Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Hyperopia”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,153 records · Page 64Linked to original sources
PubMed2002

[Summary of the practice guideline 'Refraction errors' from the Dutch College of General Practitioners].

The practice guideline 'Refraction errors' from the Dutch College of General Practitioners describes the examinations that need to be carried out in patients complaining about a gradual loss of vision. A measurement of vision by means of a Snellen chart is insufficient to determine if the condition is caused by a refraction error or if other pathology of the eye such as cataract, glaucoma or retinopathy is involved. It is therefore recommended that the vision should also be measured with a simple device containing spherical lenses of +0.5 and -0.5 dioptre, so-called diagnostic refraction. Improvement of vision with the negative lens indicates myopia. Improvement or at least a stable vision with the positive lens makes hyperopia very likely. Diagnostic refraction, which can be used in patients of six years and older, enables the general practitioner to distinguish between patients needing glasses or contact lenses, and patients requiring referral to an ophthalmologist.

Diagnosis, Differential↗
PubMed2002

Myopia and incident cataract and cataract surgery: the blue mountains eye study.

PURPOSE: To assess whether an association exists between myopia and incident cataract and cataract surgery in an older population-based cohort study. METHODS: The Blue Mountains Eye Study examined 3654 participants aged 49 years or more during 1992 to 1994 and then 2334 (75.1%) of the survivors after 5 years. A history of using eyeglasses for clear distance vision was obtained. Objective refraction was performed with an autorefractor, followed by subjective refraction with a logarithm of minimum angle of resolution (logMAR) chart. Emmetropia was defined as a spherical equivalent refraction between +1 D and -1 D, hyperopia as more than +1 D, and myopia as less than -1 D. Slit lamp and retroillumination lens photographs were graded for presence of cortical, nuclear, or posterior subcapsular cataract, according to the Wisconsin Cataract Grading System. Generalized estimating equation models analyzed data by eye. RESULTS: There was a statistically significant association between high myopia (-6 D or less) and incident nuclear cataract (odds ratio [OR] 3.3, 95% confidence interval [CI] 1.5-7.4). Incident posterior subcapsular cataract was associated with any myopia (OR 2.1, 95% CI 1.0-4.8), moderate to high myopia (-3.5 D or less, OR 4.4, 95% CI 1.7-11.5), and use of distance glasses before age 20 (OR 3.0, 95% CI 1.0-9.3), after adjustment for multiple potential confounders, including severity of nuclear opacity. Incident cataract surgery was significantly associated with any myopia (OR 2.1, 95% CI 1.1-4.2) as well as moderate (-3.5 to more than -6D; OR 2.9, 1.2-7.3) and high myopia (OR 3.4, 95% CI 1.0-11.3). CONCLUSIONS: These epidemiologic data provide some evidence of an association between myopia and incident cataract and cataract surgery, after adjustment for multiple confounders and severity of nuclear opacity. These data support other cross-sectional and longitudinal population-based findings.

Aged↗
PubMed2000

[Analysis of refractive state after excimer laser photorefractive keratectomy in myopia].

OBJECTIVE: To evaluate refractive state after excimer laser photorefractive keratectomy (PRK) in patients with myopia. METHODS: 234 cases(391 eyes) followed up for two years were divided into two groups, group I: mild and moderate myopia(< or = -6.00 D), 228 eyes; group II: High myopia(> -6.00 D), 163 eyes. The refractive state of patients at three, six, twelve and twenty-four months postoperatively were monitored. RESULTS: At two years after photorefractive keratectomy (PRK), refractive regression (> -0.5 D), overcorrection(> 1.00 D), undercorrection(> 1.00 D), postoperative residual astigmatism postoperative astigmatism and hyperopia shift in group I were 1.7%, 4.4%, 5.7%, 12.8%, 7.4% and 7.5% respectively, while in high myopia group were 15.9%, 4.9%, 23.3%, 29.7%, 31.1% and 6.7% respectively. CONCLUSION: The results prove that photorefractive keratectomy is an effective, precise, stable and safe method for correction of mild and moderate myopia, but insufficient for high myopia.

Adolescent↗
PubMed2002

[Establishment of the concept of new clinical entities--complete and incomplete form of congenital stationary night blindness].

