Post-LASIK ectasia

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Post-LASIK ectasia is a condition similar to keratoconus where the cornea starts to bulge forwards at a variable time after LASIK, PRK, or SMILE corneal laser eye surgery. [1] However, the physiological processes of post-LASIK ectasia seem to be different from keratoconus. The visible changes in the basal epithelial cell and anterior and posterior keratocytes linked with keratoconus were not observed in post-LASIK ectasia. [2]

Contents

Risk factors

Before corneal refractive surgery such as LASIK, SMILE, and PRK, people must be examined for possible risk factors such as keratoconus. [3]

Abnormal corneal topography compromises of keratoconus, pellucid marginal degeneration, or forme fruste keratoconus with an I-S value of 1.4 or more [4] is the most significant risk factor. Low age, low residual stromal bed (RSB) thickness, low preoperative corneal thickness, and high myopia are other important risk factors. [5] [6]

Treatments

Treatment options include contact lenses, [7] [8] intrastromal corneal ring segments, custom topography-guided transepithelial PRK combined with corneal collagen cross-linking, [9] or corneal transplant.

When cross-linking is performed only after the cornea becomes distorted, vision remains blurry even though the disease is stabilised. As a result, combining corneal collagen cross-linking with LASIK ('LASIK Xtra') aims to strengthen the cornea at the point of surgery and may be useful in cases where a very thin cornea is expected after the LASIK procedure. [10] This would include cases of high spectacle power and people with thin corneas before surgery. Definitive evidence that the procedure can reduce the risk of corneal ectasia will only become available a number of years later as corneal ectasia, if it happens, usually occurs in the late post-operative period. Some study show that combining LASIK with cross-linking adds refractive stability to hyperopic treatments and may also do the same for very high myopic treatments. [10] [11] [12]

In 2016, the FDA approved the KXL system and two photoenhancers for the treatment of corneal ectasia following refractive surgery. [13]

Related Research Articles

<span class="mw-page-title-main">Keratoconus</span> Medical condition involving the eye

Keratoconus (KC) is a disorder of the eye that results in progressive thinning of the cornea. This may result in blurry vision, double vision, nearsightedness, irregular astigmatism, and light sensitivity leading to poor quality-of-life. Usually both eyes are affected. In more severe cases a scarring or a circle may be seen within the cornea.

<span class="mw-page-title-main">LASIK</span> Corrective ophthalmological surgery

LASIK or Lasik, commonly referred to as laser eye surgery or laser vision correction, is a type of refractive surgery for the correction of myopia, hyperopia, and an actual cure for astigmatism, since it is in the cornea. LASIK surgery is performed by an ophthalmologist who uses a laser or microkeratome to reshape the eye's cornea in order to improve visual acuity.

<span class="mw-page-title-main">Photorefractive keratectomy</span> Refractive eye surgery procrdure

Photorefractive keratectomy (PRK) and laser-assisted sub-epithelial keratectomy (LASEK) are laser eye surgery procedures intended to correct a person's vision, reducing dependency on glasses or contact lenses. LASEK and PRK permanently change the shape of the anterior central cornea using an excimer laser to ablate a small amount of tissue from the corneal stroma at the front of the eye, just under the corneal epithelium. The outer layer of the cornea is removed prior to the ablation.

<span class="mw-page-title-main">Radial keratotomy</span> Refractive surgical procedure to correct myopia (nearsightedness

Radial keratotomy (RK) is a refractive surgical procedure to correct myopia (nearsightedness). It was developed in 1974 by Svyatoslav Fyodorov, a Russian ophthalmologist. It has been largely supplanted by newer, more accurate operations, such as photorefractive keratectomy, LASIK, Epi-LASIK and the phakic intraocular lens.

<span class="mw-page-title-main">Refractive surgery</span> Surgery to treat common vision disorders

Refractive surgery is optional eye surgery used to improve the refractive state of the eye and decrease or eliminate dependency on glasses or contact lenses. This can include various methods of surgical remodeling of the cornea (keratomileusis), lens implantation or lens replacement. The most common methods today use excimer lasers to reshape the curvature of the cornea. Refractive eye surgeries are used to treat common vision disorders such as myopia, hyperopia, presbyopia and astigmatism.

