EYE ON ASIA myopia

Document Sample
EYE ON ASIA myopia Powered By Docstoc
					                                                                                                                  EYE ON ASIA

   Abstracts of Asian research published in the                                                interviews. Both distance and lighting
   international literature                                                                    information taken from the question-
                                                                                               naire were compared with more precise
                                                                                               measurements.
Mycotic Keratitis in                           eyes were subjectively refracted, and               Diopter hours were quantified as the
Mumbai                                         corneal curvatures and ocular dimensions        duration of close work multiplied by the
                                               were measured. At the end of the study          reciprocal of the distance at which the
www
                                               period, the mean spherical equivalent           activity was performed. The intraclass
Between 1988 and 1996, 1010 clinically-
                                               refraction (SER) was -1.86 diopters (D;         correlation coefficient of the reliability of
suspected cases of mycotic keratitis
                                               SD 1.99) and 62% of the children were           distance information for each type of
were studied for evidence of fungal
                                               myopic. The annual incidence of myopia          close work activity ranged from 0.43 to
infection and for identification of the
                                               was 11.8%.                                      0.91. Home light meter readings were
aetiological agents of keratitis in Mumbai.
                                                   Children aged 10 years or less had a        significantly higher for children who
367 patients had positive specimens by
                                               greater change in SER toward myopia             were reading under both room and read-
microscopy and culture and 79.0% were
                                               than did older children. The annual rate        ing lights, and the distances noted on
aged between 21 and 50 years. Male
                                               of myopia progression for the myopic            the questionnaire were comparable with          37
patients were more often affected than
                                               children was -0.46 D (SD 0.40) and the          the measured distances. Measures of
females. 88.0% of patients were farmers
                                               rate of progression was greatest between        posture, distance, and lighting factors
or construction workers and 89.9%
                                               the ages of 6 and 10 years. Vitreous            have been developed to study possible
gave a definite history of antecedent
                                               depth/axial length elongation was the           modifiers of the effects of close work on
corneal trauma.
                                               main component contributing to the              myopia.
    A single fungal isolate was obtained
                                               progression of myopia.
from 307 patients and multiple isolates                                                               Saw SM, Nieto FJ, Katz J, Chew SJ.
                                                   These researchers concluded that
from 20. Mixed isolates of bacteria and                                                            Distance, lighting, and parental beliefs:
                                               Hong Kong schoolchildren develop                  understanding near work in epidemiologic
fungi were found in 40 patients. The
                                               myopia as early as 6 years. And the                       studies of myopia. Optom Vis Sci
predominant isolate was Aspergillus                                                                                      1999;76:355-362.
                                               myopia progresses at a greater rate
spp., which was found in 219 patients,
                                               compared with children of European
followed by Candida spp. in 36, Fusarium                                                       Progression of Myopia
                                               extraction.
spp. in 33, and Penicillium spp. in 34.                                                        and Progressive Lenses
Filamentous fungal isolates from 22 pa-
                                                Lam CS, Edwards M, Millodot M, Goh WS.
                                                                                               in Hong Kong Chinese
tients remained unidentified. Mycotic             A 2-year longitudinal study of myopia pro-   Schoolchildren
keratitis should be suspected in every           gression and optical component changes
                                                       among Hong Kong school-children.        www
patient with a corneal lesion.                            Optom Vis Sci 1999;76:370-380.       In Chinese societies, primary and
                                                                                               secondary schoolchildren perform large
    Deshpande SD, Koppikar GV. A study of
       mycotic keratitis in Mumbai. Indian J
                                               Distance, Lighting,                             amounts of reading and homework and
          Pathol Microbiol 1999;42:81-87.      and Parental Beliefs:                           thus spend long periods doing close work
                                               Understanding Close                             during their formative years. Progressive
Myopia Progression and                         Work in Myopia                                  lenses, which can permit a focused
Optical Component                              www                                             retinal image at distance, intermediate,
Changes Among Hong                             To develop measures and indices of              and near, without accommodation, may
Kong Schoolchildren                            factors (distance of eye from object,           slow the development of myopia. This
www                                            posture, and lighting) that may modify a        paper reports the results of a 2-year
This study investigated refractive errors      possible effect of close work on myopia,        longitudinal study to examine the effects
and optical component changes in 142           the duration of close work, the distance        of progressive lenses on myopia progres-
Hong Kong schoolchildren aged between          of an object from the eye, lighting             sion in Chinese children.
6 and 17 years during a 2-year period          conditions, and other sociodemographic              Prestudy vision screening tests
between 1991 and 1993. The children’s          characteristics were ascertained from           and 5 examinations, which included

Asian Journal of OPHTHALMOLOGY and Asia-Pacific Journal of Ophthalmology                                     Volume 2, Numbers 1, 2, 2000
     EYE ON ASIA

