Laser Eye Surgery & Dry Eyes

Are you contemplating laser eye surgery? 

Laser eye surgery stands out as a highly effective solution for correcting prevalent refractive errors, including:

• Near-sightedness (Myopia): This condition, characterized by clear near vision but blurry distance vision.
• Far-sightedness (Hyperopia): People with hyperopia experience blurred vision up close and, sometimes, at a distance.
• Astigmatism: Astigmatic eyes struggle to focus on both near and far objects due to the irregular curvature of the cornea.
• Presbyopia: Age-related decline in near vision.

Did you know that there were different types of laser eye surgery? 

• LASIK (Laser-Assisted In Situ Keratomileusis)
• PRK (Photorefractive Keratectomy) 
• SMILE (Small Incision Lenticule Extraction) 
• Refractive Lens Exchange 
• ICL (Implantable Collamer Lens) 

The diversity of available procedures helps necessitate a thoughtful and individualized approach when matching patients with the most suitable refractive surgery option.

LASIK 

LASIK is a highly sought-after procedure designed to correct refractive errors. It is a relatively quick and effective vision correction procedure that typically takes about 10-15 minutes per eye.

The LASIK procedure unfolds in the following steps:

1. Numbing Eye Drops: Before commencing, your ophthalmologist will administer numbing eye drops to ensure your comfort throughout the procedure.

2. Eye Stabilization: A device is used to hold your eyes open, while a suction ring prevents eye movement. You may feel mild pressure and experience a temporary dimming of your vision.

3. Creating a Corneal Flap: Your surgeon will utilize a microkeratome (surgical cutting blade) or femtosecond laser technique to create a thin corneal flap, allowing access to the corneal tissue beneath.

4. Reshaping the Cornea: With your focus fixed on a targeted light source, a programmed laser is employed to reshape your cornea. You may hear a clicking sound and notice a slight odour during this process.

5. Flap Reattachment: After corneal reshaping, the corneal flap is gently folded back into place. Remarkably, no stitches are required, as the flap naturally reattaches and begins the healing process.

PRK

PRK requires the removal of the corneal epithelium. This procedure directly addresses the corneal stromal surface using an excimer laser, completely bypassing the necessity for a corneal flap.

PRK is particularly beneficial for individuals prone to complications associated with corneal flaps or those with thinner corneas.

SMILE

SMILE stands out as a minimally invasive method designed to reshape the cornea and address refractive errors by removing a small corneal lenticule. The unique incision geometry of the SMILE procedure involves four crucial steps.

Initially, the lenticule cut takes place on the underside of the lenticule, followed by precise lenticule sidecuts. Subsequently, the cap interface is created on the upper side of the lenticule. Lastly, a small incision of 2 to 3mm is carefully crafted superiorly. The dissection of lenticule interfaces and the manual extraction of the lenticule are carried out through this small incision.

Refractive Lens Exchange 

Refractive Lens Exchange is highly recommended for individuals dealing with presbyopia or notable lens changes, such as cataracts. In this procedure, an artificial intraocular lens (IOL) takes the place of the natural lens in the eye, effectively addressing refractive errors. It stands as a viable alternative for individuals not suitable for corneal-based procedures.

There exists a range of IOLs, with multifocal IOLs, extended depth of focus (EDOF) IOLs, toric IOLs, and accommodating IOLs being the most prevalent choices in refractive lens exchange. Multifocal IOLs, available in bi- and tri-focal varieties, play a crucial role in providing comprehensive vision for near, intermediate, and distance vision needs. EDOF IOLs excel in offering clear vision for both distance and intermediate ranges, while toric IOLs effectively address astigmatism.

Despite the variety, it's worth noting that accommodating IOLs, while capable of delivering distance vision with some near vision, have diminished in popularity among many surgeons due to their limited efficacy in providing helpful near vision

ICL 

ICL lens surgery inserts a corrective lens between the natural lens and the iris, addressing moderate to high refractive errors. This cutting-edge procedure is tailored for individuals not yet experiencing presbyopia and who may not be suitable candidates for corneal-based interventions. 

Comparing Refractive Surgery Procedures 

	LASIK	PRK	SMILE	ICL
Quick Recovery	X		X	X
Minimal Discomfort	X		X	X
Thin Corneas/High Refractive Errors		X	X	X
Hyperopic Correction	X	X
2 to 3 days of Discomfort		X
Slow Visual Recovery		X
Risk of Flap Complications	X
Less Long-term Data			X
Higher Surgical Risk				X

Ideal Candidates For Refractive Eye Surgery

Refractive surgery, proves highly advantageous in addressing prevalent refractive errors like regular astigmatism, hyperopia (farsightedness), myopia (nearsightedness), and presbyopia (age-related decline in near vision).