<span class="mw-page-title-main">Phakic intraocular lens</span> Lens implanted in eye in addition to the natural lens

A phakic intraocular lens (PIOL) is an intraocular lens that is implanted surgically into the eye to correct refractive errors without removing the natural lens. Intraocular lenses that are implanted into eyes after the eye's natural lens has been removed during cataract surgery are known as pseudophakic.

<span class="mw-page-title-main">Corneal cross-linking</span> Surgical procedure

Corneal cross-linking (CXL) with riboflavin (vitamin B2) and UV-A light is a surgical treatment for corneal ectasia such as keratoconus, PMD, and post-LASIK ectasia.

<span class="mw-page-title-main">Intrastromal corneal ring segment</span> Small device implanted in the eye to correct vision

An intrastromal corneal ring segment (ICRS) (also known as intrastromal corneal ring, corneal implant or corneal insert) is a small device surgically implanted in the cornea of the eye to correct vision. Two crescent or semi-circular shaped ring segments are inserted between the layers of the corneal stroma, one on each side of the pupil, This is intended to flatten the cornea and change the refraction of light passing through the cornea on its way into the eye.

<span class="mw-page-title-main">Astigmatism</span> Type of eye defect

Astigmatism is a type of refractive error due to rotational asymmetry in the eye's refractive power. This results in distorted or blurred vision at any distance. Other symptoms can include eyestrain, headaches, and trouble driving at night. Astigmatism often occurs at birth and can change or develop later in life. If it occurs in early life and is left untreated, it may result in amblyopia.

<span class="mw-page-title-main">Corneal epithelium</span>

The corneal epithelium is made up of epithelial tissue and covers the front of the cornea. It acts as a barrier to protect the cornea, resisting the free flow of fluids from the tears, and prevents bacteria from entering the epithelium and corneal stroma.

D. Jackson Coleman is a professor of clinical ophthalmology at NewYork-Presbyterian Hospital at The Edward S. Harkness Eye Institute of Columbia University. He is the former John Milton McLean Professor of Ophthalmology and chairman emeritus at Weill Cornell Medical Center where he served as chairman from 1979 to 2006. His specialties are retinal diseases and ultrasound, working with patients at Columbia University Medical Center. Coleman is also engaged in research involving ultrasound, which he has pursued throughout his career with colleague Ronald Silverman in the Department of Ophthalmology at the Columbia University Medical Center.

<span class="mw-page-title-main">Pellucid marginal degeneration</span> Degenerative corneal condition

Pellucid marginal degeneration (PMD) is a degenerative corneal condition, often confused with keratoconus. It typically presents with painless vision loss affecting both eyes. Rarely, it may cause acute vision loss with severe pain due to perforation of the cornea. It is typically characterized by a clear, bilateral thinning (ectasia) in the inferior and peripheral region of the cornea, although some cases affect only one eye. The cause of the disease remains unclear.

The Alpins Method is a system to plan and analyze the results of refractive surgical procedures, such as laser in-situ keratomileus (LASIK). The Alpins Method is also used to plan cataract/toric intraocular lens (IOL) surgical procedures.

Peter S. Hersh is an American ophthalmologist and specialist in LASIK eye surgery, keratoconus, and diseases of the cornea. He co-authored the article in the journal Ophthalmology that presented the results of the study that led to the first approval by the U.S. Food and Drug Administration (FDA) of the excimer laser for the correction of nearsightedness in the United States. Hersh was also medical monitor of the study that led to approval of corneal collagen crosslinking for the treatment of keratoconus.

The eye, like any other optical system, suffers from a number of specific optical aberrations. The optical quality of the eye is limited by optical aberrations, diffraction and scatter. Correction of spherocylindrical refractive errors has been possible for nearly two centuries following Airy's development of methods to measure and correct ocular astigmatism. It has only recently become possible to measure the aberrations of the eye and with the advent of refractive surgery it might be possible to correct certain types of irregular astigmatism.

Corneal ectatic disorders or corneal ectasia are a group of uncommon, noninflammatory, eye disorders characterised by bilateral thinning of the central, paracentral, or peripheral cornea.

<span class="mw-page-title-main">Farhad Hafezi</span> Swiss eye surgeon and researcher (born 1967)

Farhad Hafezi is a prominent Swiss eye surgeon and researcher. Hafezi first gained recognition as a leading retina researcher in 1994, having been the first to discover a gene responsible for light-induced retinal degeneration. However, he changed his research focus to the cornea in 2003, and it is this work, particularly on corneal collagen cross-linking (CXL), which he helped pioneer, and advanced laser refractive surgery that he is internationally known for today. Hafezi's current clinical and laboratory research is focused on gaining a better understanding of the cornea. His research group at the University of Zurich has three main research foci:

PiXL is a modern non-invasive non-surgical vision correction procedure.

