Influence of Peripheral Visual Signals on Emmetropization of Infant Rhesus Monkeys / 中山大学学报(医学科学版)

[Objective]To investigate the effects of peripheral form-deprivation and central form-deprivation on em-metropization of infant rhesus monkeys.[Methods]Nineteen healthy infant rhesus monkeys,about 3 weeks of age,were divided into three groups of A(n=6),B(n=6)and C(n=7)by random.The monkeys from group A wore peripheral form-deprivation spectacle lenses over both of their eyes.The monkeys from group B wore central form-deprivation lenses over both of their eyes.The monkeys from group C were 0.00 Dlenses over both of their eyes as control.The monkeys'refractive error,corneal topography,vitreous chamber depth were measured at the start of lens wear and at 2 weeks,1.5 months, 2 months,3 months post-treatment. By these means,we can observe the changes of eye growth and refractive status dynamically.[Results]In group A,B and C,no statistically significant difference was observed between the right and left eyes in vitreous chamber depth and refractive errors pre-and post-treatment(P>0.05).During the course of study,the vitreous chamber depthelongated gradually and refractive status became less hyperopic in all animals.After 3 months'lens wear,the axial eyeball elongation amplitude(mm)of group A(peripheral form-deprivation group,1.25±0.36)monkeys was more obvious than that of group C(control group,0.55±0.19,P=0.001),but there was no statistically significant difference between group B(0.59±0.14)and C(P=0.807).The decrease of hyperopic degrees(D)of group A monkeys (-4.44±1.33)was more obvious than that of group C(-1.83±0.58,P=0.000).The eyes of group A monkeys appeared a remarkable myopic shift after treatment. No statistically significant difference was found between group B(-2.25±0.31) and C in hyperopic degrees reduction(P=0.383). Before and after lens wear,no statistically significant difference was found within or between groups in corneal Sim K values(P>0.05).[Conclusion]During the emmetropization process of infant rhesus monkeys,if the visual signals from peripheral retina are in conflict with those from central retina,the former will play a dominant role.

Diagnostic Availability of Ultra-Wide-field Fundus Imaging in Korean Patient with Retinal Break

PURPOSE: To evaluate the availability of ultra-wide-field fundus photography compared to fundus examination after pupil dilatation in Korean patients with retinal break. METHODS: For this retrospective case review of consecutive 160 patients, 230 lesions with retinal breaks were recruited. The ultra-wide-field images were taken after fundus examination with pupil dilatation performed by a retinal specialist. We analyzed ultra-wide-field images according to patient characteristics and separated area. We divided lesions into anterior and posterior areas, and each area was separated into 4 quadrants (superior, inferior, temporal, and nasal). RESULTS: The sensitivity of ultra-wide-field imaging for detecting retinal break was 72% (95% confidence interval [CI] 65-79%), and the specificity was 94% (95% CI 90-98%). The sensitivity of detection of posterior retina was 89% (95% CI 85-93%), and that of anterior retina was 72% (95% CI 66-78%); this difference was significant (p = 0.007). There was a significant statistical difference at the inferior quadrant between anterior and posterior retina, but not at superior, temporal, or nasal quadrants. The sensitivity of detection in the inferior quadrant in the anterior retina was 43% (95% CI 29-57%). CONCLUSIONS: Ultra-wide-field fundus photography can detect retinal break, but there is limitation in anterior retinal lesions, especially the inferior area. Therefore, ultra-wide-field fundus photography cannot be an alternative method instead of fundus examination with pupil dilatation.

Effect of peripheral vision control technology in the development of juvenile myopia / 国际眼科杂志(Guoji Yanke Zazhi)

AlM:To investigate the effect of peripheral vision control technology for delaying the development of juvenile myopia.METHODS:A total of ninty-nine cases of 12 ~18 year-old myopic patients were randomly divided into two groups. The experimental group was peripheral vision control technology group whose members wore the special lenses which can help correct the hypermetropic defocus of peripheral retina. The other was control group whose members wore ordinary monofocal lenses. All the subjects needed to accept re-examination every 3mo and be recorded the data of dioptre, corneal curvature and axial length.RESULTS: After 18mo, the dioptre and axial length of two groups had increased in varying degree. But the data's different quantity of the corneal curvature in each group had no statistical significance ( P > 0. 05 ). Themyopia deepen quantity in experimental group was-0. 65±0. 65D and its axial growth was 0. 23±0. 22mm, and the myopia deepen quantity in control group was -1. 17 ± 0. 50D and its axial growth was 0. 41 ± 0. 17mm. Under the circumstance of valid data, the increment of myopia and axial length in experimental group was lower than that in control group (P<0. 05).CONCLUSlON: Peripheral vision control technology can delay the development of juvenile myopia effectively.

