Visual Outcome in 879 Children Treated for Strabismus: Insufficient Accommodation and Vision Deprivation,Deficient Emmetropisation and Anisometropia

Purpose: To identify the effect of infant hypermetropia on residual amblyopia in children remaining after treatment.

Materials and Methods: 879 strabismic children had cycloplegic retinoscopy at the age of 6 months and later when strabismus was diagnosed. A total of 26 hypermetropes consistently wore glasses from the age of 6 months, and 305 other hypermetropes had their accommodation periodically assessed by dynamic retinoscopy before strabismus was diagnosed. The relation between the last known visual acuity after treatment and all other clinical findings was analysed using t-tests and regression analysis.

Results: Vision less than 6/12 in nonfixing eyes was associated with infantile hypermetropia > +5.0D, and in rare instances in excess of -3.0D of myopia. In hypermetropes only, anisometropia was associated with worse amblyopia. Astigmatism was associated with myopia and low levels of hypermetropia but not with worse vision. The vision of fixing eyes that were hypermetropic was significantly worse than that of emmetropic or myopic eyes. Wearing spectacles from the age of 6 months was associated with better vision in the nonfixing eye. Vision in the nonfixing eye of 19 hypermetropic heterotropes who started wearing glasses between 6 and 18 months of age also was better than that of those who started wearing glasses after 18 months of age. Insufficiency of accommodation was related to the degree of infantile hypermetropia, to worse vision and to failure to emmetropise. Difference in amplitude of accommodation between the eyes was largest in hypermetropes with anisometropia > +1.50 D and was marginally associated with worse vision in microtropes who became anisometropic after infancy. Hypermetropia decreased more in fixing eyes than in nonfixing eyes, thereby causing anisohypermetropia to increase after infancy. This change was most pronounced in hypermetropic microtropes. Conversely, failure of fixing eyes to emmetropise was associated with an increase in their inability to accommodate and heterotropia.

Conclusions: On the basis of these findings, severe residual amblyopia in children remaining after treatment could be explained by additional vision deprivation. It can be reduced by starting spectacle correction of hypermetropia before the age of 18 months. Anisometropia seemed the result of deficient emmetropisation.     

Refractive development in children with Down's syndrome: a population based, longitudinal study

AIMS: To study the refractive development in children with Down's syndrome longitudinally. METHODS: An unselected population of 60 children with Down's syndrome was followed with repeated retinoscopies in cycloplegia for 2 years or more (follow up 55 (SD 23) months). Accommodation was assessed with dynamic retinoscopy. RESULTS: From longitudinal spherical equivalent values of the right eye, three main categories of refraction were defined: stable hypermetropia (<1.5 D difference between the first and last visit) (n=34), increasing hypermetropia ("hypermetropic shift"; >/=1.5 D difference) (n=11), and decreasing hypermetropia/development of myopia ("myopic shift"; >/=1.5 D difference) (n=9). Patients with anisometropia (n=6) were evaluated separately. In the stable hypermetropia group three sublevels were chosen: low (+4.0 D). An accommodation weakness was found in 55% of the children. Accommodation weakness was significantly less frequent in the stable, low grade hypermetropia group (22%) than in all the other groups (p=0.008). The frequency of astigmatism >/=1.0 D at the last visit was 57%, the direction of axis being predominantly "with the rule." All the eyes with oblique astigmatism had a side specific direction of axis; the right eyes belonging to the 135 degrees axis group and the left eyes to the 45 degrees axis group. CONCLUSION: A stable, low grade hypermetropia was significantly correlated with a normal accommodation. Accommodation weakness may be of aetiological importance to the high frequency of refractive errors encountered in patients with Down's syndrome. A striking right-left specificity in the oblique astigmatic eyes suggests that mechanical factors on the cornea from the upward slanting palpebral fissures may be a major aetiological factor in the astigmatism.     

