Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “MYOPIA”

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 235 records · Page 13Linked to original sources
PubMed2005

Incidence and progression of myopia in Singaporean school children.

PURPOSE: To determine the incidence and progression rates of myopia in young Singaporean children. METHODS: A prospective cohort study, the Singapore Cohort Study of the Risk Factors for Myopia (SCORM), was conducted in two schools in Singapore (1999-2002). Children aged 7 to 9 years (n=981) were followed up over a 3-year period. Cycloplegic autorefraction and biometry parameter measures were performed annually, according to the same protocol. RESULTS: The 3-year cumulative incidence rates were 47.7% (95% confidence interval [CI]: 42.2-53.3), 38.4% (95% CI: 31.4-45.4), and 32.4% (95% CI: 21.8-43.1) for 7-, 8-, and 9-year-old children, respectively. The 3-year cumulative incidence rates were higher in Chinese (49.5% vs. 27.2%) and in 7-year-old compared with 9-year-old children at baseline (47.7% vs. 32.4%), though the latter relationship was of borderline significance after adjustment for race, gender, amount of reading (books/week), and parental myopia (P=0.057). Premyopic children with greater axial lengths, vitreous chamber depths, and thinner lenses were more prone to the development of myopia, after controlling for age, gender, race, reading, and parental myopia. The 3-year mean cumulative myopia progression rates were -2.40 D (95% CI: -2.57 to -2.22) in 7-year-old myopic children, -1.97 (95% CI: -2.16 to -1.78) in 8-year-olds, and -1.71 (95% CI: -1.98 to -1.44) in 9-year-olds. CONCLUSIONS: Both the incidence and progression rates of myopia are high in Singaporean children.

Age Distribution↗
PubMed2005

Identification of a novel locus on 2q for autosomal dominant high-grade myopia.

PURPOSE: Myopia, or nearsightedness, is a visual disorder of high and growing prevalence in the United States and in other countries. Pathologic high myopia, or myopia of </=-6.00 D, predisposes individuals to retinal detachment, macular degeneration, cataracts, and glaucoma. Autosomal dominant (AD) nonsyndromic high-grade myopia has been mapped to loci on 18p11.31, 12q21-q23, 17q21-q23, and 7q36. This is the report of significant linkage to a novel locus on the long arm of chromosome 2 in a large, multigenerational family with AD high-grade myopia. METHODS: The family contains 31 participating members (14 affected). The average spherical refractive error for affected individuals was -14.46 D (range, -7.25 to -27.00). Before a genome screening was undertaken, linkage to intragenic or flanking markers for the myopic genetic syndromes of Stickler syndrome types I, II, and III; Marfan syndrome; and juvenile glaucoma were ruled out. In addition, no linkage was found to the known AD high-grade myopia loci listed above. A full genome screen of the family was performed with 382 microsatellite markers with an average intermarker distance of 10 cM. SimWalk2 software was used for multipoint linkage analysis based on an AD model with a penetrance of 90% and a disease allele frequency of 0.01. RESULTS: Fine-point mapping with an additional nine custom-made and five commercial markers yielded a maximum two-point lod score of 5.67 at marker D2S2348. Results of multipoint analysis indicate that the 1-unit support intervals for this new locus spans approximately 9.1 cM from (238.7 to 247.8 cM) on the chromosome 2 genetic map at q37.1. CONCLUSIONS: A novel locus for AD high-grade myopia has been determined, providing further evidence of genetic heterogeneity for this disorder.

Adolescent↗
PubMed2006

Expression of collagen-binding integrin receptors in the mammalian sclera and their regulation during the development of myopia.

