Clear lens extraction

Last updated
Clear lens extraction
Other namesRefractive lensectomy or Refractive lens exchange [1]
Specialty Ophthalmology

Clear lens extraction, also known as refractive lensectomy, custom lens replacement or refractive lens exchange is a surgical procedure in which clear lens of the human eye is removed. Unlike cataract surgery, where cloudy lens is removed to treat cataract, clear lens extraction is done to surgically correct refractive errors such as high myopia. It can also be done in hyperopic or presbyopic patients who wish to have a multifocal IOL implanted to avoid wearing glasses. It is also used as a treatment for diseases such as angle closure glaucoma.

Contents

Overview

As opposed to procedures that use lasers to make corrections to the corneal surface, such as LASIK, the clear lens extraction procedure uses the same procedures as cataract surgery. [1]

Indications

Clear lens extraction can be done in patients with severe refractive error and/or presbyopia who wish to avoid spectacles. [2] [3] It is often necessary in patients with severe refractive error who cannot undergo other refractive procedures such as LASIK or photorefractive keratectomy. [2]

Clear lens extraction is also used as a treatment of choice in patients with diseases such as angle closure glaucoma. [4] A study also found that CLE is even more effective than laser peripheral iridotomy in patients with angle closure glaucoma. [5] [6] A systematic review comparing lens extraction and laser peripheral iridotomy for treating acute primary angle closure found that lens extraction potentially provides better intraocular pressure control and reduces medication needs over time. However, it remains uncertain if it significantly lowers the risk of recurrent episodes or reduces the need for additional surgeries. [7]

Procedure

Procedure is similar to cataract surgery, most commonly followed by an intraocular lens implantation. In patients requiring only distance vision correction, a conventional mono-focal intraocular lens is placed in both eyes after the clear lens is removed. [1] While distance vision is fine in this, reading glasses are required for near vision. [1] Another method is to correct one eye only for distance vision and the other eye for near vision only. [1] The best way to achieve both distance vision and near vision is to place multifocal IOLs or accommodating IOLs in both eyes. [1] [8]

The intraocular lens power calculations for clear lens extraction is similar to calculations used for conventional cataract surgery. [8]

Under topical anesthesia, through a 2.2 mm corneal incision, the lens nucleus and cortex are removed by irrigation and aspiration technique using a phaco machine. [9] After removal of lens material, the viscoelastic solution initially instilled is removed from the anterior chamber, intraocular lens is inserted and the corneal wound is closed by stromal hydration method. [9] In some people with very high myopia, the eye may be left aphakic, without intraocular lens implantation. [10]

Complications

In addition to the common complications of cataract surgery, clear lens extraction may also cause premature posterior vitreous detachment and retinal detachment. [2]

History

As opposed to the more commonly performed cataract treatment, the idea of removing the lens exclusively for refractive purposes first emerged in the 18th century. [11] French ophthalmologist Abbé Desmonceaux may be the first to suggest such an operation in 1776 for a patient with high myopia. [11] He recommended the operation to Baron Michael Johann de Wenzel, although it is not known whether he ever performed the operation. [12]

The first systematic work on clear lens extraction was carried out by Polish ophthalmologist Vincenz Fukala in Vienna. Fucala advised clear lens extraction in young high myopic (−13 diopters or more) patients with poor vision and inability to work. [11]

Related Research Articles

<span class="mw-page-title-main">Glaucoma</span> Group of eye diseases

Glaucoma is a group of eye diseases that lead to damage of the optic nerve, which transmits visual information from the eye to the brain. Glaucoma may cause vision loss if left untreated. It has been called the "silent thief of sight" because the loss of vision usually occurs slowly over a long period of time. A major risk factor for glaucoma is increased pressure within the eye, known as intraocular pressure (IOP). It is associated with old age, a family history of glaucoma, and certain medical conditions or medications. The word glaucoma comes from the Ancient Greek word γλαυκός, meaning 'gleaming, blue-green, gray'.

