To verify the changes of mesopic and photopic contrast sensitivity function of sound eye whose visual acuity was kept the same after occlusion therapy in the amblyopic children. Fourteen sound eyes of amblyopic children (mean; 7.67 years; S.D., 1.50 years) who kept their visual acuity the same after the occlusion therapy were tested. The children had 6 hours of part-time patch therapy for 3 months prior to this examination. Among 14 amblyopic children, 8 were anisometric and 6 were strabismic amblyopes. Using the visual capacity analyzer which measures the minimal contrast level at from low to high spatial frequencies, the contrast sensitivity of sound eye was measured, under both photopic and mesopic condition, before and after 3 months of occlusion therapy. Comparing the contrast sensitivity of sound eye after the occlusion therapy to that before the occlusion, there was no statistical difference in photopic condition. When it comes to mesopic condition, the contrast sensitivity decreased at the intermediate spatial frequency level (3-13 c.p.d, p=0.028) after the occlusion therapy. The occlusion caused statistically significant decrease in mesopic contrast sensitivity, when the visual acuity was not changed after the occlusion therapy. It may indicate that mesopic contrast sensitivity can be considered as a useful tool for early detection of hidden occlusion amblyopia.
Amblyopia/*physiopathology/*therapy ; Child ; *Contrast Sensitivity ; Humans ; Orthoptics ; Visual Acuity

The authors report two cases of suddenly deteriorated accommodative esotropia with amblyopia during part-time occlusion therapy. A 7-year-old girl with right accommodative esotropia, which was well controlled, showed marked increase in esodeviation after part-time occlusion and regained orthophoria without occlusion. This phenomenon was repeated. Recession of both medial recti was performed and orthophoria was well maintained at both distant and near targets. Accommodative esotropia of a 9-year-old boy with glasses also showed a striking increase in esodeviation after part-time occlusion. The authors recommended wearing only glasses without occlusion or surgery and he recovered fusion. Three months later, orthophoria was maintained at distant target, with 8PD esophoria at near target with glasses. Although this complication should be considered before occlusion therapy, it must be taken continuously if needed, because an increase of the deviation size with occlusion may simply reflect a true deviation and may not be a poor prognostic sign.
*Accommodation, Ocular ; Amblyopia/physiopathology/therapy ; Child ; Esotropia/*etiology/physiopathology ; Eyeglasses ; Female ; Humans ; Male ; *Sensory Deprivation

In order to verify that the effects of diffusion blur on Snellen and grating acuity in amblyopic eyes resemble those obtained from the peripheral or central retina in normal controls, we conducted the following experiment using a liquid crystal window (Edmund Scientific Co.) to produce diffusion blur on Snellen and grating acuity. Spatial frequencies used for a Snellen chart and Teller acuity card were 3.2, 6.5, 13.0, 26.0 cyc/cm at a working distance of 55 cm. The values of diffusive blur on central and peripheral visual acuity obtained from 20 normal healthy control eyes were compared with those values of central visual acuity in 26 amblyopic eyes. The diffusion blur had a strong negative effect on both Snellen and grating acuity in amblyopic eyes, but it had more potent effects on grating acuity (p < 0.05). The diffusion blur values obtained from the central amblyopic retina were more compatible with those of the central retina than with those of the peripheral retina in the control group (p > 0.05). Snellen acuity obtained from diffusion blur overestimated grating acuity in the normal central acuity group and amblyopic central acuity group. The result of this investigation demonstrated that the liquid crystal diffusion blur had a strong negative effect on both Snellen and grating acuity and suggested that the visual function of an amblyopic retina resembled that of a normal central retina.
Adult ; Amblyopia/physiopathology* ; Diffusion ; Female ; Fovea Centralis/physiopathology* ; Human ; Male ; Visual Acuity*