PURPOSE: The sclera has a collagen-rich extracellular matrix that undergoes significant biochemical and biomechanical remodeling during myopic eye growth. The integrin family of cell surface receptors play critical roles in extracellular matrix and biomechanical remodeling in connective tissues. This study identified the major collagen-binding integrin receptors in the mammalian sclera and investigated their mRNA expression during the development of and recovery from experimental myopia. METHODS: The presence of the alpha1, alpha2, and beta1 integrin subunits was examined by using tree-shrew-specific primers and RT-PCR. Scleral expression of alpha1beta1 and alpha2beta1 receptor proteins was further investigated by using Western blot analysis and immunocytochemistry. Myopia was induced monocularly by occluding pattern vision and scleral tissue collected after 24 hours and 5 days. In a subset of the 5-day treatment group, vision was restored for 24 hours before tissue was isolated. Total RNA was extracted, and integrin subunit expression levels were assessed with quantitative real-time PCR. RESULTS: The presence of the major collagen-binding integrin subunits alpha1, alpha2, and beta1 was confirmed by RT-PCR in both scleral tissue and cultured scleral fibroblasts. Both the alpha1 and alpha2 integrin subunit proteins were identified in tree shrew scleral tissues, and integrin receptor expression was localized to scleral fibroblast focal adhesions. After only 24 hours of myopia induction, a time when no structural elongation has occurred, significant decreases were observed in the expression of the alpha1 (-36%) and beta1 (-44%) integrin subunits. After 5 days of myopia induction, alpha1 integrin expression had returned to baseline levels, whereas the alpha2 subunit showed a significant decrease in expression (-52%). The 5-day integrin profiles were maintained during recovery from the induced myopia, with only alpha2 integrin showing a statistically significant relative decrease in expression (-41%). CONCLUSIONS: The mammalian sclera expresses the major collagen-binding integrin subunits. The alpha1 and beta1 subunit expression was decreased early during the development of myopia, whereas the regulation of alpha2 integrin occurred at a later time point. The differential regulation of alpha1beta1 and alpha2beta1 during the development of myopia may reflect specific roles for these receptors in the scleral extracellular matrix and biomechanical remodeling that accompanies myopic eye growth.

Animals↗
PubMedDate not supplied

Two different genetic markers for high and low myopia.

In myopia patients, Rh and acid phosphatase were typed in two groups: group 1 consisted of 214 patients with low myopia (-6 D or less); group 2 of 124 patients with high myopia (more than -6 D). Statistical analysis of the markers showed a good Hardy-Weinberg equilibrium for both groups. In the Rh system there was a significant difference between group 1 and the control population (p < 0.05), but not between group 2 and control (p > 0.1). In the case of ACP there was a significant difference between group 2 and the control population (p < 0.05), but not between group 1 and control (p > 0.25). We conclude that the observed association between myopia and Rh system (chromosome 1) involves low myopia, while the association between myopia and acid phosphatase (chromosome 2) involves high myopia. Further DNA research will lead to more specific results.

Acid Phosphatase↗
PubMed2005

Visual quality after wavefront-guided LASIK for myopia.

This study evaluated the visual quality after wavefront-guided laser in situ keratomileusis (LASIK) for treating myopia. Thirty-two eyes with moderate myopia (-5.78 - -2.17D) and 25 eyes with high myopia (-7.78 - -6.17D) were prospectively reviewed. The contrast sensitivity (CS), glare and the total higher order aberrations (HOA) were measured before and 1 week, 1 month and 2 months after LASIK. The pupil diameter was measured at day- and night-time illumination. The CS and glare at all spatial frequencies were not reduced after wavefront-guided LASIK (p<0.05) and the difference between the moderate and high myopia group was not significant. No significant correlation was found between the amounts of myopia and the postoperative CS (p>0.05). The area under the log contrast sensitivity function (AULCSF) showed no correlation with the total HOA (r2=-0.071, p=0.612, between the daytime AULCSF and the total HOA with a 4 mm entrance pupil, r2=-0.176, p=0.260, between the nighttime AULCSF and the total HOA with a 6 mm entrance pupil). There was no decrease in CS and glare after wavefront-guided LASIK for myopia. In conclusion, wavefront-guided LASIK based on the individual ablation patterns is a good option for refractive surgery to improve the visual quality in both moderate and high myopia cases.

Adult↗
PubMedDate not supplied

Clinical characteristics and long-term postoperative results of infantile esotropia and myopia.