<span class="mw-page-title-main">Myopia</span> Problem with distance vision

Myopia, also known as near-sightedness and short-sightedness, is an eye disease where light from distant objects focuses in front of, instead of on, the retina. As a result, distant objects appear blurry while close objects appear normal. Other symptoms may include headaches and eye strain. Severe myopia is associated with an increased risk of macular degeneration, retinal detachment, cataracts, and glaucoma.

<span class="mw-page-title-main">Farsightedness</span> Eye condition in which light is focused behind instead of on the retina

Far-sightedness, also known as long-sightedness, hypermetropia, and hyperopia, is a condition of the eye where distant objects are seen clearly but near objects appear blurred. This blur is due to incoming light being focused behind, instead of on, the retina due to insufficient accommodation by the lens. Minor hypermetropia in young patients is usually corrected by their accommodation, without any defects in vision. But, due to this accommodative effort for distant vision, people may complain of eye strain during prolonged reading. If the hypermetropia is high, there will be defective vision for both distance and near. People may also experience accommodative dysfunction, binocular dysfunction, amblyopia, and strabismus. Newborns are almost invariably hypermetropic, but it gradually decreases as the newborn gets older.

<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 astigmatism. LASIK surgery is performed by an ophthalmologist who uses a femtosecond laser or a microkeratome to create a corneal flap to expose the corneal stroma and then an excimer laser to reshape the corneal stroma in order to improve visual acuity.

<span class="mw-page-title-main">Eye surgery</span> Surgery performed on the eye or its adnexa

Eye surgery, also known as ophthalmic surgery or ocular surgery, is surgery performed on the eye or its adnexa. Eye surgery is part of ophthalmology and is performed by an ophthalmologist or eye surgeon. The eye is a fragile organ, and requires due care before, during, and after a surgical procedure to minimize or prevent further damage. An eye surgeon is responsible for selecting the appropriate surgical procedure for the patient, and for taking the necessary safety precautions. Mentions of eye surgery can be found in several ancient texts dating back as early as 1800 BC, with cataract treatment starting in the fifth century BC. It continues to be a widely practiced class of surgery, with various techniques having been developed for treating eye problems.

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

Refractive surgery is an 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">Phacoemulsification</span> Method of cataract surgery

Phacoemulsification is a cataract surgery method in which the internal lens of the eye which has developed a cataract is emulsified with the tip of an ultrasonic handpiece and aspirated from the eye. Aspirated fluids are replaced with irrigation of balanced salt solution to maintain the volume of the anterior chamber during the procedure. This procedure minimises the incision size and reduces the recovery time and risk of surgery-induced astigmatism.

<span class="mw-page-title-main">Intraocular lens</span> Lens implanted in the eye to treat cataracts or myopia

An intraocular lens (IOL) is a lens implanted in the eye usually as part of a treatment for cataracts or for correcting other vision problems such as short sightedness and long sightedness; a form of refractive surgery. If the natural lens is left in the eye, the IOL is known as phakic, otherwise it is a pseudophakic lens. Both kinds of IOLs are designed to provide the same light-focusing function as the natural crystalline lens. This can be an alternative to LASIK, but LASIK is not an alternative to an IOL for treatment of cataracts.

<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">Cataract surgery</span> Removal of opacified lens from the eye

Cataract surgery, also called lens replacement surgery, is the removal of the natural lens of the eye that has developed a cataract, an opaque or cloudy area. The eye's natural lens is usually replaced with an artificial intraocular lens (IOL) implant.

Aphakia is the absence of the lens of the eye, due to surgical removal, such as in cataract surgery, a perforating wound or ulcer, or congenital anomaly. It causes a loss of ability to maintain focus (accommodation), high degree of farsightedness (hyperopia), and a deep anterior chamber. Complications include detachment of the vitreous or retina, and glaucoma.