Refractive surgery in anisometropic adult patients induce plastic changes in primary visual cortex

Purpose: To prospectively study the effect of refractive surgery in the primary visual cortex of adult anisometropic and isometropic myopic patients. Methods: Two anisometropic and two isometropic myopic patients were examined with multifocal functional magnetic resonance imaging technique (mffMRI) before refractive surgery and at 3, 6, 9 and 12 months postoperatively. Two controls without refractive surgery were also examined with mffMRI in the beginning and in the end of the study. Anisometropic patients had only their more myopic eye operated to correct the anisometropia. The myopic isometropic patients had their both eyes operated. Results: Operated anisometropic eyes showed 65% reduced amount of active voxels in foveal data at 12 months postoperatively compared with the preoperative situation. In unoperated anisometropic eyes, the corresponding value was 86% and in myopic patients and controls 31% and 1%, respectively. To confirm this finding, the number of activated voxels representing the innermost ring of the stimulus was also calculated, and an exactly similar phenomenon was encountered in the anisometropic patients. Both anisometropic patients improved the best‐spectacle‐corrected visual acuity in the operated eye after refractive surgery. Conclusion: Our results suggest that plastic changes may take place in the primary visual cortex of anisometropic adult patients after refractive surgery.     

Association between accommodative accuracy, hypermetropia, and strabismus in children with Down's syndrome.

PURPOSE: A significant proportion of children with Down's syndrome have been shown to have reduced accommodation. The purpose of this study was to investigate any association between reduced accommodation and refractive error, strabismus, visual acuity, and other ocular parameters. METHODS: Subjects were children with Down's syndrome enrolled in a longitudinal cohort to monitor visual development. Twenty-seven children with accurate accommodation were age-matched to children with reduced accommodation based on their most recent assessment for which a full, reliable data set was available. Each child was used only once for matching. Cross-sectional ocular and visual data were analyzed using chi or Fisher's exact test, or the Mann-Whitney U test for (non-normally distributed) quantitative data. RESULTS: Children with under-accommodation were statistically more likely to have moderate/high hypermetropia (> or = +3.00 D) and to be strabismic (most with esotropia). No significant difference between the groups was found for any other ocular parameters. CONCLUSIONS: This study demonstrates the marked association between under-accommodation, hypermetropia, and strabismus in children with Down's syndrome. No causal relation can be demonstrated with these data, but findings suggest that the link between under-accommodation and hypermetropia (and between accurate accommodation and emmetropia) is present in early infancy.     

Focusing strength and a subjective method for determining refraction

Three hundred and seventy-four eyes were examined by a subjective method, by using trial lenses in natural accommodation. This yielded the following distribution of clinical refraction: hypermetropia (43.6%), emmetropia (30.8%), myopia (12.8%), and astigmatism (12.8%). The classical subjective method of refractometry is based on the schematic eye having no focusing strength. The currently available data by a number of authors show that the focusing strength of more than 0.5 diopters is typical of the human eye, which affects the results of refractometry. When the collecting glass +0.25 D or +0.5 D is applied, the eye with a visual acuity of 1.0 or more retains the level of vision due to the holding the focusing strength across the retina rather than the accommodation strength. By taking in account the correction, the distribution in the study group was as follows: emmetropia (73.0%), myopia (12.8%), astigmatism (12.8%), and hypermetropia (1.4%).     

The binocular accommodative response in uncorrected ametropia.

PURPOSE: To measure the changes in astigmatism and in the degree of anisometropia when ametropes respond to accommodative stimulation. METHODS: The accommodative responses of ametropes were binocularly measured with an improved photorefractometer (PR-1100), which objectively measured binocular refraction in all meridians simultaneously, when a visual fixation target was shown in natural space at 5 and 0.5 m. RESULTS: (1) Changes of astigmatism and anisometropia occur during binocular accommodation. (2) Changes of astigmatism mainly result from lag of accommodation in the horizontal meridian. (3) Changes of anisometropia result from the effort to focus. (4) The interaction of both eyes is suggested as the cause of the changes of astigmatism and anisometropia with accommodation. (5) In the majority of strong anisometropes (nonoverlapping group in this paper), the magnitude of anisometropia decreases (approaching isometropia) with accommodation. CONCLUSION: Changes in astigmatism and anisometropia can occur during accommodation, and these interactions of both eyes with accommodation may contribute to the development and maintenance of binocular function.     