PURPOSE: To determine the short-term (6 month) and long-term (4 year) surgical results of infantile esotropia in a control group of 100 patients, as compared to a myopia (-2.0 to -5.0 diopters [D]) group of 13 patients and to a high-myopia (greater than -8.0 D) group of 14 patients. METHOD: A retrospective chart review with selection according to inclusion criteria. RESULTS: All 14 high-myopic patients (100%) achieved short-term unacceptable result of large-angle (greater than 20 prism diopters) deviation as compared to 29 (29%) and four (31%) of the patients in the control and myopia groups, respectively (P < 0.0001). Eighty (80%) of the patients in the control group and 10 (77%) in the myopia group achieved long-term favorable postoperative results of subnormal binocular vision, microtropia, or small-angle (less than 20 prism diopters) deviation, with no statistical differences between the two groups. In contrast, 10 (71%) of the patients in the high-myopia group achieved a final unacceptable result of large-angle deviation, as compared to 20 (20%) and three (23%) in the control and myopia groups, respectively (P < 0.0001). Persistent preoperative amblyopia was associated with a higher percentage of unfavorable surgical results and was more frequent in the high-myopia group (50%) as compared to the control group (14%) (P = 0.0004). CONCLUSIONS: Careful attention must be directed preoperatively toward reversing amblyopia and correcting refractive errors because persistent amblyopia at the time of surgery was associated with a higher percentage of unacceptable postoperative large-angle deviation. The conventional amount of recession or resection of muscles should be increased in high-myopic cases with infantile esotropia, because less effect is produced per millimeter of recession/resection initially and, in the long-term, the constant stimulus to accommodative convergence apparently causes recurrent esotropia.

Accommodation, Ocular↗
PubMedDate not supplied

Near-work activity and myopia in rural and urban schoolchildren in China.

PURPOSE: To examine the prevalence of myopia in rural and urban schoolchildren in Xiamen, China, and to assess the impact of environmental factors on rates of myopia. METHODS: Second-grade children attending either a city (n=119) or rural (n=91) school in Xiamen, China, were examined using cycloplegic autorefraction and biometry. Detailed questions on socioeconomic status, near-work activity, reading and writing habits, and family histories of myopia were asked in a face-to-face interview using a standard questionnaire. RESULTS: The prevalence of myopia was 19.3% (95% confidence interval [CI], 12.3, 29) in the city and 6.6% (95% CI, 2.4, 14.3) in the countryside. The average hours per day children spent reading and writing outside of school was 2.2 hours in the city compared with 1.6 hours in the countryside (P<.0001). In both schools, the odds ratio for total reading and writing, adjusted for parental history of myopia, was 2.2 (95% CI, 1.1, 4). CONCLUSION: These data suggest the prevalence of myopia is higher in the city than in the countryside. One possible explanation for these different rates could be that schoolchildren in the city spend more time reading and writing outside of school compared with children in the countryside. Myopic children in both the city and the countryside spent more time reading and writing compared with nonmyopic children. This increased near-work activity may contribute to the prevalence of myopia.

Child↗
PubMed1996

Results of photorefractive keratectomy for myopia with the technolas keracor 116 excimer laser.

BACKGROUND: The refractive results of first consecutive 157 myopic eyes undergoing photorefractive keratectomy with the Technolas Keracor 116 excimer laser are presented with a 6-month follow up. METHODS: Preoperative refractive errors (spherical equivalent) ranged between -1.75 diopters (D) and -20.00 D (mean: -7.19 +/- 3.73). A single ablation zone ranging from 4.5 mm to 6 mm was used. In all eyes except for those with myopia over -15 D, emmetropia was a goal. Postoperatively patients used fluoromethalone drops for 1 month. RESULTS: Treated eyes were divided into four groups based on preoperative myopia. Group 1 contained 15 eyes with myopia less than -3 D (93% were within +/- 1 D postoperatively). In Group 2 there were 53 eyes with preoperative myopia between -3.25 D and -6.00 D (64.1% were within +/- 1 D postoperatively). Group 3 consisted of 53 eyes with preoperative myopia between -6.25 D and -10.00 D (41.5% were within +/- D postoperatively). Group 4 contained 36 eyes with myopia over -10.00 D (13.8% were within +/- 1 D of attempted correction and 11.1% were within +/- 1 D postoperatively). CONCLUSIONS: Our study suggests that excimer laser photorefractive keratectomy using a 4.5 to 6.0 mm ablation zone effectively reduces myopia; however, predictability decreases as the attempted correction increases.

Adolescent↗
PubMedDate not supplied

Iris-claw phakic intraocular lens for high myopia.

