Am I a Good Candidate for FLAAK? Pre-Screening Criteria Explained

By Kaşkaloğlu Eye Hospital | İzmir, Turkey

You’ve researched the FLAAK procedure. You understand how it works. You’ve looked at before and after photos and imagined what a different eye color might look like on you. But one important question remains before anything else:

Are you actually a suitable candidate?

This is the most important question in the entire process — and it is one that no website, simulator, or social media post can answer for you definitively. Only a thorough pre-operative examination by an experienced ophthalmic surgeon can do that. What this article can do is explain the key criteria we assess at Kaşkaloğlu Eye Hospital, what typically makes someone a good candidate, and what factors may require extra evaluation or rule someone out entirely.

Reading this before your consultation will help you arrive informed, ask better questions, and have realistic expectations.

Why Candidate Selection Matters So Much

FLAAK keratopigmentation is a safe, minimally invasive procedure when performed on the right patient with the right pre-operative assessment. The femtosecond laser creates a precise micro-tunnel in the corneal stroma, and biocompatible pigment is placed within it. The cornea remains intact; the internal structures of the eye are never touched.

But the cornea is not the same in every person. Its thickness, curvature, hydration, cell density, and structural integrity all vary. A cornea that is too thin, structurally irregular, or affected by certain conditions is not an appropriate candidate for the procedure — not because the technology fails, but because surgery on a compromised cornea carries risks that the procedure is not designed to take on.

This is why our pre-operative screening is comprehensive and non-negotiable. It protects you.

General Eligibility: The Basics

Before the detailed clinical assessment, there are some broad criteria that apply to almost all candidates:

Age: Candidates should be at least 18 years old. We prefer that patients are in their twenties or older, as the eye continues to develop through the late teenage years. There is no strict upper age limit, but overall ocular health becomes more relevant with age.

Stable general health: Candidates should be in good general health and free from active systemic diseases that could impair healing or increase surgical risk. Conditions such as uncontrolled diabetes, autoimmune diseases, or conditions that affect the immune system require careful evaluation and, in some cases, may rule out the procedure.

Realistic expectations: A candidate must understand what FLAAK can and cannot achieve. It permanently changes the apparent color of the eye by masking the iris with pigment placed in the cornea. The result is a natural-looking color change — not a theatrical transformation. The final color depends on your starting eye color, your skin tone, and the pigment selected in consultation with your surgeon. FLAAK does not correct vision, does not treat eye disease, and does not produce the same result in every person.

Motivation: Candidates should want the procedure for themselves — not under pressure from others. This is an elective, permanent change. We take time in our consultations to ensure that patients have considered the decision carefully.

The Clinical Assessment: What We Examine

Every candidate undergoes a comprehensive pre-operative examination at Kaşkaloğlu Eye Hospital. We use three advanced diagnostic systems — the Zeiss VisuMax 800, the Pentacam HR, and the iTrace Visual Analyzer — to build a precise picture of each patient’s ocular anatomy. Here is what we are looking for:

1. Corneal Thickness

This is one of the most critical measurements. The FLAAK procedure creates a micro-tunnel within the corneal stroma — the middle layer of the cornea. To do this safely, the cornea must have sufficient thickness to accommodate the tunnel while leaving adequate tissue above and below it.

Corneal thickness varies naturally from person to person. Most people have adequate thickness for the procedure. However, patients with thinner-than-average corneas may not be suitable, and this can only be determined through accurate measurement with instruments like the Pentacam HR, which provides a detailed three-dimensional map of the entire cornea.

2. Corneal Shape and Regularity

We assess the curvature and regularity of the cornea across its entire surface. Patients with keratoconus — a condition where the cornea progressively thins and bulges into a cone shape — are generally not suitable candidates for FLAAK. This is a firm contraindication, even in early or mild cases, because operating on a structurally compromised cornea is unsafe.

Similarly, patients with other corneal ectasias or significant irregular astigmatism require careful individual assessment.

3. Corneal Endothelial Cell Density

The endothelium is the innermost layer of the cornea — a single layer of cells responsible for keeping the cornea clear by pumping fluid out of the tissue. These cells do not regenerate. If their density is too low, the cornea’s ability to maintain its clarity is compromised.

We measure endothelial cell count as part of our pre-operative screening. Patients with significantly reduced endothelial cell density may not be suitable for the procedure.

