Depending on the fitting philosophy of the design being used, an initial base curve is chosen that is 0. Change in subfoveal choroidal thickness secondary to. This toric lens design lens, with a first lens fit success rate of 95%, was. Day is an independent lens designer and a consultant for orthokeratology in private practice in hoover, ala. This method can be used as an alternative to eyeglasses, refractive surgery, or for. The contact lens practice module has been devised to. Orthokeratology is a nonsurgical treatment that uses precise, specially shaped contact lenses to temporarily reshape the cornea in order to eliminate nearsightedness or myopia so that you can see better at distance without wearing eyeglasses or regular contact lenses throughout the day most often the doctor will prescribe specially designed rigid gas permeable rgp contact lenses that. Orthokeratology is fitting custom designed, high oxygenpermeable. Aug 03, 2014 orthokeratology power point presentation 1. Package insert euclid systems orthokeratology oprifocon a contact lenses for overnight wear important please read carefully and keep this information for future use. If this was the case, the tightfitting or adhered lenses had to be discontinued until lenses having flatter base curves were ordered. To this date, no studies have been completed on hybrid lens orthok. Ortho k short for orthokeratology is a nonsurgical procedure using specially designed contact lenses to gently reshape the curvature of the eye to improve vision.
It was not unusual to order two pairs of lenses for each patient from the beginning of the fit. Clinical study myopia control with a novel peripheral gradient soft lens and orthokeratology. Visionarys ortho k system defines efficiency with an easy to fit design and an automated tool that makes designing quick and accurate. Optic zone base curve, compression zone, bc width 5. Wantanbe discusses how orthokeratology lenses mold the corneal shape at night, the risks and benefits of this technology, and the basic principles of continue reading lecture. I have been using orthotool for the past few years for most of my initial orthok fitting and the success rate improved in a. Made with this premium lens material, emerald163 delivers the highest oxygen.
Orthokeratology orthok corneal reshaping with gp contacts. We find that this gentle pressure is no greater than that applied by any properly fit rigid gas permeable lens design. The ortho k evaluation is also a good time to discuss other considerations such as haloes and adaptation for moderatetohigh myopia. Other case reports used the same design, as did the first studies on toric ortho k lenses for astigmatism. Fifty myopic children aged between 9 and 14 years were. Eye fitted with euclid systems orthokeratology oprifocon a contact lens. Click on the link below to certified to fit the visionary mg orthok lens.
Spherical reverse geometry lens rgl designs used in orthokeratology ortho. Euclid systems orthokeratology oprifocon a contact lenses are designed to purposely net match the shape of the cornea but instead apply slight pressure to tde center of the cornea, in a design known as reverse geometry. In 1994, the fda granted the first ever daily wear approval for a lens indicated for orthokeratology to a type of lens called the contex ok lens. A 2year clinical trial article pdf available in journal of biomedicine and biotechnology 20152015. The overnight lenses are made from boston equalens ii material. Whether it is the fda approved fargo lens or the advanced isee orthok design, the gov series or paragons crt we are confident you will find a gp lens design that works for you and your patient. Prospective pilot study including 8 hyperopic eyes of 4 nonpresbyopic patients 2444 years undergoing orthokeratology with the alexa h contact lens tiedra pharmaceutical, madrid, spain, which is an aspheric pentacurve design. The ortho tool software purchase was the best investment that i ever made practicing orthok along with the trial set to define the lens design. Fitting the dreamlens is straightforward and has been found to have a success rate over 90%.
Gp specialists is also the preferred lab for the orthotool doctor designed myopia management custom contact lens software. This requires the use of highdk lens materials to ensure proper oxygen transmission to the cornea. It took a long time to achieve only a shortterm reduction of myopia. The longitudinal orthokeratology research in children loric. This study aims to analyze two commercial orthokeratology lens designs and compare their optical effects at the corneal level. Orthokeratology also known as orthok, ok, corneal reshaping, corneal refractive therapy, and vision shaping treatment is an alternative method to correct refractive errors using customdesigned rigid lenses to temporarily modify the curvature of cornea. Gov artmost platform regular ortho k design lens calculator. Patient records were identified from a specialty contact lens practice. I have been using orthotool for the past few years for most of my initial ortho k fitting and the success rate improved in a.
Orthok information brochures isee orthokeratology contact. K lens wear and after its cessation and the association of short. The ortho tool software purchase was the best investment that i ever made practicing ortho k along with the trial set to define the lens design. Reverse geometry orthok lens effective for postrefractive. The purpose of this case report is to introduce a method for a successful treatment of high astigmatism with a new orthokeratology design, called fokx falco kontaktlinsen, switzerland.
