor (all P ≤0.05). CONCLUSIONS. Orthokeratology contact lens wear reduces axial elongation in comparison to distance single-vision spectacles in children

Short-term and long-term changes in corneal power are not correlated with axial elongation of the eye induced by orthokeratology in children

PURPOSE: To assess the relationship between short-term and long-term changes in power at different corneal locations relative to the change in central corneal power and the 2-year change in axial elongation relative to baseline in children fitted with orthokeratology contact lenses (OK). METHODS: Thirty-one white European subjects 6 to 12 years of age and with myopia −0.75 to −4.00 DS and astigmatism ≤1.00 DC were fitted with OK. Differences in refractive power 3 and 24 months post-OK in comparison with baseline and relative to the change in central corneal power were determined from corneal topography data in eight different corneal regions (i.e., N[nasal]1, N2, T[temporal]1, T2, I[inferior]1, I2, S[superior]1, S2), and correlated with OK-induced axial length changes at two years relative to baseline. RESULTS: After 2 years of OK lens wear, axial length increased by 0.48±0.18 mm (P0.05). CONCLUSION: The reduction in central corneal power and relative increase in paracentral and pericentral power induced by OK over 2 years were not significantly correlated with concurrent changes in axial length of white European children

Short- and long-term changes in corneal aberrations and axial length induced by orthokeratology in children are not correlated

PURPOSE: To assess the correlation between changes in corneal aberrations and the 2-year change in axial length in children fitted with orthokeratology (OK) contact lenses. METHODS: Thirty-one subjects 6 to 12 years of age and with myopia −0.75 to −4.00DS and astigmatism ≤1.00DC were fitted with OK. Measurements of axial length and corneal topography were taken at regular intervals over a 2-year period. Corneal topography at baseline and after 3 and 24 months of OK lens wear was used to derive higher-order corneal aberrations (HOA) that were correlated with OK-induced axial length changes at 2 years. RESULTS: Significant changes in C3, C4, C4, root mean square (RMS) secondary astigmatism and fourth and total HOA were found with both 3 and 24 months of OK lens wear in comparison with baseline (all P0.05). Coma angle of orientation changed significantly pre-OK in comparison with 3 and 24 months post-OK as well as secondary astigmatism angle of orientation pre-OK in comparison with 24 months post-OK (all P0.05). DISCUSSION: Short-term and long-term OK lens wear induces significant changes in corneal aberrations that are not significantly correlated with changes in axial elongation after 2-years

The effects of entrance pupil centration and coma aberrations on myopic progression following orthokeratology

Background: The aim was to assess the potential association between entrance pupil location relative to the coaxially sighted corneal light reflex (CSCLR) and the progression of myopia in children fitted with orthokeratology (OK) contact lenses. Additionally, whether coma aberration induced by decentration of the entrance pupil centre relative to the CSCLR, as well as following OK treatment, is correlated with the progression of myopia, was also investigated. Methods: Twenty-nine subjects aged six to 12years and with myopia of -0.75 to -4.00 DS and astigmatism up to 1.00DC were fitted with OK contact lenses. Measurements of axial length and corneal topography were taken at six-month intervals over a two-year period. Additionally, baseline and three-month topographic outputs were taken as representative of the pre- and post-orthokeratology treatment status. Pupil centration relative to the CSCLR and magnitude of associated corneal coma were derived from corneal topographic data at baseline and after three months of lens wear. Results: The centre of the entrance pupil was located superio-temporally to the CSCLR both pre- (0.09±0.14 and -0.10±0.15mm, respectively) and post-orthokeratology (0.12±0.18 and -0.09±0.15mm, respectively) (p>0.05). Entrance pupil location pre- and post-orthokeratology lens wear was not significantly associated with the two-year change in axial length (p>0.05). Significantly greater coma was found at the entrance pupil centre compared with CSCLR both pre- and post-orthokeratology lens wear (both p0.05). Conclusion: Entrance pupil location relative to the CSCLR was not significantly affected by either OK lens wear or an increase in axial length. Greater magnitude coma aberrations found at the entrance pupil centre in comparison to the CSCLR might be attributed to centration of orthokeratological treatments at the CSCLR

Strategies and attitudes on the management of myopia in clinical practice in Spain

