Soon Zhou's Reflections

From this PBL activity, I have learnt how to be selective in obtaining and presenting them in a proper way such that it is more directed towards the research question we are doing. This is helpful as it provides me with an organized flow of thought and ensures that the group is progressing towards the right direction. Also, I have learnt how to evaluate my thoughts using mindmaps as it allows me to expand and broaden my scope of thought, hence, considering all the aspects of the question itself.

I think that I have done well in organizing, processing and evaluating all the information gathered so that it only the useful information would remain and the group would not be confused in our direction. Also, I think I have also done well in presenting our solution and our research through a methodical and structured way so that the reader would be clear about our research, our decisions and our results.

What I could have done better was to include primary sources in my scope of research as all my information is gathered from secondary sources, hence, being less reliable. I think that I could also be better as a leader in coordinating the group such that the pace at which everyone is progressing is the same since we were unable to progress to the next stage of our research when a part of the information was not gathered yet.

The main difficulty in the PBL was having collated all the research we have done into the report as I would need to present it in a formal and informative way, yet, could be easily understood by others. Since Ms Chua stated that the report was somewhat like a book, I decided that I write it like a guidebook for people to understand LASIK more which helped me a lot when doing the report. Also, the mindmap was also a headache as I had to categorize all our findings into proper classes and summarize them; I had to spend time thinking through how I would compare each data and to see their similarities and differences. Trying to get some members to listen properly to instructions and not do things the way they preferred was also a problem, I solved it by processing and editing what they have done.

Tuck Ging's Reflections

Personally, I feel that I did well in meeting deadlines and designing the brochure, our final product. I tried to complete my tasks by the deadline given and I succeeded. However, I could have submitted my work earlier or did a better job of it instead. I could also have designed the brochure better but I was sick and busy for the past few days doing homework and studying for tests. I faced the difficulty of balancing between school work, co-curricular activities and the various projects. I wanted to do the best for each aspect, but I end up neglecting one or another. So, I decided to draw up a schedule so that I can plan my time well.

Fangxu's Reflections

I've learnt that there are many cases in which the situational factor has affected the outcome greatly, which can

be seen from the countless examples of people who done research on the topic and went for lasik because the

odds are in their favour, but were not pleased with the results because of the inexperience of the optician who

performed the surgery. Thus, it is more important to be in control of what is varying in any circumstance as they

would decide the final outcome. I have summarized the imformation from many sources and deleted stuff that

are not significantly important. However, I could have done more research so that I could understand the

outcomes of lasik better because statistics do not show the seriousness of the problem. During the PB

process, the information on some website are either too vague or disorganised, it took time to understand and

summarise.

Andrew Sung's Reflections

2. Have you done PBL before? If yes, provide a description of how it a carried out.

I have done PBL in the previous term. We had to design and build a heat exchanger and consider all the factors needed to build it. In the end, we managed to effectively construct our heat exchanger and it could work thus we were pleased with what we have done.

12. Describe in detail how the group went about working on the PBL (from beginning to the end).

Firstly all our group members were searching for an appropriate problem statement that we could really focus on. Finally we decided on: How accurate are risks of surgeries shown by LASIK and how effectively are they conveyed?

We thought such a problem statement would allow us to assess and evaluate the effectiveness of hospitals, not just those of the government sector but also personal hospitals, on whether they could minimise the risks posed by LASIK to the patients. We were also very interested in how well hospitals were informing patients on LASIK and whether the patients fully understood the risks they were taking because we found that it would be really funny if the patient goes for LASIK without understanding the full implications because either the doctors did not inform him or he did not bother to know the risks he were taking. Moreover, we wanted to know about the risks posed by LASIK too because it seems very good to improve our eyesight and not have to wear glasses again, but rather, we want to know what would happen to us should we embark on the LASIK journey and whether there were any remedies for LASIK problems.

