During a LASIK operation, a thin superficial layer of cornea is created and temporarily peeled back to allow laser treatment of the underlying tissue. This is called the ‘lasik flap’, and is what provides the quick and painless recovery after LASIK.
Some nerve endings that go into the flap are ‘disconnected’ at the time, and this reduces the feedback that our tear glands get that stimulate tear production. Other factors contributing to dryness also include the change in front corneal curvature and intraoperative disturbances such as exposure and irrigation of the corneal surface.
The nerve endings that were disturbed at the time of LASIK typically regrow within several months, and this usually coincides with disappearance of the dry eye problem. A small percentage of patients have dry eyes out to 6 months after surgery, and among these many will continue improving out to one year or more.
In other words, it is extremely rare to get dry eye that doesn’t recover after LASIK.
Typically dry eyes that take a very long time to recover were already very dry before surgery, and it is often possible to predict the problem so that either the dry eye problem is treated intensively prior to surgery, or the patient may also in severe cases be advised not to have LASIK done.
Also, once the eye has recovered from the drying effects of LASIK, they will return to the pre-existing state of wetness or dryness (that was present before LASIK). As such, an eye that was already dry before LASIK can expect to return to that level of dryness several months after surgery.
No, dry eyes that persist after LASIK surgery are not attributable to intraoperative factors or complications.
Rather, they usually happen because there was already pre-existing dry eyes before surgery caused by things like prolonged contact lens wear, acne medication etc, and the general corneal disturbances that occur in every case exacerbated the pre-existing dry eye problem.
Punctal plugs are very effective for treating dry eyes, whether or not the problem is associated with LASIK. However, it is important to note that punctal plugs work by keeping whatever moisture is already on the eye (whether naturally produced or from eyedrops) around for a longer time, instead of allowing them to drain away into the nose. Therefore, it does not help the dryness that some people get while sleeping-and which they may experience on waking in the middle of the night or first thing in the morning.
This is because sleep related dryness is related to the lack of tear production, so in these cases there are no tears for the plugs to keep around in the first place.
If the dry eye problem is usually manifest during sleep or first thing on waking, it is best to use a gel or ointment before sleep, that will persist for the whole night rather than eyedrops which are too liquid and which will disappear within an hour or so.
Punctal plugs are very effective for treating dry eyes that occur during waking hours, whether or not the situation is associated with LASIK. They help to reduce the need for eyedrops, so are very useful for people who have to use artificial tears very frequently eg instead of having to use the eyedrops every 2-3 hourly, sometimes after the plugs are placed, the eyedrops might only be needed every 4-6 hourly. As long as there is no active eye inflammation (eg persistent eye redness/discharge), punctal plugs can help anyone with moderate dry eyes requiring frequent eyedrop instillation.
The effectiveness of punctal plugging can vary from person to person, but can be maximised by plugging all 4 of the drainage channels on both sides.
There are 2 main types of punctal plugs-temporary dissolvable plugs and permanent silicone plugs. I almost never use silicone plugs nowadays because they sometimes collect mucus and debris around them (part of the plug protrudes onto the surface of the eyelid) and they often fall out by themselves. The temporary dissolvable plugs are inserted into the tear channels and block them for a period ranging from about 3-5 months, and then disappear by themselves.
The fact that they dissolve away minimises the risk of infection, but also means that the dryness may return once they have dissolved away. In such cases, I offer patients a more permanent solution, which is called ‘punctal cautery’. This uses a special heated probe to permanently shrink and close off the tear drainage channels, and is usually only offered for people who have used the punctal plugs before and found them to be helpful.
First off, punctal plugs are generally not easily displaced, even with eye rubbing. This is especially true of the temporary types, which are inserted completely into the tear drainage channels. Secondly, it is advisable not to rub your eyes, whether or not you have had LASIK. Rubbing can potentially cause several problems, depending on how hard you do it.
The most basic way of treating dry eyes is to use artificial tears. As such, one alternative to punctal plugs is to simply use eyedrops more often or to use thicker kinds of eyedrops/preparations which will last longer on the eye.
Some other methods that have been used to treat dry eyes (with or without LASIK) include Cyclosporine eyedrops (Restasis or Ikervis) and Omega 3 supplements. The effects of these methods are variable/unpredictable and often take a while to show themselves. Still, they can be used as ‘adjuncts’ ie as methods that help the main treatment of using artificial tear drops.
If a person has tried punctal plugs before and found that they work well to reduce the dry eye problem, a permanent way to close the tear drainage channels called punctal cautery can be used with very good effect.
Most patient’s eyes will get a bit drier in the time just after LASIK (first few weeks), and this is related to the surgery. Ie you cannot influence this aspect of it that much.