PURPOSE: To evaluate the efficacy, safety, predictability, and stability of implanting a polymethylmethacrylate (PMMA) phakic intraocular lens (PIOL) (the Artisan myopia lens) to correct high myopia. METHODS: An Artisan myopia lens was implanted in 78 consecutive eyes of 49 patients with preoperative myopia that ranged from -6.25 to -28.00 D. Mean patient age was 42.4 years. Mean follow-up was 10.7 months and all patients were followed for at least 6 months; 45 eyes had follow-up of 12 months, and 10 eyes had 24 months. The desired outcome was emmetropia in all eyes except for those eyes with preoperative myopia greater then -23.00 D. RESULTS: Fifty-three eyes (67.9%) had a postoperative refraction at the last follow-up examination within +/-1.00 D of emmetropia, and 39 eyes (50.0%) had a postoperative refraction +/- within 0.50 D of emmetropia. The postoperative refraction remained stable during the entire follow-up period. Mean spectacle-corrected visual acuity improved from 20/32 preoperatively to 20/25 postoperatively. Mean postoperative uncorrected visual acuity was 20/32. There was no significant change in endothelial cell density from baseline. We did not encounter major complications. CONCLUSION: Implantation of the Artisan myopia lens to correct high myopia resulted in a stable and fairly predictable refractive outcome. A significant endothelial cell change was not detected.

Adult↗
PubMedDate not supplied

Correction of myopia of 7 to 24 diopters with the Artisan phakic intraocular lens: two-year follow-up.

PURPOSE: To evaluate the safety and efficacy of the iris claw phakic intraocular lens (Artisan; Ophtec BV, Groningen, The Netherlands) in patients with high myopia. METHODS: Between May 1999 and July 2001, 93 Artisan phakic intraocular lenses (IOLs) were implanted in 60 patients affected by high myopia. All patients underwent 24-month follow-up. The power of the lenses ranged from -7.5 to -22.0 diopters (D). Patients were divided into two groups: group 1 (68 eyes), myopia -6.75 to -15.50 D (SE), and group 2 (25 eyes), myopia -16.0 to -23.0 D (SE). Pre- and postoperative patient evaluation included manifest and cycloplegic refractions, uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), endothelial cell count, intraocular pressure, complication rate, safety, and efficacy. RESULTS: At 4 months, 83.8% (57/68) (group 1, myopia -6.75 to -15.50 D) and 68% (17/25) (group 2, myopia -16.0 to -23.0 D) of eyes achieved UCVA of > or =20/40. The BSCVA remained the same or improved in 100% of eyes. After 4 months, 69.1% (47/68) of eyes in group 1 and 52% (13/25) of eyes in group 2 were within +/-1.00 D of the desired refraction; the mean refraction was stable between 4 and 24 months. Of the intraoperative complications, 69.2% were observed in the first 25 lenses implanted; postoperative complications included iris atrophy in 11.8% (11/93), lens decentration in 5.4% (5/93), and night glare in 6.4% (6/93) of eyes. No IOLs were removed. Mean endothelial cell loss was 2.8% at 4 months, 3.9% at 12 months, and 5.4% at 24 months. CONCLUSIONS: Our results regarding implantation of the Artisan phakic IOL confirm that these lenses are safe and effective for the correction of high myopia, with a stable refractive outcome but with a higher than normal rate of endothelial cell loss during 2-year follow-up.

Adult↗
PubMed2000

[Epidemiology of myopia].

The present state of knowledge on the epidemiology of myopia is discussed. The history of myopia investigations is described. The prevalence of myopia in different ages, races and populations is presented. The factors influencing myopia occurrence are characterized. Special attention is focused on the results of studies indicating environmental and genetic reasons of myopia. Most recent investigations concerning the influence of light on myopia occurrence as well as concerning a genetic locus for high myopia are described.

Adolescent↗
PubMed2002

Nearwork in early-onset myopia.

PURPOSE: To determine the relationship of nearwork and myopia in young elementary school-age children in Singapore. METHODS: A cross-sectional study of 1005 school children aged 7 to 9 years was conducted in two schools in Singapore. Cycloplegic autorefraction, keratometry, and biometry measurements were performed. In addition, the parents completed a detailed questionnaire on nearwork activity (books read per week, reading in hours per day and diopter hours [addition of three times reading, two times computer use, and two times video games use in hours per day]). Other risk factors, such as parental myopia, socioeconomic status, and light exposure history, were assessed. RESULTS: In addition to socioeconomic factors, several nearwork indices were associated with myopia in these young children. The multivariate adjusted odds ratio of higher myopia (at least -3.0 D) for children who read more than two books per week was 3.05 (95% confidence interval [CI], 1.80-5.18). However, the odds ratios of higher myopia for children who read more than 2 hours per day or with more than 8 diopter hours (1.50; 95% CI, 0.87-2.55 and 1.04; 95% CI, 0.61-1.78, respectively) were not significant, after controlling for several factors. CONCLUSIONS: Children aged 7 to 9 years with a greater current reading exposure were more likely to be myopic. This association of reading and myopia in a young age cohort was greater than the strength of the reading association generally found in older myopic subjects. Whether these results identify an association of early-onset myopia with nearwork activity or other potentially confounding factors is discussed.

