{"id":1981,"date":"2026-10-20T08:54:41","date_gmt":"2026-10-20T08:54:41","guid":{"rendered":"https:\/\/laseristanbulclinic.com\/eye-health\/lens-and-cataract\/icl-vs-laser-for-high-myopia-and-thin-corneas\/"},"modified":"2026-10-20T12:59:37","modified_gmt":"2026-10-20T12:59:37","slug":"icl-vs-laser-for-high-myopia-and-thin-corneas","status":"publish","type":"page","link":"https:\/\/laseristanbulclinic.com\/en\/eye-health\/lens-and-cataract\/icl-vs-laser-for-high-myopia-and-thin-corneas\/","title":{"rendered":"ICL Eye Surgery vs LASIK for High Myopia and Thin Corneas"},"content":{"rendered":"\n
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  4. ICL Eye Surgery vs LASIK for High Myopia and Thin Corneas<\/span><\/li><\/ol><\/div>\t\t\t

    ICL Eye Surgery vs LASIK for High Myopia and Thin Corneas<\/h1>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t
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    \"Tweezers<\/figure>\n\t\t\t\t\t\t\t\t\t

    ICL eye surgery vs LASIK comes down to your prescription and your cornea. LASIK reshapes the cornea and suits low to moderate short sight with thick, healthy corneas. An ICL is a lens placed inside the eye; it removes no corneal tissue and can be taken out, so it is usually the better route for high myopia or thin corneas. At Laser Istanbul Clinic, Prof. Dr. Ahmet Sat\u0131c\u0131 measures your eyes and recommends one.<\/p><\/div>\n\t\t\t\t\t<\/div>\n\t<\/div><\/div>\n<\/section>\n\n\n\n\n

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    ICL eye surgery vs LASIK: what is the difference?<\/h2>\n\t\t\t

    LASIK changes the shape of your cornea; an ICL leaves the cornea alone and adds a lens inside the eye.<\/strong> That single difference explains almost everything else in this guide.<\/p>\n\t\t\t

    In LASIK (laser in situ keratomileusis), the Royal College of Ophthalmologists (RCOphth) explains that a femtosecond laser prepares a thin flap, which is lifted so that an excimer laser can remove a lens-shaped piece of tissue from the cornea beneath. The flap is then smoothed back without stitches. The change is permanent, and the more short-sighted you are, the more tissue has to be removed.<\/p>\n

    An ICL (Implantable Collamer Lens) is a phakic intraocular lens. “Phakic” means your own natural lens stays in place. The RCOphth describes ICLs as soft, flexible implants that sit just behind the pupil and in front of the natural lens, “a bit like building your contact lenses into your eyes”. You cannot see or feel one, and it needs no cleaning. Nothing is cut from the cornea, and the lens can be removed if it ever causes problems.<\/p>

    <\/th>LASIK<\/th>SMILE \/ SMILE Pro<\/th>PRK \/ surface laser<\/th>EVO ICL<\/th><\/tr><\/thead>
    What is done<\/th>Flap lifted, cornea reshaped under it<\/td>Disc of tissue removed through a small keyhole cut, no flap<\/td>Thin surface layer removed, cornea reshaped; the surface regrows<\/td>Soft lens implanted behind the iris, in front of your natural lens<\/td><\/tr>
    Corneal tissue removed<\/th>Yes<\/td>Yes (slightly more, and slightly deeper, than LASIK, according to the RCOphth)<\/td>Yes<\/td>None<\/td><\/tr>
    Can it be reversed?<\/th>No<\/td>No<\/td>No<\/td>Yes, the lens can be removed<\/td><\/tr>
    Usual prescription range<\/th>Up to about \u221210.00 D (RCOphth range for all laser methods)<\/td>As LASIK; the US FDA approval for SMILE covers \u22121.00 to \u22128.00 D<\/td>As LASIK<\/td>Up to about \u221223.50 D (RCOphth); FDA-approved EVO range \u22123.00 to \u221220.00 D<\/td><\/tr>
    Main long-term consideration<\/th>Permanent change to the cornea; dry eye and, rarely, ectasia<\/td>As LASIK<\/td>As LASIK; slower, sorer recovery<\/td>Cataract can develop earlier in life<\/td><\/tr><\/tbody><\/table><\/div>

    Sources: RCOphth patient information on laser vision correction and phakic lens implantation (2024); US FDA; Packer, 2022. D = dioptres, the unit of your glasses prescription.<\/p><\/div>\t<\/div><\/div><\/div><\/section>\n\n\n\n\n

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    Which is better for high myopia: ICL or LASIK?<\/h2>\n\t\t\t\t

    For high myopia, the research favours an ICL for safety and visual quality, while laser stays the first choice for lower prescriptions.<\/strong> The RCOphth says phakic lenses can correct a wider range of prescriptions than laser, and that patients under 60 who are unsuitable for laser are often offered one. It also says laser is generally preferred for lower prescriptions, because it carries very few longer-term risks, whereas problems including cataract can occur many years after a phakic lens.<\/p>\n

