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Management of Refractive Surgery in Refractive Abnormalities

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ORIGINAL ARTICLE Bali Journal of Ophthalmology (BJO) 2019, Volume 3, Number 2: 33-35 P-ISSN. 2581-1258, E-ISSN.2581-1266 Management of refractive surgery in refractive abnormalities Wayan Gede Jaya Negara1* ABSTRACT Refractive error is one of the most common cause of avoidable with low vision condition as the impact of the untreated refractive blindness in the word. The prevalence of refractive error occurs in disorder. Two types of refractive disorder therapies was surgical and the worldwide were increasing every years, including in the Asian non-surgical therapy. Non-surgical therapy including spectacles, regions. This condition influenced by many risk factors, which are contact lenses, and optical low vision devices. The proper both modifiable and non-modifiable risk factors. There are three management of the refractive error can improving patient’s quality types of refractive errors: myopia, hypermetropia, and astigmatism of life. Keywords: Refractive surgery, emmetropia, refractive error Cite This Article: Negara, W.G.J. 2019. Management of refractive surgery in refractive abnormalities. Bali Journal of Ophthalmology 3(2): 33-35. DOI: 10.15562/bjo.v3i2.43 1Cataract and Refractive Surgery INTRODUCTION for keratomileusis refraction (derived from Greek, Division, Departement of kerato: cornea and Mileusis: cutting), which Ophthalmology The innovation of refractive surgical techniques means reshaping the cornea. Keratomileusis can Faculty of Medicine Universitas grows with time, new tools, and techniques correct the state of myopia and hyperopia. Over Udayana/ Sanglah General developed to enhance or maintain the patient’s Hospital, Denpasar, Bali, Indonesia time, keratomileusis technique is combined with vision. Refractive surgeons are able to treat laser light and is known as laser-assisted in-situ refractive abnormalities by using various surgical keratomileusis or LASIK.3 techniques in accordance with eye anatomy. Three Refractive abnormalities can also be corrected variables play an important role in refraction; those by replacing the eye lenses with artificial intraocular are cornea, lens, and length of an eyeball. Refractive lenses. Cataract surgery using phacoemulsification strength can be changed by modifying these three 1,2 and foldable intraocular lenses is an option, smaller variables. Currently available refractive surgical incisions and multifocal lenses are expected to procedures or techniques include: refractive provide refraction abnormalities. Multifocal keratotomy, astigmatic keratotomy, photorefractive lenses can also be used to correct ametropia and keratectomy (PRK), laser epithelial keratectomy presbyopia.1 (LASEK), laser in situ keratomileusis (LASIK), intracorneal ring segment (ICRS), laser epithelial MANAGEMENT OF REFRACTIVE keratectomy (LASEK), laser in situ keratomileusis (LASIK), intracorneal ring segment (ICRS), corneal SURGERY *Corresponding author : inlay lenses (CIL), phakic intraocular lenses (phakic Refractive surgery can be performed to correct Wayan Gede Jaya Negara; IOL), clear lens extraction (CLE), presbyopia myopia, hyperopia, astigmatic refractive disorders, Cataract and Refractive Surgery surgery.1 and even presbyopia to achieve emmetropia by Division, Departement of Refractive surgery was first performed by Lendeer modifying the optic system of the eye. In this Ophthalmology Jans Lans, an ophthalmologist in the Netherlands. article, we divided refractive surgery into two Faculty of Medicine Universitas In 1896, he published a theory of penetrating Udayana/ Sanglah GeneralHospital, categories, which are corneal refraction surgery Denpasar, Bali, Indonesia, corneal cuts as management of astigmatism. Later (Keratorefractive) and lenticular or sclera refraction [email protected] on, in 1960, a doctor named Fryodorov introduced surgery. Keratorefractive surgery techniques are a radial keratotomy technique, which is a technique used to change the strength of the corneal refraction of making incisions at 90% thickness of the cornea, without change eye anatomy, and this surgery is the then adjustment of correction can be made by most common technique done recently. Surgical Received : 2020-03-30 lengthening or shortening incision site. In 1963, Accepted : 2020-04-15 techniques for lenticular or sclera refraction is Ignacio Barraguer introduced a surgical technique Published : 2020-04-30 usually done by adding a secondary lens to the eye PublishedOpen access: by DiscoverSyshttp://balijournalophth.org | Bali Journal of Ophthalmology 2019; 3(2): 33-35 | doi: 10.15562/bjo.v3i2.43 33 ORIGINAL ARTICLE or relaxing the sclera.4 The Intracorneal ring segments (ICRS) correcting The radial keratotomy procedure was first refractive