Age Distribution↗
PubMed2002

Mechanisms of myopia in Cohen syndrome mapped to chromosome 8q22.

PURPOSE: To analyze the mechanisms of myopia in Cohen syndrome (Mendelian Inheritance in Man [MIM] no. 216550). METHODS: A cross-sectional study of 22 Finnish patients (age range, 2-57 years) with Cohen syndrome, which maps to chromosome 8q22, was undertaken to record cycloplegic refraction, keratometry (corneal power and radius of curvature), biometry (anterior chamber depth [ACD], lens thickness [LT], axial [AL] and vitreal length [VL]), and Hoffer Q-modeled lens power. These components of refraction were correlated to age and spherical equivalent (SE) at the corneal plane. Contribution to total myopia of refractive (corneal and lenticular) and axial components was modeled by multiple linear regression and by estimating the effect of deviation from population mean values. RESULTS: The mean SE in patients with Cohen syndrome older than 10 years was -9.35 D; the mean cylinder power, +1.70 D; and the mean anisometropia, 0.53 D. Relative to the emmetropic eye of a young adult, the AL and VL (mean, 23.9 and 16.6 mm, respectively) and lens power (mean, 30.30 D) were higher in 74% and 93% of patients, respectively, and the ACD (mean, 2.5 mm) was smaller and the LT (mean, 4.9 mm) and corneal power (mean, 45.63 D) higher than average in all patients. Corneal power (r = 0.513, P = 0.021) increased with age, but AL and VL (P = 0.46 and 0.54, respectively) and lens power (P = 0.89) did not correlate with age. The lens power decreased with AL (r = -0.564, P = 0.029) and tended to increase with corneal power (r = 0.475, P = 0.074). Multiple linear regression identified AL and corneal power as independent predictors of SE. Based on deviation from population means, the lens power explained 55%, corneal power 23%, and AL 22% of total myopia. ACD decreased and LT increased markedly with age, rendering angle-closure glaucoma a possibility. CONCLUSIONS: Myopia in Cohen syndrome is mainly refractive in type and is due to high corneal and lenticular power, which is otherwise rare in young patients. It may be superimposed on axial myopia, probably related to polygenic factors that determine myopia in the general population. The refractive myopia in Cohen syndrome may result from dysgenesis and atrophy of the cornea, ciliary body, and iris, which in turn cause iridial and zonular laxity and spherophakia.

Abnormalities, Multiple↗
PubMed2003

[Occurrence of myopia among Polish students aged 6 to 18 years old].

PURPOSE: To determine the prevalence of myopia among students ranging from 6 to 18 years of age. MATERIAL AND METHODS: 5023 students in all, from elementary schools, junior high schools and high schools, aged 6-18 years were examined. Measurements of visual acuity as well as retinoscopy after cycloplegia have been carried out. The data was analysed using chi-square test. RESULTS: It was found that 15% of the students, aged from 6 to 18 suffers from myopia. It has been observed that from the sixth to the eighteenth years of life along with the age grows the prevalence was well as value of myopia. A major increase in the frequency of myopia occurrence among students over the age of 14 has been found. Significant differences between prevalence of myopia among boys and girls was not observed. CONCLUSIONS: (1) 15% of students in the age from 6 to 18 suffer from myopia. (2) Along with the age the prevalence of myopia increases.

Adolescent↗
PubMed1992

Myopia and educational attainment in 421,116 young Singaporean males.

Data of 421,116 Singaporean males aged 15 to 25 (mean 17.75) years who underwent compulsory medical examination in 1974-84 and 1987-91 were used to estimate the prevalence of myopia and to study the correlation between the prevalence and severity of myopia and educational attainment. The estimated myopia prevalence rate was 26.3% in 1974-84 and 43.3% in 1987-91. This rise in the rate was accompanied by an increase in the proportion of males who achieved higher levels of education over the same period. The overall myopia prevalence rate was 30.4%. Both the prevalence and severity of myopia were higher as the level of education attained increased. The myopia prevalence rate was 15.4% in males with no formal education and increased steadily through groups with intermediate education to 65.2% among those with GCE 'A' level education, 57.5% among diploma holders and 65.1% among university graduates in 1987-91. Seventy out of 173 (40%) myopes with no formal education compared to 1035 out of 1612 (64%) myopes with university degrees had unaided visual acuity worse than 6/60 in 1987-91. Our findings confirm indications from other sources that the association between the prevalence and severity of myopia and education attainment is real. A combination of genetic and environmental factors may be the cause of this association.