     Table 1. Mean refractive error and mean myopic progression over 2 years in 68 children with myopia   pressure, refractive error, and corneal
     using single vision or progressive lenses.
                                                                                                          curvatures were also recorded.
                                     Single vision      + 1.5 D progressive      + 2.0 D progressive          The mean ± SD central corneal thick-
                                      lenses (D)             lenses (D)               lenses (D)
                                                                                                          ness of the right and left eyes were 575 ±
       Mean refractive error             -3.67                 -3.73                    -3.67             32 µm and 574 ± 31 µm, respectively.
       Mean myopic progression           -1.23                 -0.76                    -0.66
                                                                                                          No significant difference in central corneal
                                                                                                          thickness was found between the right
     noncycloplegic refraction, were conducted          school eye screening activities were sent         and left eyes or between male and female
     at half-yearly intervals. Of those who             to 200 randomly selected districts. Data          subjects. Central corneal thickness de-
     completed the study, 32 children wore              from 61 districts were analysed, using pro-       creased with increasing age but this effect
     single vision lenses (SV group) and 36             cess indicators to assess performance at          was only apparent in females. The maxi-
     wore progressive lenses. Of the latter, 22         different stages of the screening procedure.      mum decrease in central corneal thick-
     wore a +1.50 D addition (P1 group) and                  Teachers screened 5.39 million children      ness occurred in the 10 to 25 years age
     14 wore a +2.00 D addition (P2 group).             in 61 districts. Refraction was performed         group, and central corneal thickness and
     Refractive error, corneal curvature, axial         for 205,082 children (3.8%), and 43,922           age were significantly correlated in both
     length, vitreous depth, and intraocular            children (0.8%) were provided with spec-          males and females in this age group.
38
     pressure were measured at every exam-              tacles. Children aged from 10 to 15 years             Intraocular pressure and central cor-
     ination. Height was measured as an                 had the most refractive errors.                   neal thickness was significantly correl-
     index of general growth.                                Vision screening in schools has been         ated. There was no correlation between
         Progressive lenses significantly re-           taken up successfully in many districts           central corneal thickness and refractive
     tarded the progression of myopia in these          in India, which has reduced the work-             error or between central corneal thickness
     children. Initially, the mean refractive           load of eye care staff. The simplicity of         and corneal curvatures.
     error of the SV group was -3.67 D, -3.73 D         the procedure facilitates widespread                  Central corneal thickness decreased
     in the P1 group, and -3.67 D in the P2             application, although monitoring and              with increasing age in females. Central
     group. The mean myopic progression                 reporting needs to be improved.                   corneal thickness was significantly cor-
     during the study period was -1.23, -0.76,                                                            related with intraocular pressure, but not
     and -0.66 D for the SV, P1, and P2 groups,          Limburg H, Kansara HT, d’Souza S. Results        with refractive error or corneal curvatures.
                                                               of school eye screening of 5.4 million
     respectively (table 1).                                   children in India — a five-year follow-
                                                                                                          These patients also had significantly
         These researchers concluded that                          up study. Acta Ophthalmol Scand        thicker corneas than those reported for
     progressive lenses reduce the progression                                     1999;77:310-314.       Caucasian subjects.
     of myopia. It may be that the interaction
     of progressive lenses with the accommo-            Central Corneal                                     Cho P, Lam C. Factors affecting the central

     dation system is the cause of this reduc-          Thickness of Hong                                            corneal thickness of Hong Kong-
                                                                                                                         Chinese. Curr Eye Res 1999;
     tion in myopia progression since the
                                                        Kong Chinese                                                                       18:368-374.
     +2.00 D addition appeared to be more               www
     effective than the +1.50 D addition.               The aims of this study were to investi-           Burden of Visual
                                                        gate the effect of age, intraocular pres-         Impairment in Southern
       Leung JT, Brown B. Progression of myopia         sure, refractive error (spherical equiva-         India
         in Hong Kong Chinese schoolchildren is
           slowed by wearing progressive lenses.        lent) and corneal curvatures on the               www
                Optom Vis Sci 1999;76:346-354.          central corneal thickness of Hong Kong            To assess the prevalence and causes
                                                        Chinese people. The central corneal thick-        of moderate visual impairment in an
     School Eye Screening                               ness of Hong Kong Chinese people was              urban population in southern India, a
     for Indian Children                                compared with those previously reported           population-based, cross-sectional study
     www                                                for other ethnic groups. The central              was performed. 2522 patients were in-
     To assess the results of a vision-screening        corneal thickness of 151 patients aged            cluded from 24 clusters representative
     programme in schools in India 5 years              from 10 to 60 years was measured using            of the population of Hyderabad. Eligible
     after its introduction, questionnaires on          an ultrasound pachometer. Intraocular             subjects underwent a detailed ocular