Importance of studying the accommodation function in the diagnosis of clinical forms of hypermetropia

Two hundred and thirty-one patients, aged 6 to 18, with hypermetropia were examined. They were shared between two groups with respect to an accommodation state: group 1--patients with weak accommodation, group 2--patients with normal accommodation. The below ocular parameters were registered for groups 1 and 2, respectively: axial size--22.35 mm and 21.58 mm, corneal diameter--11.48 mm and 10.74 mm, scleral ring diameter in the projection of the scleral central portion--14.66 mm and 13.98 mm, ocular refracting power--59.79 d and 62.23 d, corneal refraction--41.85 d and 42.82 d, and lens refraction--22.05 d and 24.03 d. New clinical signs were specified for uncomplicated type of congenital hypermetropia. The parameters of patients with normal-accommodation hypermetropia are typical of axial hypermetropia in adults due to growth inhibition, while the parameters of patients with weakened accommodation are typical of optical hypermetropia as a variation of normal eye development.     

22例学龄儿童调节痉挛临床诊治体会

目的观察儿童调节痉挛的临床表现,探讨诊疗特点。方法回顾性分析22名调节痉挛患者的临床资料,总结诊治经验。结果22名患儿44只眼初诊平均裸眼视力0．27±0．07,小瞳电脑验光结果均表现近视,等效球镜均值-2．75±0．35D;经0．5％托吡卡胺快速散瞳后检影验光等效球镜均值＋0．68±0．64D,平均矫正视力0．47±0．05;经1％硫酸阿托品凝胶点眼,2次／天,连续5天后检影验光,中度远视者23眼、低度远视者17眼,轻度近视者4眼,44眼散光值均不超过1．0D,等效球镜均值＋2．96±0．93D,矫正视力均可达到0．8以上。结论学龄儿童过强的调节力可导致部分远视患者表现为假性近视状态;对于远视导致调节痉挛的儿童宜使用阿托品散瞳验光。     

Emmetropisation in normal and strabismic children and the associated changes of anisometropia

The purpose of this study was to measure whether emmetropisation failed in children who had strabismus irrespective of their refraction in infancy, and to record simultaneous changes in anisometropia. We also report how often hypermetropia increased before these children presented with esotropia. A total of 2920 infants had a cycloplegic retinoscopy at age 5-7 months and again at 42 months or when defective vision was identified. Changes of refraction in 210 children with strabismus are compared with the remaining 2710 who did not. When the spherical equivalent of the fixing eyes was > +2.75 D in infancy, hypermetropia decreased less in both eyes of those who had microtropia (p <.001) and heterotropia (p <.001) than in normal children. When it was < +2.75 D, the spherical and/or cylindrical refraction more often remained outside the 'normal' range in both eyes of those who had microtropia and heterotropia (p <.05). Emmetropisation was deficient in both eyes of at least 80% of these strabismic children irrespective of their refraction in infancy. Furthermore, in the strabismic children, the mean change of refraction was less (p <.05) in their fellow eyes than in their fixing eyes, the difference between the two eyes being on average three times greater than that in those who had normal vision. Thus, anisometropia increased in 53% of those who had strabismus but remained within normal limits (< ca. 0.75 D spherical equivalent) in 94 % of those who did not. 'Abnormal' anisometropia in infancy did not, per se, permanently affect vision because 72% of all those who had it did not have strabismus. Finally, the spherical hypermetropia of fixing eyes increased in only 35% of the children with esotropia - similar to the incidence in those who had a microtropia (p =.36). This does not obviously support the concept that increasing hypermetropia causes accommodation to increase before convergence.     

Reduction of astigmatism after infancy in children who did and did not wear glasses and have strabismus

The purpose of this study was to record and explain the changes in astigmatism as normal and strabismic infants grew. Two-hundred-and-eighty-nine hypermetropic infants were randomly allocated to wear glasses from the age of six months. Changes in astigmatism and in hypermetropia of the horizontal and vertical meridia were compared in those who did and did not wear glasses and have strabismus. Mean astigmatism decreased significantly (p &lt; 0.001) in both eyes of normal and strabismic children, but the ‘last’ astigmatism was significantly (p &lt; 0.001) larger in both eyes of those who had strabismus. There was a similar progressive decrease of hypermetropia in both meridia of both eyes within each diagnostic group, but with the exception of the vertical meridian of the non-fixating eyes (in which the difference approached statistical significance), this was significantly (p &lt; 0.01) larger in the normal children. The consistent wear of glasses was not associated with change in both meridia of both eyes in the normal children (p &lt; 0.005), but had no significant effect on the changes in astigmatism. Since the changes in the two meridia were proportional to the starting level, hypermetropia decreased more in the meridian which was, initially, the more hypermetropic one, and the difference between them, i.e. astigmatism, tended to disappear whether or not the child eventually had strabismus.     

