Introduction

In the management of postoperative cataract patients, primary care practitioners often face challenges due to the lack of specialized diagnostic tools, such as a visual acuity chart, slit lamp, or indirect ophthalmoscope. This creates limitations in accurately diagnosing and addressing potential complications. Recognizing the importance of equipping pharmacists for their role in providing informed advice and facilitating timely interventions, this chapter has been meticulously designed as a study resource for candidates preparing for the PEBC (Pharmacy Examining Board of Canada) exams.

The objective of this chapter is to familiarize readers with the critical signs and symptoms that mandate an urgent referral to an ophthalmologist. These complications include postoperative infections, glaucoma, inflammation, and any suspected healing abnormalities. 

Additionally, the chapter provides an in-depth review of the pharmacological agents commonly used in postoperative care. These medications play a crucial role in prophylaxis and therapeutic management, addressing issues such as:

• Prevention of infection

• Management of increased intraocular pressure (IOP) 

• Prevention of cystoid macular edema (CME) 

• Facilitation of the healing process

This comprehensive content ensures that pharmacy professionals are equipped to guide patients effectively and contribute to optimal postoperative outcomes.

Goals of Therapy

Understanding the therapeutic objectives in perioperative and postoperative care is essential for pharmacy practice, particularly in providing evidence-based counseling. This chapter outlines the following goals to enhance candidates’ clinical acumen for the PEBC exams:

Perioperative Prophylactic Treatment Goals

• Control inflammation: Prevent excessive inflammatory responses that can hinder healing.

• Prevent infection: Minimize the risk of postoperative infections, a common but serious complication.

• Maintain eye comfort: Alleviate discomfort to improve patient compliance and quality of life during recovery.

• Promote early visual rehabilitation: Facilitate the restoration of visual function as quickly and safely as possible.

Postoperative Assessment Goals

• Early detection of intraocular infection: Identify signs of endophthalmitis or other infections promptly to prevent vision loss.

• Monitoring for postoperative uveitis and IOP elevation: Recognize and address inflammation or pressure changes to avoid long-term complications.

• Identification of additional abnormalities: Detects issues such as retinal detachment, iris prolapse, wound leaks, flat anterior chamber, excessive corneal edema, or intraocular hemorrhage, which may arise during the postoperative course.

Red Flags Requiring Urgent Referral

On History:

• Trauma to the eye postsurgery

• Blurry or worsening vision

• Persistent or progressively painful eye (may also have headache, nausea, vomiting, or feel unwell) or light sensitivity

• Persistent or progressive shadows, flashes, or floaters

On Examination:

• Swollen or red eyelids or conjunctiva

• Hypopyon (white layer) in the anterior chamber

• Flat (poorly formed) anterior chamber

• Elevated intraocular pressure

• Hazy cornea

• Poor or absent red reflex with direct ophthalmoscopy

• Seidel-positive wounds (leakage of fluid from the anterior chamber when fluorescein is instilled in the eye) or iris peaking toward the wound or prolapsing from the wound

Therapeutic Choices

Cataract surgery is one of the most commonly performed surgical procedures worldwide. However, approaches to preoperative and postoperative care can vary significantly depending on the preferences and clinical habits of individual surgeons. Understanding these variations is crucial for pharmacists, especially when advising patients and ensuring adherence to prescribed therapies.

Pharmacologic Options

Antibacterials

Preventing postoperative endophthalmitis, a serious eye infection, is a critical component of perioperative care. Key strategies include the preoperative application of iodized povidone, the administration of antibiotics preoperatively and postoperatively, and the use of intracameral antibiotics during surgery.

• Topical Antibacterials: Broad-spectrum antibiotics, such as fourth-generation fluoroquinolones (e.g., besifloxacin, gatifloxacin, moxifloxacin), are commonly used perioperatively. These agents have contributed to a decline in infection rates over recent decades, reflecting advancements in surgical techniques and prophylactic measures.

• Combination Preparations: Fixed-dose combinations of antibiotics and corticosteroids, such as tobramycin/dexamethasone, are often preferred for their convenience, which can enhance patient compliance.

