Nutrition & Cataracts

When I was young, I didn’t worry much about health care as both my parents were pretty tough and healthy except for occasional coughing and cold, my siblings and I hardly visited the doctor.  Now after 30 years later, my parents are getting older and they both need reading glasses, especially for my dad, who started to wear glasses while driving as he couldn’t stay within the lines and it is dangerous driving at night if eyesight is not well. Usually presbyopia develops gradually after the age of 40 and then, cataracts will develop depending on the health of our eyes due to the decrease of our eyes’ refractive power and the flexibility in our eyes.  Slowly when we want to look at closer items, we will find it hard to focus and the items will be blurred.  In order to settle such situation, we will start to use glasses or patients with cataracts will need surgery to remove the cataracts. 

Cataracts are formed due to oxidation of lens proteins and research has suggested that dietary antioxidants may play a big role in prevention. Since taking care of our health is part of our life mission, why not think about eating healthily or taking vitamins regularly to prevent cataract formation? That’s like killing two birds with one stone. I am sure a lot of people know about that but I am also sure that there are also a lot who don’t know the relation between nutrition and cataracts or bother doing that since people are busier now. Usually we realize the existence of certain health problems only when it happens to a family member or friend or even on ourselves. Then we start to think about the prevention that may be too late for some people as the condition could have reached the final stage. Instead of waiting for it to happen, we should also think about the prevention method by doing online research or yearly health check up and not wait for others to feed us with information.      

Healthy Eye

Immature Senile Cataract

Mature Senile Cataract

Hypermature Senile Cataract

Cataract is basically a clouding that develops in the crystalline lens of the eye or in its envelope varying in degree from slight to complete opacity and it will gradually obstruct the light passage. Its category is wide from age-related to systemic conditions like metabolic and nutritional diseases depending on the position of cataract (posterior or anterior). Hydrogen peroxide present in the aqueous can give rise to reactive oxygen species such as superoxides, which can damage our lens components like crystalline proteins, lens fiber membranes and lipids, leading to lens opacities.  Due to this, many observational epidemiologic studies of dietary factors in cataract have focused on the amount of antioxidant nutrients contained in the diet by either examining the intake of specific nutrients or serum concentration of nutrients or biomarkers of fruit and vegetable intake or the development of cataract in relation to specific foods or food groups including cigarette smoking as an establish risk factor since it is an important source of oxidative stress. Evidence has also shown that smoking has a direct deleterious effect on the human lens and it decreases plasma concentration of ascorbate and indirectly aid cataract formation by lowering the plasma concentrations of nutrients that are important to the maintenance of lens transparency.

So what should we eat? Well since everyone has been talking about consuming enough vitamin C to strengthen our immune system, we could now find vitamin C in fruits, vegetables, health drinks and supplements.  It will be good to keep it up as research has shown that higher serum concentrations of vitamin C were associated with a lower prevalence of nuclear cataract in many studies. Vitamin C is well known for its antioxidant properties and it is found in high concentration within the lens, aqueous humor and vitreous humor of humans and lenses with higher vitamin C concentration were protected from oxidative damage.  Even just by consuming orange juice was also shown to increase plasma vitamin C concentration significantly and significant protective association was also found between increasing consumption of fruit juices and incident nuclear cataract. In addition, vitamin C combined with other antioxidants like vitamin E, beta-carotene and zinc, had a protective association with long term (10y) incidence of nuclear cataract which support that diet and supplement intakes of vitamin C and other antioxidants may exert age-related ocular benefits as well as beneficial effects on aging itself.  

Even if you think you are getting enough nutrients from the food you are eating everyday, the amount of daily nutrients might not be enough especially if you are a picky eater or vegetarian.  In that case, it is important to consume supplements like multi-vitamins every 2 days to make sure that your body is getting enough nutrients. There is no need to over-consume supplements if you are eating well unless you are sick or under doctor’s advice as there would be adverse effect to our body. For example, we know that we need to consume vitamin A to maintain good eyes but do you know that, if we over-consume vitamin A, our vision will start to blur?  This actually happened to one of my professor’s mom and our professor was the one who advised us on this.  So if you are not sure about the amount of nutrients your body might need, I recommend going to a dietician to get a body examination and proper advice.  Well, remember it is your body and it will be up to you to make the changes for a healthier body!