I summarized our long-term study to prove that the complete and incomplete types of congenital stationary night blindness (CSNB) are different clinical entities and that the latter is a newly identified disease which has never been reported in the past. CSNB with normal fundi and negative electroretinogram (ERG) showing selective reduction of the b-wave was previously known as the "Schubert-Bornschein type". For the sake of convenience, we classified the disease into two types according to the absence or the presence of rod function: complete CSNB and incomplete CSNB. The hereditary mode of the former is X-linked recessive and autosomal recessive, while that of the latter is X-linked recessive. They are never found together in a single family. We found several additional differences between the two types, including ERG oscillatory potentials, cone mediated ERG, and refractive errors, all leading us to hypothesize that the two types are not variants of a single disease but are the sum of two different clinical entities. Our hypothesis has recently been proven true by molecular genetical analysis. Namely, the mutated gene in X-linked recessive complete CSNB was found in the nyctalopin (NYX) gene, while that in incomplete CSNB was found in the calcium channel (CANCA1F) gene which encodes the retina-specific calcium channel alpha 1-subunit. These results proved that complete and incomplete CSNB are different clinical entities and that the latter is the first disease of the eye which discloses mutation of this region. We classified 90 patients to include 49 complete and 41 incomplete types. Fifteen incomplete CSNB patients underwent gene analysis and they all showed mutation of the CACNA1F gene. We also examined for gene mutation in several patients who had progressive retinal disease and negative ERG and found two siblings with CANA1F gene mutation. This finding indicates that the mutation of the CACNA1F gene can also cause progressive retinal disease in addition to incomplete CSNB. Gene analysis of 11 patients with complete CSNB was performed and 6 revealed mutation of the NYX gene. The remaining 5 patients showed neither NYX nor CACNA1F gene mutation, suggesting they are of autosomal recessive complete CSNB where gene mutation has not been identified. The comparison of our phenotype and genotype diagnosis indicated that a precise ERG analysis can provide correct differentiation between complete and incomplete types. Other clinical findings include moderately low visual acuity in both types, high or moderate myopia in complete CSNB, and wide distribution from myopia to hyperopia in incomplete CSNB. Pathophysiology studies using clinical patients and animal models suggested that complete CSNB has a complete defect of the ON-bipolar cells or their synapses in the rod and cone visual pathways, leaving the OFF pathway intact (OFF-retina). On the other hand, the incomplete CSNB has an incomplete defect of the ON and OFF bipolar cells or their synapses in the rod and cone visual pathways. The macular function is relatively well preserved in both types, which was shown by focal macular ERG. The incomplete CSNB patients seldom complain of night blindness, which causes us to overlook this disease because we then tend not to perform ERG testing. This disease is not so rare and clinicians should be more aware of its existence. The incomplete CSNB is a new hereditary retinal disease detected by Japanese investigators just like the Oguchi disease, and it has much unknown pathophysiology which needs to be identified in the future. Since the namings of complete and incomplete CSNB may be misunderstood as indicating functional classification of one disease, it has been proposed internationally to change the name "complete type" to CSNB1 and that of "incomplete type" to CSNB2.

Humans↗
PubMed2001

The effect of anisometropia on binocular visual function.

PURPOSE: To investigate the effects of anisometropia on binocular vision. METHODS: One to three dioptres of unilateral hyperopia, myopia or astigmatism was induced in 30 normal adults. The effect on binocularity was assessed with the Worth-four dot test, Titmus stereo test and Bagolini's lenses. RESULTS: Binocular vision deteriorated with increasing anisometropia. Spherical anisometropia was more deleterious than astigmatic anisometropia. CONCLUSION: In addition to amblyopia, the potential effect of anisometropia on binocular vision should be considered while prescribing spectacles in young children during the sensitive period.

Adult↗
PubMed2003

[Surgical treatment of retinal detachment with bilateral idiopathic retinal dialysis].