Then we did a mind map on our problem statement so that we would understand it better and found out that we had to concentrate on different procedures of LASIK as there were many and thus our group leader assigned each of us to research on different procedures of LASIK and record the importance of each procedure, who it was targeted at, how it was done, what were some of its side-effects, whether there were any solutions to problems caused by it, and whether there were any alternatives to this procedure. With all our data collected, we then discussed about the different types of LASIK that could be used in surgery and which method was the best.

13. Describe some of the difficulties that you faced during the PBL and how you or the group went about solving them.

Our group had lots of problems communicating because each of us had different timetables and other priorities too. Hence we had trouble sharing information with one another and sometimes even had trouble trying to agree on a certain thing. From this experience, I feel that we should take an active role in helping one another out because some of us may not be available and others thus have to cover him and help him out. As such, I think that being in the class really helped a lot because we could easily communicate and tell each other what has to be done.

14. In what ways has the PBL helped you to understand the topics taught in this module?

The PBL covers important topics such as refraction and lens because these 2 topics are usually associated with our eyes. I have understood more about refraction after the PBL due to lots of reading about how light rays are refracted through the various layers in our eyes and also about lens because the light rays are converged to form an image in our eyes too. Moreover, the PBL also lets me learn more about the various techniques of LASIK and understand how we can adjust and alter our eyes so that we are able to perfect eyesight, as well as how people having short and far sightedness experience different problems in their visions.

On top of that, I think that what the PBL has benefited me the most is training my research skills. I had to read up on lots of material and take out what was important and also paraphrase lots of stuff because we wanted to write our own report. It was quite an experience but I think it was worth it because I had great time learning about LASIK, which I think is extremely interesting and probably the reason why there is a large number of eye surgeons and ophthalmologists in Singapore. Thus I felt that the whole PBL experience was both beneficial to my learning of this module and my researching skills.

15. In what ways has PBL made learning more interesting for you? How has it motivated you in your learning?

PBL has allowed me to explore various areas of studies and I am not limited to just dead facts as when I study from notes and textbooks. I get to know more about the thoughts of the different people undergoing LASIK too: the patients, the surgeons, experts and even the people who are not undergoing LASIK. Some people are very supportive of LASIK whereas others do not really find it reliable. Hence I get to hear both sides of the story and varying views on the topic. Moreover, I also had lots of fun watching a video whereby a doctor was encouraging the public to go for LASIK whereas he was wary of the dangers of LASIK. Thus it was rather ironical.

PBL has motivated me to work hard on it because I want to do well in it. I have researched very widely on the topic because I want to get everything I can find about it. Thus it has been very encouraging to do PBL.

16. How has working with others benefitted you? What were you able to learn from each other?

Working with others allows me to cultivate my teamwork spirit. I had to coordinate a lot with my friends and all of us had to be aware of what we were supposed to do so that we would not get mixed up and feel lost about what we have to do. Moreover, we also wanted to prevent each other from doing the same thing and thus wasting each others time. I was able to learn a lot from what others have done because we were doing on different procedures and hence were presenting on different stuff. Hence it was really enriching to be working together on a project and I feel it is better to have a group working on a project than individuals because the workload can be divided and everyone can share their ideas. And most importantly, we really enjoyed each other.

17. In what ways did the PBL require you to view the problem from multiple perspectives?

As we were researching on both the advantages and disadvantages of various LASIK procedures, hence we could view each procedure with both a positive and negative mindset. This was very useful because we did not immediately say that this procedure was good or bad just by looking at it but had to think before we made our opinion. It was not as easy as looking at drugs and say that it is bad. Moreover, different group members all had differing opinions and hence we had lots of ideas and multiple perspectives from everyone and all of us could argue our points and it was kind of a debate thus it was very enjoyable.

