The truth about silicone hydrogel contacts – the new wave of high oxygen, high discomfort lenses
May 18, 2008
For the last year, I’ve been doing battle with Acuvue Oasys lenses. Optometrists and opthamologists have been telling me that maybe I can’t wear contacts anymore, maybe my lens cleaning solution isn’t right, maybe I should wear my contacts less. These were all interesting things to say, given that I’d never had any problems with eye irritation with my old Acuvue 2 lenses. I recently became aware that my story isn’t rare, and I found out some more with a little digging through medical journals that others in my situation might like to know.
Look into the research and you’ll see that the high-oxygen silicon-hydrogels (like Acuvue Oasys and CIBA Vision’s Focus) are really NOT all that they’re cracked up to be. That discomfort you’re feeling doesn’t make you weird or mean that you’ve not been caring for your contacts properly. Chances are, the contacts themselves are to blame. In one study of contact lens comfort, more than a quarter of people who had been using traditional soft contacts had experiences so bad with the silicon-hydrogels that they had to drop out of the study. These new lenses are certainly not ALL bad (my girlfriend uses them and is quite happy with them), but they are certainly not the holy grail of contacts the optometrists and relentless marketing campaigns would have you believe. They are expensive though!
Before the change to Oasys, I’d worn Acuvue 2 and regular Acuvue lenses since the age of 12. That makes 13 years of absolutely trouble-free use. Nary an eye-infection, nary a sign of keratitis. Nothing. I’d wear them for 18 hours of sports, studying, and all around living life. I’d worn them for extended periods around the globe and NEVER had a single problem.
The last year, I’ve been plagued with eye problems. Throbbing, burning, redness, dryness, expensive doctor visits, wasted time, etc. I thought maybe I’d reached an age where I was just getting allergies. No such luck, though wearing the Oasys lenses definitely give me seasonal-allergy like symptoms. This is a repeatable reaction. I have done some patient and extensive testing on my body’s reaction to these lenses, with yesterday’s test resulting in a pretty gnarly sinus infection with sore throat and headache this morning. Yesterday’s test makes all the symptoms of the last year make a lot of sense.
So I did some research so that I can go to the optometrist armed with information so he (or perhaps a new optometrist) can’t try to argue me back into getting these things.
All the big name companies will tell you that silicone-hydrogel is so much more comfortable and healthier for you than old style hydrogel lenses like Acuvue 2. It isn’t true for everyone. There are some studies that say, yeah, these are more comfortable and make a difference to the health of your eye, but they are often with a short term study window. My contacts were comfy for the first month or so, but I’ve realized that they had a big role in the sudden presentation of uncontrollable “seasonal allergies” last year.
So look at this study by the British Journal of Opthamology. This is a study the ads often quote as proving that these new-fangled contacts are better for you. They did a 12 month survey of all contact lens wearers who showed up with non-severe and severe keratitis (inflammation of the cornea that can lead to scarring and impairment of vision) in hospitals in Manchester. What did they find?
They found that nondisposable daily wear hydrogels (like acuvue2) had a non-severe keratitis (NSK) rate of 14.1 per 10,000 people. For their new-fangled silicone-hydrogel counterparts? 55.9! That’s about 4 times the incidence rate!
Extended wear hydrogels had an NSK rate of 48.2 per 10,000 people. Extended wear silicone-hydrogels? 98.8! Almost twice the incidence rate!
The study concludes that sleeping in contacts (extended wear) increases your chances of getting severe keratitis (SK), and that patients who sleep in them should wear silicone-hydrogels since the incidence of severe keratitis is much reduced that way. This is true by the numbers [96.4 versus 19.8] Of course, if you have twice the chance of having non severe keratitis, I don’t know how effective you can really say silicone hydrogels are at keeping your eye healthy.
Finally, I mentioned that short-term studies trumpet the benefits of silicon hydrogel without taking a long view of patient satisfaction. Well, look at a 6-month follow up study of 49 “successful daily disposable lens wearers.”
These people had been wearing regular hydrogels. 30 were switched over to silicone-hydrogel. 19 were left as a control group.
Here is a snippit from the results:
No substantial changes in subjective vision, refraction, visual acuity or overall lens comfort occurred for those completing the study, although five SiH (silicon-hydrogel) lens wearers did discontinue due to reduced comfort, eyelid problems or seasonal allergy. Contact lens induced peripheral ulcers (CLPU) were observed in three patients in the first 3 months in the SiH lens group and these were also discontinued.
So you had 30 people switched to silicon-hydrogel and 8 had to drop out within a 6 month window. 26.67% of the study group had to drop out due to discomfort/health issues. Within three months, 10% developed ulcers in their eyes directly related to the silicone hydrogel contacts! Even when you exclude the people who had to drop out because the lenses were too uncomfortable, there was still no significant increase in reported comfort from those who stuck it out!
It’s quite funny that the “official site of silicone hydrogel lenses” wonders aloud on its homepage “Why haven’t SiH contact lenses conquered the world (yet)?”
The simple answer is they are uncomfortable and cause all manner of eye problems. Apparently they haven’t read or are simply ignoring the research.
For more testimonials on the way silicone hydrogels have ruined the lives of people like you and me go to Straight from the Doc and view the comments below the entry.