RESUMO
Ocular accommodation refers to the process by which the ciliary muscle creates a clear image of the object in the retina by changing the refractive power of the lens. When the accommodation ability of the eye is insufficient, the imaging focus falls on the region behind the retina and hyperopic defocus is easily formed, resulting in axial growth and leading to the development of myopia, and it is found that most myopic patients usually have some accommodation dysfunction. Myopia has become a public health problem in China, and the prevalence of adolescents has increased dramatically. How to prevent and stop the occurrence and development of myopia is a major challenge. Previous studies have found that ocular accommodation dysfunction is associated with the occurrence and development of myopia, and the measurement of parameters related to accommodation function has certain guiding significance for the prevention and control of myopia. The purpose of this paper is to review the correlation between myopia and ocular accommodation function, with a view to providing new ideas for the prevention, control and treatment of myopia.
RESUMO
?AlM: To discuss the differences in accommodative lag of different stimulation between the adolescent myopes who wore rigid gas permeable contact lens ( RGPCL ) and spectacles for one year. ?METHODS: Totally 85 myopes between 10-16y were enrolled in the study. Every subject was examined with the visual function test, medical optometry, corneal topography and ocular health check etc. of eyes. According to the above measurements and the compliance of children and their parents, 41 subjects were selected to wear RGPCL, 44 subjects were chosen to wear spectacles. Based on maximum plus to maximum visual acuity ( MPMVA) , accommodative lag was determined by dynamic retinoscopy method in two groups. The subjects were examined once every 3mo, accommodative lag was measured again using the same method for comparative analysis after one year. Wearing a year later, myopia progression of the two groups was measured and compared. ?RESULTS: There was no significant difference between two groups of initial accommodative lag (P>0. 05). After wearing one year, there was also no significant difference between the accommodative lag examined and the initial lag in RGPCL group (P>0. 05), the results demonstrate significant difference between the accommodative lag examined after wearing one year and the initial lag in spectacles group ( P ?CONCLUSlON:After wearing RGPCL and spectacles one year in high accommodative stimulus, there is an obviously decreased in accommodative lag in RGPCL group, which suggests that RGPCL can control the progression of myopia in adolescents. The accommodative lag of the two groups increase obviously with increasing stimulation, which suggest that the adolescents need keeping good habits of reading.
RESUMO
PURPOSE: To determine the relationship between the high-frequency component of accommodative microfluctuation (HFC) and accommodative lag in presbyopic eyes and how they affect the subjective accommodation power with other ophthalmic factors, such as pupil diameter and corneal multifocality. METHODS: Forty subjects (80 eyes) were included in this study, and the non-corrected distance and near visual acuity was measured and then converted to log MAR vision. The addition power for 33 cm near visual work was also measured and the accommodative power was measured by the push-up method. The HFC, accommodative lag and pupil size according to accommodative stimuli (-1.0 to -3.0 D) was measured by Speedy-i Autorefractor (Right Mfg Co., Tokyo). The corneal multifocality and corneal astigmatism was measured by corneal topography (TMS-4; Tomey, Erlangen, Germany). RESULTS: The mean age was 60.0 +/- 4.66 years (51-68) and there were 23 male and 17 female subjects (1.35:1). The HFC and pupil size showed no significant change according to accommodation demand, however, the accommodative lag showed a statistically significant increase (p < 0.001 by one-way ANOVA). Accommodative lag (-2.0 D) showed a statistically significant negative correlation with the subjective accommodative power, and the pupil size (0 D) showed a positive correlation with the subjective accommodative power. CONCLUSIONS: In presbyopia patients, the objective accommodative lag and initial pupil size showed a statistically significant relationship with subjective accommodative power. On the other hand, HFC, pupil size and corneal multifocality, alone may not be indicators to predict accommodative power, but these are important components to explain the dynamic aspect of accommodation.