Anyone who does not have the luxury of 20/20 vision and requires the aid of glasses or contact lenses for corrective vision has been a regular to an optometrist for eye care. The use of technology within the Optometry industry has impacted people's lives immensely. The use of a computer is used for simple tasks such as word processing, writing referral letters to specialists. Also keeping patients records secure on file on a computer database. Computer and software applications are also used, For example, they use computerized optometry equipment such as keratometers, phoropters, tonometer's, visual field instruments and digital cameras to assess patients' visual acuity and eye wellbeing. These Products have evolved through technology and are used every day in an optometrist practice. The use of laser eye surgery for an example has rid people from the burden of wearing corrective lenses on a daily basis. There is nothing worse than stepping out on a rainy day and have you glasses fog up. It has major benefits to a person's life.
In this paper I will look at the technological changes in Optometry throughout time and the technological products available to those who work in this practice and the benefit it has for patients. As a person who wears glasses for corrective vision I understand the burden corrective lenses have on a person life and the benefit such technologies as laser eye surgery would have on a person's life. The use of Information Technology in Optometry practices is widespread and likely to continue to increase in the years ahead. Information Technology may be a key element in the future success of optometry practices in an increasingly competitive marketplace.
1. Introduction
The 20th century is denoted by the constant of an ever-increasing technology base that facilitates eye care specialists to do more for more people. An accredited optician provides individuals with a variety of vision aids such as contact lenses or glasses. Optometrists are able to perform intricate eye surgeries and provide patients with other types of care. Someone working as an accredited optician must oversee vision tests to establish the source of an individual's eye predicaments. These tests typically include the patient having to read a series of lines of text that contains variously sized letters. Based on the exam results, the optician may establish that the patient is short-sighted, long-sighted or suffering from some other kind of vision imperfection. A licensed optician will write a prescription for contact lenses or glasses of the correct strength and type to improve the patient's sight. The term "optometry", this comes from the Greek word optos meaning vision and metria meaning measurement. The practice of optometry dates back to the 13th Century. In 1263, Roger Bacon first declared lenses as being useful to those who suffered with weakness of sight. It was another 20 years or so before spectacles were invented in Northern Italy. Johannes Kepler, a German scientist, uncovered how the retina in the eye generates vision in 1604. In 1623 the earliest book on the study of the anatomy of the eye as well as how to appropriately create glass lenses to improve vision was authored by Benito Daza de Valdes. Since this pioneering book, numerous improvements have been made in the field of optometry. Cataracts were first effectively removed from the eye in 1748 and masses now undergo the procedure every year. A correction for astigmatism, which I suffer from, was designed in 1827. Astigmatism relates to any other alteration of the cornea, which bends or warps and causes imperfect vision. The creation of the bifocal in 1760, the growth of optical companies and the development of new diagnostic technology in the 19th century, and the introduction of contact lenses in the late 20th century. The early stages of laser surgery can be trailed back to 1983 when Dr Stephen Trokel, a New York eye surgeon, launched lasers into eyes removed from the cadavers of cows in an attempt to discover a more detailed means of refractive surgery.
Figure 1: Anatomy of the Eye
2. New Technologies
The use of new technology is changing the ways of optometry. Technological advances in glasses and contact lenses have increased the demand of skilled, knowledgeable eye care professionals. As a result, eye care practitioners deal today with an expanding amount of imaging and analysis equipment that allows opticians to improve their understanding of the ocular structure and function as never before. New imaging devices, surgical procedures, and use of the internet are examples of advances that have made an important impact on ophthalmology. New imaging devices, such as optical coherence tomography (OCT), have allowed opticians to view details of ocular anatomy that up to then were not visible. Optical coherence tomography has become widely used in adults both for diagnosis and monitoring of diseases such as glaucoma. While this technology holds potential in its application to paediatric optic nerve disorders, paediatric normative values are just recently being published for retinal nerve fibre layer (RNFL) and macular thicknesses.
3. Standard Eye Exam
An eye examination is a series of tests performed by an ophthalmologist, optometrist, assessing vision and ability to focus on and distinguish objects, as well as other tests and examinations relating to the eyes. The main instruments in an eye exam are a Slit lamp,a Phoropter, Tonometry and a Keratometer
The slit-lamp examination examines the structures at the front of the eye. The slit-lamp is a low-power microscope merged with a high-intensity light supply that can be fixated to shine in a thin beam. Patients undergoing an eye exam sit in a chair with the device placed in front of them. A persons chin and forehead is rested on a support to keep your head stable. The optician will proceed to examine the eyes, particularly the eyelids, cornea, conjunctiva, sclera, and iris. More often than not, a yellow dye known as fluorescein is used to assist the examination of the cornea and tear layer. The dye is usually added as a drop. The dye washes out of the eye with tears as one blinks. Next, drops may be placed in the eyes to dilate the pupils. The drops take several minutes to work. The slit-lamp examination is then repeated using another small lens held close to the eye, in order to examine the back of the eye. This test is used to inspect the conjunctiva,corenea, eyelids, iris, lens and sclera.
