Handling comorbidities prior to surgery

When considering referral for a procedure, review the issues that might need to be addressed before surgical measurements are performed. (Adobe Stock / Syda Productions)

Surgeons’ list of pet peeves is topped by optometrists referring cataract patients without addressing other pathology or comorbidities. To their point, cataract surgeons are increasingly busy and prefer to see patients ready for phacoemulsification rather than address other conditions or see those requiring a referral to a retinal specialist prior to surgery.

The looming shortage of ophthalmologists (OMDs) supports our diligence to refer patients who are ready and desiring surgery. A shortage of 6000 ophthalmologists is predicted by 2025. One reason for this is an increasing age of OMDs. From 1995 to 2017, the amount of OMDs older than 55 years of age increased from 0.37 to 0.82 per 100,000 citizens.¹ Residency positions are limited by the Centers for Medicare & Medicaid Services. Remarkably, the number of ophthalmologists has not increased from 1990, while patient numbers are expected to increase by 42% by 2030.² About 450 new OMDs graduate yearly while approximately 500 to 550 retire annually, resulting in an overall reduction. Most ophthalmologists practice in major cities, and there are shortages in rural areas.

Optometry must step up in the comanagement area. Comanagement begins before you make the referral for surgery. It begins by learning about surgeons practicing around you and how they manage their surgical patients. Are they aggressive or conservative? How do they feel about premium lenses? Do they perform refractive procedures if required by residual refractive error or perform lens exchanges? Do they prefer superficial keratectomy over phototherapeutic keratectomy? How is their bedside manner in clinic and the operating room? Should your patient expect to be seen quickly or is the surgeon booked out for months? Will the visit be short or long? The more you know about the surgeon you choose for your particular patient, the better the patient experience and outcome. Ask colleagues before you refer and ask patients afterward to gather their perceptions.

Some patient issues may direct to whom you refer. For example, has the patient had refractive surgery? Surgeons who perform both LASIK and phacoemulsification are more comfortable with postrefractive IOL calculations and are more likely to perform keratorefractive surgery after phaco in the event of a refractive surprise. A history of head trauma may suggest loose zonules and a more complicated procedure. An old fingernail injury may increase risk of recurrent corneal erosion. A history of retinal detachment or diabetic laser treatment may require retinal consultation prior to and at the time of cataract surgery referral. Patients with limited hand dexterity may benefit from a surgeon who uses punctal plugs for delivery of steroids or no drop procedures.

Preoperative considerations

When considering referral for a procedure, review the issues that might need to be addressed before surgical measurements are performed. For example, is the cornea ready for preoperative intraocular lens measurements? Moderate to severe ocular surface disease such as meibomian gland dysfunction, entropion, blepharitis, superficial keratitis, and allergic conjunctivitis should be controlled prior to referral.

Figure 1A. Persistent epithelial defects and resultant neovascularization may cause reduced vision.

Figure 1B. Scarring noted on AS-OCT in same eye.

Figure 1C. Keratitis causing irregular topography. This patient’s vision may be limited after cataract surgery because of the irregular astigmatism. This should be addressed prior to cataract surgery referral.

Corneal disorders affecting keratometry include corneal scars, map-dot-fingerprint dystrophy, keratoconus, and pterygium (Figure 1). Addressing map-dot-fingerprint with a superficial keratectomy if the central cornea is significantly involved may improve vision prior to phacoemulsification and improve the measurements (Figure 2).

Figure 2A. Pterygium may need to be corrected prior to IOL measurement.

Figure 2B. Irregular astigmatism from a pterygium.

Patients with Fuchs dystrophy are more likely to experience corneal edema after phacoemulsification, especially when the cataract is dense. Pterygiums that affect central vision or are chronically irritated may need removal prior to phaco. Keratoconus that limits visual outcome after phaco should be addressed with patient education prior to referring for cataract surgery, especially if scleral lenses will need to be reordered to address new refractive error.

Patients with a history of recurrent herpetic disease may benefit from preventive measures to reduce the likelihood of recurrence. Using oral antivirals prior to surgery and while on topical steroids may reduce risk. Postkeratorefractive patients may have significantly altered corneal powers, which may complicate IOL calculations. Patients should be warned about refractive surprise and may benefit from intraoperative aberrometry.

Figure 3.

Retinal issues such as microaneurysms should be evaluated by a retinal specialist prior to cataract surgery.

Macular degeneration may limit the visual outcome as well, and patients need to be educated about this fact. Some patients mistakenly think that everyone gets better vision after cataract surgery despite having “the macular.” Addressing this prior to referral will reduce misconceptions with realistic expectations. There remains a question of increased risk of AMD progression following cataract surgery, but studies are not conclusive.³ Retinal issues such as hypertension retinopathy, geographic atrophy, microaneurysm (Figure 3), or lattice degeneration should be evaluated prior to surgery. These referrals may be made such that retina can comment and/or treat the retinal issue prior to phacoemulsification.

Combination glaucoma/cataract treatment should be considered now that microinvasive glaucoma surgery procedures are widely available. Consider the amount of medications/drops your patient is using and what procedures are available to yield the required IOP reduction. Patients with early glaucoma may be successfully managed using selective laser trabeculoplasty or Schlemm canal–based stents. Greater pressured reductions are obtained using suprachoroidal shunts, which bypass outflow resistance and limits from episcleral venous pressure.⁴ For reimbursement purposes, a visual field in the last year and optic nerve OCT history are required, and these should be sent to the surgeon with the cataract referral.