<span class="mw-page-title-main">Iridectomy</span> Surgical removal of part of the iris

An iridectomy, also known as a surgical iridectomy or corectomy, is the surgical removal of part of the iris. These procedures are most frequently performed in the treatment of closed-angle glaucoma and iris melanoma.

<span class="mw-page-title-main">Glaucoma surgery</span> Type of eye surgery

Glaucoma is a group of diseases affecting the optic nerve that results in vision loss and is frequently characterized by raised intraocular pressure (IOP). There are many glaucoma surgeries, and variations or combinations of those surgeries, that facilitate the escape of excess aqueous humor from the eye to lower intraocular pressure, and a few that lower IOP by decreasing the production of aqueous humor.

Laser blended vision is a laser eye treatment which is used to treat presbyopia or other age-related eye conditions. It can be used to help people that simply need reading glasses, and also those who have started to need bifocal or varifocal spectacle correction due to ageing changes in the eye. It can be used for people who are also short-sighted (myopia) or long-sighted (hyperopia) and who also may have astigmatism.

Micro-invasive glaucoma surgery (MIGS) is the latest advance in surgical treatment for glaucoma, which aims to reduce intraocular pressure by either increasing outflow of aqueous humor or reducing its production. MIGS comprises a group of surgical procedures which share common features. MIGS procedures involve a minimally invasive approach, often with small cuts or micro-incisions through the cornea that causes the least amount of trauma to surrounding scleral and conjunctival tissues. The techniques minimize tissue scarring, allowing for the possibility of traditional glaucoma procedures such as trabeculectomy or glaucoma valve implantation to be performed in the future if needed.

<span class="mw-page-title-main">Phacolytic glaucoma</span> Medical condition

Phacolytic glaucoma (PG) is a form of glaucoma which is caused due to a leaking mature or immature cataract. Inflammatory glaucoma which occurs in phacolysis is a condition which is a result of the leakage of protein within the lens into the capsule of a mature or hyper mature cataract and involves a simple procedure to be cured that is referred to as cataract extraction.

<span class="mw-page-title-main">Secondary glaucoma</span> Eye disorder

Secondary glaucoma is a collection of progressive optic nerve disorders associated with a rise in intraocular pressure (IOP) which results in the loss of vision. In clinical settings, it is defined as the occurrence of IOP above 21 mmHg requiring the prescription of IOP-managing drugs. It can be broadly divided into two subtypes: secondary open-angle glaucoma and secondary angle-closure glaucoma, depending on the closure of the angle between the cornea and the iris. Principal causes of secondary glaucoma include optic nerve trauma or damage, eye disease, surgery, neovascularization, tumours and use of steroid and sulfa drugs. Risk factors for secondary glaucoma include uveitis, cataract surgery and also intraocular tumours. Common treatments are designed according to the type and the underlying causative condition, in addition to the consequent rise in IOP. These include drug therapy, the use of miotics, surgery or laser therapy.

Manual small incision cataract surgery (MSICS) is an evolution of extracapsular cataract extraction (ECCE); the lens is removed from the eye through a self-sealing scleral tunnel wound. A well-constructed scleral tunnel is held closed by internal pressure, is watertight, and does not require suturing. The wound is relatively smaller than that in ECCE but is still markedly larger than a phacoemulsification wound. Comparative trials of MSICS against phaco in dense cataracts have found no statistically significant difference in outcomes but MSICS had shorter operating times and significantly lower costs. MSICS has become the method of choice in the developing world because it provides high-quality outcomes with less surgically induced astigmatism than ECCE, no suture-related problems, quick rehabilitation, and fewer post-operative visits. MSICS is easy and fast to learn for the surgeon, cost effective, simple, and applicable to almost all types of cataract.

Vincenz Fukala was a Polish ophthalmologist and ophthalmology historian better known for early works on Clear lens extraction, the surgical removal of natural lens of the eye, as a treatment of high myopia. He also developed successful techniques for the treatment of ectropion.