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Figure 2: Slit Lamp
A Phoropter is an instrument used during an eye examination to measure refractive error and determine eyeglass prescriptions. Usually, the patient sits behind the phoropter, and looks into it at an eye chart. The optometrist then varies lenses and other settings, while asking the patient for feedback on which settings give the best vision.
Phoropter
Figure 3: A Phoropter
Tonometry is the method eye care professionals use to determine the intraocular pressure, this is the fluid pressure inside of the eye. This test is important in the assessment of patients at risk from diseases such as glaucoma. Most tonometers are calibrated to measure pressure in millimeters of mercury (mmHg). It blows puffs of air into the eye.
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Figure 4: Tonometry
A keratometer, also known as a ophthalmometer, is a diagnostic instrument for measuring the curving of the frontal surface of the cornea, particularly for assessing the degree and axis of an astigmatism.
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Figure 5: A Keratometer
4. Laser Eye Surgery
Laser eye surgery is the restructuring of the cornea, the translucent 'window' at the fore of the eye, by by means of an excimer laser. This then amends focusing complications. To help quicker recovery and enhanced outcomes the thin external surface layer of the cornea is moved to the side before the laser treatment is executed. The exterior layer is then gently relocated back into place. The rectification of short-sightedness, a condition also acknowledged as myopia, is the most common use for laser eye surgery. Laser eye surgery is likewise used in the treatment of long-sightedness and mild astigmatism. It is not however suggested for improving reading prescriptions, also known as presbyopia, as these prescriptions alter as you age and may result in you still needing reading glasses. Also some high prescriptions are not appropriate for laser surgery. While they may possibly be adjusted via a method of non-laser eye surgery. The majority of people who choose laser eye surgery are pleased with the results. The most familiar forms of treatment used are LASIK and LASEK. These methods are different in the way the surface layer is repositioned aside. There is another type of treatment called PRK, but this is not often used. There are two types of surgery available, Standard and Advanced CustomVue WaveFront. Like a persons fingerprint, their vision is unique to them. Advanced CustomVue WaveFront improves vision according to the individual imperfections of a persons eyes. This means that each laser treatment is specific to the person undergoing the procedure. This technology was initially established for use in high powered telescopes to decrease distortions when observing far-off objects in space. Advanced CustomVue WaveFront uses an remarkably advanced scanner called the WaveScan which produces a precise map of how light routes through the eye. This map, and the measurements acquired are 25 times more accurate than measurements acquired during a routine sight test. It delivers measurements of your prescription but also the natural imperfections unique to each of a persons eyes. These imperfections have a momentous influence on vision and have been related to glare and halos, especially at night time. Benefits of this technology include better quality night vision than previously available. Since WaveFront technology permits us to correct specific perfections, it has the prospective to correct vision to an even enhanced level than possible with glasses or contact lenses.
4.1. LASIK
Lasik is the most recognized and widespread method of laser eye surgery, so much so that it's virtually used as a common term for the process. But there are really numerous procedures that a doctor/surgeon can perform when it comes to using a laser to right your vision.
Laser-Assisted In-Situ Keratomileusis (LASIK) has become the most commonly worked form of refractive surgery to date. The aim of this surgical procedure is to alter the anterior corneal shape by ablating tissue from the stroma via excimer laser after creating a hinged corneal flap. This way, we are able to change the refractive status of the patient, providing better unaided vision. Continuous improvements in the original technique have made the surgical procedure safer, more accurate and repeatable. Continuous improvements in the original technique have made the surgical procedure safer, more accurate and repeatable. These progressions are due to the development of novel technologies that are the responsible for new surgical instrumentation, which makes the surgical procedure easier for the surgeon, and better excimer laser ablation algorithms, which increase the optical quality of the ablation and thus the safety of the vision correction procedure. This article aims to describe the more relevant advances in LASIK that have played an important role in the spread and popularity of this technique. The IntraLase technique is also available to those who chose LASIK. The IntraLase Method is the most innovative and accurate manner in which to create the flap during your LASIK procedure. The blade-free technique uses Femtosecond pulses of laser to produce the flap. The IntraLase method provides an exceptional end result and it has been shown to improve outcomes for more patients. It has been shown to improve outcomes for more patients. Patients usually experience quicker recovery, fewer LASIK flap-related problems and rarer induced higher order aberrations.
