As a Certified Paraoptometric (CPO), you will assist with a variety of ophthalmic procedures, including laser treatments and intravitreal injections. Understanding these procedures, the equipment involved, and your specific role in each is essential for both the exam and clinical practice.
YAG Laser Capsulotomy
The Nd:YAG laser capsulotomy (pronounced "yag") is one of the most common laser procedures you will encounter. After cataract surgery, the posterior capsule, the thin membrane behind the intraocular lens, can become cloudy over time. This is called posterior capsular opacification (PCO), sometimes called a "secondary cataract," though it is not a true cataract.
The YAG laser creates a small, precise opening in the cloudy capsule, restoring clear vision. Think of it as a clean hole-punch through a frosted plastic film. The procedure is quick, typically under five minutes, and is performed at the slit lamp with a special contact lens.
Your role as a CPO includes preparing the patient by instilling a dilating drop, explaining what they will see (flashes of light) and hear (clicking sounds), and positioning them correctly at the laser. After the procedure, you will typically instill an anti-inflammatory drop and review post-procedure instructions.
Selective Laser Trabeculoplasty (SLT)
Selective Laser Trabeculoplasty (SLT) is a laser procedure used to lower intraocular pressure (IOP) in patients with open-angle glaucoma or ocular hypertension. The laser targets pigmented cells in the trabecular meshwork, the drainage structure of the eye, stimulating them to improve aqueous outflow and reduce IOP.
Unlike older argon laser trabeculoplasty, SLT is "selective" because it does not scar trabecular tissue, making it repeatable if IOP rises again years later. It is an alternative or adjunct to topical glaucoma medications.
Your responsibilities include measuring baseline IOP before the procedure, instilling the required pre-procedure drops (commonly brimonidine to blunt any IOP spike), assisting with patient positioning, and checking IOP approximately 30 to 60 minutes after SLT to confirm no dangerous pressure elevation occurred.
Intravitreal Injections
Intravitreal injections deliver medication directly into the vitreous cavity, the gel-filled center of the eye. The most common agents are anti-VEGF drugs, which block vascular endothelial growth factor (VEGF), a protein that drives abnormal blood vessel growth. These medications include bevacizumab, ranibizumab, and aflibercept, and are used for conditions such as:
- Neovascular (wet) age-related macular degeneration (AMD)
- Diabetic macular edema (DME)
- Retinal vein occlusion
The injection is performed in a sterile fashion using a very fine needle passed through the pars plana, a safe zone on the sclera approximately 3.5 to 4 mm posterior to the limbus. Despite sounding daunting, the procedure is brief and well-tolerated with topical anesthesia.
The CPO Role in Laser and Injection Procedures
Across all these procedures, your core responsibilities follow a consistent pattern:
- Pre-procedure: Obtain and document visual acuity and IOP, instill any required pre-procedure drops, explain the procedure to the patient, and set up required instrumentation.
- During the procedure: Assist the physician, ensure the patient is positioned correctly, and maintain a calm environment.
- Post-procedure: Instill post-procedure drops, check IOP when indicated, document findings, and review discharge instructions with the patient.
Key Takeaways
- YAG capsulotomy treats posterior capsular opacification (PCO) after cataract surgery by creating an opening in the cloudy capsule.
- SLT lowers IOP in glaucoma by stimulating the trabecular meshwork to improve drainage; effects take several weeks to appear.
- Intravitreal anti-VEGF injections treat wet AMD, diabetic macular edema, and retinal vein occlusion by blocking abnormal vessel growth.
- The CPO role involves preparation, patient education, pre- and post-procedure measurements, and assisting the physician.
- Always confirm and document baseline IOP and visual acuity before and after pressure-related procedures.