Two-year add-on effect of using low concentration atropine in poor responders of orthokeratology in myopic children

Axial Length Shortening after Combined Repeated Low-Level Red-Light Therapy in Poor Responders of Orthokeratology in Myopic Children

Purpose

To investigate the efficacy and safety of orthokeratology (ortho-k) and repeated low-level red-light (RLRL) therapy in treating poor responders of ortho-k in myopic children.

Methods

Study participants were 100 myopic children who completed two years of ortho-k treatment in a retrospective study. In the first year of ortho-k treatment (phase one), they experienced axial elongation of 0.30 mm or greater (defined as poor responders to ortho-k). Children were divided into two groups: the orthokeratology group (OK, n = 45) continued to receive ortho-k monotherapy and the combination group (OK-RLRL, n = 55) received RLRL in addition to ortho-k for the next year (phase two). Axial elongation over time between the groups was compared.

Results

The mean age, male-to-female ratio, axial length (AL), and axial elongation in phase one were comparable between OK and OK-RLRL groups (all P > 0.05). During phase two, significant AL shortening was observed in the OK-RLRL group compared with children in the OK group (-0.10 ± 0.16 mm vs 0.30 ± 0.19 mm, P < 0.001). Among these 55 myopic children in the OK-RLRL group, 35 (63.6%), 25 (45.4%), 11 (20%), 6 (10.9%), and 3 (5.4%) of them had AL shortening over 0.05 mm/year, 0.10 mm/year, and 0.20 mm/year, 0.3 mm/year, and 0.4 mm/year, respectively. Older baseline age (β = -0.02), higher treatment compliance (β = -0.462), and AL change at 1 month (β = 1.263) were significantly associated with less AL elongation (all P < 0.05).

Conclusions

For poor responders of orthokeratology, RLRL could slow axial elongation in addition to the ortho-k treatment effect. Those who respond poorly to ortho-k with elder age might benefit more from combined therapy.

Combined 0.01% atropine with orthokeratology in childhood myopia control (AOK) study: A 2-year randomized clinical trial

BACKGROUND

To investigate whether combining 0.01% atropine with orthokeratology (AOK) has a better effect in retarding axial elongation, compared with orthokeratology alone (OK) over two years.

METHODS

A total of 96 Chinese children aged six to < 11 years with myopia (1.00 - 4.00 D, inclusive) were randomized into either the AOK or OK group in a 1:1 ratio. Axial length (the primary outcome), and secondary outcomes (e.g. pupil size and choroidal thickness) were measured at 1-month and at 6-monthly intervals after commencement of treatment.

RESULTS

Both intention-to-treat and per-protocol analyses showed significantly slower axial elongation in the AOK group than OK group over two years (P = 0.008, P < 0.001, respectively). AOK subjects had statistically slower axial elongation (adjusted mean [standard error], 0.17 [0.03] mm vs 0.34 [0.03] mm, P < 0.001), larger increase in mesopic (0.70 [0.09] mm vs 0.31 [0.09] mm, P = 0.003) and photopic pupil size (0.78 [0.07] mm vs 0.23 [0.07] mm, P < 0.001), and greater thickening of the choroid (22.6 [3.5] µm vs -9.0 [3.5] µm, P < 0.001) than OK subjects over two years. Except for a higher incidence of photophobia in the AOK group (P = 0.006), there were no differences in the incidence of any other symptom or adverse events between the two groups. Slower axial elongation was associated with a larger increase in the photopic pupil size and a greater thickening in the choroid in the AOK group.

CONCLUSIONS

Slower axial elongation following 2-year AOK treatment may result from increased pupil dilation and a thickening in the choroid observed in the AOK group.

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.

Use baseline axial length measurements in myopic patients to predict the control of myopia with and without atropine 0.01

PURPOSE

Identifying axial length growth rate as an indicator of fast progression before initiating atropine 0.01% for myopia progression in children.

METHOD

From baseline, axial length growth over six months was measured prospectively. Subjects were then initiated on atropine 0.01% if axial length growth was greater than 0.1mm per 6 months (fast progressors), axial length and spherical equivalent change measurements recorded every six months. The rate of change was compared to the baseline pre-treatment rate. If axial length change was below the threshold, subjects received monitoring only.

RESULTS

73 subjects were identified as fast progressors and commenced atropine 0.01%, (mean baseline refraction of OD -2.9±1.6, OS -2.9±1.8 and a mean baseline axial length OD 24.62 ± 1.00 mm, OS 24.53 ± 0.99 mm). At six months, the mean paired difference of axial length growth rate was significantly reduced by 50% of baseline (all 73 subjects, p<0.05). 53 subjects followed to 12 months, and 12 to 24 months maintained a reduced growth rate. Change in mean spherical equivalent was significantly reduced compared to pre-treatment refractive error (mean paired difference p<0.05) and at each subsequent visit. 91 children were slow progressors and remained untreated. Their axial length growth rate did not change significantly out to 24 months. Spherical equivalent changed less than -0.5D annually in this group.

CONCLUSION

Identifying fast progressors before treatment initiation demonstrated a strong treatment effect with atropine 0.01% reducing their individual rate of myopia progression by 50%. Another large group of myopic children, slow progressors, continued without medical intervention. A baseline axial length growth rate is proposed as a guideline to identify fast progressors who are more likely to benefit from atropine 0.01%.