Anastasios John Kanellopoulos is a Greek-American eye surgeon specializing in corneal transplantation, cornea crosslinking for keratoconus, complicated cataract surgery and complicated glaucoma. Widely known for research and clinical contributions in micro-incision cataract, customized laser refractive surgery and corneal cross-linking propagation and most innovations, reducing corneal transplants for advanced keratoconus.

Tibor Juhasz is an American-Hungarian physicist and an academic. He is a professor at the Gavin Herbert Eye Institute and the Department of Biomedical Engineering at the University of California, Irvine as well as the CEO of ViaLase.

References

  1. ↑ "Ectasia After LASIK". American Academy of Ophthalmology.
  2. ↑ "What Is Keratoconus? Everything You Need to Know". Clearview Vision Institute. 15 December 2020. Retrieved 15 December 2020.
  3. ↑ Finn, Peter (20 December 2012). "Medical Mystery: Preparation for surgery revealed cause of deteriorating eyesight". The Washington Post.
  4. ↑ Rabinowitz, YS; McDonnell, PJ (1989). "Computer-assisted corneal topography in keratoconus". Refractive & Corneal Surgery. 5 (6): 400–8. doi:10.3928/1081-597X-19891101-10. PMID   2488838.
  5. ↑ Kohlhaas, M; Spoerl, E; Schilde, T; Unger, G; Wittig, C; Pillunat, LE (February 2006). "Biomechanical evidence of the distribution of cross-links in corneas treated with riboflavin and ultraviolet A light". Journal of Cataract and Refractive Surgery. 32 (2): 279–83. doi:10.1016/j.jcrs.2005.12.092. PMID   16565005. S2CID   30983601.
  6. ↑ Randleman, JB; Banning, CS; Stulting, RD (January 2007). "Corneal ectasia after hyperopic LASIK". Journal of Refractive Surgery. 23 (1): 98–102. doi:10.3928/1081-597X-20070101-17. PMID   17269252.
  7. ↑ Marsack, Jason D.; Parker, Katrina E.; Applegate, Raymond A. (December 2008). "Performance of Wavefront-Guided Soft Lenses in Three Keratoconus Subjects". Optometry and Vision Science. 85 (12): E1172–E1178. doi:10.1097/OPX.0b013e31818e8eaa. PMC   2614306 . PMID   19050464.
  8. ↑ Marsack, JD; Parker, KE; Niu, Y; Pesudovs, K; Applegate, RA (November 2007). "On-eye performance of custom wavefront-guided soft contact lenses in a habitual soft lens-wearing keratoconic patient". Journal of Refractive Surgery. 23 (9): 960–4. doi:10.3928/1081-597X-20071101-18. PMID   18041254.
  9. ↑ Lam, Kay; Rootman, Dan B.; Lichtinger, Alejandro; Rootman, David S. (6 January 2013). "Post-LASIK ectasia treated with intrastromal corneal ring segments and corneal crosslinking". Digital Journal of Ophthalmology. 19 (1): 1–8. doi:10.5693/djo.02.2012.10.001. ISSN   1542-8958. PMC   3689440 . PMID   23794955.
  10. 1 2 Stephenson, Michelle (2014). "LASIK Xtra: Is It for Everyone?". Review of Ophthalmology. Jobson Medical Information LLC.
  11. ↑ Kanellopoulos, AnastasiosJohn; Pamel, GregoryJ (2013). "Review of current indications for combined very high fluence collagen cross-linking and laser in situ keratomileusis surgery". Indian Journal of Ophthalmology. 61 (8): 430–2. doi: 10.4103/0301-4738.116074 . PMC   3775081 . PMID   23925331.
  12. ↑ LASIK Treatment
  13. ↑ "Highlights of Prescribing Information: PHOTREXA VISCOUS (riboflavin 5'-phosphate in 20% dextran ophthalmic solution) 0.146% for topical ophthalmic use PHOTREXA (riboflavin 5'-phosphate ophthalmic solution) 0.146% for topical ophthalmic use For use with the KXL® System" (PDF). U.S. Food and Drug Administration. pp. 5–14.
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