Strabismus and binocular function in children with Down syndrome. A population-based, longitudinal study

PURPOSE: We have performed a population-based, longitudinal study on strabismus in children with Down syndrome. The aims of the study were to examine the frequency and type of strabismus, the age at onset, and the binocular potential. METHODS: An unselected population of 60 children with Down syndrome born 1988-1999 was followed with repeated examinations. Mean follow-up time was 55+/-23 months (range 24--115). The alignment of the eyes was examined using Hirschberg corneal reflex test and cover test for near fixation. To evaluate binocular function, Titmus House Fly Test and Lang's stereo test were used. RESULTS: Twenty-five patients (42%) had strabismus (21 esotropias, two exodeviations and two vertical deviations). Only one case of infantile esotropia was found, the other esotropias were acquired forms. The mean age at "onset" (e.g. when strabismus was first noticed) was 54+/-35 months. In the acquired esotropia group (n=20), 15 (75%) were associated with hypermetropia (mean spherical equivalent +4.3+/-1.7 D). Seventeen of the strabismic patients had an accommodation weakness. Eleven of the strabismus patients gave a clearly positive response to one or both stereotests. CONCLUSIONS: The majority of the Down syndrome children with strabismus have an acquired esotropia and hence a potential for binocularity. Hypermetropia and accommodation weakness are probably important factors in esotropia in Down syndrome patients.     

Emmetropisation in normal and strabismic children and the associated changes of anisometropia

The purpose of this study was to measure whether emmetropisation failed in children who had strabismus irrespective of their refraction in infancy, and to record simultaneous changes in anisometropia. We also report how often hypermetropia increased before these children presented with esotropia. A total of 2920 infants had a cycloplegic retinoscopy at age 5-7 months and again at 42 months or when defective vision was identified. Changes of refraction in 210 children with strabismus are compared with the remaining 2710 who did not. When the spherical equivalent of the fixing eyes was &gt; +2.75 D in infancy, hypermetropia decreased less in both eyes of those who had microtropia (p &lt;. 001) and heterotropia (p &lt;. 001) than in normal children. When it was &lt; +2.75 D, the spherical and/or cylindrical refraction more often remained outside the ‘normal’ range in both eyes of those who had microtropia and heterotropia (p &lt;. 05). Emmetropisation was deficient in both eyes of at least 80% of these strabismic children irrespective of their refraction in infancy. Furthermore, in the strabismic children, the mean change of refraction was less (p &lt;. 05) in their fellow eyes than in their fixing eyes, the difference between the two eyes being on average three times greater than that in those who had normal vision. Thus, anisometropia increased in 53% of those who had strabismus but remained within normal limits (&lt; ca. 0.75 D spherical equivalent) in 94 % of those who did not.‘Abormal’ anisometropia in infancy did not, per se, permanently affect vision because 72% of all those who had it did not have strabismus. Finally, the spherical hypermetropia of fixing eyes increased in only 35% of the children with esotropia – similar to the incidence in those who had a microtropia (p =. 36). This does not obviously support the concept that increasing hypermetropia causes accommodation to increase before convergence.     

Effect of spectacles on changes of spherical hypermetropia in infants who did, and did not, have strabismus

AIM: To explore why emmetropisation fails in children who have strabismus. METHODS: 289 hypermetropic infants were randomly allocated spectacles and followed. Changes in spherical hypermetropia were compared in those who had strabismus and those who did not. The effect of wearing glasses on these changes was assessed using t tests and regression analysis. RESULTS: Mean spherical hypermetropia decreased in both eyes of "normal" children (p<0.001). The consistent wearing of glasses impeded this process in both eyes (p<0.007). In the children with strabismus, there were no significant changes in either eye, irrespective of treatment (p>0. 05). CONCLUSIONS: In contrast with normal infants, neither eye of those who had strabismus emmetropised, irrespective of whether the incoming vision was clear or blurred. It is suggested that these eyes did not "recognise" the signal of blurred vision, and that they remained long sighted because they were destined to squint. Hence, the children did not squint because they were long sighted, and glasses did not prevent them squinting.     

Strabogenesis in case of low hypermetropia, in addition a simple comparison test to detect aniseikonia (author's transl)]

Author attempts to explain the rise of infantile convergent squint, when the hypermetropia is less than 3,5 diopter. In such cases the low hypermetropia is relative in the sense of Donders, because a sometimes isometropic aniseikonia prevents the fusion. To examine the aniseikonia he recommands a very simple procedure, the comparison test, carried out joined to the cover test.     