abnormalities by inserting the ring into performed in the United States in 1978 and was the peripheral part of the cornea to make the cornea used to treat corneal astigmatism before or after even flatter or reduce the corneal curvature. The the cataract surgery1. The optical zone determines diamond blade is used to make a 2 mm incision at some effect of refraction, the number of incisions, the steepest part of the cornea with a depth of 70% and the depth of the incision. For example, patients corneal thickness, then the ring is inserted, and with myopia can have a corneal stromal incision the incision is sewn using nylon.1 This procedure in the paracentral and peripheral areas to give a is indicated for patients with myopia < 4.5 Dioptri flat effect on the central part of the region. Radial and keratoconus. Keratoconus patient preparation keratotomy gives the best results in patients with not only based on refractive abnormalities but mild-moderate refractive abnormalities, whereas in also based on corneal topography. The advantages patients with high refraction abnormalities give very of ICRS include: corneal shape are not disrupted, varied results. The patient’s age also plays a role in reversible processes, safe surgical techniques, and determining the correction limit. The National Eye minimal external predictable outcome.5,6 Institute (NEI) reports the results of a multicenter Thermokeratoplasty procedure includes study, about 70% leaving a refractive abnormality radial keratoplasty, Holmium laser keratoplasty, of 1.0 Dioptri. Refraction after keratotomy is also or conduction thermokeratoplasty. Thermo- still inadequate, and the procedure has begun to be keratoplasty lasers use infra-red light and can replaced by a keratorefractive procedure using an be used to correct hyperopia1. Thermal energy excimer laser. Astigmatic keratotomy is a procedure will shrink the peripheral or paracentral corneas, of making a straight line or arcuate (curvilinear), thereby increasing the power of the central cornea. which is perpendicular to the steep astigmatic This treatment option can be done with hyperopia meridian. Generally, 1.5 Dioptri astigmatic is a less than 4.0 Dioptri and astigmatism less than 0.75 candidate for keratotomy. More in-depth and Dioptri. longer cuts will have a more significant effect. The phakic intraocular lens is a surgical LASEK is a combination of PRK and LASIK procedure of adding an artificial lens (intraocular surgery techniques. It is safer surgical techniques, lens/IOL) into the eyeball. This therapeutic choice has faster corneal epithelial healing process, and is usually made in patients with high refractive minimal postoperative pain. This procedure is abnormalities, which cannot be corrected using performed in patients over the age of 21 years corneal surgery5. IOL can be positioned in front of old, with stable refractive abnormalities, sufficient or behind the iris, and then peripheral iridectomy thickness of the central cornea for correction of is performed. This therapeutic procedure can myopia -3.00 Dioptri to -6.00 Dioptri, hyperopia maintain accommodation and correct high + 4.00 Dioptri and astigmatic 4.00 Dioptri. refractive abnormalities. Possible complications Contra indications for LASEK procedure include include astigmatism, secondary glaucoma, chronic keratoconus, herpes infections of the cornea, inflammation, pigmental dispersion, uveitis, corneal dystrophy, amblyopia, corneal melting, and endothelial cell damage, cataracts, endophthalmitis, unstable refractive abnormalities. Postoperative glare, and poor vision at night when pupils are patients will have periodic examinations on the wide.1,7 first day, first week, sixth week, and sixth month to Various therapies for refractive disorder patients assess visual acuity and complications.1 such as glasses and contact lenses, the higher the LASIK is a refractive surgery on the corneal refractive disorders, the risk of therapy is not stromal lining by using an excimer laser to correct maximum. Over the past two decades, refractive refractive abnormalities. It was first done by surgery has grown in popularity and has given good Pallikaris et al. in 1990 to correct myopia, hyperopia, progressivity. This refractive surgery procedure and astigmatism. It has generally been indicated to is similar to cataract surgery, but the lens that is patients with stable refractive abnormalities and removed is not cloudy. This surgical procedure is over 21 years of age. LASIK contraindications are indicated in patients with myopia > - 6.00 D and keratoconus, central corneal thickness <410 mcm, hyperopia. Complications found are almost the history of infection, corneal dystrophy, or systemic same with post-cataract surgery patients; this diseases related to corneal melt. Postoperative includes astigmatism,
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