Adolescent↗
PubMed2004

[The posterior portion of the eyeball and the muscle cone in cases of high myopia].

PURPOSE: To study the displacement of the eyeball of high myopia in the muscle cone. METHODS: Three patients with esotropia with high myopia(myopic esotropia group), seven patients with high myopia without esotropia (high myopia group), and eight controls(control group) were examined. Using magnetic resonance imaging, the outer axial length and the displacement of the posterior portion of the eyeball in the muscle cone were measured. In order to neglect individual differences, the coronal scanning was perpendicular to the orbital axis. The displacement was measured in the plane 2 mm and 4 mm anterior from the globeoptic nerve junction. The distance of the displacement was represented by the distance from the center of the globe to the center of the muscle cone. RESULTS: The displacement in the plane 4 mm anterior (mean +/- standard deviation) was greater in the order of the myopic esotropia group(1.6 +/- 0.64 mm), the high myopia group(1.2 +/- 0.51 mm), and the control group(0.059 +/- 0.35 mm). The displacement of the eyeball was largest in the myopic esotropia group(p < 0.001). The outer axial length and the distance of the displacement in all cases was correlated significantly(r = 0.93, p < 0.01). Moreover, the eyeballs of the myopic esotropia group and the high myopia group were displaced upwards in the temporal area. CONCLUSIONS: The posterior portion of high myopia was displaced upwards in the temporal area in the muscle cone regardless of the presence or absence of esotropia. The eyeball originally elongates upwards in the temporal area, not towards the weakest part of the muscle cone.

Adult↗
PubMed2004

Dissecting the genetics of human high myopia: a molecular biologic approach.

PURPOSE: Despite the plethora of experimental myopia animal studies that demonstrate biochemical factor changes in various eye tissues, and limited human studies utilizing pharmacologic agents to thwart axial elongation, we have little knowledge of the basic physiology that drives myopic development. Identifying the implicated genes for myopia susceptibility will provide a fundamental molecular understanding of how myopia occurs and may lead to directed physiologic (ie, pharmacologic, gene therapy) interventions. The purpose of this proposal is to describe the results of positional candidate gene screening of selected genes within the autosomal dominant high-grade myopia-2 locus (MYP2) on chromosome 18p11.31. METHODS: A physical map of a contracted MYP2 interval was compiled, and gene expression studies in ocular tissues using complementary DNA library screens, microarray matches, and reverse-transcription techniques aided in prioritizing gene selection for screening. The TGIF, EMLIN-2, MLCB, and CLUL1 genes were screened in DNA samples from unrelated controls and in high-myopia affected and unaffected family members from the original seven MYP2 pedigrees. All candidate genes were screened by direct base pair sequence analysis. RESULTS: Consistent segregation of a gene sequence alteration (polymorphism) with myopia was not demonstrated in any of the seven families. Novel single nucleotide polymorphisms were found. CONCLUSION: The positional candidate genes TGIF, EMLIN-2, MLCB, and CLUL1 are not associated with MYP2-linked high-grade myopia. Base change polymorphisms discovered with base sequence screening of these genes were submitted to an Internet database. Other genes that also map within the interval are currently undergoing mutation screening.

Case-Control Studies↗
PubMed1992

Night myopia: implications for the young driver.

A total of 380 randomly selected patients aged 16 to 80 years who did not have eye disease underwent testing for night myopia between August and October 1989 with a laser speckle generator under both photopic and scotopic conditions. For the first 308 subjects the speckles were continuously run, and for the next 72 subjects a timer was used to minimize the accommodative stimulus. An increase in myopia of 0.75 dioptres or more from the photopic to the scotopic state, equivalent to a visual acuity of 20/45 or less, was considered indicative of night myopia. Overall, 17% of the subjects were found to have night myopia. Of the 26 subjects aged 16 to 25 years in the timer group 38% had night myopia of 0.75 D or more, 23% had night myopia of 1.00 D or more, and 4% had night myopia of 2.50 D, which is equivalent to an acuity of 20/265. The results indicate that driving in the dark could create visual difficulties for certain younger patients that a night myopic correction would eliminate.

Adolescent↗