儿童远视眼的屈光演变

目的：探讨儿童远视服的屈光演变规律。方法：观察197例(394眼)3～8岁远视儿童，按首诊年龄分6组，按有无斜视分2组，按远视程度分3组。每年扩瞳孔验光1次，连续5年观察远视度数的发展规律。结果：3～8岁年龄组儿童远视眼的远视球镜部分和远视散光部分，每年平均降低的幅度相邻组比较差异无显著性；斜视组和屈光不正组，远视平均每年降低的幅度比较差异无显著性；轻度、中度、高度远视服，远视平均每年降低的幅度比较，差异有高度显著性。结论：儿童远视服远视屈光度(球镜)部分逐年降低，平均每年降低幅度相近，远视散光部分变化较小；斜视和屈光不正儿童，远视度数逐年降低的幅度相近；屈光程度越高远视度数逐年降低的幅度越多；儿童远视散光95％为顺规性散光。     

Accommodation demand and deprivation in kitten ocular development

The effects of accommodation demand and deprivation on the development of ocular optics was investigated in four groups of kittens (total n = 29). Group 1 consisted of five normal kittens; group 2 (nine kittens) had monocular radial keratotomy to induce relative hypermetropia and more accommodation demand as well as to impart interocular refractive differences (anisometropia); group 3 (eight kittens) received daily monocular atropine; and group 4 (seven kittens) had binocular radial keratotomy combined with daily monocular atropine. Regular examination provided documentation of ocular development from the first through the sixth months of life. Subsequently, the focal lengths of the crystalline lenses were determined in vitro. An apparent tendency for kitten eye pairs to grow toward isometropia, even when anisometropia had been induced early in life, was seen in those eyes in which the accommodative mechanism had been left intact (groups 1 and 2), but without accommodation anisometropia resulted (groups 3 and 4). There was relatively more elongation of the globe (3.08 +/- 0.22%) as well as shorter than normal focal lengths of the crystalline lens (-4.91 +/- 1.62% anterior, -2.78 +/- 1.54% posterior) in the eyes of the second group, and the eye pairs regained isometropia. In those eyes of the third and fourth groups that received atropine daily, there was relatively less elongation of the globe (-3.09 +/- 0.59% and -3.22 +/- 0.67%, respectively) and shorter crystalline lens focal lengths (-3.50 +/- 1.18% and -4.62 +/- 1.07% anterior, -2.64 +/- 1.02% and -1.59 +/- 0.62% posterior, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Laser in situ keratomileusis to correct myopia, hypermetropia and astigmatism after penetrating keratoplasty for keratoconus: a series of 27 cases.

BACKGROUND: Excimer laser treatment has been shown to be effective and safe in correcting anisometropia following penetrating keratoplasty (PKP). In this report we review our experience with excimer laser in situ keratomileusis (LASIK) to correct refractive myopia, hypermetropia and astigmatism in patients who had undergone PKP for keratoconus. METHODS: We reviewed the records of 22 patients (27 eyes) who had undergone LASIK to correct myopia, hypermetropia or astigmatism, in simple or combined forms, following corneal transplantation for keratoconus. LASIK was performed at a hospital in Curitiba, Brazil, between September 1998 and February 2000. The eyes were classified into two groups: those with a negative spherical equivalent and those with a positive spherical equivalent. LASIK was performed using the Moria LSK microkeratome and the Nidek EC-5000 excimer laser. RESULTS: The mean length of follow-up was 9.52 months for the 23 eyes with myopia and 5.75 months for the 4 eyes with hypermetropia. The mean refractive spherical equivalent in the myopic eyes was -5.27 (standard deviation [SD] 1.91) dioptres before LASIK and -0.45 D (SD 1.68 D) at the last follow-up visit. The corresponding values in the eyes with hypermetropia were +5.18 D (SD 1.46 D) and + 1.18 D (SD 0.94 D). The rate of regression of astigmatism in the myopic eyes was 76%. After surgery 18 (78%) of the myopic eyes and all the hypermetropic eyes had an uncorrected visual acuity of 20/40 or better. The best spectacle-corrected visual acuity was better than 20/25 in 22 (95.7%) of the myopic eyes and all the hypermetropic eyes. One eye lost 1 line of best spectacle-corrected Snellen visual acuity, and one eye lost 6 lines secondary to epithelial ingrowth. Wound dehiscence, intraoperative flap complications, graft rejection or other complications did not develop in this series. INTERPRETATION: In this series, LASIK proved to be relatively safe and effective in correcting refractive errors after PKP for keratoconus.     

