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At least 649 records · Page 36Linked to original sources
PubMed1991

A nation-wide study of myopia prevalence in Israel. Findings in a population of 312,149 young adults.

We conducted a nation-wide survey of the Prevalences of Myopia and other refractive errors in Israel, from data of medical examinations of an unselected population of 312,149 subjects ages 17 to 19 years. 80.47% of the population were emmetropic in both eyes. Myopia in both eyes was found in 16.27% of the population. The prevalence of monocular myopia was 1.69%. Manifest hyperopia in both eyes was found in 0.93% and astigmatism at least in one eye was found in 7.13%. The various errors of refraction (myopia, hyperopia and astigmatism) were more common among females.

Adolescent↗
PubMedDate not supplied

[A comparative analysis of hemodynamic parameters within the evaluation of the glaucomatous process in patients with myopia].

One hundred and eighty (180) persons (363 eyes), mean age 63.7 +/- 5.2, mean follow-up--6.1 +/- 1.2, were investigated. Control group 1 comprised 46 patients (92 eyes) with emmetropia and different-degree myopia; control group 2 had 74 persons (148 eyes) with primary open-angle glaucoma (POAG). The main group had 60 patients (119 eyes) with POAG combined with myopia. The ocular hemodynamics parameters were found to reliably differ, in patients with myopia, without glaucoma and with the anterior-posterior eye axis of 25 mm, from the similar parameters in persons with emmetropia. The process aggravates in myopic patients with glaucoma due to reliably worsened ocular hemodynamics parameters and due to a higher intraocular pressure without any reliably changing systemic hemodynamics. The measuring of ophthalmoplethysmography parameters could be handy in examining the POAG patients with myopia in order to detect if glaucoma is progressing or not.

Adult↗
PubMed2004

Fundus analysis and visual prognosis of macular hemorrhage in pathological myopia without choroidal neovasculopathy.

PURPOSE: To analysis and evaluate the fundus characteristics and visual prognosis of macular hemorrhage in pathological myopia without choroidal neovasculopathy. METHODS: Thirty-seven patients (38 eyes) of pathological myopia with macular hemorrhage and without choroidal neovascularization (CNV) underwent color photograph and fundus fluorescein angiography (FFA) examinations. Indocyanine green angiography (ICGA) was also performed on 11 patients (11 eyes). Follow-up ranged from 3 to 21 months. RESULTS: The macular hemorrhage in pathological myopia without CNV demonstrated oval, less than 1PD, without edema and exudation. Lacquer cracks appeared at the site of previous subretinal bleeding in 84.2% of the eyes. The visual acuities were improved in 81.6% of eyes during the follow-up period. ICGA revealed linear hypofluorescence in 7 of 11 eyes (63.6%), indicating a ruptured Bruch's membrance at the onset of subretinal bleeding. CONCLUSION: A rupture of choriocapillaris complex and Bruch's membrane causes macular hemorrhage of pathological myopia without CNV, leading to the formation of a new lacquer crack. Its prognosis is favorable.

Adolescent↗
PubMedDate not supplied

[Conditions for the development of myopia in schoolchildren].

School myopia is a most common health problem in schoolchildren, in adolescents in particular. School myopia resulted from connective tissue failure of the whole organism. Some data, such as the association of school myopia with the HLA system confirm this idea. New investigations in this direction will assist in concretizing the real cause of this type of myopia. The interaction between the lighting conditions and the development of refraction is also of interest.

Child↗
PubMed2004

[Effect of time limited form deprivation on the development of myopia in guinea pigs].

OBJECTIVE: To investigate the effect of time limited form deprivation on the development of form-deprived-myopia (FDM) in guinea pigs. METHODS: Four-week-old guinea pigs (n = 20) were randomly divided into four groups. Group I was used as normal control without any treatment. In group II-IV, unilateral form deprivation was produced with eye patch for 4 weeks. In group II, eye occlusion was fitted continuously. In group III and IV, occlusion was removed each day for 1 or 4 hours. Refractive development was monitored by retinoscopy and A-scan ultrasonography before and after experiment. RESULTS: After 4 weeks, varied degree of axial myopia was developed in the groups II and III with eye occlusion. Continuous form deprivation produced -5.49 D of relative myopia and the fellow eyes produced +0.76 D of relative hyperopia. One hour of unrestricted vision was sufficient to reduce the degree of FDM by about 50%. The eyes allowed 4 hours of unrestricted vision did not result in myopia. CONCLUSION: Long periods of form deprivation can be counterbalanced by quite short periods of unrestricted vision.