The retrospective study was aimed at demonstrating anatomical and functional results of surgical treatment in patients with bilateral idiopathic retinal dialysis (BIRD). In the period of 1985-2001 the authors operated on BIRD in 10 eyes of five patients (three men and two women). No eye injury or inflammation was present in the case history of the patients. The age of the patients was between 11 and 30 years, the mean age was 19.2 years. The symptoms typical for retinal detachment were present in four eyes only and absent in the other six eyes. Hyperopia of both eyes in analogy with myopia of both eyes was observed in two patients, respectively, whereas emmetropia was present in one patient. The retinal dialysis (RD) occurred in lower temporal quadrant in all eyes (100%), in one eye (10%) it also occurred together with an discontinuous RD in upper temporal quadrant and in another eye it was extended into lower nasal quadrant. Demarcation lines were present in 5 eyes (50%), subretinal solid strands in 1 eye (10%). Scleral buckling procedures were performed as the primary surgical procedure in all 10 eyes of 5 patients. Eight eyes was operated on with the use of segmental circumferential sponge buckles of silicone and two eyes with the use of encircling elements of solid silicone. Retina was successfully reattached postoperatively in 9 eyes (90%) and remained detached in one eye (10%). The visual acuity preoperatively 6/12 or better remained unchanged postoperatively in 8 eyes (80%). The visual acuity postoperatively improved in 1 eye (10%) and in 1 eye (10%) visual acuity was decreased. The mean period of observation of the patients was 86 months. The necessity of a routine examination of the extreme retinal periphery of the fellow asymptomatic eye of the young adult with no history of trauma and with the retinal detachment associated with retinal dialysis in one eye is also discussed.

Adolescent↗
PubMed2003

Acute esotropia in heroin withdrawal: a case series.

BACKGROUND: Esotropia during opiate withdrawal is a new clinical syndrome that has only recently been reported in the literature. METHODS: Clinical case series. RESULTS: Five patients with acute esotropia during opiate withdrawal are presented. In four there was evidence of underlying hyperopia and/or other strabismogenic features. CONCLUSIONS: The precise cause of esotropia with heroin withdrawal is uncertain. Most (and possibly all) of these patients have one or more objective strabismogenic features, and these are probably a large factor in the causation.

Acute Disease↗
PubMed2003

The efficacy of photoscreening for amblyopiagenic factors in a high risk population.

BACKGROUND: Amblyopia is the leading cause of monocular "legal" blindness in children and young adults, affecting 3% to 5% of the population. Factors producing amblyopia can be detected through a complete eye examination. Although it is important to treat children at risk for amblyopia as early as possible, appropriate screening methods for severely impaired individuals are lacking. The purpose of this study was to assess the ability of a photoscreening camera to detect amblyopiagenic factors (strabismus, unequal refractive error, and media opacities) in a group of disabled children, who were currently unscreenable with standard methodology. METHODS: Fifty-four high risk individuals, 6-20 years in age, were evaluated for amblyopiagenic factors using the MTI photoscreening camera, pre- and post-cycloplegia. The "gold standard" for comparison was a concurrent complete eye examination, including ocular health, visual acuity estimation, motility, ophthalmoscopy and clinical cycloplegic refractive error determination. Criteria for a "failure" on the clinical examination included myopia greater than -1.00 diopters (D), hyperopia greater than +3.00 D (2-6 years) and greater than +2 D (over 6 years), astigmatism greater than 1.5 D, unequal refractive error greater than 1.5 D, any strabismus, or any media opacity. RESULTS: Fifty- four individuals with disabilities, deemed untestable by standard vision screenings, were evaluated. The number of children with amblyopiagenic factors by complete cycloplegic ophthalmologic examination was 30 (55%) and by photoscreening was 25 (46%). Using the MTI photoscreener, the sensitivity was determined to be 83% with a specificity of 79%. The positive and negative predictive values of photoscreening were 83% and 79% respectively. CONCLUSIONS: The MTI photoscreener can detect such amblyopiagenic factors as high refractive error, strabismus, unequal refractive error, and significant media opacity. Photoscreening is an excellent way of obtaining valid vision screening with limited patient cooperation. Using photoscreening data, proper referrals can be made and prioritized for disabled individuals.

Adolescent↗
PubMed2003

[Visual screening to discover ophthalmologic disorders in children].