Hereditary high hypermetropia in the Faroe Islands

PURPOSE: To characterize the phenotype of two families with high hypermetropia from the Faroe Islands. METHODS: Ophthalmologic evaluation including ultrasound oculometry and anthropometric measurements. RESULTS: Of the 40 examined family members, 15 individuals (8 males, 7 females; ages: 6-77 years; mean: 36.5 years) had small deep-set eyes with high hypermetropia (median: + 16.5 D; range: + 7.75 to + 22), short axial eye length (< 21 mm), and a thickened eye wall. The median corrected visual acuity was 0.4 (0.2-0.9). Ocular complications included angle-closure glaucoma in six eyes, uveal effusion in three eyes, cataract in two eyes, and esotropia with amblyopia in three eyes. An emergency case of uveal effusion and retinal detachment after Yag iridotomy eventually responded to systemic corticosteroids and scleral resection surgery with a slow visual recovery. No associated ocular or systemic malformations were found in the series. In addition to the two examined families, six smaller Faroese families with high hypermetropia are briefly reported. CONCLUSIONS: The study highlights the signs and symptoms of a rare hereditary phenotype characterized by a short axial length mainly confined to the posterior segment of the eye, a shallow anterior chamber, and a thickened eye wall. The morphological characteristics predispose for sight-threatening complications such as angle-closure glaucoma, chorioretinal pathology including uveal effusion, and amblyopia. Regular ophthalmic follow-up is therefore of obvious importance in families known to have small eyes/high hypermetropia. An endemic high prevalence in the Faroe Islands suggests the presence of a founder effect, and further genetic research would probably indicate pseudodominant rather than dominant transmission     

近视患者SMILE术后双眼视觉功能变化

目的 探讨飞秒激光小切口角膜基质透镜取出术（SMILE）后双眼视觉功能的变化及其临床意义。方法 前瞻性临床研究。选取2016年3月至2017年10月在中南大学湘雅医院眼科激光治疗中心接受SMILE的近视患者58例（116眼）,术前矫正视力≥5.0。所有患者按术前等效球镜度（SE）分为低中度近视（≥-6.00 D）组38例（76眼）,高度近视（<-6.00 D）组20例（40眼）。所有患者按优势眼分为主导眼组58例（58眼）和非主导眼组58例（58眼）。分别测量术前,术后1周、1个月、3个月的调节功能（包括调节幅度、正/负相对调节、双眼调节灵活度、调节反应）及聚散功能（隐斜、正/负融像范围、集合近点）变化。组间手术前后各时间点数据比较采用重复测量方差分析和两样本t检验。结果 ①低中度近视组和高度近视组患者术后1周、1个月、3个月SE均较术前减小（P<0.05）。低中度近视组术后3个月主导眼调节幅度、正相对调节均较术前增大（P<0.05）,术后1、3个月双眼调节灵活度较术前增大（P<0.05）,高度近视组调节幅度、正/负相对调节、双眼调节灵活度手术前后各时间点比较差异均无统计学意义。低中度近视组与高度近视组主导眼与非主导眼调节幅度手术前后各时间点比较差异均无统计学意义。②低中度近视组与高度近视组术后远/近距隐斜、正/负融像范围、调节性集合/调节比值与术前相比差异均无统计学意义。低中度近视组与高度近视组术后集合近点均较术前增大（P<0.05）。结论 SMILE手术对低中度近视患者术后调节功能及聚散功能均具有积极的影响,但对于高度近视患者,术后双眼视觉功能变化不明显。     

近视青少年配戴角膜塑形镜前后调节参数变化

目的：:观察近视青少年配戴角膜塑形镜前后调节参数及隐斜度的变化,探讨角膜塑形镜延缓近视进展的机制及近视发病病因。方法：:回顾性研究。收集2011年1月至2019年3月在中国医科大学附属第一医院眼科门诊进行角膜塑形镜配戴前后调节参数资料完整的患者51例（102眼）,比较角膜塑形镜配戴前、配戴后1、12个月或以上的正负相对...