Animals↗
PubMed2004

[Phototherapeutic keratectomy combined with photorefractive keratectomy for the treatment of myopia with corneal scars].

OBJECTIVE: To evaluate the effects of phototherapeutic keratectomy (PTK) combined with photorefractive keratectomy (PRK) in the treatment of myopia with corneal scars. METHODS: Corneal epithelium was removed with laser plus scraping (d=7.0 mm). Corneal scars were removed with PTK (d=7.0 mm) and followed by PRK for myopia (d=6.0 mm). Healon was used to make corneal surface smoother during operation. RESULTS: 79 eyes of 54 cases of myopia with corneal scars were followed up at least for one year. Mean refractive degree was (-6.73 +/- 4.17) D and corrected vision was 0.63 before operation. After operation,corneal scars in 50 eyes (63.3%) were removed in operative zone and corneal haze was less than I degree. The vision acuity in 69 eyes (89.9%) was equal to or better than preoperative best correction. Mean postoperative vision was 0.74. Corneal surface was smoother and astigmatism was reduced after surgery. CONCLUSION: PTK combined with PRK is a safe and effective treatment for myopia with corneal scars.

Adolescent↗
PubMed2004

[Morphological parameters of the optic disc in patients with primary open angle glaucoma and low myopia].

PURPOSE: To compare the morphological parameters of the optic disc in patients with low myopia and primary open angle glaucoma (POAG) and in patients with glaucoma without refractive errors. MATERIAL AND METHODS: 53 patients, aged 33-88 (56.2 +/- 11.9) with POAG were qualified for our study. The group was divided into two: first group consisted of 14 patients--11 women and 3 men, aged 41-83 (58.2 +/- 10.9) comprising 28 eye balls with low myopia (-0.5 Dsph to -3.5 Dsph) and POAG. The second group consisted of 38 patients: 24 women and 14 men, aged 33-80 (51.0 +/- 13.4) comprising 71 eye balls including 43 emetropic eyes, 26 eyes with hyperopia (+0.5 Dsph to +3.0 Dsph) and 2 eyes with astigmatism. All patients demonstrated early changes in visual field 1-2 stage due to the Aulhom classification. The measurements of the morphological parameters of the optic disc were made with confocal scanning laser ophthalmoscopy using Heidelberg Retina Tomograph--HRT II with glaucoma software. We analyzed the following parameters: optic disc area, cup area, rim area, cup/disc ratio, linear c/d ratio, mean cup depth, maximum cup depth. The statistical analysis was made using Kolomogarow-Smirnow test. RESULTS: All analyzed parameters were higher in patients with low myopia and POAG than in patients with only POAG. The results in both groups were different but still no statistically significant. CONCLUSIONS: Low myopia has an influence on the optic disc morphology in patients with POAG.

Adult↗
PubMed2004

[Effect of pentoxifylline on Doppler blood flow parameters in the central retinal artery and the short posterior ciliary arteries in adolescents with progressive myopia].

PURPOSE: To evaluate the effect of pentoxifylline on blood flow in the central retinal artery and the short posterior ciliary arteries in patients with progressive myopia. MATERIAL AND METHODS: 48 eyes of 24 healthy patients aged between 12 and 18 years (mean 15.1 years) with myopia from -5.0 to -12.75 Dsph (mean -7.56 Dsph), were examined using color Doppler ultrasonography. The examination was performed before and after 10 days of intravenous administration of 200 mg of pentoxifylline. The peak-systolic, end-diastolic flow velocities, pulsatility, resistance and systolic/diastolic ratios were measured. RESULTS: The use of pentoxifylline significantly increased PSV and EDV in the central retinal artery and in the short posterior ciliary arteries (p=0.0001) in patients with progressive myopia and in the same time decreased PI, RI and S/D (p=0.0001). There was no correlation between Doppler blood flow parameters and dioptres or axial length. CONCLUSIONS: pentoxifylline increases retinal and choroidal blood flow in young patients with progressive myopia.

Adolescent↗
PubMed2004

Clinical description and genome wide linkage study of Y-sutural cataract and myopia in a Chinese family.