18. In what ways has PBL enhanced your understanding of how real-world problems are solved?

The PBL emphasizes a lot on teamwork and social skills. This is very similar to problems in our real-world because we find that we usually need to coordinate a lot with other people and lots of negotiation and discussion has to be done before something is agreed. For example, the Singapore government itself often needs to go to Parliament and such to discuss certain issues related to Singapore and how to solve the problems. Hence our PBL was very much like that in the sense that we were doing lots of discussions and were each putting forth our views such that we found ourselves at times agreeing but at other times disagreeing.

19. In what ways can you apply the knowledge/skills learnt in other areas?

I have certainly learnt many important skills during the course of the PBL. Technically, I have learnt different software and how to do it efficiently, such as mind maps, online surveys and also researching tools. I find it very convenient to research now due to the vast amount of information on the Internet and am pleased with what I have found. Problem solving skills have also definitely been improved and now it becomes instinctive for me to look at a problem at different areas so as to fully understand and produce the ideal solution for the problem. Besides, through mind mappings, I have learnt to be more organized and concise with my points and thoughts. I also find I can apply these skills to other subjects such as mathematics whereby everything needs to be clear and concise. Furthermore, a time management skill is gained too. As all of us have very tight schedules, I think that being able to meet datelines nonetheless is a commendable feat.

20. In what ways were the blogs (yours and other groups') useful while working on the PBl activity?

Blogs are easy editing tools and allows us to post lots of information for others and ourselves to read. It is also very convenient to surf other groups’ blogs to read up on what they have done so that we can get an idea of the standard of other groups. Furthermore, I found it very good to post and read comments which I felt helped us a lot in letting us know our weak areas and what we can do to improve on our work. Overall, it was good to use blogs not only as a medium to communication but also as a source of information.

21. Describe some ways in which the web 2.0 tools (e.g. Wiki, Blog, Chat tools, bubbl.us etc.) have been useful for the PBL?

I really feel that all these web tools enhanced our learning process. The wikispaces allowed us easy access of materials, bubbl.us made it easy to construct mind maps which were effective in our learning and chat tools like msn messenger allowed fast and convenient communication. Also, I find it very good to be able to use such technology as they allow us to study faster and better.

22. In the PBL, you were required to construct mindmaps, which went through a few rounds of editing. In what ways has the mindmap and the process been useful in helping you to solve the task for the PBL activity?

The mind maps allowed me to understand the problem statement better because I could expand on certain areas that I was not really sure about and also made it easy for the whole group to share their ideas because everyone could put in something. Furthermore, the editing of the mind map allowed us to also decide on what parts of the PBL to include and what to exclude, hence it made the group more focused on the problem statement.

Thus thanks to the mind maps; I was better able to understand what the PBL demanded to us and what we had to do. Three cheers to it!

23. After doing the Learning Needs Survey (your responses here), you would now have a better understanding of your learning style (description found here). In what ways has the PBL activity catered to your style of learning?

I love to look at diagrams and the PBL certainly offers it as there are lots of mind maps to look at which help in my learning. Moreover, I find that I study better with all the information and hence with the PBL, I can get everything I wanted and it has been really beneficial to me.

24. After doing the Learning Needs Survey (your responses here), you would now have a better understanding of your learning style (description found here). In what ways has the PBL activity NOT catered to your style of learning?

I find that the PBL has been largely catering to my learning style.

Product

We have decided to do a brochure of the LASIK centre we are going to set up as it shows what the benifits of our surgeries are and also our research on the history of LASIK and its surgeries. It is also informative in telling patients whether they should be going for LASIK surgeries if they were to have some medical disorders beforehand.

The first picture shows the coverpage on the right and last page on the left while the second picture shows the second page on the left while the third page is on the right. This is because the brochure is folded.