Identifiable Peripheral Retinal Lesions Using Ultra-Widefield Scanning Laser Ophthalmoscope and Its Usefulness in Myopic Patients

PURPOSE: To investigate identifiable peripheral retinal lesions in patients with myopia or high myopia and to evaluate the usefulness of ultra-widefield scanning laser ophthalmoscope in retina clinic settings. METHODS: We evaluated fundus images of 149 patients acquired using an ultra-widefield scanning laser ophthalmoscope. Manual fundus examination by a retinal specialist was performed and sensitivity and specificity were calculated by comparing the findings of the two different fundus examination methods. RESULTS: Variable peripheral retinal lesions were observed: lattice degeneration (24.1% in myopia, 36.6% in high myopia), white without pressure (17.7% in myopia, 20.7% in high myopia), retinal break (5.1% in myopia, 7.5% in high myopia) and retinal detachment (1.3% in myopia, 4.2% in high myopia). The incidence of lattice degeneration was significantly higher in myopic eyes than in highly myopic eyes (p = 0.043). The examination sensitivities were as follows: lattice degeneration (84.2% in myopia, 91.0% in high myopia), white without pressure (100.0% in both myopia and high myopia), retinal break (75.0% in myopia, 43.8% in high myopia) and retinal detachment (100.0% in myopia, 66.7% in high myopia). The examination specificities were 100.0% in all cases. CONCLUSIONS: Diagnostic sensitivities of ultra-widefield scanning laser ophthalmoscope were 90.8% in patients with myopia, 91.0% in patients with high myopia and 90.9% in totally myopic patients, which were relatively high values. Therefore, the ultra- widefield scanning laser ophthalmoscope is useful as auxiliary equipment for myopic patients in retina clinic settings.

Identifiable Peripheral Retinal Lesions Using Ultra-Widefield Scanning Laser Ophthalmoscope and Its Usefulness in Myopic Patients

PURPOSE: To investigate identifiable peripheral retinal lesions in patients with myopia or high myopia and to evaluate the usefulness of ultra-widefield scanning laser ophthalmoscope in retina clinic settings. METHODS: We evaluated fundus images of 149 patients acquired using an ultra-widefield scanning laser ophthalmoscope. Manual fundus examination by a retinal specialist was performed and sensitivity and specificity were calculated by comparing the findings of the two different fundus examination methods. RESULTS: Variable peripheral retinal lesions were observed: lattice degeneration (24.1% in myopia, 36.6% in high myopia), white without pressure (17.7% in myopia, 20.7% in high myopia), retinal break (5.1% in myopia, 7.5% in high myopia) and retinal detachment (1.3% in myopia, 4.2% in high myopia). The incidence of lattice degeneration was significantly higher in myopic eyes than in highly myopic eyes (p = 0.043). The examination sensitivities were as follows: lattice degeneration (84.2% in myopia, 91.0% in high myopia), white without pressure (100.0% in both myopia and high myopia), retinal break (75.0% in myopia, 43.8% in high myopia) and retinal detachment (100.0% in myopia, 66.7% in high myopia). The examination specificities were 100.0% in all cases. CONCLUSIONS: Diagnostic sensitivities of ultra-widefield scanning laser ophthalmoscope were 90.8% in patients with myopia, 91.0% in patients with high myopia and 90.9% in totally myopic patients, which were relatively high values. Therefore, the ultra- widefield scanning laser ophthalmoscope is useful as auxiliary equipment for myopic patients in retina clinic settings.

The Effect of LASIK on the Retina in Patients with High Myopia

PURPOSE: To investigate the effect of LASIK on the peripheral retina in patients with high myopia. SUBJECT AND METHOD: The difference between preoperative and postoperative retinal findings was investigated in 454 high myopic eyes underwent LASIK. RESULT: At postoperative 6 month, we did not observe any change in the preoperative retinal findings. CONCLUSION: From the above results, it is concluded that there is no significant effect of LASIK on the retina in patients with high myopia, at postoperative 6 month.

The effects of diffusion blur on Snellen and grating acuity and foveal function in amblyopia

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). 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.

Endoscope Assisted Ophthalmic Microsurgery

We would like to introduce endoscope assisted ophthalmic microsurgery. The endoscope system is made of endoscope body, colored moniter, handpiece. The handpiece consists of a 19G or 20G probe housing a fiber optic cable for the camera of a 380.000 pixel resolution, a fiber optic cable for a xenon light source and a working channel. The endoscope was useful to visualize the areas, such as the peripheral retina, posterior side of iris, that were not readily seen by conventional nor wide angle viewing techniques without indentation. Also it gave us good results in the hard visual field cases of corneal opacification or during fluid-gas exchange. using the endoscope permitted the vitreous base to be accurately observed and managed surgically through good visualization of peripheral retina. Intraocular procedure such as vitrectomy, subretinal fluid drainge, endophotocoahulation was performed easily under the endoscopic view, With the improvement of resolution power of the endoscope and the development of stereovision, the range of clinical usage of this technique will be expanded.

The Effects of Diffusive Blur on Snellen and Grating Acuity in Amblyopia

Amblyopia is a disturbance of spatial or form vision that develops early in life, usually in association with strabismus, anisometropia, high refractive errors and so on. It was reported that the visual functions obtained from the foveal region of an amblyopic eye resembled those obtained from the peripheral retina rather than central retina of a normal eye. We designed this experiment which examines the effects of diffusion blur on grating and Snellen acuity in normal and amblyopic eyes, using a liquid crystal window. We obtained the value of diffusion blur in 26 amblyopic eyes and then compared the result with that of normal eyes. The diffusion blur had a strong negative effect on both the Snellen and grating acuity but it had a more potent effect on grating acuity. Because there is a significant difference in the diffusion blur produced by an amblyopic eye and a normal eye at the same vision, there is a difference between visual function of amblyopic eyes and that of normal central retina.