PURPOSE: [corrected] To report the frequency of common childhood ocular disorders in a pediatric population. To address the issue of access to care for vision screening programs. METHODS: Prospective vision screening for a period of 2 years (February 2001-February 2003) which enroll 254 children from 3 villages (Cepleniţa, Vlădeni, Aroneanu) sponsored by World Vision Romania. The study asses refractive errors, strabismus, amblyopia and other ocular abnormalities. RESULTS: The mean age was 8.09 +/- 2.88 with the following distribution: preschool 19%, first grade 56%, second grade (over 10 years of age) 25%. Refractive errors requiring correction were observed frequently in this group of children (especially mild hyperopia, small myopia, astigmatic refractive errors). Strabismus was identified în 7.87% of cases and amblyopia în 11.42% (1/3 of cases mild and severe). CONCLUSIONS: The frequency of common visual disorders in this population sample was larger than previously published studies. In poor economic subgroups the first ophthalmologic examination was performed after school age. Access to care is an integral part of any vision screening program. We are trying to highlight the importance of effective follow-up programs for all children especially those with limited resources for health care.

Adolescent↗
PubMed2003

[Research on human eye cornea's mathematical model and application in diopter correction].

The excimer laser diopter correction has proven to be efficient and safe. This paper presents the principle of excimer laser refractive surgery. Based on analyzing the mathematics model of the human eye cornea, the authors have proposed a new model which can be used to proceed the myopia, hyperopia, astigmatism diopter correction. Also studied were the excimer laser's ablation mechanism and the flying-spot scanning technology. The research results have been directly applied to Ophthalmic excimer laser system. The correction of diopter is well improved.

Algorithms↗
PubMedDate not supplied

Choroidal neovascularization following laser in situ keratomileusis.

Two cases of choroidal neovascularization occurring after laser in situ keratomileusis (LASIK) are presented from two separate centers. In the first case, an extrafoveal choroidal neovascular membrane, apparently associated with age-related macular degeneration, occurred 3 months after a LASIK procedure was performed on a 64-year-old man with hyperopia. Argon laser treatment and subsequent photodynamic therapy were performed and resulted in stabilization of vision. The second case involved neovascularization 3 weeks following a LASIK procedure for myopia, apparently associated with the myopia. No treatment was recommended and the vision stabilized at 20/50. Although the cause is not clear, careful preoperative macular evaluation and attention to symptoms that might herald the presence of choroidal neovascularization are recommended for patients undergoing LASIK.

Choroidal Neovascularization↗
PubMed2003

[Photorefractive keratectomy for correction of anisometropia after cataract surgery].

OBJECTIVE: To determine the visual and refractive outcome of photorefractive keratectomy (PRK) in patients with anisometropia after cataract surgery. METHODS: We studied a series of 31 eyes of 24 patients who underwent PRK for the correction of anisometropia after cataract surgery. Pre- and post-operative vision, refraction, anisometropia and surgical complications were observed. These patients were followed-up at 12.2 months after laser ablation. RESULTS: One week following PRK, the uncorrected visual acuity (UCVA) and the best correct visual acuity (BCVA) were improved significantly (P < 0.01). Mean spherical equivalent refraction (MSER) was decreased significantly to (1.12 +/- 0.55) D after PRK. The MSER was (1.27 +/- 0.56) D in myopia eyes and (0.81 +/- 0.38) D in hyperopia eyes one week after PRK, the difference between these two groups was statistically significant (P < 0.01). Astigmatism was decreased significantly after PRK (P < 0.01), the mean astigmatism was (0.49 +/- 0.38) D one week after the operation. Anisometropia was decreased from (3.44 +/- 1.07) D to (0.58 +/- 0.31) D after PRK, the difference between the pre-operative and post-operative anisometropia was statistically significant (P < 0.01). No serious complications occurred during or after the operation. CONCLUSION: PRK is a safe, reliable and effective method for correction of anisometropia after cataract surgery.

Adult↗
PubMed2004

[The study of photorefractive keratectomy induced defocus on emmetropization in infant monkeys].