• Intracameral Antibiotics: Administered directly into the anterior chamber of the eye at the end of surgery, this approach has shown varying degrees of effectiveness. While some studies highlight its benefits, others raise concerns about risks such as toxic anterior segment syndrome or rare complications like hemorrhagic occlusive retinal vasculitis (HORV) associated with agents like vancomycin. Selection of an intracameral antibiotic often depends on factors such as local bacterial resistance patterns, cost, and surgeon preference.

Glaucoma Medications

Postoperative elevations in intraocular pressure (IOP) are a common concern, particularly in patients with preexisting glaucoma.

• Medications: Noninflammatory IOP-lowering agents such as alpha-adrenergic agonists, beta blockers, or carbonic anhydrase inhibitors are typically prescribed for short-term use.

• Management of IOP Spikes: Postoperative IOP spikes are generally transient and can be managed with topical medications. In rare cases, an anterior chamber paracentesis may be required.

Anti-inflammatory Agents

Inflammation is a significant postoperative concern, as it can delay healing and increase the risk of complications such as cystoid macular edema (CME).

• NSAIDs and Corticosteroids: Ophthalmic NSAIDs, either alone or in combination with corticosteroids, are effective in reducing inflammation and preventing CME. Topical NSAIDs may also enhance visual recovery and reduce postoperative pain. The choice of anti-inflammatory agent often depends on surgeon preference.

Ophthalmic Dilators and Cycloplegics

These medications are used during the early healing period to keep the iris away from the intraocular implant and to alleviate ciliary muscle spasms, improving patient comfort.

Analgesics and Systemic Medications

• Pain Management: Mild to moderate postoperative discomfort can be managed with oral analgesics such as acetaminophen (e.g., 500 mg every 4–6 hours).

• Systemic Medications: Patients should continue systemic medications, including anticoagulants and antiplatelets, unless advised otherwise by their surgeon. Adjustments to diabetic medications may be necessary to mitigate risks such as hypoglycemia or lactic acidosis.

Therapeutic Tips for PEBC Candidates

• Timing of Antibacterials: Initiate topical antibacterial drops immediately after surgery rather than waiting until the first postoperative day.

• Eye Drop Administration: Advise patients to separate the administration of different eye drops by at least five minutes. For medications with systemic absorption risks, recommend occluding the inner canthus (lacrimal punctum) for 30–60 seconds after instillation to reduce systemic absorption.

• Urgent Symptoms: Any postoperative worsening of vision, floaters, eye pain, or redness, particularly within the first week, should prompt urgent referral to an ophthalmologist as these symptoms may indicate endophthalmitis.

• Medication Disposal: Since most postoperative medications are prescribed for a limited duration, unused eye drops should be properly discarded after treatment.

• Cost Considerations: Encourage the use of cost-effective medications where possible, as there is often no significant difference in efficacy between expensive and less expensive options.

Preoperative and Postoperative Considerations

• Medication Use on Surgery Day: Patients undergoing clear corneal cataract surgery should continue their usual medications, including anticoagulants and antiplatelets, unless specifically directed otherwise. Adjustments to diabetic medications, such as withholding insulin secretagogues or metformin, may be required to reduce the risk of hypoglycemia or lactic acidosis. Close glucose monitoring is advised for such patients.

• Coordination with the Ophthalmologist: Any changes to the postoperative medication regimen should be made in consultation with the treating ophthalmologist to ensure continuity of care.

Cataract Surgery Postoperative Assessment Algorithm

1. History:

• If: Vision is clear, the eye is comfortable, and there are no shadows, floaters, or flashes.

• Action: Normal.

• If: Vision is not clear, the eye is uncomfortable, or the patient reports seeing shadows, floaters, or flashes.

• Action: Call an ophthalmologist.

2. Physical Examination:

• If: Lids and/or conjunctiva are red/swollen, or the ophthalmoscope does not reveal a clear view of the optic disc and a good red reflex.

• Action: Call an ophthalmologist.

• If: Lids and/or conjunctiva are white with minimal swelling/redness, and the ophthalmoscope shows a clear view of the optic disc and a good red reflex.

• Action: Normal.

Here is the algorithm formatted as a table:

Cataract Surgery Postoperative Assessment Algorithm