|
|
|
Top search choices8. Floaters 9. Optic Nerve 12. Vision Rehabilitation of Infants
Hot Topics Hot Topics:
Smoking Linked to Macular Degeneration
Vitamin E and Macular Degeneration
AREDS2 Nutritional Study for AMD
|
Glasses and Amblyopia By L. E. Leguire Ph.D. MBA Article Reviewed: Chen, P L., Chen, JT., Tai, M C., Chang, C C., and Lu, D W. "Anisometropic Amblyopia Treated With Spectacle Correction Alone: Possible Factors Predicting Success and Time to Start Patching," Am. J. Ophthalmology, 2007 Jan, 143 (1): p54-60. The authors of this study examined 60 children between the ages of three and seven years (average age of 5.3 yrs) who were newly diagnosed with anisometropic amblyopia. Anisometropic amblyopia is amblyopia due to a difference in refractive error between the eyes and, in their case, the children had an average difference in refractive error between the eyes of about three diopters. A difference of three diopters would be like having one eye focused on an object one meter from your face and the other eye focused at an object at 1/4 meters from your face. Because the eyes cannot focus at the same time on an object, the eye that cannot focus on the object becomes amblyopic. The authors wanted to know how often glasses alone (without patching therapy, at least at first) might improve or even "cure" the amblyopia. The authors gave the children glasses and followed the children every month to chart their progress in visual acuity in the amblyopic eye. The results showed that a vast majority of the children (93 percent) showed at least a two-line improvement in visual acuity in the amblyopic eye because of wearing the glasses alone (a two-line improvement on the eye chart the investigators used is equal to about a 37 percent improvement). Forty-five percent of the children had their amblyopia cured or resolved with glasses alone. The average improvement in these children was 3.8 lines on the visual acuity chart. When looking at the improvement in visual acuity over time (every month), the investigators found that most of the improvement in visual acuity occurred in the first three months, after that visual acuity improved very slowly. For those children in which the amblyopia was cured, the duration of wearing glasses alone ranged from one to about 10 months. For those children whose amblyopia was cured by glasses alone, these children initially had better visual acuity to begin with; their visual acuity ranged from about 20/32 (two lines below 20/20) to about 20/80 (six lines below 20/20). In addition, the children who were cured by glasses alone had, on average, less of a difference in refractive error between the eyes (i.e., less anisometropia): less than four diopters. The investigators conclude by saying that glasses alone might cure about 50 percent of younger children with anisometropic amblyopia. After about four months and assuming there is no further improvement of visual acuity with the glasses alone, patching or penalization (i.e., use of dilating eye drops in the good eye) should be considered. Additional Information Glasses alone might even help older children with amblyopia. For example, a multi-center clinical trial of treating older amblyopic children, between the ages of seven and 17 years, found that glasses alone benefited about 25 percent of children between seven and 12 years and 23 percent of children between 13 and 17 years. (For more information about this study, Click Here). Although most of the children had some remaining amblyopia following the termination of treatment, the improvement found with glasses alone could be of real benefit depending on the circumstances, especially later in adult life when visual acuity may be a qualifying factor for certain occupations. For example, to qualify for a commercial motor vehicle (CMV) license and to drive a commercial truck throughout the United States, you have to have at least 20/40 visual acuity in your worst eye. Therefore, if you have amblyopia and one eye is 20/20 and the other eye is 20/60 you would not qualify for a CMV license. However, if you wore your glasses on a regular basis (and assuming that you have anisometropic amblyopia) your vision could improve to say 20/40 and you would qualify for the CMV license. Finally, it is important to note the importance of wearing glasses, particularly glasses made with polycarbonate lenses, to protect the remaining good eye. Amblyopic individuals are at increased risk of injury to the good eye - so wear the safety glasses made with polycarbonate lenses.
|
W. R. Bryan Diabetic Eye Disease Research Fund 2008 OLERF Annual Report (PDF file) |