Fiftytwo eligible subjects were randomly assigned to pr ortho k group n 26 and control group n 26. First orthok course in australia was run and soon about 30 practitioners were fitting contex and gelflex orthok lenses. Created by and named for the english mathematician jesse ramsden in the 1700s, this is a symmetrical two element design using two planoconvex elements eye lens and field lens. Trouble shooting guide for orthok lenses clover sites. Orthokeratology orthokeratology is the use of a corneal reshaping device, to mould the cornea to reduce or correct myopic shortsighted and mild astigmatic refractive errors of the eye. Reverse geometry ortho k lens effective for postrefractive surgical case.
In june 2002, paragon vision sciences corneal refractive therapy lens was the first ortho k design to gain fda approval for overnight wear. New reverse geometry contact lens designs and materials have led to a renewed interest in this field. Data were obtained from myopic patients who were prescribed ortho k wear. Orthokeratology orthok ckr design for orthokeratology. The plain side of both elements faces outward and the image is formed between the eye element and the observers eye, making the ramsden design a positive ocular. Mar 01, 2017 although advances in ortho k have led to the creation of lenses designed to treat hyperopia and presbyopia herzberg, 2010, this article focuses on myopic ortho k lens design. Click on the link below to certified to fit the visionary mg ortho k lens. To evaluate the preliminary clinical outcomes of a new contact lens design for orthokeratology in hyperopia. Check out the courses page for whats currently available to help your eyeballs thats the magic words you need to whisper conspiratorially, for anyone in the mainstream to acknowledge the. Trouble shooting guide for orthok lenses the basic design of the third generation e lens for orthokeratology 1. Initially, it was postulated that this represented cellular movement away from the region of lens. The percival philosophy is similar to that used in modern spectacle lens design. Bard is in practice in dallas, texas, where he specializes in orthokeratology and dry eyes. Demographic data at baseline included age at commencement of ortho k and.
Pdf analysis of two orthokeratology lens designs and. With regards to vision shaping treatment this means. Morphology, topography, and optics of the orthokeratology. To investigate changes in subfoveal choroidal thickness sfcht during orthokeratology ortho. A short guide to clinical digital photography in orthodontics. Methods and analysis this study is a 2year longitudinal, doublemasked, partially randomised study. This book is no longer in print, but is available in pdf. Research has also demonstrated that orthokeratology. Dreamlens orthokeratology art optical contact lens, inc. You would want alignment staining in the return zone area 360 degrees around, with no bubbles.
This package insert is intended for the eye care practitioner, but should be made available to patients upon request. The new emerald163 orthokeratology contact lens has all the proven performance characteristics of the leading emerald orthok lens design, manufactured from menicon za, tisilfocon a, a highquality lens material with a hyper dk of 163. Diagnostic fitting is not necessary with this method where accurate keratometric and spectacle refraction measurements. Orthokeratology a guide to overnight orthokeratology. Troubleshooting your orthokeratology fit eyedolatry. With either method, it is important to remember that centration of the lens over the cornea is the key to success in orthokeratology. The ideal lens is well centered on the eye with a central treatment zone of about 34 mm diameter. Al nagler formulated a short focal length eyepiece design that incorporates a pair of elements that essentially serve as a permanent, builtin barlow lens note the two elements that constitute the field group at the far left in the diagram below and achieved an incredible 82degree apparent field of view coupled with comfortable eye relief.
Orthokeratology is nicknamed orthok and sometimes called corneal reshaping cr, corneal refractive therapy or vision shaping. The dreamlens does not incorporate diagnostic fitting and only requires ks and spectacle rx for use with the dreamlens proprietary software design program. Other associated clinical signs that have been documented a corneal dimpling corneal dimpling may be seen after the first night of orthokeratology lens wear. Other case reports used the same design, as did the first studies on toric orthok lenses for astigmatism. I have been using orthotool for the past few years for most of my initial ortho k fitting and the success rate improved in a great deal when the diagnostic fitting was incorporated. Orthokeratology with a new contact lens design in hyperopia. Ckr is a continuous aspheric reverse geometry lens design based on corneal topography measurements. If you want to get started improving your own eyesight, i offer a number of courses, including options for oneonone support with me personally.
Trouble shooting guide for ortho k lenses the basic design of the third generation e lens for orthokeratology 1. Nineteen 79% pr ortho k subjects achieved successful. Orthokeratology lenses for myopia and hyperopia can induce significant structural and optical changes in as little as 15 minutes. The purpose of this study is to assess visual, refractive, topographic. For more information on how a camera operates, see chapter 1, how. Mar 26, 2018 orthokeratology contact lenses are becoming increasingly popular as a method of slowing the progression of myopia in children as well as providing reversible corrected day time vision. It is a temporary, reversible, and alternative option to refractive surgery. Subtractive or difference maps are ideal for showing the overnight change after ortho k. Hybrid contact lenses for daily wear orthokeratology. Orthokeratology lenses are worn at night whilst sleeping, and are taken out in the morning. The longer the focal length, the more the lens magni.
