LASIK
LASIK (Laser in-situ Keratomileusis) is a surgical procedure combined with laser to reshape the cornea in order to correct refractive errors including myopia, hypermetropia and astigmatism. Laser refractive surgery was introduced in Hong Kong in 1992, and The Hong Kong Eye Day Surgery Centre had provided such services since its inception. Tens of thousands of patients had received the procedure successfully since 2005. Our centre has experienced attending doctors, all specialists in ophthalmology and professionally trained in refractive surgeries. With more than a decade of experience and after more than ten thousand cases, our results have been both satisfactory and reliable.
The WaveLight EX500 Excimer Laser System can correct 1.00 dioptre of myopia or astigmatism in just 2.5 seconds. The aspheric property of the cornea (known as the ‘Q value’) may affect visual quality under dim lighting conditions. The German manufacturer Wavelight pioneered wavefront-optimised ablation profiles, thus integrating an important wavefront-guided treatment feature in standard laser vision correction. The small diameter of the spot allows a high-precision contouring of the correction profile, while minimising the total overall ablation depth. A wavefront-optimised beam profile together with small laser spots allow operations in large optical zones and ensure optimal transitional zones. As a result, patients have the best quality image even under demanding lighting conditions with the least amount of distortions.
WaveLight EX500 Excimer Laser
The WaveLight EX500 Excimer Laser is a state-of-the-art excimer laser used in refractive surgeries. With a laser pulse frequency of 500Hz, it shortens the treatment time. The eye tracking system operates at 1050Hz, allowing for approximately 1050 eye position adjustments per second with a response time of approximately 0.02 seconds. This greatly reduces the risk of laser misalignment. It is applied in procedures such as LASIK (Laser-Assisted In Situ Keratomileusis) and PRK (Photorefractive Keratectomy) to provide patients with excellent visual restoration
Excimer Laser Correction
Laser refractive surgery is a procedure that can correct visual problems such as myopia, hyperopia, and astigmatism by altering the shape of the cornea. By modifying the cornea’s curvature, the surgery aims to adjust the refraction of light, enabling it to accurately focus on the retina.
LASIK surgery consists of first creating a partial thickness lamellar flap of the cornea and followed by laser polishing of the underlying stromal bed. The cornea curvature is therefore reshaped as programmed and the refractive outcome achieved accordingly. After laser application, the cornea flap is replaced and heals naturally.
A partial thickness lamellar flap of the cornea is created.
Laser is applied to the underlying stromal bed of the cornea, reshaping as programmed.
The cornea flap is replaced and heals naturally.
The characteristics of LASIK
More satisfactory results for correction of myopia under 15 dioptres, and able to correct hypermetropia and astigmatism under 6 dioptres.
Surgery completed in minutes, vision correction achieved on the day.
No need to attend a hospital/ to have anesthetic injection.
Stable and precise corrections.
Comparing different vision correction surgeries
After undergoing the preoperative eye examination, the doctor will determine the suitable surgical options for you. You can also discuss with the doctor to make a decision together.
| SMILE PRO | SMILE | LASIK | ICL | |
| Degree of correction |
Up to -10.00 diopters of myopia Up to -5.00 diopters of astigmatism |
Up to -15.00 diopters of myopia Up to +6.00 diopters of hyperopia Up to +6.00 diopters of astigmatism |
Up to -18.00 diopters of myopia Up to +10.00 diopters of hyperopia Up to +6.00 diopters of astigmatism | |
| Technique | Cornea cutting; no need for cornea flap creation | Creation of corneal flap, followed by laser reshaping of the corneal inner layer beneath the flap | Implantation of ICL lens between the eye's natural crystalline lens and iris | |
| Surgical duration | 5 minutes per eye | 10 minutes per eye | 10-15 minutes per eye | |
| Laser procedure time | 10 seconds per eye | 25 seconds per eye |
I. Corneal flap creation: approximately 10 seconds II. Corneal reshaping (depending on the degree): 10-30 seconds | NA |
| Size of incision | 2-4mm | Approximately 20mm | Approximately 3mm | |
| Postoperative dry eye condition | Slight | Mild | Slight | |
| Natural cornea healing time | Several days | Several weeks | Several days | |
| Chance of cornea flap displacement | None, no need for cornea flap creation | Yes | None, no need for cornea flap creation | |
| Odor produced during the surgical procedure | None | Slight burning odor | None | |
Corneal Collagen Cross-Linking (determined by Doctor)
Corneal Collagen Cross-Linking (CXL) is a surgical technique used to enhance corneal strength in the treatment of corneal deformities and weakening conditions, primarily for the management of keratoconus.
Conventional laser refractive surgeries can weaken the cornea. However, the enhanced versions (Xtra) of LASIK Xtra and SMILE Xtra surgeries are specifically designed for individuals with higher refractive errors and thinner corneas. These procedures utilize cross-linking techniques to strengthen the cornea’s collagen structure, thereby consolidating the refractive correction outcomes.
Corneal Collagen Cross-Linking (CXL) Procedure:
- Administer topical anesthesia eye drops.
- Apply a special solution of vitamin B2 (riboflavin) onto the cornea as a supplement.
- Expose the cornea to ultraviolet light to activate the vitamin B2.
- The procedure typically takes approximately 30 minutes to 1 hour.
Am I a Suitable Candidate for LASIK
In general, if you fulfill the requirements below, you are a suitable candidate:
- At least 18 years old
- No health issues which affect your eyes, no special issues which may influence the healing of wound
- Having a stable contact lens or glasses prescription
To find out if LASIK is suitable for you, you should have a comprehensive eye examination by our ophthalmologist. During the examination, we will give you more specific information and answer any questions you may have.
Prepare for LASIK
- To schedule an eye examination prior to the surgery (approximately 2 hours), please click here.
- If the doctor determines that you are suitable for the procedure, you can then schedule a surgery appointment.
- Before the eye examination and SMILE®pro surgery, it is necessary to discontinue wearing contact lenses:
– Soft lens wearers should stop wearing them three to seven days prior.
– Rigid or gas-permeable lens wearers should stop wearing them one to two weeks prior.
Lasik Q & A
Is it painful during the procedure?
Anesthetic eyedrops will be applied before LASIK, therefore it is not painful during the procedure.
When can the vision recover?
Most people recovers 80% within 24 hours.
Is it once in for all?
LASIK improves unaided vision, therefore the dependence on glasses or contact lenses. Most people stabilise within a few months.
Is it safe?
LASIK incorporates laser technology, which has proven safety and accuracy. Previous complications arising from the laser were due to undesired eye movements during treatment. This problem is now solved by the integral infrared tracking device, which ensures laser precision.
Is there much problem in creating the corneal lamellar flap?
With the improved instrumentation, this process is straightforward. Coordination between the patient and the surgeon remains important. If flap creation has not been satisfactory, the complete surgery will be postponed until the corneal healed in approximately three months.
Are there any side effects or complications?
After LASIK surgery, the following may occur:
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Glare or halo (these will diminish over a short period of time)
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If the corneal flap heals unsatisfactorily or if cornea developed striae after undesired eye rubbing, then visual quality may be compromised.
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Some patients may develop astigmatism but the degree is usually mild without affecting visual quality.
Is it necessary to attend a hospital?
No. Modern LASIK surgery is fast and safe; injectional anesthesia is not required. Therefore there is no need to attend a hospital.
Free Seminar
Our center regularly hosts free seminars conducted by specialized ophthalmologists, explaining the principles, procedures, preparations, and precautions of eye surgery.