Final Mindmap

Recommendation Report

Introduction to LASIK

LASIK or laser-assisted in situ keratomileusis is a form of eye surgery which is able to cure myopia, hyperopia as well as astigmatism. All LASIK surgeries make use of the latest technology to alter the shape of the cornea in the eye by removing, shrinking or expanding tissues in the eye to solve these problems. Today, many people resort to LASIK eye surgeries to solve their eye problems so that they would not need to wear glasses or contact lenses since it is a nuisance in our daily lives. However, there are many types of LASIK eye surgeries which are targeted to different medical disorders, make use of different tools and involve different set of side-effects. The main issue is that many people are not fully aware of the risk they are taking when undergoing a LASIK surgery, hence, putting themselves in potential danger. There are mainly 5 LASIK surgeries, namely Automated Lamellar Keratoplasty, Photorefractive Keratectomy, Laser Thermal Keratoplasty, Conductive Keratoplasty, Radial Keratotomy.

Surgeries

Automated Lamellar Keratoplasty

Function

This surgery solves severe levels of myopia or mild levels of hyperopia.

Procedure

Firstly, the doctor calculates the shape to cut according to the patients eye(s). The eye is then anesthetized and a ring is fixed so that it remains opening. A microkeratome is then used to incompletely cut a thin flap of cornea so as to expose the layer of tissue below . Then, the microkeratome is used again to carve the right shape in the cornea so as to change the shape of the eye lens. The flap is then replaced for it to heal.

However, if the patient is hyperopic, the flap is replaced back without removing anything. This is because the cornea stiffens during recovery.

This operation usually takes less than an hour.

Recovery

Just 24 hours after the operation, patients are almost healed and able to see clearly. Besides, patients may feel very comfortable after the surgery although it may take months to regain vision stability. Ideally, the patient will have perfect vision after the surgery.

Possible Side-effects

Glare, inability to wear contact lenses, infections, corneal scarring, over or under-correction, inflammation can be the side-effects of Automated Lamellar Keratoplasty when the surgery is not done properly.

Pros and Cons

Automated Lamellar Keratoplasty is able to cure both myopia and hyperopia. Also, it only requires 24 hours for the cornea to heal after surgery. However, the risks taken when undergoing this surgery is high as it may lead to inflammation, infections and corneal scarring which may result in permanent, incurable and serious effects on the patients eye. Moreover, the time taken for the surgery is very long.

Photorefractive Keratectomy

Function

This surgery solves myopia, hyperopia as well as astigmatism. However, this surgery is best suited for patients with myopia and most patients would take this surgery so that they would not need to wear spectacles or contact lenses.

Procedure

The ophthalmologist will firstly execute a refraction to ensure the refractive alteration the surgeon will instruct the excimer laser is right. After the eye is numbed, the surgeon places a speculum in the eye to keep the eyelids apart and disallow movement. The patient stares at the twinkling light of a laser microscope and must keep his gaze steady on that light, staying motionless at the same time. After the the laser co-ordinatesis double checked, the eye surgeon takes away the epithelium with a sponge, mechanical blade, or the excimer laser. With the epithelium totally taken away, the surgeon will start reconstructing the cornea.

The whole process is approximately 10 minutes.

Recovery

A bandage contact lens would need to be worn on the treated eye to protect it and allow the healing process to take place; it also eases some of the pain of the exposed cornea. Anti-inflammatory and antibiotic eye drops needs to be applied to stop infection and reduce pain.

Possible Side-effects

If the surgery is not done properly, patients may experience glare, vision fluctuation, development of irregular astigmatism, vision distortion (even with corrective lenses), glaucoma, loss of best visual acuity, and, though extremely rare, total vision loss. A more common side-effect is long-term haze as it is resulted by aggressive healing processes which form corneal scars.

Pros and Cons

Although this surgery takes only a short time and is able to solve myopia, hyperopia as well as astigmatism, the patient is at a high risk of having long-term haze which would be a burden when we use our eyes. Also, total vision loss may also occur in extremely rare cases.