PURPOSE: To describe the clinical characteristics of a Y-sutural cataract associated with myopia in a large Chinese family and to identify the causative gene and mutation. METHODS: An autosomal dominant Y-sutural cataract and myopia were identified in members of a large family of Han ethnicity living in southern China. Ophthalmological examinations were performed and a medical history was taken. Blood samples were collected for DNA isolation. A genome wide scan was performed using markers spaced at about 10 cM intervals for genotyping and two point linkage analysis. Candidate genes were sequenced. RESULTS: Bilateral lens opacities, the only sign of cataract in early childhood and the most prominent sign in all affected individuals, involved the entire anterior Y and posterior inverted Y sutures, showing a feather duster like appearance. The Y-sutural cataract in this family mapped to an 11.4 cM (13.5 Mb) region between D3S3606 and D3S1309 on chromosome 3q22 with a maximum lod score of 5.7 at theta=0 for D3S1292. Sequence analysis of the beaded filament structural protein 2 (BFSP2) gene identified a previously described c.697_699delGAA (E233del) mutation which was present in all individuals with Y-sutural cataract but not in unaffected individuals and controls. Myopia, observed in 10 out of 12 cataract patients and significantly higher than that in unaffected offspring and siblings (1 out of 8), was independently mapped to a 61.2 cM (59 Mb) region between D3S3606 and D3S1262 on 3q21.3-q27.2 with maximum lod score of 3.79. CONCLUSIONS: This Y-sutural cataract is caused by an E233del mutation in BFSP2 which provides additional evidence supporting mutations in BFSP2 as a cause for cataract and demonstrates phenotypic variability in cataracts caused by BFSP2. The Y-sutural opacity in the lens might be the typical and earliest sign for cataract caused by the BFSP2 mutation. In addition, these results demonstrate a myopia susceptibility locus in this region, which might also be associated with the mutation in BFSP2.

Adolescent↗
PubMed2005

[Clinical investigation of epipolis laser in situ keratomileusis on high myopia].

OBJECTIVE: To investigate the surgical characteristics and clinical results of Epi-LASIK on high myopia. METHODS: Epi-LASIK was performed with a rotational epikeratome, which features a blunt oscillating blade. Corneal epithelial separation was achieved mechanically without the use of alcohol. Laser ablation was performed with Zeiss Mel-80 excimer laser. After ablation, epithelial sheet was repositioned and a therapeutic contact lens was applied to the eye for 3 to 5 days. The postoperative symptom, epithelial flap, contrast sensitivity, wavefront aberration and haze formation were investigated. The period of follow-up ranged from 3 to 6 months. RESULTS: 52 eyes of 30 patients with a mean spherical equivalent (SE) of (-12.82 +/- 4.38) D were included in the clinical trial. Among which 36 eyes were pathologic myopia and 16 eyes were simple high myopia. Patient age ranged from 20 to 50 years. Integrated epithelial flap with a diameter of 8 to 9 mm was made in 49 eyes leaving an about 3 mm superior hinge. Epithelial flap contained part of stroma tissue was seen in one eye. Free epithelial flap was made in 2 eyes. 4 eyes had moderate photophobia, tearing and foreign body sensation. Other patients only had mild discomfort. No patient reported other subjective symptom after 2 days with the exception of mild foreign body sensation. In 3 months after surgery, spherical equivalent of 44 eyes (84.61) were within +/- 1.00 D of attempted refraction. No eye lost more than one line of best spectacle-corrected visual acuity (BSCVA), whereas 10 eyes (19.23%) gained one or two lines of BSCVA. Grade 0.5 haze was found in 8 eyes (15.38%) and grade 1 haze was found in 2 eyes (3.84%). In 6 months after surgery, Grade 0.5 haze was found in 3 eyes. Contrast sensitivity decreased 1 month postoperatively and recovered to preoperative lever gradually 3 months postoperatively. Higher order aberration was increased postoperatively. CONCLUSIONS: Epi-LASIK is a safe and efficient method to correct high myopia with the advantages of having mild irritating symptom and haze. Larger series with adequate follow-up are needed to observe the long term clinical results and haze.

Adolescent↗
PubMedDate not supplied

[Progressing myopia in children: does it need treatment or not?].

The purpose of the case study was to evaluate the remote consequences of a complex of laser and repeated surgical sclerorestorative procedures made in progressing myopia and its complications. Three hundred and forty-six children, aged 8-10, with rapidly progressing uncomplicated myopia of 4.25 to 9.5 D were shared between 2 groups. Two hundred and forty patients of the experimental group were made sclerorestorative procedures and transscleral low-energy laser stimulation of the ciliary muscle by means of infrared laser MACDEL-09. No such treatment was applied to patients of the control group. When indicated, preventive laser coagulation of the retina was made in both groups. The dynamic 10-year follow-up over the status of refraction and eye bottom showed that the complex scheme of repeated sclerorestorative procedures and low-energy laser treatment combined with preventive peripheral laser coagulation of the retina cut the rate of progressing myopia and prevented peripheral vitreoretinal dystrophy and retinal detachment in children and teenagers with progressing myopia.