It is especially beneficial for individuals with stable vision prescriptions, ideally with no spherical change greater than 0.5D in the last 2 years. Candidates should exhibit good overall eye health and maintain realistic expectations about the outcomes of the procedure.

Here are the key prerequisites to be considered a suitable candidate for laser eye surgery:

1. Age: While laser eye surgery can be considered from the age of 18, it's generally preferable to wait until you're over 21 to ensure that your vision has stabilized.

2. Stable Prescription: Your prescription for corrective lenses should not have significantly changed in the past year.

3. Refractive Error: Laser eye surgery is most effective for near-sightedness, farsightedness, and astigmatism.

4. Corneal Thickness and Eye Health: Your corneas should be thick enough for laser surgery, and your overall eye health should be optimal.

5. Realistic Expectations: It's essential to have a clear understanding of both the risks and benefits associated with laser eye surgery.

Certain medical and eye conditions may make laser eye surgery less suitable or riskier. Individuals with the following issues may not be ideal laser eye surgery candidates:

• Unstable Refractive Errors
• High Degrees of Near-sightedness, Far-sightedness, or Astigmatism
• Dry Eye Disease
• Thin or Cone-Shaped Corneas (Keratoconus)
• Corneal Disease or Scarring
• Cataracts
• Glaucoma
• Prior Eye Infections, Injuries, or Diseases
• Poorly Controlled Diabetes
• Autoimmune Disorders (e.g., Rheumatoid Arthritis)
• Weakened Immune System
• Engagement in Contact Sports with Eye and Face Injury Risk
• Pregnancy or Breastfeeding

Risks and Side Effects of Laser Eye Surgery

Serious complications following laser eye surgery are infrequent, but there are common side effects that patients may experience, some of which may be temporary, while others could be long-lasting. It's important to understand the potential outcomes:

1. Dry Eyes: Reduced tear production and increased tear evaporation can lead to dry eye discomfort. Eye lubricants can offer relief, but severe cases may require punctal plugs to retain moisture on the eye's surface.

2. Visual Disturbances: Glare, halos around lights, light sensitivity, and double vision are common in the initial days or weeks after laser eye surgery, particularly at night or in dim lighting conditions.

3. Refractive Issues: Under-corrections or over-corrections may occur if the laser removes too little or too much corneal tissue during surgery. Under-corrections can often be corrected with a follow-up laser eye surgery, but over-corrections can be more challenging to address.

4. Astigmatism: Uneven removal of corneal tissue may result in astigmatism after laser eye surgery. Correcting this may necessitate further refractive surgery or the use of glasses or contact lenses.

5. Corneal Flap Healing: Poor healing of the corneal flap created during laser eye surgery can potentially lead to eye infections and excessive tearing.

6. Vision Changes: In rare instances, patients may experience vision loss, regression, or unpredictable vision changes post-surgery.

In some cases, laser eye surgery may result in vision under-correction or over-correction. Patients have the option to use glasses or contact lenses or consider additional refractive surgery to address these issues.

Preparing for Laser Eye Surgery

Before undergoing laser eye surgery, proper preparation is vital for a smooth experience. Here are essential steps to follow:

1. Cost Consideration: Laser eye surgery is typically considered an elective procedure and may not be covered by medical or vision insurance. Consult with your laser eye surgery surgeon to understand the expected charges and make financial arrangements accordingly.

2. Transportation Planning: Arrange for transportation to and from the surgical facility since you may experience side effects from medications and temporary blurry vision post-surgery, making driving unsafe.

3. Contact Lens Usage: Cease wearing contact lenses in the weeks leading up to your surgery, as advised by your ophthalmologist. Glasses should be worn instead.

4. Eye Hygiene: In the days preceding laser eye surgery, refrain from using creams, lotions, and eye makeup. Eyelid cleansers are recommended to maintain clean eyelids and lashes, reducing the risk of infection after the procedure.

Post-Operative Eye Care

Following laser eye surgery, it's normal to experience some discomfort in the hours or days that follow. Symptoms may include watery eyes, itching, a gritty sensation, mild eye pain, and initial blurred vision, which will gradually improve.