Fine, slightly curved fibrillary lines in the anterior stroma may be seen but have no known adverse consequences on vision or ocular health. Reim is an independent orthokeratology lens designer in private practice in indian harbor beach, fla. Orthokeratology lens an overview sciencedirect topics. This novel toric orthokeratology contact lens design, the fitting approach and the performance of fokx lenses will be illustrated in the form of a case report. Package insert euclid systems orthokeratology oprifocon a. Some new orthok lens designs are also available for farsightedness and presbyopia. Introduction eight eyes of four healthy subjects 2425 years old, all current soft contact lens wearers, were empirically fitted with the chow 5. I have been using orthotool for the past few years for most of my initial orthok fitting and the success rate improved in a great deal when the diagnostic fitting was incorporated. Euclid systems orthokeratology oprifocon a contact lenses. Improved rigid gas permeable rgp contact lens materials have reduced the potential for corneal insult. Comparison of reversegeometry lens designs for overnight.
No significant lens binding, corneal staining, or other adverse events were observed during this period of lens wear. Principles and practice by mountford, ruston and trusit. Pdf correction of high amounts of astigmatism through. From a practical point of view, focal length can be thought of as the amount of magni. High myopiapartial reduction orthokeratology hmpro. The median range subjective myopia of the right eye at baseline was 6. Above, superior decentration of a spherical ortho k lens on a toric cornea with no corneal touch in the steepest. When the lens is removed, the vision is much improved and the tissue memorizes the shape. The anatomy of ortho k lenses has undergone a significant transformation since the 1960s, when the idea was first put into. Nightwear ortho k solutions were available to consumers in many countries outside the us much earlier than within the us, due to international differences between regulatory controls and bodies.
Burge 8 issues with the sharp corner provides highest accuracy, and is easy to verify potentially large contact stresses for most applications, these will not cause any risk sharp corners are susceptible to damage or to burrs standard practice of breaking corners will result in loss of accuracy sharp corner with radius 0. Patients were typically checked after four hours of lens wear to check for lens tightening andor adhesion. To this date, no studies have been completed on hybrid lens ortho k. The specificity of the new lens designs merely reshapes the anterior corneal surface through gentle pressure on the surface. However, as with the wear of any type of contact lens there is a slight risk of complications. The lens may be fitted either empirically via the internet through a direct connection between the corneal topographer and laboratory or by using a diagnostic lens fitting set to choose the appropriate lens. Today, several companies manufacture ortho k lenses. Mounting of optical components university of arizona. Orthokeratology orthok, or corneal refractive therapy, is a specialty contact lens fitting in which gas permeable gp contact lenses are worn overnight to change the corneal curvature, thus modifying the corneas refractive power. With high dk rgp materials and reverse geometry designs australian practitioners started overnight wear for orthok with no daytime lens wear. Objective to present the study design and the baseline data of a prospective cohort study investigating the safety, refractive correction and effectiveness of myopia control in subjects fitted with orthokeratology ortho k lenses of different compression factors. The nature of the central epithelial thinning in ok is unclear.
Orthokeratology also referred to as orthok, ok, overnight vision correction, corneal refractive therapy, crt, and gentle vision shaping system, gvss refers to the use of gaspermeable contact lenses that temporarily reshape the cornea to reduce refractive errors such as myopia, hyperopia and astigmatism. Orthokeratology is defined as the temporary reduction in myopia by the programmed application of rigid gaspermeable contact lenses. Tangential maps are best used for lens positioning in ortho k, while refractive maps speak to the quality of vision. Software orthotool custom contact lens design software. The first contact lens specifically designed for your. Spherical ortho k lens is effective against low central corneal astigmatism, in patients with less than 1.
History orthokeratology, also referred to as orthok was first introduced to contact lens practitioners by the famous optometrist george jessen in 1962. The lens may be fitted either empirically via the internet through a direct connection between the corneal topographer and. The emerald design vision shaping treatment certification test. Visionarys orthok system defines efficiency with an easy to fit design and an automated tool that makes designing quick and accurate. Orthokeratology with increased compression factor okic. Design for near and distant viewing distances is essentially identical. New reverse geometry contact lens designs and materials have. Clinical data recorded at baseline and at years 1, 2 and 3 included subjective refraction, corneal topography, corneal curvature, axial length, pupil size, and lens design, changes in lens. Ecoo position paper the orthokeratology procedure pdf.