     Volume 2, Numbers 1, 2, 2000                                                Asian Journal of OPHTHALMOLOGY and Asia-Pacific of Ophthalmology
                                                                                                                    EYE ON ASIA

evaluation, including logarithm of the           from dealing with blindness, should             Phacoemulsification was successfully
minimum angle of resolution (logMAR)             address the issue of the relatively easily      and safely performed in appropriately
visual acuity, refraction, slit-lamp biomicro-   treatable uncorrected refractive error as       selected patients with white hypermature
scopy, applanation tonometry, gonios-            the cause of moderate visual impairment         cataract.
copy, cataract grading, and stereoscopic         in an estimated 10.9 million persons in
dilated fundus evaluation. Automated             urban India.                                       Vajpayee RB, Bansal A, Sharma N, et al.
                                                                                                   Phacoemulsification of white hypermature
threshold visual fields and slit-lamp                                                                      cataract. J Cataract Refract Surg
and fundus photography were performed                 Dandona L, Dandona R, Naduvilath TJ,                              1999;25:1157-1160.
                                                 et al. Burden of moderate visual impairment
when indicated.                                      in an urban population in southern India.
    In addition to the 1% prevalence of                    Ophthalmology 1999;106:497-504.       Blindness and Cataract
blindness in this sample, moderate visual                                                        Surgery in China
impairment was present in 303 subjects,          Phacoemulsification of                          www
an age-gender-adjusted prevalence of             White Hypermature                               A population-based, cross-sectional
7.2% (95% confidence interval [CI],              Cataract                                        study was performed among 5342
4.5%-9.9%; design effect, 2.7). The              www                                             persons older than 50 years to assess
major cause of moderate visual impair-           To evaluate the safety of phacoemulsifi-        blindness prevalence and that caused             39
ment was refractive error (59.4%, 95%            cation of white hypermature cataract,           specifically by cataract in rural southern
CI, 52.3%-66.5%) followed by cataract            which is common in developing coun-             China. Visual acuity and eye examinations
(25.3%, 95% CI, 19%-31.6%).                      tries, a prospective evaluation of              were performed in 1997 in a random
    Multivariate analysis showed that            phacoemulsification in 25 eyes of 25            sample of villages in Doumen County.
the prevalence of moderate visual impair-        consecutive patients with hypermature               Bilateral blindness (presenting visual
ment was significantly higher in those           cataract was performed. Patients with           acuity < 0.10) was found in 4.37%
aged 40 years or older (odds ratio, 10.9;        good pupil dilation, optimal endothelial        (95% confidence interval, 3.67%- 5.06%).
95% CI, 8-15) and females (odds ratio,           cell count, and disease-free ocular and         Blindness was associated with increasing
1.89; 95% CI, 1.41-2.53) and lower in            systemic status were included. High             age (p < 0.001) and with lack of education
those belonging to the highest socio-            magnification, sodium hyaluronate, and          (p < 0.01).
economic group (odds ratio, 0.27; 95% CI,        a Utrata capsulorhexis forceps were                 Cataract was the principal cause of
0.14-0.51). However, because of the              used to perform continuous curvilinear          blindness in at least one eye in 61.5%
pyramidal age distribution of the popu-          capsulorhexis (CCC).                            of blind people, with refractive error res-
lation, 38.1% of the total moderate                  The stop and chop technique was             ponsible for another 10%. An estimated
visual impairment was present in those           used for nuclear emulsification. A 5.5 mm       40% of people with cataract underwent
younger than 40 years old. The pro-              optic allpoly (methyl methacrylate)             surgery; surgical coverage was lowest
portion of moderate visual impairment            intraocular lens (IOL) was implanted, and       among the elderly, women, and those
caused by refractive error was higher in         wound closure was sutureless.                   without schooling, although not at
the younger than in the older age groups             Successful CCC was performed for            statistically significant levels.
(p < 0.0001).                                    23 of 25 patients. In 2 patients, the CCC           Despite the increased attention
    Projecting the results to the 26.5%          edge extended toward the periphery and          given to eye care in Doumen County,
urban population of India, there would           a Vannas scissors was used to achieve           blindness remains a major public health
be 18.4 million (95% CI, 11.5-25.2 million)      an even cut. No complications were seen         problem, with cataract surgery reaching
persons with moderate visual impair-             during nuclear emulsification and IOL           fewer than half of those who could
ment in urban India alone. The absolute          implantation.                                   benefit from it.
proportion of moderate visual impairment             80% of patients had a visual acuity of
in those aged younger than 40 years              20/40 or better on the first postoperative      Li S, Xu J, He M, et al. A survey of blindness
                                                                                                     and cataract surgery in Doumen County,
was considerable.                                day. Five patients had significant corneal                  China. Ophthalmology 1999;106:
    The eye care policy of India, apart          oedema that resolved within 1 week.                                                1602-1608.




Asian Journal of OPHTHALMOLOGY and Asia-Pacific Journal of Ophthalmology                                       Volume 2, Numbers 1, 2, 2000

				
DOCUMENT INFO
Shared By:
Categories:
Tags: ASIA, myopia
Stats:
views:10
posted:7/30/2010
language:English
pages:3
Description: EYE ON ASIA myopia