LASEK vs LASIK

For people like me who have been wearing glasses or contact lenses for more than 10 years, I am pretty sure we all have experienced dry eyes, headaches, tiredness, red or teary eyes, and others due to long hours of wearing glasses or contact lenses.  Wearing contact lenses for a long time is also not good for the eyes as you would find a lot of protein deposits beneath your eyelids especially for those who are using yearly disposable contact lenses rather than weekly or daily disposable contact lenses and the deposits will irritate the eyes and might cause cloudy lenses, which interfere with our vision in the future.

With all these reasons, I have been thinking about going for the vision correction surgery especially after knowing that my friends and cousins had their eyes corrected recently. At the moment, LASEK and LASIK are the two most common vision correction methods for people who have low to mid myopia and astigmatism and ASA LASEK & Intraocular Lens Insertion are used for people with high myopia and astigmatism.  Usually the consultants and doctors will discuss the suitable method and cost depending on your eye condition and you could make the decision depending on your budget. 

So what are LASEK and LASIK? Basically in LASEK, the surgeon will scrap the top corneal layer and laser is used to correct your vision whereas in LASIK, a thicker corneal flap is created, flipped open and then, laser is used to correct the vision. In traditional LASIK, a metal blade (M-LASIK) is used to create the corneal flap and until recently, laser (i-LASIK) is introduced to create the corneal flap by creating closely-arranged bubbles within the cornea.  Nowadays, M-LASIK is usually cheaper than LASEK and i-LASIK is the most expensive one since laser is used twice during the surgery. People with thin corneas might not be suitable candidates for LASIK as thicker corneal flap is created and too little is remained after creation. There will be a thorough eye examination including pachy test to determine corneal thickness and a topographer to measure surface contour. Using this information, the surgeon will calculate the amount and location to remove corneal tissue during the operation.

Apart from LASEK and LASIK, each clinic labels the method differently depending on the excimer laser machine available in the clinic like Da Vinci, Epi-LASIK, IntraLASIK, CustomVue and MEL-80.  I would recommend reviewing the differences online and have a rough idea before going to the consultation. Not only that, I would also recommend checking the doctor’s qualifications and online reviews as excellent surgical skill is as important as using a high-quality excimer laser machine. 

After deciding on the clinic, you would have to make considerations for the recovery time as it takes about 3 days to recover for LASEK and 4 hours to a day for LASIK.  If you are working and do not have enough vacation, you might want to opt for LASIK as the cornea is healed naturally and it remains in position almost immediately after the surgery. Regarding LASEK, you would expect constant tearing and some pain for up to 3 days as the cornea is still growing to replace the lost tissue. On top of that, you might have difficulty looking at nearer objects for the first month but you would not have problem looking at further objects.

The common complications for both methods include: dry eyes, glare or halos, under or over correction, corneal haze, scarring and increased sensitivity. These could be temporary or permanent depending on individuals. If you are unhappy with the outcome, you could choose to have a re-correction unless your cornea is too thin and it should be free of charge for the first year.

Ultimately, you should feel safe and comfortable with the clinic and the doctor before making the decision and have suspicions if it is too cheap or expensive as your decision will affect your eyes for the rest of your life.       

Difference between MEL 80 (WaveFront) & VISX S4 (CustomVue)

For a newbie, how would I know what the difference between MEL 80 and VISX S4 is? I believe writing this blog is also a way of answering my own inquiries and I hope in some way, I would be able to help someone who is having difficulty making decisions about laser eye surgery.  Though it is not just a laser machine that matters when making decision, it is actually self-assuring to be able to understand the background work before going through the surgery.