Objective In 2019, an international survey was conducted to evaluate strategies and attitudes in the management of myopia in clinical practice worldwide. This study reports on the results found in Spain and how these results compare with those from other regions of the world. Methods A self-administrated, internet-based questionnaire was distributed to eye care professionals around the world through professional associations. The questions examined were based on the available strategies and their use. Results A total of 173 Spanish optometrists, of the 1,336 practitioners from the five different continents who participated in the study, responded to the online survey. Spain, Asia and South America were found among the regions with the highest concern regarding the increased incidence of myopia (p ≤ 0.001). However, in these regions, the prescription of single-vision spectacles and single-vision contact lenses continues to be the main methods of visual correction prescribed to young myopic patients (p ≤ 0.001). Spanish practitioners, like those from other regions, considered orthokeratology to be the most effective treatment to control myopia progression (p ≤ 0.001). The major reasons why Spanish practitioners were not prescribing myopia control strategies were increased cost, inadequate information and unpredictable outcomes (p < 0.05). Conclusions The uptake of myopia control methods by Spanish practitioners is relatively low, despite the increase in the prevalence of paediatric myopia as well as increased concern and perceived clinical activity in the area in recent years

Strategies and attitudes on the management of myopia in clinical practice in Spain - 2022 update

Objective: This study analyses strategies and attitudes on myopia management reported by eye care practitioners (ECP) from Spain in 2022. Methods: A questionnaire was distributed to ECPs worldwide via the internet through professional associations. The questionnaire was distributed by email to all registered Spanish optician-optometrists. Questions examined awareness of increasing myopia prevalence; perceived efficacy; uptake of available approaches; and reasons preventing further uptake of specific approaches. Results: Of 3,107 practitioners who participated in the study, 380 were Spanish ECPs. Using a 10-point scale, Spanish practitioners reported less concern about increasing pediatric myopia (8.3 ± 1.6) compared to ECP's worldwide (8.5 ± 1.9) (p 0.05); however, around half of all prescribed treatments were single-vision distance spectacles/contact lenses both in Spain and in most regions, with Spanish practitioners prescribing less single-vision spectacles than African and Asian (p 0.05), with the former being perceived as the most effective myopia control method followed by orthokeratology. No significant differences were found between Spain and the world's average in factors preventing the prescription of myopia control approaches (p > 0.05). Spanish practitioners reported that embracing myopia management has a positive, but lower impact on customer loyalty, practice revenue and job satisfaction compared with the other regions (all p < 0.001). Conclusions: Myopia control is increasing, although around half of practitioners still prescribe single-vision distance spectacles/contact lenses to young/progressive myopes. Combined therapy followed by orthokeratology were perceived as the most effective treatments. Embracing myopia management improved patient loyalty and job satisfaction

Efficacy of a gas permeable contact lens to induce peripheral myopic defocus

Purpose. The purpose of this work was to evaluate the potential of a novel custom-designed rigid gas permeable (RGP) contact lens to modify the relative peripheral refractive error in a sample of myopic patients. Methods. Fifty-two right eyes of 52 myopic patients (mean [TSD] age, 21 [T2] years) with spherical refractive errors ranging from j0.75 to j8.00 diopters (D) and refractive astigmatism of 1.00 D or less were fitted with a novel experimental RGP (ExpRGP) lens designed to create myopic defocus in the peripheral retina. A standard RGP (StdRGP) lens was used as a control in the same eye. The relative peripheral refractive error was measured without the lens and with each of two lenses (StdRGP and ExpRGP) using an open-field autorefractometer from 30 degrees nasal to 30 degrees temporal, in 5-degree steps. The effectiveness of the lens design was evaluated as the amount of relative peripheral refractive error difference induced by the ExpRGP compared with no lens and with StdRGP conditions at 30 degrees in the nasal and temporal (averaged) peripheral visual fields. Results. Experimental RGP lens induced a significant change in relative peripheral refractive error compared with the nolens condition (baseline), beyond the 10 degrees of eccentricity to the nasal and temporal side of the visual field (p G 0.05). The maximum effect was achieved at 30 degrees. Wearing the ExpRGP lens, 60% of the eyes had peripheral myopia exceeding j1.00 D, whereas none of the eyes presented with this feature at baseline. There was no significant correlation (r = 0.04; p = 0.756) between the degree of myopia induced at 30 degrees of eccentricity of the visual field with the ExpRGP lens and the baseline refractive error. Conclusions. Custom-designed RGP contact lenses can generate a significant degree of relative peripheral myopia in myopic patients regardless of their baselin spherical equivalent refractive error.Jaume Paune´ has proprietary and financial interests in the manufacturing and distribution of lenses evaluated in this study. The remaining authors declare that they do not have any proprietary or financial interest in any of the materials mentioned in this article. This work was partially funded by Fundação para Ciência e Tecnologia, Portugal, Projects: PTDC/SAU-BEB/ 098392/2008 and PTDC/SAU-BEB/098391/200