Prevalence of Dry Eye Conditions
The prevalence of undiagnosed dry eye disease (DED) is extremely common among the general population. It affects hundreds of millions of people around the globe. You would think that everyone who has dry eye disease would be well-aware, but that is not true. Symptoms often are not obvious until the latter stages of the condition. Quite often the signs of chronic dry eye appear first during a comprehensive eye examination where the doctor is inspection the front of the eye with an instrument called a slitlamp biomicroscope. This provides for an objective evaluation of the front structures of the eye, like the eyelids, cornea, and conjunctiva.
Analyzing the Tearfilm Ahead of Surgery
The more sophisticated analysis of the tearfilm requires some application of dyes like fluorescein and lissamine green. Fluorescein, in conjunction with a cobalt blue filter (blacklight) is commonly used to detect corneal abrasions or irritation. If the eye is irritated or inflamed, the fluorescein will be brightly illuminated to disclose the area of the cornea or conjunctiva that is involved. Lissamine green is actually a forest green dye applied to the eye with a paper strip and stains the white part of the eye where the conjunctiva will display dead and rubbed off cells.
Other more sophisticated observations are also made to look at the blink pattern, shape and presence of the oil glands (called Meibomian glands) with infrared photography called meibography. Tear osmolarity testing will quantify the amount of saltiness of the tears due to excessive evaporation of the watery layer of the tears. The higher the amount of salt or osmolarity, the worse the dry eye condition is. Testing for the volume of tears involves a test call Zone-Quick or the older Schirmer’s test.
Learn about diagnosing oil vs. water deficient dry eye using the Zone-Quick Test.
Middle-aged and older patients are typically the ones who are subject to the most common types of ocular surgery—mostly for glaucoma and cataracts. Other cosmetic procedures like blepharoplasty and refractive surgery have a large impact on the health of the ocular surface, too. Prior LASIK, RK, PRK, and SMILE refractive surgeries have a dramatically deleterious impact on the development of dry eyes over the post-operative ensuing years. Many women have undergone permanent eyeliner tattooing, which is very detriment to the ocular surface. This is most popular in the Asian populations.
In fact, the difference between success and failure of all of these surgeries depends on the pre-surgical health of the lids, blinking and the tear quality. Studies show that approximately 60% of patients who are candidates for penetrating keratoplasty have DED. Likewise, 78% of glaucoma patients, and 27% of LASIK showed positive for fluorescein staining and an abnormal tear film breakup time. These obvious signs of clinically significant dry eye should be easy enough to identify and remedy prior to surgical intervention.
In all actuality, surgeries are performed every day on patients who should have had their ocular surface conditions improved prior to surgery. The outcomes of these surgeries would be much more robust if dry eye would have been diagnosed and treated in advance of the surgery. It is easy to tell a patient that they have cataracts and need surgery. It is more difficult for the surgeon to delay the surgery for a few weeks or months until the tearfilm is stable and the ocular inflammation is reduced to the point that the pre-surgical measurements will be much more accurate outcomes. Noted eye surgeon, Bill Trattler contends that only 22% of pre-surgical patients were aware that they had a dry eye condition prior to presenting for surgery.
If ocular surface irregularities are prioritized in a pre-surgical workup, more accurate pre-operative findings and measurements will yield better outcomes. If patients were more aware of their dry eye condition—only 22% of them knew they had a problem according to Trattler, the refractive and ocular surface irregularities could have taken some priority to improve prior to surgery. The accuracy of pre-surgical measurements like corneal topography and biometry could largely affect refractive outcomes. Optometrists who are diligent in pre-operative analysis of the ocular surface can be integral to improving ocular surgery visual outcomes.
If you’re looking for an optometrist to help diagnose and treat your dry eye, our team at Brill Eye Center is ready to give you the specialized care you need. Learn more about our process.
What Should I Know Before Having Eye Surgery?
Elective refractive procedures like LASIK, PRK, and SMILE (small incision lenticule extraction) are usually done by youthful patients. Their awareness of dry eye symptoms is less frequent, much to the detriment of their refractive outcomes. The more sophisticated the ocular surgery procedure, the more important it is that the ocular surface is pristine prior to surgery. Persistent corneal staining defects are extremely detrimental to achieving best visual acuity after surgery.
Patients determined to have ocular surface disease irregularities should be discouraged from having elective operations for cataract and refractive surgery until the integrity of the cornea can be restored. This may take weeks or months to resolve.
The Standard Patient Evaluation of Eye Dryness (SPEED) test is a quick and easy way for eliciting patients with symptoms, especially when patients feel that their chronic dry eye symptoms are part of the “new normal.” This simple 3-minute survey should be administered to all pre-surgical patients as an easy screening device.
How to Recover from Eye Surgery
If surgery ensues without acknowledgement of significant dry eye, the post-operative healing process may be impaired. Anti-inflammatory agents like non-steroidal and steroid drops may need to be taken for a longer course of administration. More follow-up appointments will most likely be necessary. Surgery, of course, will exacerbate signs of dry eye. Post-surgical symptoms may still not be obvious due to the desensitization that occurs during surgery when corneal nerves are severed. Anti-inflammatory drops like Lotemax SM, Inveltys, Prolensa, Restasis, and Xiidra may need a prolonged course and tapered accordingly after professional follow-up appointments with the post-surgical provider. The patient will still need ocular surface remediation.
One day, one week, and one month cataract or refractive surgery follow-ups should include evaluation of the eyelids, corneal staining, tear osmolarity, and topography to assess the progress of the dry eye condition resolution. Significant ocular redness is not always evident in light of the rampant use of vasoconstrictors like Visine and the new over-the-counter non-rebound vasoconstrictor drug called Lumify. Objective measurements of tear film function should be used to assess progress of the ocular surface through the post-operative course.
Glaucoma patients have additional concerns for the medications that are most commonly used, like prostaglandin analog drops (Lumigan, latanoprost, travoprost), which are known to be pro-inflammatory and tend to induce ocular redness. Alpha-adrenergic agonists like Alphagan also are notable for allergic symptoms of itching and redness. So do beta blockers like timolol cause inflammation. Benzylkonium Chloride (BAK) preservative is a known pro-inflammatory agent and can cause significant inflammation. Unfortunately, BAK is a common preservative in eye pressure lowering agents. While there are some unpreserved glaucoma treatment drops, most are difficult to get access to because of pharmaceutical benefit manager restrictions that necessitate lesser costly drugs to be used as a first priority.
Importance of Dry Eye Tests Prior to Eye Surgery
Eye surgery is very common with the older generations in America. Optometrists need to screen for dry eye disease as part and parcel of a pre-operative work-up. The Brill Eye Difference takes these matters very seriously when considering referral for ocular surgery. The prevalence of MGD and dry eye disease in our screen-watching society makes identification and treatment of dry eye imperative. Successful visual outcomes depend on our awareness of the prevalence of dry eye and how to identify and resolve these concerns.
Ready to take the next step to treat your symptoms of dry eye? Talk to Brill Eye Center and find out how we can get you on the right track to improve your vision and overall eye health today!