This study both measured and compared the mesopic contrast sensitivity function and the visual acuity in both normal and amblyopic eyes from amblyopic children using an ACV (visual acuity analyzer). Twenty one amblyopic children (mean age, 8.48 years; S.D., 1.68 years), 11 strabismic amblyopes and 10 anisometropic amblyopes, were tested. Based on a display of the standard optotypes, the minimal contrast level, at which the optotypes were correctly read for all sizes of displays from a distance of 1m, was measured. The contrast ranged from 1% to 99% and the spatial frequencies ranged from 0.6 to- 30cpd using a Landolt ring composed of low (0.6- 2.9 c.p.d.), intermediate (3.0 - 12.9 c.p.d.) and high level (13.0- 30.0 c.p.d.) frequencies. As the visual acuity decreased, the mesopic contrast sensitivity function decreased along the contrast sensitivity axis. However, the peak sensitivity was noted at the same spatial frequencies. A comparison between the normal eye and the corresponding amblyopic eye showed that under mesopic conditions, the contrast sensitivity functions decreased more in the intermediate spatial frequencies than in the other spatial frequencies. The mesopic contrast sensitivity function decreased in the amblyopic eyes, which suggests the possibility of its use an adjunct to an evaluation of amblyopia.
Amblyopia/*physiopathology ; Case-Control Studies ; Child ; *Contrast Sensitivity ; Female ; Human ; Male ; Visual Acuity

Higher order aberrations (HOAs) were measured in 54 anisometropic amblyopic children using the ZY-WAVE II aberrometer. The results were compared in normal fellow and amblyoic eyes which were determined by the corrected visual acuity. Between the normal eyes and anisometropic amblyopic eyes, no statistically significant difference were found in mean root square of total HOAs, total coma (TC), total spherical aberration (TSA), and the 5th root mean square (RMS5). There was no correlation among best corrected visual acuity (BCVA), HOAs, TC, TSA, and RMS5. There was some positively correlation between the degree of anisometropia and TC. HOAs increase with the increasing of the degree of anisometropic amblyopia. Lower order aberrations are the main refractive factors leading to amblyopia, and HOAs is related to anisometropia amblyopia. The study helps us understand the mechanism of amblyopia and make the further study.
Aberrometry ; Adolescent ; Amblyopia ; diagnosis ; physiopathology ; Child ; Corneal Wavefront Aberration ; physiopathology ; Female ; Humans ; Male ; Refraction, Ocular ; physiology ; Visual Acuity ; physiology

PURPOSE: This study was conducted to investigate the role of the pattern visual evoked potential (pVEP) as a predictor of occlusion therapy for patients with strabismic, anisometropic, and isometropic amblyopia. The secondary aim was to compare the characteristics of pVEP between strabismic and anisometropic amblyopia. METHODS: This retrospective comparative case series included 120 patients who had received occlusion therapy or a glasses prescription for correction of strabismic, anisometropic, and isometropic amblyopia (20 patients had strabismic amblyopia, 41 patients had anisometropic amblyopia, and 59 patients had isometropic amblyopia). For each patient, the value of the P100 latency on pVEP at the time of the initial diagnosis of amblyopia was collected. Subsequently, the P100 latency was compared according to types of amblyopia. Fifty of 120 patients (7 patients with strabismic amblyopia, 21 patients with anisometropic amblyopia, and 22 patients with isometropic amblyopia) who were followed-up for longer than 6 months were divided into two groups based on the value of their P100 latency (Group 1, P100 latency 120 msec or less; Group 2, P100 latency longer than 120 msec.) The amount of visual improvement after occlusion therapy or glasses was compared between two study groups. RESULTS: The mean P100 latency was 119.7+/-25.2 msec in eyes with strabismic amblyopia and 111.9+/-17.8 msec in eyes with non-strabismic (anisometropic or isometropic) amblyopia (p=0.213). In Group 1, the mean visual improvement after occlusion therapy or glasses was 3.69+/-2.14 lines on Dr. Hahn's standard test chart; in Group 2, the mean improvement was 2.27+/-2.21 lines (p=0.023). CONCLUSIONS: The P100 latency on pVEP at the time of initial diagnosis was significantly related to the visual improvement after occlusion therapy or glasses in patients with strabismic, anisometropic, and isometropic amblyopia. Therefore, it was presumed that patients with a delayed P100 latency might have less visual improvement after occlusion therapy or glasses. In addition, there was no apparent difference in P100 latency between patients with strabismic and non-strabismic (anisometropic or isometropic) amblyopia.
Adolescent ; Amblyopia/*physiopathology/*therapy ; Anisometropia/physiopathology/therapy ; Child ; Child, Preschool ; Evoked Potentials, Visual/*physiology ; Female ; Humans ; Male ; Retrospective Studies ; *Sensory Deprivation ; Strabismus/physiopathology/therapy ; Treatment Outcome ; Visual Acuity

OBJECTIVETo investigate the relationship between the characteristics of spatial vision deficit and the degree of amblyopia in monocular amblyopes, and to analyze its mechanism with the theory of Magnocellular and Parvocellular pathways.