4. Intraocular Pressure

Elevated intraocular pressure (IOP) is a key indicator of glaucoma — a serious eye condition involving damage to the optic nerve. Patients with glaucoma or ocular hypertension require careful evaluation. In many cases, well-controlled, stable glaucoma is not an automatic disqualification, but it requires discussion with your surgeon about the specific risks and benefits in your individual case.

5. History of Previous Eye Surgery

Many patients who have had previous refractive surgery — such as LASIK, PRK, or SMILE — can still be candidates for FLAAK, but this requires individual assessment. Previous surgery alters the cornea’s thickness and structural properties. Our diagnostic systems can evaluate whether sufficient corneal integrity remains for the FLAAK procedure to be performed safely.

Patients who have had corneal transplants are generally not suitable candidates.

6. Active Ocular Disease or Infection

Any active infection, inflammation, or disease affecting the eye at the time of evaluation will need to be resolved before the procedure can be considered. This includes conditions such as active uveitis, dry eye disease of significant severity, blepharitis, or conjunctivitis.

Dry eye syndrome deserves specific mention. Mild to moderate dry eye is common and does not automatically rule out FLAAK. However, severe dry eye requires treatment and stabilisation before surgery can be considered, as a compromised tear film affects both the surgical environment and the healing process.

7. Systemic Conditions Affecting Healing

Certain systemic conditions affect the body’s ability to heal corneal tissue. These include:

• Uncontrolled diabetes — elevated blood sugar impairs wound healing and increases infection risk
• Autoimmune conditions — diseases such as rheumatoid arthritis, lupus, or Sjögren’s syndrome can affect ocular surface health and healing
• Immunosuppression — patients taking immunosuppressive medications for any reason require individual assessment
• Connective tissue disorders — conditions affecting collagen structure may affect the corneal stroma

None of these are automatic disqualifications in every case, but all require thorough discussion with your surgeon.

Who Is Typically a Good Candidate?

Based on the criteria above, an ideal FLAAK candidate is generally:

• An adult in good general health, without active systemic disease affecting healing
• Free from keratoconus or other corneal ectasias
• With adequate corneal thickness as confirmed by pre-operative measurement
• With good endothelial cell density and normal intraocular pressure
• Without active ocular disease at the time of the procedure
• With clear, realistic expectations about the outcome
• Someone who has considered the decision carefully and wants the change for themselves

Most healthy adults who are interested in FLAAK will meet these criteria. But the only way to know for certain is the pre-operative examination.

What Happens If You Are Not Suitable?

If our pre-operative assessment reveals that you are not a suitable candidate, we will tell you clearly and explain why. We will not perform the procedure on a patient whose corneal health puts them at unacceptable risk — regardless of how much they want the outcome.

In some cases, a temporary condition (such as active dry eye or a corneal infection) can be treated, after which the patient may become suitable. In other cases, a structural contraindication like keratoconus is permanent.

We believe that an honest answer before the procedure is the most important thing we can offer you. The goal is a beautiful, safe outcome — and that requires starting from a foundation of appropriate candidacy.

The Consultation Process at Kaşkaloğlu Eye Hospital

Many of our international patients begin with a remote pre-consultation — sharing their medical history, any previous eye examination results, and their questions with our team before travelling to İzmir. This allows us to give you an early indication of whether the procedure is likely to be appropriate for you, so you are not travelling unnecessarily.

The formal pre-operative examination takes place in person at our hospital in İzmir, typically on the day before the procedure. All diagnostic testing is performed on-site. If any finding on examination means that the procedure cannot proceed safely, we will advise you before any surgical step takes place.

A Final Word

FLAAK Pro keratopigmentation has an excellent safety profile when performed on appropriate candidates by experienced surgeons. Candidate selection is not a bureaucratic hurdle — it is the foundation of that safety record.

If you are curious about whether you might be suitable, the best first step is to get in touch with our team. We are happy to review your history, answer your questions, and guide you toward the right decision — whether that decision is to proceed, to wait, or to explore other options.

Contact  Ms.Derya WhatsApp: +90532 5961601

Kaşkaloğlu Eye Hospital, İzmir, has been performing keratopigmentation (FLAAK) procedures for patients from Turkey and across the world for many years. Our pre-operative screening protocol uses Pentacam HR, iTrace, and Zeiss VisuMax 800 diagnostics to ensure every patient is assessed to the highest clinical standard.