Refractive surgery has transformed the lives of countless individuals, offering freedom from glasses and contact lenses by reshaping the cornea or replacing the natural lens. For ophthalmology residents and fellows seeking expertise in this field, understanding the potential side effects and complications is just as critical as mastering the surgical techniques.
There are three major complications that residents and fellows should be well-versed in to ensure safe and effective refractive surgeries for their patients. While there is a much more robust list of complications, luckily, refractive surgery has been deemed one of the safest and most effective medical procedures ever to be performed.1
Familiarizing yourself with every possible outcome is what differentiates you as a refractive specialist versus a comprehensive ophthalmologist who performs refractive procedures.
This article will focus on the most common complications a refractive surgeon will encounter and must learn how to navigate.
1. Corneal ectasia
Corneal ectasia is a rare but serious complication that can occur after corneal refractive surgeries, such as laser in situ keratomileusis (LASIK), photorefractive keratectomy (PRK), and small incision lenticule extraction (SMILE).
This progressive thinning and bulging of the cornea results in a distorted corneal shape associated with irregular astigmatism and a potential decrease in visual quality. Corneal ectasia can range from mild visual changes or can lead to significant visual impairment if not managed promptly.
Causes and symptoms of corneal ectasia
Corneal ectasia is thought to arise due to the removal of excessive anterior corneal collagen tissue during refractive surgery. The loss of corneal thickness weakens the stromal collagen structural integrity of the cornea, making it susceptible to weakening and deformation over time.
Other contributing factors may include pre-existing corneal thinning, abnormal healing responses, or genetic predisposition. The most common associated factor, however, is eye rubbing, and all corneal refractive surgery patients should be counseled against eye rubbing.
Patients who develop corneal ectasia may experience symptoms such as:
- Progressive, uncorrectable blurred vision
- Irregular astigmatism
- Increased sensitivity to light (photophobia)
- Glare and halos around lights
- Frequent changes in eyeglass or contact lens prescriptions
Strategies for preventing and managing corneal ectasia
Preventing corneal ectasia primarily involves careful patient selection and pre-operative evaluation. Residents and fellows should scrutinize corneal topography and thickness maps, assessing risk factors and ensuring that the patient's cornea is suitable for the procedure.
Additionally, adherence to conservative treatment guidelines and not pushing the limits of corneal thickness is vital to minimize the risk of ectasia. In cases where corneal ectasia has developed, it is crucial to promptly diagnose and manage the condition.
Techniques such as corneal collagen cross-linking (CXL) and intracorneal ring segments can be employed to stabilize and potentially improve the corneal shape. In advanced cases, a corneal transplant (keratoplasty) may be necessary to restore visual function.
2. Dry eye syndrome
Dry eye syndrome is a common side effect following refractive surgery, affecting the quality and quantity of tears produced, leading to ocular discomfort and visual disturbances. It is particularly prevalent in procedures that affect corneal nerves, like LASIK and PRK.
Causes and symptoms of dry eye syndrome
The creation of corneal flaps or surface epithelial removal during refractive surgery can disrupt corneal sensitivity and tear film production. This disruption can result in reduced tear volume and impaired tear film stability, leading to dry eye symptoms.
Dry eye is common and should be noted it is due to damage to the peripheral corneal nerves that will ultimately regenerate after about 3 to 4 months.
Residents and fellows should be aware of the following symptoms of dry eye syndrome in refractive surgery patients:
- Dryness and scratchiness
- Redness, burning, or stinging sensations
- Foreign body sensation
- Blurred or fluctuating vision
- Photophobia
Approaches for preventing and managing dry eye syndrome
Prevention and management of dry eye syndrome in refractive surgery patients involve thorough pre-operative evaluation and patient education:
- Pre-operative assessment of tear film quality and quantity.
- Identification of pre-existing dry eye conditions, including meibomian gland dysfunction, blepharitis, and Demodex infection.
- Patient counseling regarding the risk of dry eye and the use of lubricating eye drops.
- Post-operative management with lubricating eye drops, punctal plugs, and, in some cases, prescription medications.
Residents and fellows should be prepared to address dry eye symptoms promptly and effectively to enhance patient comfort and satisfaction after refractive surgery. It is imperative to mention this prior to surgery so patients are not surprised if this occurs.
3. Glare and halos
Glare and halos are visual phenomena characterized by the perception of rings, streaks, or halos around light sources, especially at night or in low-light conditions. These visual disturbances can be particularly troublesome for patients after refractive surgery, impacting their quality of life.
Causes and symptoms of glare and halos
Glare and halos are commonly associated with refractive surgery procedures that alter the shape of the cornea or replace the natural lens. Changes in corneal curvature, optical zones, and irregularities in the tear film can contribute to these visual disturbances.
Patients may experience more pronounced glare and halos in low-light situations, such as while driving at night.
Residents and fellows should be attentive to patients' complaints of glare and halos, which may manifest as:
- Rings or circles around point light sources, such as headlights and streetlights
- Blurring or distortion of light sources
- Reduced contrast sensitivity, especially in low-light conditions
- Difficulty with night vision
- Increased sensitivity to glare
Techniques for preventing and managing glare and halos
Preventing and managing glare and halos requires careful patient selection, pre-operative evaluation, and patient counseling:
- Comprehensive pre-operative assessment to identify patients at higher risk of experiencing glare and halos. Key things to look out for are large pupil size, excessively flat or steep K’s, and patients who are already sensitive to glare and halos pre-operatively.
- Informed patient consent that includes a discussion of the potential for these visual disturbances.
- Employing advanced surgical techniques and wavefront-guided technology to minimize higher-order aberrations.
- Post-operative management with medications and strategies to enhance tear film stability and quality of vision.
Educating patients about the possibility of glare and halos is essential to managing their expectations and alleviating concerns. In most cases, glare and halos improve over time as the eyes adjust to the refractive changes, but some patients may require additional interventions for symptom relief.
In conclusion
Ophthalmology residents and fellows must be well-prepared to recognize, manage, and educate patients about potential complications in refractive surgery. Corneal ectasia, dry eye syndrome, and glare/halos are among the major concerns that require vigilance and a proactive approach.
By understanding these complications and their preventative and management strategies, residents and fellows can contribute to safer and more successful refractive surgery outcomes, ensuring patient satisfaction and visual clarity.
