18. May 2013 10:08
Limbal stem cell deficiency is a serious eye condition that sometimes affects contact lens wearers. Recently, a team of researchers has conducted a special study to investigate the issue.
The researchers carried out a database search of patients suffering from the severe form of the condition associated with contact lens wear and reviewed 12 charts with data on 18 eyes. In their analysis, they included such factors as demographic data, the type of contact lenses worn, duration of contact lens use, symptoms, the characteristics of limbal stem cell deficiency, comorbid eye diseases and the treatment that each patient had been undergoing.
Most of the patients were female (67%) and their average age was 42 years. By the beginning of the study, they had been wearing contact lenses for a mean of 14 years and their vision was decreased to 20/78 on average. Most of them also suffered from the symptoms of photophobia and pain.
Conservative treatment was ineffective in all of the subjects and consequently three quarters of them underwent limbal stem cell transplantation.
The researchers concluded limbal stem cell deficiency should be recognised by ophthalmologists and they should immediately initiate surgical treatment, as conservative therapy does not usually bring positive results.
16. May 2013 12:21
The comfort of contact lens wear depends not only on which contact lenses a patient uses, but also on the preferred combination of lenses and lens care products. A group of researchers have recently conducted a study investigating the matter and published its results.
The study included 37 contact lens wearers and used different lens/lens care product combinations chosen by the researchers. The subjects did not know anything about the combinations they were assigned and used them for eight days. During and after the study, the subjects filled in special questionnaires, which included questions concerning comfort and dryness. After a short washout period, the subjects were given another lens/lens care product combination and the procedure was repeated.
When all the data were analysed, the researchers concluded that eye comfort varied significantly between study groups, so it is worth looking for lens/lens care product combinations that improve patient experience and solve his or her problems associated with dryness and ocular irritation.
13. May 2013 08:02
An interesting study has recently been carried out by a group of Japanese researchers, who wanted to find out how cosmetic contact lenses affect eye wavefront aberrations.
The researchers (N. Takabayashi, T. Hiraoka, T. Kiuchi T and T. Oshika) used a wavefront analyser and checked higher-order aberrations in patients wearing different kinds of contact lenses (Acuvue 1-Day, Acuvue 1-Day Define [Accent and Vivid styles]). The lenses were made of the same material and had the same parameters (apart from the tint).
When aberrations were measured for 4mm pupils, there were no differences between the lenses. However, some types of aberrations were significantly larger with cosmetic lenses when the researchers analysed 6mm pupils. What is more, when cosmetic lenses were fitted poorly, the aberrations were even larger, affecting the subjects’ quality of vision.
Takabayashi and his associates concluded that poorly fitting cosmetic contact lenses can decrease vision and eye care practitioners should take appropriate measures to make sure such lenses are not decentred.
10. May 2013 11:59
Contact lens users sometimes suffer from lens-related dry eye syndrome, which – as a number of studies have shown – is mostly associated with lens dehydration.
According to the latest research, lens dehydration is closely connected with water content. To be more precise, as far as traditional contact lenses are concerned, the higher the water content, the higher the level of lens dehydration. In addition, silicone hydrogel contacts with lower water content often help patients complaining about dry eye symptoms, especially elderly ones.
Other factors contributing to lens dehydration include the environment, lens power (which affects its thickness), and the ability of the lens material to bind water.
Bulk dehydration is an important contact lens property, but, the results of a recent study suggest, it is not directly associated with comfort. This feature is more affected by wettability and surface hydration, and these are what contact lens manufacturers have been focusing on.
On the whole, silicone hydrogel materials are considered to be the most comfortable and the safest option, offering low bulk and surface dehydration as well as excellent wettability, resulting in fewer cases of dry eye syndrome.
2. May 2013 13:04
Scientists have discovered a gene that causes the development of myopia, thanks to which – at some point in the future – a cure for this condition could be found, making contact lenses for a great number of people unnecessary.
The discovery of a group of British researchers may have huge consequences for millions of patients, especially children, in whom dangerous complications of short-sighted can occur (macular degeneration, retinal detachment).
The first gene that is associated with the development of short-sightedness was discovered by Professor Chris Hammond (King’s College London) in 2010. According to the expert, the carriers of the identified genes are ten times more likely to suffer from myopia than other people.
However, more research is needed to find out how to prevent the condition, and – considering how thoroughly every new medicine needs to be tested before being approved – we will have to wait at least 15 years before we can forget about our contact lenses. Another thing is that the potential cure will only deal with one (though probably the most significant) factor contributing to the occurrence of short-sightedness. We may also need to find a way to change our lifestyles to get rid of myopia once and for all.