A Randomized Trial Using Progressive Addition Lenses to Evaluate Theories of Myopia Progression in Children with a High Lag of Accommodation

Abstract

The statistically significant, but clinically small, PAL effect suggests that treatments aimed at reducing foveal defocus may not be as effective as previously thought in myopic children with high accommodative lag. Finding no evidence of treatment loss after discontinuing PAL wear supports hyperopic defocus-based theories such as accommodative lag; however, not finding an association between accommodative lag and myopia progression is inconsistent with the PAL effect being due to decreased foveal blur during near work. (Clinical Trials.gov number, NCT00335049.).

The progression of corrected myopia

“…According to our model, under-correction of myopia should reduce the progression of myopia only slightly, since the eye is still substantially corrected. Reports of the effect of under-correction, for distance and near, are varied as the following reports exemplify [12][13][14][15][16][17][18][19]. The conflicting results may be due to the small effect of under-correction and the difficulty of the experiment.…”

Higher spherical equivalent refractive errors is associated with slower axial elongation wearing orthokeratology

“…At present, orthokeratology (OK) is the most effective non-pharmacological method in slowing down myopia progression compared to the use of single-vision spectacle lenses (SV) [3][4][5], bifocal spectacles [6], progressive addition lenses [7,8], soft lenses [9], and rigid gas-permeable contact lenses (RGP) [10]. However, the biggest challenge is to identify those children who may benefit from the use of OK. Investigators have tried to identify the factors affecting the efficacy of OK in myopic control such as initial age [11][12][13][14], spherical equivalent refractive errors (SER) [11][12][13][14][15], pupil diameter [13,16], age of myopia onset [13], myopia progression 2 years before baseline [13], anterior chamber depth [13], and parental refraction [13].…”

Value of Confocal Microscopy of the Cornea in Assessment of the Adaptation Period at Patients with Myopia when Using Orthokeratological Lenses

“…В настоящее время у детей и подростков для коррек-ции и контроля миопии применяются различные виды оптических средств коррекции зрения [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15], в том чис-ле ортокератологические линзы (ОКЛ) [16][17][18][19][20][21][22][23]. Извест-но, что для создания рефракционного эффекта в дизай-не ОКЛ используется принцип «обратной» геометрии.…”