"Why Does the LASIK Exam Take So Long?" An Optometrist Answers

10 minutes for surgery, 90 minutes for the exam. Unveiling the safety blueprint of your eyes hidden within that timeframe.

Hello, this is BGN Eye Clinic, Jamsil Lotte Tower Main Branch.

Working in the clinic, there is a question I hear multiple times a day: "I heard the surgery only takes 10 minutes. Why does the examination take so long?" Every time I hear this, I smile to myself. The truth is, the 'success' of a LASIK surgery is already determined right here in the examination room.

(I sometimes jokingly say, "The surgeon performs the operation, but I set the stage.") Today, I would like to explain why the 'Comprehensive Pre-LASIK Exam' I conduct takes so long, and exactly what happens during that process.

10 Minutes for Surgery, 1.5 Hours for Preparation? The Reason Why

LASIK surgery actually takes only about 10 minutes for both eyes combined. However, the 'comprehensive examination' conducted beforehand takes an average of 1 to 1.5 hours. What we do during this extensive time is not a simple "vision test."

We are meticulously scanning the micro-universe of your eye, checking corneal thickness, curvature, astigmatism axis, pupil size, and even the quality of your tear film. It is the process of predicting and designing with data whether surgery is possible, which method is the safest, and how stably your vision will be maintained years into the future.

The LASIK exam is the process of drawing a 'blueprint of the eye.' If the surgery is the 'construction,' the exam is the 'drafting process.' Just as a building leans if the blueprint is drawn incorrectly, if even a single examination item is inaccurate, the surgical outcome can change.

Step-by-Step: The Extensive Pre-LASIK Exam Process

To briefly introduce my examination sequence, it goes like this:

• 1. Vision and Refraction Test: Precisely measuring your eyeglass prescription and analyzing the eye's 'focusing power.'
• 2. Corneal Thickness Measurement (Pachymetry): Checking the safety margin that can be incised during surgery, ensuring there are no excessively thin or uneven areas.
• 3. Corneal Topography (TOPOLYZER): Analyzing the elevation and curvature of the cornea in 3D to detect even the most minute asymmetries or protrusions.
• 4. Pupil Size and Reaction Test: Measuring changes in pupil size in both dark and bright environments to proactively predict potential issues with glare or night vision.
• 5. Intraocular Pressure and Dry Eye Test: Checking the pressure of the eye and the stability of the tear film to identify factors that may affect postoperative recovery.
• 6. Optic Nerve and Retina OCT Exam: Using tomography to examine the nerves and membranes deep inside the eye to confirm it is safe for laser application.

This entire process involves moving between more than 10 different machines. We also include breaks to administer artificial tears or eye drops to reduce eye fatigue. So, whenever patients laugh and ask, "Are we still doing tests?", we think to ourselves, "Yes, this time is what makes your surgery perfect."

Finding the 'Safety Margin' is the Most Important Part of the Exam

Many people ask, "Is it better to have thick corneas?" The answer is that 'the remaining thickness is more important than the initial thickness.' Because LASIK involves creating a flap on the cornea and reshaping the tissue underneath, calculating how much tissue to leave untouched is the core of the procedure.

If the remaining thickness is too thin, your vision might be fine initially, but the cornea could weaken years later. Therefore, during the exam, we repeat measurements dozens of times, calculating down to the 1μm (1/100th the thickness of a hair) level. This isn't just a number; it is the 'safety margin of the eye.'

Recently, a female professional in her 30s was surprised to hear this during her exam. "I was told my corneas were thick, so I assumed everything was fine!" However, because the 'remaining margin' is more critical than the total thickness, we recommended SMILE LASIK, which preserves more tissue, instead of traditional LASIK. This is why the exam inherently takes time. It’s not simply about determining "possible / impossible," but about finding the absolute safest option for your specific eyes.

To Those Who Say, "My Eyes Feel Dry During the Exam"

Many people feel eye fatigue or dryness during the OCT exam because they have to keep their eyes open and fixated. This happens because the corneal surface reacts sensitively. Specifically, a 'tear film test' is mandatory before LASIK because if the tear layer is unstable, the laser correction cannot be applied evenly.

Simply put, the first safety condition for LASIK is "moist eyes." Therefore, patients with severe dry eye syndrome may undergo preliminary treatments like artificial tears or IPL before their surgery.

Data Analysis Driven by the Optometrist's Sincerity

A LASIK exam comprehensively analyzes thousands of variables:

• Corneal Curvature: Evaluating the eye's optical properties and refractive state
• Pupil Size: Predicting night vision and potential glare
• Axial Length & Axis: Precise focus adjustment
• Tear Film Quality: Securing surface uniformity after laser correction
• Corneal Thickness: Calculating the remaining safety margin after flap incision
• Optic Nerve & Retinal Structure: Ensuring the safety of laser application

The Optometrist's Sincere Message

In the consultation room, I often say this: "LASIK is actually a surgery where half the work is already done during the examination." Because every eye has a different structure, corneal thickness, and safety margin, a longer examination process directly translates to higher postoperative satisfaction and fewer side effects.

If you felt a bit bored or frustrated by the long examination time, it is actually a very good sign. It means we are examining each eye with the utmost care. As I look at our clients' eyes, I always think to myself, "I need to handle these eyes this meticulously to ensure safety." Please remember that the long hours spent in the examination room ultimately lead to the safety and satisfaction of your surgery.