You can however, minimise the effects of dryness on the eye after LASIK by
Actually the main factors you should consider in whether to have LASIK done, is just the same as anyone else ie the same as those without dry eyes.
These include, your main reasons for getting LASIK done-why you do not like glasses/contact lenses, how you feel about the potential risks/side effects of surgery, and depending on your age you may also need to consider how you would like to manage the problem of presbyopia/Lao Hua.
If you have already decided to have LASIK done based on the above considerations, then you should see a doctor for a LASIK assessment, and at that time he/she will assess the degree of dry eye you have and advise you accordingly. In many cases, a period of stopping contact lens wear together with regular artificial tear use may improve your dry eye state to a condition where LASIK will be just fine. On the other hand, if the doctor feels that your dry eye situation is too severe for LASIK, then he/she will advise you accordingly as well.
Dry eye syndrome can span a spectrum from mild to moderate and severe. Treatment protocols also may vary from clinic to clinic, but it is worth mentioning the goals of treatment and the general principles that can be used to alleviate the problem.
Among the problems associated with dry eyes is the development of punctate corneal epithelial erosions (little dry spots on the cornea). If a large number of these appear and if they develop in the centre of the cornea, vision will become blurred. In the worst cases, some amount of scarring can also develop. Treatment aims to minimize or eliminate these erosions, as well as to minimize eye irritation and feelings of eye dryness/discomfort.
Treatment for dry eyes with any protocol always starts with frequent artificial tear use, and in the case of moderate to severe dry eye conditions, preservative free preparations are used. If significant inflammation is noted, topical steroids or cyclosporine can be added as well. This is done in conjunction with general measures such as stopping contact lens wear and frequent breaks from computer use, as well as treatment of any contributing eyelid condition such as blepharitis.
If a dry eye state persists and requires very frequent eyedrop use, but where the inflammation is under control or is not a significant factor, then punctal plugs are very useful.
These methods are used to achieve a state where there are minimal punctate erosions, and where there are minimal symptoms, before a patient would be considered for surgery.
If a patient has severe dry eyes that require more intensive treatment than this, or where it is associated with an underlying systemic disease, most doctors would advise against laser refractive surgery.
Those most at risk of dry eyes after LASIK, are those who have the driest eyes before LASIK. The causes of these pre-existing dry eyes are the same as those in other people not going for LASIK.
They include long term contact lens use, and general factors including age, long hours of visual work and working in dry environments, and other eye conditions such as blepharitis.
Having said that, patients with dry eyes related to contact lens use often feel better after LASIK because they do not wear lenses afterwards and this helps reduce their dry eye problem.
A particular risk factor for post LASIK dry eye is an anti-acne medication called Accutane (Isotretinoin). Patients who are taking this medication are generally advised to wait until at least 6 months after stopping the medication before considering laser refractive surgery, because of the severe dry eye that this medication can cause. Sometimes the dry eye caused by this medication may be permanent and preclude the patient from having LASIK afterwards.
Rarely, systemic diseases like Sjogren syndrome are the cause of the dry eye. If known beforehand, these patients are generally advised not to have laser refractive surgery.
Dry eye assessment, whether in association with a pre-LASIK assessment or not, involves both history taking (which can be simplified with various questionnaires) as well as an anterior segment eye examination using a slit lamp microscope, in conjunction with eyedrops such as fluorescein. Less commonly used tests include Schirmer testing, where a piece of filter paper is placed on the eyelid for 5 minutes and the amount of paper wetting measured.
Unfortunately, it has been found that the results from this are variable and often do not correlate with the other symptoms and signs found in a particular patient. Therefore this is rarely used nowadays.
Briefly, dry eye patients that I advise against laser refractive surgery include those with a recent history of Accutane use or systemic disease associated with dry eyes such as Sjogren syndrome. Also, those with significant corneal ‘dry spots’ (punctate corneal epithelial erosions) which extend to the centre of the cornea would be pre-treated for their dry eye first. After a varying period of time, if the condition improves significantly, laser refractive surgery can then be considered. There are some patients where the dry eye state persists despite intensive treatment, in which case they would be advised against surgery even without a history of systemic disease.
I believe that no ethical doctor would ‘push’ a patient towards having LASIK done, if he/she honestly believes that the patient is at high risk of suffering from the effects of very dry eye afterwards. In any case, if you have any doubts about the procedure at all, remember that glasses and contact lenses are perfectly good alternatives for providing good, clear vision.
Which eye drop is best depends on the situation. After LASIK, all patients are routinely given preservative free artificial tears such as Tears Naturale Free or Refresh Plus. Relatively liquid preparations such as these are usually used first as they feel comfortable and ‘refreshing’ when applied.
