A: While modern cataract surgery is extremely advanced — with high patient satisfaction and patient outcomes — a small percentage of premium IOL patients can be challenging. Specifically, when these patients do not get the desired outcome, the result is patient frustration.
This article will focus on the most common reason for that, untreated dry eye disease (DED), and the clinical pearls to improve poor outcomes.
Untreated DED can contribute to residual refractive error. Both of these undesired conditions can limit the outcome in cataract patients, especially in some advanced technology IOLs. This is because premium IOLs (multifocal and extended depth of focus, or EDOF) split light, decreasing contrast sensitivity, losing some light energy in the process. Residual refractive error compounds this. As such, the best method to prevent dissatisfaction post-surgery, is to be proactive before surgery.
As age is the No. 1 risk factor for DED, cataract patients are at high risk. One study, Prospective Health Assessment of Cataract Patients Ocular Surface (PHACO), shed light on just how disproportionately cataract patients are affected by DED. The purpose of the study was to determine the prevalence of DED in patients undergoing cataract surgery. The results are summarized here:
- A total of 171 eyes (62.9%) had a TBUT of less than 5 seconds.
- A total of 209 eyes (76.8%) had corneal staining.
- A total of 136 eyes (50%) showed central corneal staining.
- A total of 132 eyes (48.5%) had a Schirmer score of 10 or less, and 58 eyes (21.3%) scored less than 5.
Anecdotal evidence and studies show DED can limit the accuracy of preoperative testing, such as topography and biometry. These measurement errors from poor pre-op data can lead to the wrong axis placement with a toric IOL or even the wrong chosen IOL power. This situation increases the likelihood of residual refractive error post operatively. I have found that small amounts of residual refractive error, even as much as 0.50 D, can limit the VA for patients wearing multifocal IOLs. This can happen in EDOF IOLs as well, but I have found they are more forgiving than multifocal IOLs. Uncontrolled DED has even been reported to cause residual refractive errors by as much as 1.00 D to 2.00 D due to inaccurate pre-op calculations.
Bottom line: The cataract patient is a DED patient, unless proven otherwise. Thus, to reduce the chance of undesired post-surgical outcomes, both aqueous deficient and evaporative DED caused by meibomian gland dysfunction (MGD) must be treated prior to surgery, if diagnosed. (See “Steps in Pre-Op Cataract Patient Experience,” p.21.)
I find most patients have both aqueous deficient and evaporative DED, so I treat both conditions pre-surgery concurrently. A common treatment approach is to start with palliative treatment using artificial tears. These can be used two to four times a day, and when needed more frequently than that, I recommend a more viscous tear or a non-preserved artificial tear. Nighttime ointments work well in patients who have lagophthalmos and incomplete nocturnal lid closure. Clinically significant DED needs treatment that decreases inflammation by prescribing immunosuppressive topical drops, such as cyclosporine A 0.05% twice a day, lifitigrast 0.5% and ester-based steroids used short term. (Cyclosporine 0.09% was FDA approved in 2018, with commercial availability coming in a few months, which will give another treatment option for clinicians and patients.)
Steps in Pre-Op Cataract Patient Experience
If the optometrist needs to rehabilitate the cornea even quicker, amniotic membranes have become a widely accepted treatment option. These can help decrease inflammation and symptomatic pain from DED and promote healing and nerve regeneration, improving the symptoms and signs of patients who have moderate to severe DED. Nutritional supplements are useful, and studies have shown EPA, DHA, GLA, omega-3 and omega-6 all work to decrease inflammation, increase tear production and improve meibomian gland secretions. Lid hygiene with lid scrubs and lid massage after heating the lids with eye masks help improve secretion from the meibomian glands. Treatment of MGD with thermal pulsation, meibomian gland expression and other devices also are options for treating MGD prior to surgery. Topical antibiotics, steroids and combination topical drops and ointments offer good efficacy in treating MGD. (See more DED treatments in “Other Treatment Options Summary” above and/or consult Practicing Medical Optometry’s “DED Therapy Options” at bit.ly/DEDThera .)
|Keratoconjunctivitis Sicca, not specified as Sjogren’s||H16.22-|
|Dry Eye Syndrome||H04.12-|
|Sicca Syndrome (Sjögren’s Syndrome)||M35.0|
|Meibomian Gland Dysfunction||H02.88-|
|Anterior Basement Membrane Dystrophy||H18.59-|
There are other anterior segment and corneal problems that can limit the surgical outcome in a premium IOL patient. These also need to be diagnosed prior to surgery and include:
- Anterior basement membrane dystrophy
- Salzman’s nodular dystrophy
- Fuch’s corneal dystrophy
- Corneal scars
- Exposure keratitis
Should the worst happen — for whatever reason — and the patient arrives at the office post-surgery still unhappy, I may say something along the lines of: “Mrs. Smith, I see you are experiencing some blurry vision. I can confirm that to be the case by looking at the tests we performed today. Cataract surgery is refractive surgery, but not as accurate as something like LASIK. The good news is we can fix your blurry vision very easily. Once you have completely healed and your refractive error is stable, safe procedures, either LASIK or PRK, can be performed that will treat your blurry vision and eliminate some of your frustrations. We have a few more weeks to let you completely heal, but rest assured we can help you.”
The next step is to follow the patient (usually two to three months after cataract surgery) to make sure the eye is healed and the refractive error is stable. Once the manifest refraction is stable and there are no other limiting factors, plan PRK or LASIK to treat the residual refractive error. DED can also be presumed to be worse after surgery, so optometrists need to evaluate and treat that if the patient is experiencing symptoms of DED.
Other Treatment Options Summary
→ PUNCTAL OCCLUSION: After inflammation has been treated and tears without inflammatory cells are produced, this helps increase the tear reservoir, thereby offering relief.
→ LID DEBRIDEMENT: This can remove the bacterial biofilm that contributes to inflammation and decreased meibomian gland function.
→ AUTOLOGOUS SERUM TEARS: These offer natural tears in patients suffering from severe DED.
→ INTENSE PULSED LIGHT: Also known as IPL, this provides thermal heating of the glands, thereby increasing gland secretions, destroying inflammatory feeder blood vessels on the lid margin and decreasing some of the bacterial load on the lid margin..
→ SLEEP GOGGLES.
→ HUMIDIFIERS NEAR BED WHILE SLEEPING.
→ NEUROSTIMULATION DEVICES.
Consult Practicing Medical Optometry’s “DED Therapy Options” at http://bit.ly/DEDThera for a full list of treatment options at your disposal.
Optometry is the best profession to treat pre and postoperative DED and other ocular surface diseases to help our patients achieve the best possible surgical outcomes. If O.D.s diagnose and proactively treat OSD, they will have much happier patients. We have all had unhappy postoperative cataract patients in our chairs. Years ago, the blame would lie 100% with the surgeon. Today, optometrists play a large part in the surgical process, so we need to know what’s best for our patients. OM