    In the studies below, “high myopia” means roughly \u22126 D and beyond.<\/p>

    Study<\/th>What it compared<\/th>What it found<\/th><\/tr><\/thead>
    Cochrane review, Barsam and Allan, 2014<\/th>Excimer laser vs phakic lenses: 3 randomised trials, 228 eyes, \u22126.0 to \u221220.0 D<\/td>20\/20 or better without glasses at 12 months was not significantly different. Phakic lenses lost significantly less best-corrected vision, gave better contrast sensitivity and were preferred by patients. The authors concluded that phakic lenses are safer. The trials predate the EVO lens.<\/td><\/tr>
    Cao et al., BMC Ophthalmology<\/em>, 2021<\/th>ICL vs SMILE: 5 observational studies, 555 eyes, \u22126 to \u221212 D<\/td>ICL had better efficacy and safety indices (more eyes gained lines of vision, fewer lost lines). Accuracy was similar. ICL carried a higher risk of halos but induced fewer higher-order aberrations (subtle optical errors).<\/td><\/tr>
    Li et al., International Journal of Ophthalmology<\/em>, 2023<\/th>ICL vs SMILE: 10 studies, 1,036 eyes (503 ICL, 533 SMILE)<\/td>Efficacy and predictability were comparable. ICL had a better safety index; beyond 6 months it showed lower higher-order aberrations and better contrast sensitivity.<\/td><\/tr>
    Chen et al., Acta Ophthalmologica<\/em>, 2019<\/th>ICL in one eye, laser in the other, in 26 patients over 3 years<\/td>Both worked. ICL eyes (more short-sighted at the start, \u221214.11 D vs \u22128.75 D) had a better safety index (1.84 vs 1.32), better efficacy (1.40 vs 1.11), more stable results (\u22120.52 D vs \u22120.77 D drift) and lower higher-order aberrations.<\/td><\/tr><\/tbody><\/table><\/div>

    What this means for you.<\/strong> All four point the same way for high prescriptions: similar sharpness, but fewer lines of vision lost and better optical quality with an ICL. Treat the numbers with care. Most are small or observational studies, and the Cochrane trials used older lens designs. The one consistent downside for ICL is halos around lights. The US FDA trial of the EVO ICL (629 eyes, \u22123.00 to \u221220.00 D) found that 90.5% of eyes were within 0.50 D of the planned correction at 6 months, with no pupillary block and a mean loss of 2.3% of endothelial cells (the pump cells lining the inside of the cornea).<\/p>\n

    A second reason to favour an ICL at high prescriptions: stability.<\/strong> Laser results can drift back in strongly short-sighted eyes. EyeWiki, the American Academy of Ophthalmology’s (AAO) clinical encyclopedia, reports that in long-term LASIK studies, eyes over \u221210.0 D regressed by about 0.25 D a year, and that at 15 years the mean regression was \u22121.66 D in eyes that started at about \u22129.5 D. Laser can be repeated if the cornea is thick enough, but each repeat removes more tissue.<\/p>\n

    A prescription is not the whole picture.<\/strong> An ICL is not automatically right just because the number is high. It needs enough space inside the eye and healthy endothelial cells, and age matters (see below).<\/p><\/div>\t<\/div><\/div><\/div><\/section>\n\n\n\n\n

    Why can thin corneas rule out LASIK?<\/h2><\/div>

    LASIK permanently removes corneal tissue, and a cornea that is too thin cannot lose more and stay strong.<\/strong> The cornea is the clear window at the front of the eye. After a LASIK flap is made and tissue is removed, the layer that remains underneath, the residual stromal bed, has to hold the shape of the eye for life.<\/p>\n

    EyeWiki lists a low residual stromal bed, generally under 250\u2013300 \u00b5m (micrometres, thousandths of a millimetre), as a risk factor for ectasia, a weakening and bulging of the cornea. Other risk factors are abnormal corneal scans (a hint of keratoconus), high myopia, a thin cornea before surgery and younger age. A review of ectasia risk (Santhiago et al., 2016) found that the risk rises quickly when the percentage of corneal tissue altered passes 35% and is highest at 40% or more. The US FDA warns that performing a refractive procedure on a cornea that is too thin may result in blinding complications, and the AAO lists corneas that are too thin among the reasons a person is not a good LASIK candidate.<\/p>\n

    High prescriptions and thin corneas often go together.<\/strong> The stronger your prescription, the more tissue the laser must remove, so a high-myopia cornea of average thickness can still leave too little behind. An ICL avoids the problem, because it removes no corneal tissue at all. EyeWiki notes that phakic lenses avoid the risk of laser-induced ectasia and preserve corneal tissue.<\/p>\n

    How common is ectasia?<\/strong> It is uncommon when screening is careful. A 2021 systematic review (Moshirfar et al.) reported ectasia in eyes without pre-existing risk factors at about 90 per 100,000 eyes after LASIK, 20 per 100,000 after PRK and 11 per 100,000 after SMILE. The RCOphth states that fewer than 1 in 5,000 patients need a corneal transplant to restore vision after laser surgery. The key word is screening: the 2021 figures are for eyes with no recognised risk factors before surgery.<\/p>\n

    A thin cornea needs a closer look, not a guess.<\/strong> Sometimes thinness is normal, and sometimes it is an early sign of keratoconus. In stable keratoconus, one published study of 30 eyes (Antonios et al., 2015) found that a toric ICL implanted after corneal cross-linking improved vision, and no eye lost two or more lines. Do\u00e7. Dr. Muhammet Derda \u00d6zer, our cornea and keratoconus specialist, reviews scans where the cornea looks thin, irregular or suspicious before any procedure is chosen.<\/p><\/div><\/div><\/div><\/div><\/div><\/section>\n\n\n\n\n

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    ICL vs LASIK vs SMILE vs PRK: do the other lasers change the answer?<\/h2>\n\t\t\t\t\t\t

    SMILE and PRK change the balance for borderline corneas, but not for very high prescriptions.<\/strong> The RCOphth says visual results at three months are equally good for all types of laser vision correction; the real differences are recovery and which eyes each method suits.<\/p>\n\t\t\t\t\t\t