OBJECTIVE: To investigate the effect of photorefractive keratectomy (PRK) induced defocus on emmetropization in infant rhesus monkeys and to determine the role of visual feedback on emmetropization. METHODS: PRK was performed in 8 healthy rhesus monkeys age ranging from 2 to 3 months. Either 3.00 D of relative hyperopic or myopic defocus was produced in one eye and the fellow eye as controls. The eyes were examined periodically with corneal topography, cycloplegic retinoscopy, A-scan ultrasonography, and slit-lamp biomicroscopy. RESULTS: All operated eyes demonstrated re-epithelialization within 3 days post-surgically and maintained transparent. Compensating axial length growth occurred throughout the observation period. The rate of vitreous chamber elongation varied with the post-PRK refractive status of the eye. The hyperopia-induced eyes exhibited a vitreous chamber elongation faster than the fellow eyes (t = 3.656, P = 0.0354), whereas myopia-induced eyes demonstrated a vitreous chamber elongation slower than the fellow eyes (t = 3.576, P = 0.0374). CONCLUSIONS: PRK-induced-defocus altered axial growth rates and emmetropization in infant monkeys predictably. These results indicate that primate emmetropization is regulated by visual feedback and correction of refractive error on children should be careful. PRK-induced-defocus is a promising method for myopic animal model and for the investigation of vision science.

Animals↗
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↗
PubMed2000

Results from a pediatric vision screening and its ability to predict academic performance.

BACKGROUND: Children attending three New York City public schools were screened in 1998-1999. These three schools were previously screened in 1996-1997. This allowed comparison of referral rates between the two years. In addition, we were able to follow individual children who attended the schools between these two years. Finally, using results of the citywide achievement test scores, we were able to correlate the specific vision screening tests with academic performance. METHODS: Results from each of the years were analyzed to determine if any trend existed in referral frequency and screening procedures failed. Referral criteria were failure on one or more of the screening battery tests. In addition, the children's vision screening performance was compared with their reading achievement test scores. Vision screening results of children in both the top 25% and bottom 25% of the class were evaluated and academic improvement based on optometric intervention was also monitored. RESULTS: Twenty-nine percent (29%) of children screened in 1996-1997 were referred. This matched the 25% referral rate found in 1998-1999. The screenings in 1998-1999 yielded a higher referral rate (35%) in functional vision tests as opposed to visual acuity screening procedures than the screening in 1996-1997 (30%). The King Devick Eye Movement Test and the hyperopia assessment screening showed significant correlation with citywide achievement test scores. Both these tests were significant for predicting those students in the lower 25% of the class for all grades in both years of the screenings. CONCLUSIONS: Early detection and remediation increased the potential for more effective learning in a small sample size of 25 children. Further studies involving larger sample sizes are indicated.

Child↗
PubMed2004

Refractive errors in medical students in Singapore.

INTRODUCTION: Refractive errors are becoming more of a problem in many societies, with prevalence rates of myopia in many Asian urban countries reaching epidemic proportions. This study aims to determine the prevalence rates of various refractive errors in Singapore medical students. METHODS: 157 second year medical students (aged 19-23 years) in Singapore were examined. Refractive error measurements were determined using a stand-alone autorefractor. Additional demographical data was obtained via questionnaires filled in by the students. RESULTS: The prevalence rate of myopia in Singapore medical students was 89.8 percent (Spherical equivalence (SE) at least -0.50 D). Hyperopia was present in 1.3 percent (SE more than +0.50 D) of the participants and the overall astigmatism prevalence rate was 82.2 percent (Cylinder at least 0.50 D). CONCLUSION: Prevalence rates of myopia and astigmatism in second year Singapore medical students are one of the highest in the world.

Adult↗
PubMed2002

The management of secondary glaucoma in nanophthalmic patients.

PURPOSE: To investigate the clinical characteristcs, management of secondary glaucoma in nanophthalmos, and the prevention of its complications. METHODS: Retrospectively, 9 cases (17 eyes) with nanophthalmic glaucoma were studied. RESULTS: The axial length of the eyes ranged (14.36 - 19.33) mm; All of the cases combined with hyperopia ranged (+7.00 +/- 16.00) D. All 17 eyes had the manifestation like angle-closure glaucoma. The glaucoma was controlled in 9 of 17 eyes at the early stage, which underwent laser iridotomy (4 of 9 eyes also underwent laser iridoplasty). 1 eye underwent ciliary photocoagulation because its visual acuity was lost and the patient complained of pain. The other 7 eyes underwent filtration surgery and 3 of them had permanent loss of vision caused by disastrous complications after the surgery. CONCLUSIONS: Management of secondary glaucoma in nanophthalmos is complicated. The laser iris surgery is safe and effective in glaucoma at the early stage. Vortex vein decompression, sclerotectomy or anterior sclerotomy may be performed to reduce disastrous complications.

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↗