Figure 4.

Evaluate lids and lash health for meibomian gland dysfunction, demodex blepharitis, and trichiasis (shown here).

(All images courtesy of Tracy Schroeder Swartz, OD, MS, FAAO.)

Chronic lid disease is often noted in the elderly population. Meibomian gland dysfunction, Demodex blepharitis, and entropion should be addressed prior to referral. Trichiasis (Figure 4) may cause significant discomfort and require epilation.

Patients with a history of head trauma or connective tissue disorders such as Marfan syndrome may suffer from zonular weakness. Zonulopathy may occur in patients with pseudo-exfoliative syndromes, previous ocular injuries or vitreoretinal surgery, myopia degeneration, and homocystinuria.⁵ In eyes with weakened zonules, the cataract pushes the back of the iris forward, shallowing the anterior chamber. A shallow chamber is an eye with a normal or long axial length. It is unexpected and may indicate zonulopathy. In severe cases, zonules may be missing or the cataract may be decentered. Capsular retractors (also called hooks) may be used to stabilize the capsular bag during cataract surgery. A capsular tension ring may be required to redistribute tension forces upon the functional zonules, reducing the risk of capsular failure and posterior lens dislocation.

Consider oral medications and supplements when referring patients for surgery to alert the surgeon of possible complications. Aspirin, nonsteroidal anti-inflammatories (NSAIDs), warfarin (Coumadin; Bristol-Myers Squibb), apixaban (Eliquis; Bristol-Myers Squibb), and other blood thinners may increase bleeding. Supplements such as omega-3 fatty acids and Ginkgo biloba may also increase bleeding. Intraoperative floppy iris syndrome (IFIS) may occur in patients with a history of using alpha-adrenergic blockers such as tamsulin (Flomax; Astellas Pharma) to treat benign prosthetic hypertrophy. Note that this class of medications may also be used to treat urinary retention or hesitancy in women. Saw palmetto, while a supplement rather than a prescribed medication, may also cause IFIS. Chronic narcotics or pain management may reduce the pupil’s ability to dilate well. Note patients with small pupil dilations may require iris hooks intraoperatively.

Autoimmune disease associated iritis may flare up or be more likely to rebound following cessation of topical steroids. Those with systemic autoimmune disease without ocular inflammation do not need a modified steroid regime.⁶

Patients with diabetes are at greater risk for macular edema and may require pretreatment with a topical NSAID. Significant, nonproliferative retinopathy may require a referral to a retinal specialist prior to cataract surgery. Anti-VEGF injections may be performed with 1 week of cataract surgery. Also consider the patients’ blood glucose levels. Surgery centers may avoid procedures in patients below 70 mg/dL or above 350 mg/dL.⁷ Surgery centers may have similar guidelines for blood pressure in patients with hypertension.

Premium lenses require a healthy cornea and retina. Postrefractives make this challenging. Multifocal and toric lenses are contraindicated in patients with moderate to severe keratoconus, severe ocular surface disease, and corneal scarring as well as macular disease. Issues with ocular surface disease and dry eye may reduce satisfaction with premium lenses.

Conclusion

Knowing what may create complications for phacoemulsification is critical for proper referrals. Managing comorbidities and communicating ocular history are critical for success. Addressing issues prior to referral will facilitate the referral process and enable more efficient care for your patient as well as maximize outcomes.

References

1. Young A. Supply and demand: navigating the future of ophthalmology. Ocular Surgery News. July 9, 2021. Accessed March 25, 2023. https://www.healio.com/news/ophthalmology/20210707/supply-and-demand-navigating-the-future-of-ophthalmology

2.Terveen D. Ophthalmology numbers cause for concern. Young Ophthalmologists, American Academy of Ophthalmology. August 19, 2022. Accessed March 25, 2023. https://www.aao.org/young-ophthalmologists/yo-info/article/ophthalmology-numbers-cause-concern

3. Chen Z, Zeng Y, Tian F. Effect of cataract surgery on the progression of age-related macular degeneration. Medicine (Baltimore). 2022;101(44):e31566. doi:10.1097/MD.0000000000031566.

4. Dhingra D, Bhartiya S. Evaluating glaucoma surgeries in the MIGS context. Rom J Ophthalmol. 2020;64(2):85-95.

5. Oudjani N, Renault D, Courrier E, Malek Y. Phacoemulsification and zonular weakness: contribution of the capsular tension ring with a thread. Clin Ophthalmol. 2019;13:2301-2304. doi:10.2147/OPTH.S212063.

6. Nau SA, Scott R, Patnaik J, Palestine A, Reddy AK. Cataract surgery outcomes in patients with non-ocular autoimmune disease. Invest Ophthalmol Vis Sci. 2022;63(7):2889-F0026.

7. Alldredge B, Norris K. Systemic disease can affect cataract surgery outcomes. Primary Care Optometry News. December 13, 2018. Accessed March 25, 2023. https://www.healio.com/news/optometry/20200408/blog-systemic-disease-can-affect-cataract-surgery-outcomes.