Well, MEL 80 Excimer Laser System was established by Carl Zeiss Meditec, Germany and it is an excimer laser designed for LASIK (Laser-Assisted in Site Keratomileusis) to reduce or eliminate nearsightedness and astigmatism. The system is designed for patients with a near-sightedness of less than or equal to -7.0 D with or without refractive astigmatism of less than or equal to -3.0 D and patients who are over 21 years old with stable eyesight. After numerous clinical trials, it was found that 93% of patients were corrected at three months to 20/20, 41% were corrected to 20/12.5 or better at six months and it was finally approved by USFDA in Apr 2006.

Next, VISX Star S4 IR Excimer laser system was developed by AMO, USA and received FDA approval in 2007. It is designed for wavefront-guided LASIK treatment and it treats nearsightedness by removing tissue from the centre of cornea to flatten it and astigmatism by flattening the central cornea by different amounts and at different orientations to correct for uneven focus. It has also been through numerous clinical trials (more than 3 million) with IntraLase system and it is considered the most internationally-recognized laser system.

MEL-80 is known for its short ablation time as this means procedure time is reduced for greater patient comfort and with its small 0.7mm spot, it allows the finest corrections while maintaining the benefits of smooth ablation. With its shortened stroma exposure time, this also means faster visual recovery for the patients and it also has an active eyetracker with excellent feedback times with an ultra-rapid IR camera to catch the exact positions of both pupil and limbus during the laser treatment.

As for VISX S4, it uses invisible UV light pulses to remove precise amount of corneal tissue, an active 3D eye-tracker to detect the eye position and align the laser pulse with the cornea, a diagnostic wavefront sensor for the automated measurement, analysis and recording of refractive errors and lastly, it has an automated Iris Registration (IR) system to rotate and align the treatment while compensating for eye cyclo-rotation and physiologic pupil migration. On top of that, its Variable Spot Scanning (VSS) delivers variable beam sizes from as small as 0.65mm to 6.5mm over the treatment area which conserves tissue, optimizes treatment times, reduces corneal drying and adverse thermal load to the delicate corneal tissue. Together with Variable Repetition Rate (VRR), the laser’s repetition rate varies from 6 to 20 Hz and by changing the size and placement of laser beam continuously, VISX is able to deliver the required ablation pattern rapidly and precisely.

So after all the information, which one should I choose for my vision correction surgery? Actually depending on the seriousness of your eyesight, the ophthalmologist will decide which is suitable for your eyes.  So how does the surgeon know which is suitable for you? The first thing after stepping into the eye clinic and going through the registration is that, the eye specialist will do a thorough eye examination test including vision test, intraocular pressure, pupil size, ORB scan, pachy and endothelium cell test, which will take about 1 hour.  Next, with this information the consultant will explain to you the available laser surgery (LASEK/LASIK) methods in the clinic, differences and which one is suitable for your eyes. A good consultant will lay out the price list for the surgeries that you could go through instead of picking out the most expensive one for you. With your budget, you could decide the one that is the best for you.

With this information in mind before making the decision, you will have a chance to meet the surgeon and the surgeon will explain the suitable method to you and answer your inquiries. The surgeon will also examine your eyes again to check whether there are any abnormalities in your eyes. After that you will have another meeting with your consultant to decide whether you will have the surgery or you will call again to confirm.  Before the actual surgery, there should be another eye examination to ensure the eye power is stable. 

At present, there are many eye clinics offering laser surgeries at very low prices but I think for the sake of the eyes, it is not advisable to choose the cheapest one without being given sufficient information. Sometimes consultants do not provide all the facts about the patient’s eye condition because firstly, the clinic only has one laser system and secondly, they don’t want to lose their customers even though they could not correct your eyes using their system. Serious side-effects and permanent damage could occur if serious consideration is not taken. So with all these in mind, check out my next article on LASEK and iLASIK in 2 weeks time