Age Factors↗
PubMed2005

[The treatment of retinal apoptosis by Caspase 3 inhibitor Ac-DEVD-CHO in experimental myopia].

OBJECTIVE: To investigate the mechanism of retinal apoptosis in chick experimental myopia and the therapy of Caspase 3 inhibitor Ac-DEVD-CHO. METHODS: Chick myopia was induced by lid-suture. After Ac-DEVD-CHO had been injected into vitreous, myopia was confirmed by optometry. Subsequently, chick eyeballs removed were measured its extro-dimensions, and the change of fundus were observed. Retinal apoptotic cells were determined by electron microscopy, TUNEL technique and flow cytometry. Retinal Caspase 3 proteins and its activities were measured by immunohistochemistry, flow cytometry and a colorimetric method using Ac-DEVD-pNA as a substrate. RESULTS: Ocular diopters and extro-diameters in all sutured eyes remarkly increased in comparison with its control eyes at 12 weeks after lid-suture. Lacquer crack lesions were found in 41 of 90 sutured eyes (45.56%). Apoptotic cells were observed in retinal outer and inner nuclear layer of the sutured eyes, and its apoptotic rate was significantly more than in control eyes (P < 0.05). Moreover, the expression of retinal Caspase 3 proteins and its activities were increased. After Ac-DEVD-CHO was injected into vitreous, the decrease of retinal apoptotic rate, Caspase 3 proteins and its activities was found. The treated effect of Ac-DEVD-CHO was in a dose dependent manner. CONCLUSIONS: Caspase 3 plays an important role in retinal apoptosis of chick myopia. Ac-DEVD-CHO can effectively ameliorate retinal apoptosis by blocked the effect of Caspase 3.

Animals↗
PubMed2005

[Dynamic expression of VIPR2 in form deprivation myopia].

OBJECTIVE: To investigate the dynamic expression and significance of vasoactive intestinal peptide receptor 2 (VIPR2) on retina-choroid-clera in high myopia. METHODS: Twenty-one yellow chicks of 1 day old were used in the research. The right eyes were the experimental group, covered continuously for 1 week, 2 weeks and 4 weeks respectively. The left eyes were not covered as the normal control group. Both groups were detected diopter degrees using retinoscopic refraction, determinated eyeball axis using ophthalmology ultra-A, and investigated VIPR2 expression on retina-choroid-sclera in both groups at three stages by SP immunohistochemical staining. RESULTS: The experimental eyes changed from hypermetropia at pre-experiment to high myopia during the experiment stages, and the diopter degrees were deeper and eyeball axis was longer along with the period of being covered. Both groups had strong expression of VIPR2 on photoreceptor-outer segment of the retina and choroids. The expression was down-regulated with the time in both groups. Compared with the control group, VIPR2 expression of the experimental group was significantly up-regulated (P < 0.05). CONCLUSION: Form deprivation could induce high myopia. The expression of VIPR2 existed on photoreceptor-outer segment of the retina and choroids. VIPR2 may play an important role on the formation and development of myopia.

Animals↗
PubMedDate not supplied

[Long-term results of xenoscleroplasty of the posterior pole of the eyeball in the treatment of patients with progressive myopia].

The study deals with the development of an effective, atraumatic and easy-to-use treatment for patients with progressive myopia, by using a discoid xenograft. The treatment involves implantation of a discoid xenograft to the episclera of the posterior pole of the eye. The xenograft is a white disk prepared from the treated bovine pericardium and it has 2 mm in thickness and a diameter of 13 mm. Clinical studies were performed in 89 patients (161 eyes) operated on by the proposed procedure, by evaluating the stabilized progression of myopia 4 years later. In the late period of a follow-up, the stabilization effect was 88.3 to 92.6% in relation to the degree of myopia. There was evidence for increases in the thickness of the sclera (and its acoustic density) on the posterior pole of the eye, for improved regional hemodynamics and better electrophysiological functions of the retina in the postoperative period. Xenoscleroplasty of the posterior pole of the eye with a bovine pericardial xenograft is an easy-to-use, pathogenetically oriented, highly effective, and safe treatment in patients with progressive myopia.

Adolescent↗
PubMed2006

[Effect of pirenzepine on form deprivation myopia in chicks and its possible mechanism].

