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CONTEXT: Authors have refined myopia control strategies (MCS) from their experience treating more than 800 children who were followed at the Montreal School of Optometry Clinic (CUV). They developed a treatment algorithm known as the Montreal Experience (ME). Contrary to many other MCS, treatment modalities are selected after careful evaluation of a patient’s parameters (rate of progression, age of myopia onset, corneal parameters, pupil area), the risk factors for ocular pathology (growth charts), and taking into account the patient’s lifestyle and potential compliance. This represents a customized approach for each patient. PURPOSE: To evaluate the efficacy of MCS used following ME algorithm; the primary outcome relates to axial length progression over 24 months. METHODS: This is a retrospective study, conducted after approval of University IRB. Data were extracted from the file of each patient who: (1) consulted CUV between January 2017 and December 2018 and (2) were kept under the same MCS (same design/concentration). Clinical population is composed of 298 patients (35% Caucasian; 45% Asian; 20% others), with a median age of 11 (range 5–18). The treatment options were orthokeratology (OK-4 designs; N = 140), multifocal soft contact lenses (SMCL; 5 designs; N = 128), and low-dose atropine (LDA 0.01% to 0.25%; N = 42). RESULTS: Results are analyzed through sophisticated statistical models, designed for this purpose. At the end of a stepwise selection process that sequentially removed model terms that were not statistically significant, nine model terms remained: month, modality, the interaction of month and modality, refraction (SEQ), the interaction of SEQ and modality, gender, age, the interaction of age and month, and the interaction of age and modality. A total of 298 files were kept for analysis. Participant age varied from 9.7 to 12.5 years old. Baseline AL varied from 24.9 to 25.3 mm and SE refraction was −3.7 + 1.7 D on average. This study population was divided between Caucasian (34%), Asian (44%), and other ethnic origins (22%). Overall results indicate that results vary according to modality and months only. There is no statistical difference based on age, gender, and SEQ. All methods used were effective to slow the natural AL growth. Evolution was the lowest when using smaller treatment zones OK lenses (0.249 mm) and the highest (0.376 mm) for those treated with LDA. This OK advantage was statistically significant versus other modalities at 1 and 2 years. CONCLUSION: The Montreal Experience reveals that personalized MCS may be effective to manage myopia efficiently. It shows AL evolution comparable to the documented natural evolution of emmetropes, especially when using customized or smaller treatment zone OK lens design. Future work on other populations will confirm this tendency.

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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.

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Purpose: The purpose of this study was to retrospectively examine data from patients who had undergone orthokeratology (OK) to quantify the amount of mid-perpheral steeping in tangential curvature (MP-TC) and total refractive power (TRP) changes. Methods: Charts were reviewed from participants and data from the Pentacam instrument were collected prior to OK and after the final visit. Variables included central flattening (C-TC), the e-value, the mid-peripheral tangential curvatures (MP-TC), total corneal refractive power (TRP), the initial Rx (sphere) and initial corneal curvature (flat K). The group was further subdivided into high and low myopia for comparison. All participants were fitted with the Paragon CRT lenses. Data analysis was conducted to analyse the effects of lenses on TC and TRP. Results: A total of 40 patients (80 eyes) age13.95±6.80, 34 M and 46 F, were successfully fitted with CRT lenses. The average sphere was -4.23±0.90D for Group 1 and -1.89±0.62D for Group 2 The changes in TC and TRP from baseline were significant (both P<0.0001). The difference between the amount of C-TC and the maximum area of MPTC was ≈4.00D in the horizontal meridian and ≈3.00 in the veritcal meridian. The amount of MP-TC change from baseline was ≈2.00D in both meridians. There was a similar change in TRP: the distance from the centre to mid-periphery ≈2.50D. For C-TC, C-TRP, MP-TC, MP-TRP there was no significant difference between the 2 groups, overall (P=0.541 (TC) and P=0.321(TRP)). Conclusion: Results from this study should provide valuable insights into the topographic and refractive changes occurring with orthokeratology.

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