In this episode of Interventional Mindset, Preeya K. Gupta, MD, is joined by Dagny Zhu, MD, to discuss how to efficiently manage inflammatory and mixed-mechanism dry eye in pre-surgical patients.
Dr. Zhu is a cornea, cataract, and refractive surgery specialist who practices as Medical Director and Partner of NVISION Eye Center in Rowland Heights, California.
How to streamline pre-surgical dry eye assessments
Studies have found that upwards of 50% of patients presenting for cataract evaluations have ocular surface disease (OSD) and are asymptomatic, making it easy to miss the diagnosis pre-operatively.1
Further, tear film instability can lead to deviations in corneal refractive power and astigmatism measurements, contributing to prediction errors in intraocular lens (IOL) power calculations, and subsequently, unhappy post-op patients.2
As such, it is critical to have a comprehensive workflow to screen patients for dry eye to diagnose and treat the root cause to optimize surgical outcomes.
Dr. Zhu’s practice relies on a few key diagnostic tests to identify dry eye in peri-operative patients, such as:
- Clinical examination
- Slit lamp exam with fluorescein dye
- Measure tear breakup time (TBUT) to assess patients for evaporative dry eye, which is the leading cause of dry eye disease (DED),3 and contributes to fluctuating vision after surgery
- Assess patients with the look, lift, pull, and push (LLPP) examination to evaluate the blink quality and quantity, examine the eyelids, check for collarettes on the lash margin, and express the meibomian glands
- Slit lamp exam with fluorescein dye
- Objective testing
- Tear osmolarity
- A significant inter-eye difference and hyperosmolarity (ex., >318 mOsms/L) are key signs of DED that can help confirm the diagnosis,4 and prevent unexpected refractive error and patient dissatisfaction5
- As tear hyperosmolarity is the first sign of an unstable tear film, monitoring this can help identify mild and asymptomatic dry eye patients
- Note: Changes in tear osmolarity do not linearly correspond to improvements in DED signs and symptoms6
- Corneal topography
- In particular, Scheimpflug or Placido disc imaging can be helpful for identifying tear film instability, and can be used in conjunction with tear osmolarity to confirm a diagnosis of evaporative dry eye
- Both Drs. Gupta and Zhu explained that they have treated patients who seemed to have keratoconus based on the initial topography, but after a few weeks of punctal plugs, lubrication, and steroids, the results normalized
- Tear osmolarity
Determining when dry eye patients are ready for ocular surgery
Once the patient has been diagnosed with dry eye, Dr. Zhu’s practice staff knows to schedule either a 2- or 4-week follow-up visit to assess the effectiveness of the treatment before surgery. At this follow-up, if the patient hasn’t improved enough for surgery, they are scheduled for another 2-week follow-up and potentially prescribed an additional therapy.
She explained that it is crucial not to just treat the patient and then jump into surgery without checking if they have improved. Further, because Dr. Zhu’s practice performs office-based procedures, she occasionally opts to recheck biometry on the day of surgery to see if the measurements are consistent across devices.
Dr. Gupta agreed, adding that she always orders a second set of biometry for premium IOL patients, whether they have dry eye or not, and has been surprised to hear how many people don’t repeat biometry and then are surprised that they have refractive misses. She explained that measuring biometry multiple times helps her feel more confident as a refractive surgeon that the lens is the right choice for the patient.
Treating inflammatory dry eye in pre-surgical patients
Dr. Zhu emphasized that aggressively treating dry eye pre-operatively is key to optimal surgical outcomes, and she assumes that all patients have some degree of dry eye, so she counsels them on it regardless of whether they have symptoms.
Unfortunately, many surgeons don’t catch asymptomatic dry eye before surgery, so when patients complain of dry eye after the procedure, they try to “throw the kitchen sink” at them, but by then, they have already missed the boat.
She tends to prescribe a low-potency topical steroid and lubricants (though many patients are already using eye drops regularly) at the first visit for patients who report dry eye risk factors, even if they are asymptomatic, to tame any inflammation right away. Then, if she sees corneal staining with significant punctate epithelial erosions (PEEs) and an aqueous deficient component, she recommends a punctal plug.
For patients who have already been diagnosed with dry eye or have uncontrolled symptoms, she opts for an immunomodulator to address the chronic nature of the inflammation. She explained that XIIDRA (lifitegrast ophthalmic solution 5%, Bausch + Lomb) is her go-to immunomodulator drop, which she prescribes in combination with the aforementioned therapies.
Studies on the efficacy and rapid onset of XIIDRA
This choice is based on the results from a 2020 study that demonstrated that lifitegrast 5% BID significantly improved pre-operative corneal surface measurement accuracy after 4 weeks of treatment in 100 patients with confirmed dry eye who were scheduled for cataract surgery.7
The accuracy of the biometry readings before and after the initial lifitegrast treatment was as follows:7
- Within 0.25D in 47% of eyes before and 50% of eyes after
- Within 0.50D in 71% of eyes before and 79% of eyes after
- Within 0.75D in 81% of eyes before and 91% of eyes after
While 0.75D may not sound like a huge difference, Dr. Zhu emphasized that it is enough to be noticeable to patients, especially for those receiving premium IOLs. Dr. Gupta added that in two of four clinical studies, XIIDRA reduced symptoms of eye dryness as quickly as 2 weeks.8 This is particularly important for peri-operative patients, wherein rapid onset is critical to getting patients to surgery quickly.
Managing mixed-mechanism dry eye
For patients with mixed-mechanism dry eye, Dr. Zhu noted that XIIDRA and MIEBO (perfluorohexyloctane ophthalmic solution, Bausch + Lomb) are her go-to medications because they work synergistically to address the vicious cycle of dry eye.
MIEBO preserves tear film stability by reducing evaporation while XIIDRA treats chronic inflammation, leading to a self-reinforcing loop of symptom relief for dry eye patients.
Setting pre-surgical patient expectations with dry eye treatments
When discussing dry eye therapies with patients, Dr. Gupta highlighted that letting them know how long it will take for the medication to kick in and how long they can expect to feel the effects of the medication are key points to cover. In her experience, patients on XIIDRA have reported feeling improvements in dry eye symptoms for several months.
She added that patients always appreciate understanding that there are two reasons for their blurry vision, dry eye and cataract, and one is a chronic disease that requires long-term management, while the other she can fix surgically. Often, patients aren’t upset that they have DED; they’re upset that no one informed them of the diagnosis before now.
Conclusion
While it may be daunting at first, Dr. Gupta recommended that refractive surgeons formulate their own protocol by trialing different medications to get a feel for what works best for their practice.
However, once a clear workflow has been established and go-to medications have been identified, treating dry eye in pre-surgical patients becomes a much easier and more predictable process.