However, being very liquid and runny, if the dryness is more intense than usual a patient may feel they have to use these drops very often. This is because their effects may feel very temporary and the dry effects (including eye irritation and/or fluctuating vision) return in a very short while.
As such, slightly thicker eyedrops such as Opticlear, Systane Ultra or Optive Fusion may be used for those patients who have drier eyes than usual. The thicker eyedrops may feel a bit sticky but will last longer on the eye so that the drops don’t have to be instilled as often.
Gels such as Vidisic or Genteal gel can be used at night for patients whose dryness is most prominent in the middle of the night or first thing on waking in the morning.
Rarely, if an eye becomes unexpectedly extremely dry with diffuse dry spots over the cornea after LASIK, I have used serum (obtained from the patients’ own blood) and made it into an eyedrop that the patient can instil into the eyes. Serum eyedrops have various growth factors including nerve growth factor, vitamins and other molecules not present in regular artificial tears. In these severe cases, autologous serum eyedrops can often speed up healing of the corneal dry spots/erosions, so improving vision and comfort.
In most cases, artificial tear eyedrops should be used regularly for the first month. Thereafter, they can be used as necessary depending on how dry the eyes feel. If you are not sure about how long and how often the drops need to be used for, do ask your doctor as he/she will be best placed to answer your question after examining your eyes. As artificial tears have no side effects, and some patients also have pre-existing dry eyes, sometimes patients may also use them indefinitely.
A dry eye state that starts after LASIK and persists for longer than a year can still recover over time (I have come across cases that took around 2 years or so) but yes, in some ways it is true that it is more likely to persist compared with a dry eye state that is just a few months out from surgery.
It is important to bear in mind that a dry eye state (even of the post-LASIK variety) is often multifactorial in nature. That means there are often other reasons contributing to the dry eyes, such as activities requiring prolonged visual work (computers, document reading, etc), a very dry environment (air-conditioned offices, aeroplanes, etc), and local eye conditions like blepharitis/eyelid inflammation.
As such, anyone with post-LASIK dry eyes for such a long time should have a comprehensive eye examination to look into and address all the other possible contributing factors. With timely and appropriate intervention (and there are many effective methods as mentioned in the other answers above), dry eyes need not be a long term or permanent problem.
All kinds of laser refractive surgery, whether surface ablation (PRK/TransPRK/epiLASIK/LASEK-they are all the same), LASIK or ReLEx SMILE will induce some amount of post-operative dry eyes. However, if you look purely at the disturbance to the corneal nerve endings and how long they may take to regenerate, it is likely that the problem is least with surface ablation, then SMILE, and then LASIK. There are also some studies which show that the degree of post-operative dryness is less with SMILE compared with LASIK.
However, consider this:
Dry eyes span a spectrum from mild-moderate-severe. Generally, mild to moderate cases do well with any of the above techniques (with appropriate pre and post-operative treatments), or in other words the difference between them is usually not so great as to make a big difference in the time to recovery for these patients. On the other hand, if I had a patient whose eyes were so dry that I thought they were unsuitable for LASIK, I would probably not recommend that they have any of the other techniques of refractive surgery as well.
In considering the choice of laser technique, I feel it is more important to consider their other pros and cons. For example, with surface ablation there is no post-operative flap and the cornea is theoretically weakened the least. On the other hand, recovery from both discomfort and blur is slowest of all. With SMILE, there is no post-operative flap but recovery of vision is still often delayed, there is only manual compensation for eye rotation in the case of astigmatic corrections, and there is no wavefront guided treatment. With LASIK, you get the fastest recovery of vision and comfort, with automatic rotation compensation and wavefront guided treatments. And while there is a flap, this flap itself makes any future enhancement procedure very simple and also recover just as fast as in the original surgery.
The above are just a few of the pros and cons of the common laser procedures. Have a think about the properties of each of them and your priorities eg do you worry about having a flap that might get poked because you play very rough contact sports? Or would you like to have a procedure that gives you the clearest possible vision in the fastest possible time? In my opinion, these are usually more important factors to consider, rather than the state of dryness of the eye, when trying to choose the type of laser surgery to go for.
Unfortunately at this time there is really no treatment to improve vision that has been affected by optic nerve damage.
There are many diseases that can affect the optic nerves, and any treatment or management done would depend on what it is. In most cases, the treatment or management aims to limit the damage or prevent it from getting worse, rather than to improve vision.
This is particularly true for traumatic optic neuropathy. In the past, people have investigated the use of high dose steroids in the immediate post injury period, but the results are controversial with no benefit found in the IONTS study. Surgery may be considered but only in the immediate post injury period if there is a bony fragment pressing on the optic nerve.
If your vision is affected badly enough, then the best course of action is to have a low vision clinic assessment and consider getting some low vision aids. These can make a big difference to quality of life in many cases.