OBJECTIVE: To observe the effect of M1-selective muscarinic antagonist, pirenzepine, on form deprivation myopia and investigate the expression of MMP-2 and its inhibitor TIMP-2 in the fibrous sclera in order to better understand the mechanism by which pirenzepine inhibits myopia. METHODS: 40 chicks after birth one day were divided into 4 groups randomly: I. Control group; II. Form deprivation group; III. Vehicle application group; IV. Pirenzepine injected group. Form deprivation myopia was established in right eyes of group II, III, IV by placement of a translucent occluder. The deprived eyes of group III and IV received daily subconjunctival administration of vehicle PBS and pirenzepine respectively. Optical measures such as refraction, axial length, equatorial diameter were made at the end of the experiment. Total RNA and protein were extracted from the posterior fibrous sclera chicks. The expression of MMP-2 and TIMP-2 mRNA and protein were investigated with RT-PCR and Western blot analysis respectively. RESULTS: Refraction status, axial length, equatorial diameter of the eyes in pirenzepine injected group were significantly lower when compared with form deprivation group (P < 0.01), but the parameters were higher when compared with normal control group therefore relatively myopic changes were detected. There were no significant difference between drug control and pirenzepine injected group when optical measures and the expression of MMP-2, TIMP-2 were concerned (P > 0.05). The expressions (mRNA and protein) of both MMP-2 and TIMP-2 were significantly different in form deprivation group when compared with normal control group (MMP-2 mRNA increased by 143.51%, P < 0.01; protein increased by 114.60%, P < 0.01; TIMP-2 mRNA decreased by 55.05%, P < 0.01; protein decreased by 53.73%, P < 0.01). In pirenzepine injected group the relative expression of MMP-2 mRNA and protein were decreased obviously by 41.95% (P < 0.01) and by 36.16% (P < 0.01), while TIMP-2 mRNA and protein expression was increased significantly by 72.46% (P < 0.01) and by 53.05% (P < 0.01) respectively compared with the form deprived group. CONCLUSION: Subconjunctivally administration of the M1 selective muscarinic antagonist, pirenzepine, partly prevents or restrains form deprivation induced myopia. It may exert its inhibitory effect by modulating the expression of MMP-2 and TIMP-2 in fibrous sclera.

Administration, Topical↗
PubMedDate not supplied

[Reflex therapy, massage, and manual therapy in the treatment of progressive myopia in children and adolescents].

The paper describes the methods and results of multimodality treatment for progressive myopia in children and adolescents, by applying acupuncture, massage, and manual therapy. Thirty-three patients aged 7 to 17 years who had progressive myopia of 0.5 to 10.8 diopters were treated by an original procedure as repeated courses. Their follow-up lasted 2 years. A beneficial therapeutic effect as increases in uncorrected and subcorrected visual acuity, ocular accommodation reserves, and myopia regression rates was observed in 64% of the patients. Two-year myopia stabilization was achieved in 45% of cases. There were neither complications nor side effects. The possible mechanism of the remedial effect of the procedure is discussed in the paper.

Accommodation, Ocular↗
PubMed1991

[A study of the mechanism of production of night myopia at low luminance environment].

The mechanism of production of night myopia was investigated in detail by using a laser-speckle refractometer. Night myopia begins to appear at the luminance level with the emergence of rod (scotopic) vision and increases to a maximum average of 1.35 D with further decrease of environmental luminance for the completion of rod vision. It is demonstrated experimentally that both spherical and chromatic aberrations of the eye do not play an important role in the production of night myopia. It is therefore concluded that night myopia is posed on the dark focus of accommodation of the resting state focus of the eye in the absence of adequate stimulus during scotopic vision.

Accommodation, Ocular↗
PubMed1991

[Changes in ocular structure and in blood-ocular barrier permeability of experimental myopia induced in monkeys].

We induced myopia by eyelid suturing in one eye each of six 9-month-old cynomolgus monkeys to elucidate the condition by studying changes in the ocular structure and the blood-ocular barrier (BOB) permeability. Optical elements were measured by A-mode ultrasonography; vitreous fluorophotometry was carried out to document BOB permeability before eyelid suturing and 3, 10, 16, and 28 months after suturing. The axial length of the sutured eyes increased significantly compared with that of the non-sutured contralateral eyes at 10 months after suturing and continued to lengthen with time. The dioptric power (D) of the sutured eyes changed in the same way. (mean, -3.08D 28 months after suturing). The permeability of the blood-retinal barrier of the sutured eyes significantly increased from 10 months after suturing compared with that of the fellow eyes, and continued to increase over the period of observation. The permeability index of the blood-aqueous barrier also increased significantly from only 16 months after suturing further increasing as the period of observation lengthened. We hypothesize that in the transition from emmetropia to myopia, the permeability of the BOB rises, and continue to rise as myopia develops. Thus, the breakdown of the BOB, i.e., the breakdown of the ocular homeostasis, is considered to be closely related to the occurrence and the development of myopia.

Animals↗