Dry eye disease (DED) is defined as “a disorder of the tear film due to reduced tear production or excessive tear evaporation, which causes damage to the inter-palpebral ocular surface and is associated with symptoms of ocular discomfort and/or visual symptoms”.
A more descriptive definition given by the dry eye workshop defines it as “a multifactorial disease of the tear film and ocular surface that results in symptoms of discomfort, visual disturbance, and tear film instability with potential damage to the ocular surface.
It is accompanied by increased osmolality of the tear film and inflammation of the ocular surface”
Dry eyes are a common complication following refractive cataract surgery. While normally temporary, the condition can have a negative effect on visual recovery, patient satisfaction and overall quality of life.
One of my favorite quotes on this subject is from Dr. Eric Donnenfeld: “If you diagnose dry eye prior to cataract surgery, it’s an expectation; if you don’t diagnose it until after surgery, it is a complication.”
Many of our colleagues, both optometrists and ophthalmologists, may not recognize the value of actively looking for dry eye disease (DED) in our preoperative patients or are unsure of how to do so.
Others may feel it may have a negative effect on the flow and efficiency in the office. Given the prevalence of post-surgical dry eye, it is essential to detect it before surgery — in order to manage the patient’s expectations, prevent DED from compromising surgical outcomes and devise a treatment plan for the aggravated condition that is likely to present after surgery.
Trattler et al reported that the percentage of patients scheduled for cataract surgery who have signs or symptoms of dry eye is higher than anticipated; the majority of patients screened for cataract surgery do not have symptoms, but up to 80% had conjunctival or corneal staining.
Gupta et al similarly found that objective findings of DED were common among patients presenting for cataract surgery, yet many were undiagnosed. Ocular surface disease (OSD) can reduce quality of vision and adversely affect accuracy of IOL power calculations prior to cataract and refractive surgery.
Our colleagues reported patients with hyperosmolarity had greater variability in keratometry readings resulting in variability in IOL power calculations.
Furthermore, ocular surgery can induce or exacerbate DED, which can compromise quality of vision, worsen dry eye symptoms and lead to dissatisfied patients.
In fact, dry eye is one of the most frequent complaints in the postoperative period. Dry eye after cataract surgery was categorized as a surgically induced iatrogenic DED by the Tear Film and Ocular Surface Society International Dry Eye Workshop (TFOS DEWS) II iatrogenic report.
The exacerbation of dry eye signs and symptoms after cataract surgery is multifactorial: a combination of damage to the corneal nerves from the corneal incision, heat and light from the microscope, postop inflammation and drops containing preservatives can contribute.
Although NSAIDs are effective in decreasing the prevalence and severity of postoperative CME, they can cause adverse side effects, including ocular surface abnormalities. According to Oh et al, the duration of surgery was associated with a decrease in goblet cell density in the conjunctiva.
They discovered that more severe inflammatory responses and longer surgery times can damage the ocular surface and reduce goblet cell density.
Park et al evaluated the ocular surface after cataract surgery, noting that lid margin abnormalities and quality of meibum decreased in patients with dry eye after cataract surgery.
An increased awareness of the high prevalence of OSD in this population, including asymptomatic patients, should lead to careful evaluation, counseling and treatment of the ocular surface both before and after surgery.
DED is a multifactorial condition that can be challenging to diagnose and treat. Nonetheless, taking a systematic approach will help with evaluation, treatment decisions and management strategies.
The use of a patient-reported symptom questionnaire, such as the Ocular Surface Disease Index (OSDI) or the Standardized Patient Evaluation of Eye Dryness (SPEED), as a first step in screening is suggested to assess the patient’s awareness of their ocular surface issues.
Point-of-care diagnostic tests, such as tear osmolarity (TearLab; I-Pen, I-Med Pharm), MMP-9 (InflammaDry, Quidel) or meibography (LipiScan, Johnson & Johnson Vision; Keratograph 5M, Oculus; HD Analyzer, Visiometrics) may be triggered by symptomatic patients.
Topography can be used to assess subtle signs of OSD. We want to see whether the visual symptoms of patients are related to the degree of cataract and not to other comorbidities.
Not only may topography help diagnose DED, but it can also help detect other pathologies, including epithelial basement membrane dystrophy, irregular astigmatism and keratoconus — all of which may not be visible at the slit lamp.
Using a combination of these diagnostic instruments, as well as a thorough history and clinical examination, is important to determine if OSD is present.
Because it is more challenging to treat asymptomatic dry eye patients, we believe that educating patients about their pre-existing dry eye condition and discussing the consequences of proceeding with cataract surgery without treatment helps to improve patient understanding and compliance.
We show patients their photos if they have keratitis, unstable tear film (reduced tear breakup time) and abnormal meibomian glands.
These objective findings provide a platform for explaining the cause of their problems, their therapeutic options and the likelihood that therapy must be continued after surgery.
Currently no prophylactic treatments or drops approved for use in preventing the development of postoperative dry eye are on-label. Your best chance to combat it remains actively screening and evaluating for DED, patient education and optimizing the health of the ocular surface preoperatively.
Therapy for perioperative dry eye should be determined based on type and severity of dry eye. Preservative-free lipid-containing artificial tears are a first-line treatment for meibomian gland disease (MGD) and may be adequate for mild dry eye symptoms after cataract surgery.
However, with more severe or persistent complaints, adjunctive therapy should be added based on the underlying condition. Reducing inflammation on the ocular surface is the primary goal in treating moderate to advanced DED.
Immunomodulators including cyclosporine (Restasis, Allergan; Cequa, Sun Ophthalmics) or lifitegrast (Xiidra, Novartis) target the inflammatory pathway and are an effective treatment option for patients with postoperative DED.
In addition, using a mild short-term topical steroid such as loteprednol etabonate 0.25% (Eysuvis, Kala Pharmaceuticals) or fluorometholone acetate (Flarex, Eyevance) provides a tool to rapidly reduce inflammation.
A high-quality omega-3 supplement has also been shown to improve both signs and symptoms of DED and is recommended in most of the DED algorithms. After cataract surgery, corticosteroid and NSAID drops are often included in the regimen to reduce the inflammatory response; these are usually tapered over the first month.
Most topical NSAIDs are weakly acidic, which can be more irritating. They may also contain preservatives such as benzalkonium chloride, which increase ocular surface irritation.
With persistent dry eye symptoms, we continue their omega-3 supplements and immunomodulator indefinitely; an additional short-term course (2 to 4 weeks) of a mild topical corticosteroid that is friendly to the ocular surface (such as loteprednol etabonate ophthalmic suspension 0.25% or fluorometholone acetate ophthalmic suspension) can be very effective in relieving dry-eye exacerbations.
If the source is MGD, in-office thermal treatments, such as thermal pulsation with expression (LipiFlow, Johnson & Johnson Vision; iLux, Alcon; TearCare, Sight Sciences), have been shown to be very effective in restoring meibomian gland function, stabilizing the tear film and reducing dry-eye symptoms.
Symptomatic patients with aqueous tear deficiency may benefit from punctal occlusion, however, ensure that the integrity of the tear film has been optimized. If this is done prematurely, patients tend to become more symptomatic due to the inflammatory mediators that remain in the tear film.
Development or exacerbation of dry-eye symptoms is extremely common after cataract surgery. Because this can adversely affect patient outcomes and satisfaction, providers should recognize the condition before surgery, be aware of the impact it can have and treat it appropriately.
Optimizing the health of the ocular surface perioperatively results in happier, more satisfied patients and improved surgical outcomes.