Your surgeon may recommend pain medication, over-the-counter eye drops, or artificial tears to alleviate discomfort and expedite healing. Wearing an eye shield during sleep may also be advised until your eyes are fully healed.

Your first follow-up appointment, scheduled 24-48 hours after surgery, is crucial to monitor healing progress and address any complications. Subsequent follow-ups in the coming weeks will continue to ensure your eyes are healing as expected.

Maintaining eye cleanliness by avoiding makeup, creams, and lotions is essential, as is refraining from swimming, hot tubs, and contact sports as per your eye doctor's recommendations.

Adequate rest before and after laser eye surgery surgery is paramount for optimal results. Following your surgeon's guidance for healing and recovery is essential to minimize eye strain and promote a speedy recovery.

Expected Results After Laser Eye Surgery

The timeline for improved vision varies among patients, with some experiencing immediate enhancements, while others may require several months. While achieving 20/20 vision or better is possible, it's not guaranteed and depends on various factors.

The need for glasses or contact lenses post-surgery may still exist, particularly for reading or specific visual tasks. Remarkably, for 8 out of 10 laser eye surgery patients, this procedure eliminates the need for glasses or contact lenses altogether.

However, it's important to note that individual results are influenced by pre-existing refractive errors. In rare instances, vision may regress due to factors like poor healing, hormonal imbalances, or the development of cataracts.

Minimizing Complications After Laser Eye Surgery

Serious complications post-laser eye surgery are uncommon. However, taking proactive steps can further reduce the risk:

1. Choose the Right Eye Doctor: Selecting a highly skilled and experienced eye surgeon is paramount. Research and seek recommendations to find the most suitable practitioner for your laser eye surgery procedure.

2. Comprehensive Evaluation: Undergo a thorough pre-operative evaluation to ensure you're an ideal candidate for laser eye surgery. Your eye surgeon will assess your eye health, prescription, and overall suitability.

3. Adherence to Instructions: Following your surgeon's instructions diligently before and after laser eye surgery is crucial. This includes proper pre-operative preparations and post-operative care routines.

4. Allow for Adequate Rest: After the procedure, give your eyes ample time to rest and recover. This helps minimize the risk of complications and promotes optimal healing.

Potential Complications

While rare, potential complications after laser eye surgery may include:

1. Corneal Ectasia

Corneal ectasia represents a rare yet significant complication that may manifest following 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 give rise to a distorted corneal shape, resulting in irregular astigmatism and a potential decline in visual quality. Corneal ectasia can manifest as subtle visual changes or escalate to substantial visual impairment if not promptly addressed.

The genesis of corneal ectasia is believed to stem from the excessive removal of anterior corneal collagen tissue during refractive surgery. This loss of corneal thickness compromises the stromal collagen structural integrity, rendering the cornea susceptible to weakening and deformation over time.

Various contributing factors include pre-existing corneal thinning, abnormal healing responses, or genetic predisposition. However, the most prevalent associated factor is eye rubbing, and it is imperative that all corneal refractive surgery patients receive counselling against this practice.

2. Dry Eyes 

Dry eye syndrome frequently manifests as a common side effect following refractive surgery, impacting both the quality and quantity of tears produced. This, in turn, gives rise to ocular discomfort and visual disturbances, particularly in procedures such as LASIK and PRK that influence corneal nerves.

The creation of corneal flaps or the removal of surface epithelium during refractive surgery has the potential to disrupt corneal sensitivity and impede tear film production. This disruption often leads to a reduction in tear volume and compromised tear film stability, resulting in the manifestation of dry eye symptoms.

It is essential to recognize that dry eye is a prevalent issue associated with damage to peripheral corneal nerves. However, it is crucial to note that these nerves typically regenerate within a span of about 3 to 4 months, emphasizing the transient nature of the condition.

3. Glare and Halos

Glare and halos manifest as visual phenomena characterized by the perception of rings, streaks, or halos around light sources, especially in low-light conditions or at night. These disturbances can significantly impact the quality of life for patients who have undergone refractive surgery.

These visual issues are often linked to refractive surgery procedures that modify the corneal shape or replace the natural lens. Alterations in corneal curvature, optical zones, and irregularities in the tear film can contribute to the occurrence of glare and halos.

Patients may encounter more pronounced glare and halos, particularly in low-light scenarios such as driving at night.

4. Eye Infections

5. Post-surgery vision issues

Which may persist despite glasses or contact lenses.

6. Partial or Complete Blindness