Laser Thermal Keratoplasty

Functions

Laser Thermal Keratoplasty is only able to help patients with mild hyperopia

Procedure

A Holmium laser (an infrared laser that emits heat to reduce the size of the corneal tissue) is used to reshape the cornea for low ranges of hyperopia. It is then used to heat the stromal collagen in a circle around the outside of the pupil. The heat results in the tissue becoming much smaller, forming a tightening effect. The side of the cornea is then pulled, causing the center to protrude. Because the cornea of a farsighted eye is too flat, this bulging effect, when carefully controlled, corrects the problem.

Recovery

After LTK surgery, subsequent appointments are needed for the very next day and for one week, one month, and 3-6 months after the procedure. An object in your eye may be felt for the first 24 hours following LTK. Eye drops can help relieve this, but only to a certain extent. Light sensitivity may also be felt for the first 24 hours and sunglasses may be advisable.

Possible Side-effects

There aren’t any serious side-effects to the Laser Thermal Keratoplasty as it is done using laser to change the formation of the cornea. The most common, mild side-effect would be over and under-correction which could be solved easily through another minor surgery.

Pros and Cons

Although this surgery is only able to cure mild hyperopia, causes much irritation to the eye during the first 24 hours and requires the patient to constantly revisit the doctor for checking, it is extremely safe compared to the other surgeries as the side-effects involved are not serious and can be solved easily.

Conductive Keratoplasty

Function

This surgery solves mild hyperopia and astigmatism. Most elderly undergo this surgery so that they do not need glasses when reading.

Procedure

A corneal topographer first maps the curvature of the eye. The eye is then anesthetized and a speculum is used to prevent the eye from blinking. After the treatment pattern is imprinted, a hand-held instrument with a tiny probe would then apply low-level radio frequency energy to the specific spots that form a circular pattern on the outer part of the cornea to a specific depth.The connective tissues in this area would then shrink causing the circular band to act like a belt that "tightens" and steepens the cornea, hence, changing curvature of the eye's surface.

The entire process last a few minutes

Recovery

There is no recovery period for this surgery as no tissue is removed from the eye; hence, no healing is required.

Possible Side-effects

The only side-effect is that the distant view of the patient might be affected to a minor extent. That is why doctors recommend patients who undergo this surgery to have good distant vision. However, if the patient has presbyopia, the condition of the eye may worsen after time. That is why doctors go through thorough checks to ensure that the patient does not have presbyopia.

Pros and Cons

This surgery last only a few minutes, does not require any form of recovery, does not remove any tissue from the cornea and has only one minor side-effect. However, the result might not be ideal if the patient were to have presbyopia, hence, doctors need to be cautious when allowing patients to undergo this surgery.

Radial Keratotomy

Function

Radial Keratotomy cures mild myopia and astigmatism. Patients should not have pathological myopia and degenerative changes caused by severe myopia, such as retinal tears or disease of the cornea, should not be present.

Procedure

The eye is anesthetised and a ring is fixed to it in order to prevent if properly positioned and flat. A precision calibrated diamond knife is used to make four to eight incisions perpendicular to the circumference of the cornea. To achieve high efficiency, the incisions usually reach deep into the cornea. This will cause the cornea to flatten and thus change the shape of the lens.

Recovery

Radial Keratotomy causes more discomfort and requires a much longer time to heal as compared other surgeries. The results are also more unpredictable. However, the incisions are suspected to never heal entirely. There have been reports of unhealed incisions even after 20 years of surgery. Patients have to return to doctors frequently for the first year in order to prevent these inflammation and infections to occur in the unhealed cornea.

Possible Side-effects

An improperly carried out surgery may lead to infection, inflammation, glaucoma, puncture of the cornea, loss of fine depth perception and more scattering of light.

Pros and Cons

Radial Keratotomy involves many serious side-effects including inflammation and infection. It is also troublesome as it requires the patients to revisit the doctor constantly within a year to prevent these side-effects from surfacing. Because this surgery is done by using a diamond knife, it may lead to unpredictable results if not carried out properly.

Research

Final refined research questions:

What are the best surgeries to be used when setting up a LASIK centre?

