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Chung K, Mohidin N, O’Leary DJ. Vision Research 2002;42:2555-9.
Myopia is not just a refractive condition that you can just compensate for with glasses, contact lenses, or even refractive surgery. I emphasize the semantic ”compensate” because, even with surgery where all the data should ideally show a situation close to plano, even if you no longer refract myopically, you ARE still a myope. In treatment for myopia, Sherwin J. Isenberg used the term management because the myopia is not cured. He stated that the use of the word cure indicates that the patient is being restored to his or her former state of health.
The prevalence of myopia in the adult population in most Eastern countries is upwards of 80%. The impact of myopia on the economic, social, and well being of the population may have irreversible impacts such as a higher risk for glaucoma and retinal detachment. Liang et al. confirmed high myopia is potentially associated with complications that may lead to blindness. The prevention of myopia is very important, especially among young children.
There are many studies addressing the why and how to cure myopia, or in a more realistic approach, how to slow down myopia. Investigations include acupuncture, the effect of ambient light, ortho-K, atropine, near add, dual or progressive addition lenses (PAL), and vision therapy (VT). The article presented is on the topic of under correction.
Ninety-four subjects (myopes aged 9-14 years) participated in the study for a period of 2 years. Half were given the full correction for full time wear and the other half was the under-corrected for a maximum visual acuity of 6/12 as part of a full examination. The exclusion criteria included more than 2 diopters of astigmatism in each eye, significant binocular problems, and abnormal ocular health.
The results of the 2 year study demonstrates a mean progression in the under-corrected group of -1.00D while in the fully corrected group, there was an increase of -0.77 D. The study shows no significant differences in other ocular parameters nor in the reading hours.
Some considerations about the methodology should be brought to the forefront.
- The authors speak about a full optometric routine examination, but what is included in this examination?
- How was “no binocular vision problems” determined ? What testing was completed ?
- Follow up was performed every 6 months. Why was it not appropriate to get an appointment as soon as the subject noticed a decrease in his acuity ?
- The study used a coin-toss method for randomization which was well explained
- The initial refraction was on average -2.68 D but one could question if this was already too late or too high an amount to start off patients. What if they started with children with less myopia or myopia that had just started ?
Are there any other alternatives/recommendations to the criteria ?
The criteria of a VA of 6/12 seems to be inappropriate because crisper vision in school is needed for distance activities. No binocular vision testing appears to have been completed!
Interestingly, the research seems to demonstrate that during the first six months that the axial length did not change in either group, but there was already a change in the level of myopia! We could conclude there is a lag between the functional change and the organic change. Could we conclude that function leads the organ? In my opinion, a six month period for check ups is too long. I would recommend a 3 month period or sooner if a change in vision was reported.
Was the purpose of this research to demolish ideas, or perhaps create some awareness on how to lead visual care? As readers and eye care specialists, it is our role and responsibility to look closely. Reading just the title and the abstract is not enough and may mislead our judgment, and worse, mislead our patients. When reading new information we need to fully understand and have a positive but critical attitude to get and to share the right information for the benefit of our patients.