METHODSOne hundred and eleven patients with monocular amblyopes aged 7-34 were included in this study. Distance best corrected visual acuity (BCVA) in logMAR units and contrast sensitivity function test were performed on both eyes in all patients with ETDRS digital visual chart and functional test system OPTECR 6500. The spatial vision of amblyopic and non-amblyopic eyes was evaluated by the AULCSF, Smax, Frmax and cutSF derived from the curve of contrast sensitivity function.

RESULTSThe degree of amblyopia was significantly correlated with the difference of AULCSF between the amblyopic and non-amblyopia eyes (r=-0.83, P<0.01). BCVA of amblyopic eyes was significantly correlated with AULCSF, CutSF, Smax, Frmax(r=-0.68, -0.80, -0.73, -0.56, respectively; P<0.01). In amblyopic eyes, significant difference in BCVA, AULCSF, Smax, Frmax and CutSF was seen among different amblyopic groups (P<0.01), which was defined by the degree of amblyopia. In non-amblyopic eyes,no significant difference in BCVA, AULCSF, Smax, Frmax and CutSF was noted among different amblyopic groups (P>0.05). In mild amblyopes, no significant difference in AULCSF and Frmax was found between the amblyopic eyes and non-amblyopic eyes (P>0.05), while Smax and CutSF were significantly different. However, in moderate and severe amblyopes, significant differences in BCVA, AULCSF, Smax, Frmax and CutSF was seen between the amblyopic and non-amblyopic eyes (P<0.01). In amblyopic eyes, significant difference in contrast sensitivity was noted in all kinds of spatial frequencies among different amblyopic groups (P<0.01), and in non-amblyopic eyes, significant differences in contrast sensitivity was not seen in all kinds of spatial frequencies among different amblyopic groups.

CONCLUSIONSThe AULCSF, CutSF, Smax and Frmax are accorded with visual acuity for evaluation of the spatial vision of amblyopia. As the severity of amblyopia increases, the overall function of spatial vision in amblyopic eyes gradually decreases, the resolution ability of high spatial frequency is gradually weaken, the peak of contrast detection function gradually descends, and the optimal spatial frequency for contrast detection offsets toward low level of spatial frequency. Mild monocular amblyopia produces spatial contrast sensitivity loss in high spatial vision, suggesting there may be decreased sensitivity of the Parvocellular pathway, and no significant anomalous processing of Magnocellular Pathway. Whereas, in moderate and severe amblyopes, a generalized loss of sensitivity is observed at each spatial frequency. This result shows that both Magnocellular and Parvocellular pathways are damaged in different degrees, especially in Parvocellular pathway.

Adolescent ; Adult ; Amblyopia ; physiopathology ; Child ; Contrast Sensitivity ; Female ; Humans ; Male ; Vision, Ocular ; physiology ; Visual Acuity ; Young Adult

OBJECTIVETo explore electrophysiology mechanism of acupuncture for treatment and prevention of visual deprivation effect.

METHODSEighteen healthy 15-day Evans rats were randomly divided into a normal group, a model group and an acupuncture group, 6 rats in each one. Deprivation amblyopia model was established by monocular eyelid suture in the model group and acupuncture group. Acupuncture was applied at "Jingming" (BL 1), "Chengqi" (ST 1), "Qiuhou" (EX-HN 7) and "Cuanzhu" (BL 2) in the acupuncture group. The bilateral acupoints were selected alternately, one side for a day, and totally 14 days were required. The effect of acupuncture on visual evoked potential in different spatial frequencies was observed.

METHODSUnder three different kinds of spatial frequencies of 2 X 2, 4 X 4 and 8 X 8, compared with normal group, there was obvious visual deprivation effect in the model group where P1 peak latency was delayed (P<0.01) while N1 -P1 amplitude value was decreased (P<0.01). Compared with model group, P1 peak latency was obviously ahead of time (P<0.01) while N1-P1 amplitude value was increased (P<0.01) in the acupuncture group, there was no statistical significance compared with normal group (P>0.05). Under spatial frequency of 4 X 4, N1-P1 amplitude value was maximum in the normal group and acupuncture group. With this spatial frequency the rat's eye had best resolving ability, indicating it could be the best spatial frequency for rat visual system.

CONCLUSIONThe visual system has obvious electrophysiology plasticity in sensitive period. Acupuncture treatment could adjust visual deprivation-induced suppression and slow of visual response in order to antagonism deprivation effect.