Which surgeries provide the least risks of having side-effects to the patients?

Which surgeries is less of a burden to the patients during recovery period?

Which surgeries are able to solve the most common eye problems?

Solution:

Choice

For setting up a LASIK centre, we have decided to use only Conductive Keratoplasty and Laser Thermal Keratoplasty among the five surgeries.

Side-effects

For Conductive Keratoplasty, the only side-effect is that the distant view of the patient might be affected to a minor extent. Although if the patient has presbyopia, the condition of the eye may worsen after time, this can be easily avoided through thorough medical check of the patient beforehand.

For Laser Thermal Keratoplasty, there aren’t any serious side-effects as it is done using laser to change the formation of the cornea. The most common, mild side-effect would be over and under-correction which could be solved easily through another minor surgery.

For the other surgeries, Automated Lamellar Keratoplasty and Radial Keratotomy involve side-effects such as infection and inflammation which is very serious and lethal to the eye. Especially when infection and inflammation may lead to eye diseases like retinitis pigmentosa which are incurable it should be avoided. As for Photorefractive Keratectomy, there is a high risk of having long-term haze which would be a burden when we use our eyes. Also, total vision loss may also occur in extremely rare cases.

Recovery

Conductive Keratoplasty requires no recovery at all since no tissue is removed from the cornea.

Laser Thermal Keratoplasty would only cause irritation to the eye for one day after surgery although it requires the patient to visit the doctor frequently for checkups for six months.

Automated Lamellar Keratoplasty patients would feel uncomfortable after the surgery and it may take months to regain vision stability. For Photorefractive Keractectomy, a bandage would need to be worn and anti-inflammatory and antibiotic eye drops needs to be constantly applied to the eye after surgery. Radial Keratotomy causes much discomfort and the eye might remain unhealed even after 20 years. The patient would even need to visit the doctor regularly for one whole year after sugery.

Functions

Compared to the other three surgeries, Conductive Keratoplasty and Laser Thermal Keratoplasty are able to solve only hyperopia and astigmatism but not myopia.

Summary:

Overall, Conductive Keratoplasty and Laser Thermal Keratoplasty is still the best choice although both are unable to cure myopia because the risk involved in both surgeries are much lesser and less serious than other surgeries and the it does not bring much problems to the patient during recovery stage compared to other surgeries too.

Eligibility

• Pregnancy
• Breast-feeding
• Very small or very large refractive errors (Myopia up to -15.00 diopters, astigmatism from -0.50 diopters to -4.00 diopters and hyperopia from +1.00 diopters to +5.00 diopters are allowed)
• Scarred corneas
• Macular Disease
• Autoimmune disease
• Diabetes
• Glaucoma
• Persistent blepharitis

Statistics of LASIK

• Around 30 patients per week per centre
• 80% of the patients were satisfied with their surgery
• 53% experince at least one side-effect
• 22% experinced side-effects which lasted more than 6 months

Definitions

Cornea- Clear structure that covers the front part of the eye. The cornea provides most of the eye’s optical power, while the crystalline inner lens, located behind the iris serves to “fine tune” the focus of the images.

Collagen- In referring to the eye, collagen is the protein fibrils within the corneal tissue that help sustain its shape. Some new refractive vision correction procedures heat these fibrils with a special laser causing them to shrink and change the shape of the cornea.

Myopia (nearsightedness)- The front curvature of the cornea is too steep in a nearsighted person, causing good reading vision but poor distance vision.

Pathological Myopia- Also known as degenerative myopia is characterized by marked fundus changes and associated with a high refractive error and subnormal visual acuity after correction. This form of myopia gets progressively worse over time.

Hyperopia (farsightedness)- Vision that results when there is too short a distance from the cornea to the retina. This can be caused by an eye that has a vertical oval shape or a cornea that is flatter than normal.

Presbyopia- Deterioration in the ability of the eye’s natural crystalline lens to expand or contract in order to focus on close objects.