<span class="mw-page-title-main">History of cataract surgery</span> Development of the procedure for removing an opacified lens from the eye

Cataract surgery has a long history in Europe, Asia, and Africa. It is one of the most common and successful surgical procedures in worldwide use, thanks to improvements in techniques for cataract removal and developments in intraocular lens (IOL) replacement technology, in implantation techniques, and in IOL design, construction, and selection. Surgical techniques that have contributed to this success include microsurgery, viscoelastics, and phacoemulsification.

References

  1. 1 2 3 4 5 6 "Clear Lens Extraction (CLE)". Moran Eye Center | University of Utah Health. 13 September 2021. Archived from the original on 28 July 2023. Retrieved 28 July 2023.
  2. 1 2 3 "Clear Lens Extraction - EyeWiki". eyewiki.org. Archived from the original on 2023-07-28. Retrieved 2023-07-28.
  3. ↑ Michelle, Stephenson. "A Review of Refractive Lens Exchange". Review of Ophthalmology. Archived from the original on 2023-07-28. Retrieved 2023-07-28.
  4. ↑ "Clear Lens Extraction: First-Line Treatment for Primary Angle-Closure Glaucoma?". American Academy of Ophthalmology. 28 October 2017. Archived from the original on 28 July 2023. Retrieved 28 July 2023.
  5. ↑ Azuara-Blanco, Augusto (2013-01-18). "The effectiveness of early lens extraction with intraocular lens implantation for the treatment of primary angle closure glaucoma: a randomised controlled trial (EAGLE)". doi: 10.1186/isrctn44464607 .
  6. ↑ Tanner, Luke; Gazzard, Gus; Nolan, Winifred P.; Foster, Paul J. (January 2020). "Has the EAGLE landed for the use of clear lens extraction in angle-closure glaucoma? And how should primary angle-closure suspects be treated?". Eye. 34 (1): 40–50. doi:10.1038/s41433-019-0634-5. ISSN   1476-5454. PMC   7002615 . PMID   31649349.
  7. ↑ Ong, Ariel Yuhan; McCann, Paul; Perera, Shamira A; Lim, Fiona; Ng, Sueko M; Friedman, David S; Chang, Dolly (2023-03-08). Cochrane Eyes and Vision Group (ed.). "Lens extraction versus laser peripheral iridotomy for acute primary angle closure". Cochrane Database of Systematic Reviews. 2023 (3). doi:10.1002/14651858.CD015116.pub2. PMC   9994579 . PMID   36884304.
  8. 1 2 Alió, Jorge L.; Grzybowski, Andrzej; Romaniuk, Dorota (10 December 2014). "Refractive lens exchange in modern practice: when and when not to do it?". Eye and Vision. 1 (1): 10. doi: 10.1186/s40662-014-0010-2 . ISSN   2326-0254. PMC   4655463 . PMID   26605356.
  9. 1 2 Joshi, RajeshSubhash (2020). "Clear lens extraction for patients who are unfit for laser-assisted in situ keratomileusis and implantable contact lenses in central Indian population". Indian Journal of Ophthalmology. 68 (12): 3002–3005. doi: 10.4103/ijo.IJO_1307_20 . PMC   7856966 . PMID   33229686.
  10. ↑ Azar, Dimitri T. (2007). "lenticular and scleralrefractive surgical procedures". Refractive Surgery (2nd ed.). Mosby / Elsevier. p. 13. ISBN   978-0-323-03599-6.
  11. 1 2 3 Themes, U. F. O. (10 October 2019). "Refractive Lens Exchange". Ento Key. Archived from the original on 28 July 2023. Retrieved 28 July 2023.
  12. ↑ Schmidt, Dieter; Grzybowski, Andrzej (January 2013). "Vincenz Fukala (1847–1911) and the early history of clear-lens operations in high myopia". Saudi Journal of Ophthalmology. 27 (1): 41–46. doi:10.1016/j.sjopt.2012.11.002. PMC   3729753 . PMID   23964186.
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