Acupuncture Points ; Acupuncture Therapy ; Amblyopia ; physiopathology ; therapy ; Animals ; Evoked Potentials, Visual ; Female ; Humans ; Male ; Rats ; Rats, Long-Evans

BACKGROUNDAmblyopia is a common ophthalmological condition and the wavefront aberrometer is a relatively new diagnostic tool used globally to measure optical characteristics of human eyes as well as to study refractive errors in amblyopic eyes. We studied the wavefront aberration of the amblyopic children's eyes and analyzed the mechanism of the wavefront aberration in the formation of the amblyopia, try to investigate the new evidence of the treatment of the amblyopia, especially in the refractory amblyopia.

METHODSThe WaveScan Wavefront System (VISX, USA) aberrometer was used to investigate four groups of children under dark accommodation and cilliary muscle paralysis. There were 45 cases in the metropic group, 87 in the amblyopic group, 92 in the corrected-amblyopic group and 38 in the refractory amblyopic group. One-way analysis of variance (ANOVA), t-test and multivariate linear regression were used to analyze all the data.

RESULTSThird order to 6th order aberrations showed a decreasing trend whereas in the higher order aberrations the main ones were 3rd order coma (Z(3)(-1)-Z(3)(1)), trefoil (Z(3)(-3)-Z(3)(3)) and 4th order aberration (Z(4)(0)); and 3rd order coma represented the highest percentage of all three main aberrations. Within 3rd order coma, vertical coma (Z(3)(-1)) accounted for a greater percentage than horizontal coma (Z(3)(1)). Significant differences of vertical coma were found among all clinical groups of children: vertical coma in the amblyopic group (0.17 +/- 0.15) was significantly higher than in the metropic group (0.11 +/- 0.13, P < 0.05). In addition, the vertical coma in the refractory amblyopic group (0.19 +/- 0.15) was higher compared with the metropic group (P < 0.05), the 5th order aberration (0.11 +/- 0.08) was also significantly higher than in the metropic group (0.07 +/- 0.04, P < 0.05). No significant difference was found in vertical coma and 5th order aberration between the corrected-amblyopic group (0.13 +/- 0.11) and metropic group (0.07 +/- 0.04) (P > 0.05).

CONCLUSIONSAlthough lower order aberrations such as defocus (myopia and hyperopia) and astigmatism are major factors determining the quality of the retinal image, higher order aberrations also need to be considered in amblyopic eyes as their effects are significant.

Aberrometry ; Amblyopia ; pathology ; physiopathology ; Child ; Child, Preschool ; Female ; Humans ; Male ; Refraction, Ocular ; physiology ; Refractive Errors ; diagnosis ; pathology

PURPOSE: To determine the outcome of part-time occlusion therapy in children with anisometropic amblyopia detected after they were 8 years of age. METHODS: We analyzed 29 eyes with anisometropic amblyopia in children 8 years of age and older. The mean age was 8.79+/-0.98 (range 8~12) years old. The subjects whose best-corrected visual acuity (BCVA) did not improve by two lines or better within 2 weeks of wearing glasses full-time were prescribed occlusion therapy for 6 hours a day outside of school hours, along with the instruction to wear glasses full-time. Subjects who complied with occlusion for more than 3 hours a day were considered to comply well. RESULTS: The major component of the anisometropia was hyperopia in 51.7% of the subjects, and hyperopia plus astigmatism was found in 24.1%. The mean pretreatment BCVA score was 0.51+/-0.23 (LogMAR). Compliance was 89.66%. The mean posttreatment BCVA was 0.03+/-0.01 (LogMAR), and the success rate, based on a posttreatment BCVA of 0.1 (LogMAR) and better, was 96.43%. It took an average of 4.79+/-3.35 months to reach the desired posttreatment BCVA. The mean posttreatment stereopsis was 79.78+/-37.61 seconds of arc. The recurrence rate was 8%. The visual improvement was related to the degree of compliance (p=0.000). The time taken to reach the posttreatment BCVA was shorter in subjects with a better pretreatment BCVA (p=0.019), but it did not relate to the compliance (p=0.366). CONCLUSIONS: The most common component of anisometropia detected after 8 years of age was hyperopia. The part-time occlusion therapy, which had been carried out after school hours, was successful in most cases.
Visual Acuity ; Treatment Outcome ; Time Factors ; *Sensory Deprivation ; Male ; Humans ; Follow-Up Studies ; Female ; Child ; Amblyopia/physiopathology/*therapy