Astigmatism- Uneven curvature of the cornea in which refractive light rays are bent out of focus resulting in distorted vision. Those people with astigmatism are usually born with the disorder and it does not worsen with age. Often occurs in conjunction with nearsightedness or farsightedness.

Glaucoma- Condition caused by excessive buildup of fluid inside the eye putting pressure on the retina. Glaucoma has few if any symptoms, but a simple, painless eye test detects the problem. If untreated, glaucoma can result in gradual, painless, irreversible loss of vision.

Inflammation- Redness, swelling, pain, tenderness, heat, and disturbed function of an area of the body, as a reaction of tissues to injurious agents.

Retinal- A form of vitamin A called retinal is responsible for transmitting light sensation in the retina of the eye. Deficiency of vitamin A leads to night blindness.

Macular Disease (Macular Degeneration)- Degeneration of the photoreceptors in the macula or central region of the retina. This area of the retina is responsible for central vision, used for reading, seeing faces, and so on. Often associated with aging.

Autoimmune- Of or relating to an immune response against one of the body's own tissues or cells.

Diabetes- Any of several disorders characterized by increased urine production.

Blepharitis- Common, persistent and sometimes chronic inflammation of the eyelids, resulting from bacteria that reside on the skin. Blepharitis is usually only a minor irritation.

Holmium Laser- Infrared (thermal) laser which its beam is cool and can remove small areas of tissue without affecting surrounding tissue. The Holmium laser is used to shrink the peripheral area of the cornea in order to make its shape steeper and correct mild to moderate cases of farsightedness. The laser works when moisture in the cornea absorbs energy from the laser pulses causing corneal tissue to heat up and shrink.

Microkeratome- Sophisticated surgical device used to shave a very thin amount of the cornea at a predetermined depth. Used to create the corneal “flap” which is lifted.

References

http://dictionary.reference.com/browse/inflammation?r=75 http://en.wikipedia.org/wiki/Myopia http://dictionary.reference.com/browse/autoimmune?r=75 http://dictionary.reference.com/browse/diabetes http://www.allaboutvision.com/visionsurgery/ck_ltk_eye_surgery.htm http://www.webmd.com/eye-health/radial-keratotomy-rk-for-nearsightedness http://www.docshop.com/education/vision/refractive/other-treatments/ http://www.lasikcomplications.com/RK-radial-keratotomy.html http://en.wikipedia.org/wiki/Radial_keratotomy http://www.healthcentre.org.uk/laser-eye-surgery/laser-thermal-keratoplasty.html http://www.visionrx.com/Library/enc/enc_ltkeratoplasty.asp www.visionrx.com/library/.../innov_laser_thermal.asp http://www.youreyeguide.co.uk/ltk/ltk-sideeffects-aftercare.html http://www.urologicinstituteofnj.com/images/stonesLaser.jpg http://www.visionrx.com/library/enc/tableac.asp http://www.lasikeyesurgerycorrection.com/lasik_risks.html http://www.webmd.com/eye-health/night-vision-problems-halos-blurred-vision-night-blindness

http://www.fdanewsalert.com/id580.html http://blogs.consumerreports.org/health/2009/07/lasik-eye-surgery-lasik-survey-getting-the-best-price-for-lasik-survey.html

http://www.realself.com/Lasik/reviews?sort=most_discussed http://www.surgeryencyclopedia.com/Pa-St/Photorefractive-Keratectomy-PRK.html http://en.wikipedia.org/wiki/Automated_lamellar_keratoplasty http://www.webmd.com/eye-health/keratoplasty-eye-surgery-alk-myopia-hyperopia http://www.the-lasik-directory.com/alk.html

http://www.eyecare-information-service.org.uk/lasereyesurgery/alk.html http://blogs.consumerreports.org/health/2009/07/lasik-eye-surgery-lasik-survey-getting-the-best-price-for-lasik-survey.html