Figure 6: LASIK Eye Surgery
4.2. LASEK
Laser-Assisted Sub-Epithelial Keratectomy (LASEK) is a procedure very similar to LASIK. During surgery, a considerably thinner piece of the cornea is taken away. LASEK is a procedure your doctor may vouch for if for some purpose you cannot have LASIK surgery. People who have very thin corneas, for example, occasionally opt for LASEK. People with slimmer corneas choose LASEK over LASIK as it is a less intrusive and seen as a less risky procedure because it doesn't go as deep into the tissue bed. LASEK is often referred to as EPI-LASEK. LASEK procedures are said to be slightly more uncomfortable than LASIK and there is a longer healing time. Revolutionary surgery is now enabling blind people to see again with the inserting of an artificial retina, an electronic chip positioned at the back of the eye which can then transmit images.
Figure 7: LASEK Eye Surgery
4.3 PRK
PRK (photorefractive keratectomy) is a style of refractive surgery to correct nearsightedness, farsightedness and astigmatism. PRK was the first type of laser eye surgery for vision correction. PRK works by restructuring the cornea using an excimer laser, allowing this allows the light entering the eye to be properly focused onto the retina for clear vision. In PRK the cornea's complete outer layer is detached to expose the area and no flap is created, the excimer laser then shapes the stromal layer of the cornea to correct your refractive error. PRK is executed by the surgeon first eradicating a central area of corneal epithelium with an alcohol solution, a polishing device or a unsharpened surgical instrument. Afterward, an excimer laser is used to accurately restructure the curvingof the cornea's surface. This computer-controlled, highly specific laser provides pulses of cool ultraviolet light that remove microscopic amounts of tissue in a precise arrangement. A soft contact lens known as a bandage is then positioned on the cornea to help shield the eye. New epithelial cells normally grow back within five days, after which the bandage contact lens is removed by the eye doctor.
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Figure 8: PRK Eye Surgery
5. Health
Ophthalmologists are capable of identifying health disorders, for instance diabetes, vascular disease, hypertension and some tumors within the brain by inspecting the retina and observing changes that occur due to these ailments. Smart technology permits the use of complex equipment to observe minor variations and note differences earlier than ever before. A newly established electronic system that screens for diabetic retinopathy uses Smart technology that permits primary care physicians to review retinal alterations that lead to blindness in diabetic patients. The capability to evaluate retinal changes without referring a patient to an eye care specialist controls medical costs, improves early screening compliance, and enables early referral and treatment if a change is discovered.
For numbers of individuals unable to pay for or access regular eye exams from an onsite ophthalmologist, it may soon be viable to check for refractive eye problems using the camera on your mobile phone device. Refractive errors are the most familiar conditions needing corrective eyeglasses for illnesses such as near or far sightedness. While presently in early experimenting, smart technology lets a simple portable devise to be clipped onto your mobile phone and is exercised to test for refractive errors as precisely as in office testing. Results are gained within one to two minutes and prescriptions sent to your phone. This will lower the cost of otherwise costly in office testing and raise the number of people who are able to access early screening options.
6. Technological Developments
There are many new technological developments available to those in the eye care profession which include VisionCare's Implantable Miniature Telescope, Optovue iVue Optical Coherence Tomography, TearScan, Contrast Sensitivity Testing, Color Vision Testing and Vitamin E Infused Contact Lenses. There is also a color blindness test application available for your smartphone.
The Implantable Telescope Technology policy includes wide-angle micro-optical lenses in a Galilean telescope design. Built on this patented technology, VisionCare's main invention (Implantable Miniature Telescope by Dr. Isaac Liphitz), along with the cornea, increases images in fore of the eye approximately 2.2 or 2.7 times their normal size, this depends the model used. The magnification permits central images to be propelled onto healthy perimacular areas of the retina in its place of the macula alone, where collapse of photoreceptors and damage of vision has occurred. This helps lessen the 'blind spot' and permits the patient to differentiate and determine images that may have been unrecognizable, distorted or difficult to see.
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Figure 9: Implantable Miniture Telescope
Optovue has obtained FDA authorisation for its iVue compact SD-OCT (spectral-domain optical coherence tomography). Optical coherence tomography uses the dispersion of light in tissue to construct elevated resolution 3D images, however is restrained to visualizing tissue 1 to 2 mm beneath the exterior. The iVue system can image both the cornea and retina. It is the replacement to the RTVue system from the same company contributing a more dense system with related scanning expertise.
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Figure 10: The iVue
Academics at the University of Florida in Gainesville have created Vitamin E immersed contact lenses. This forceful antioxidant is boxed in bunches within the contact lens and is gradually discharged onto the eye. The Vitamin E compositions act like 'nano-bricks' through which drug fragments cannot pass, but instead must go round. These nano-bricks are so significantly larger than drug molecules and they invent an obstacle course for the drug molecules so that they need to travel a much longer route. This expands the length of the drug delivery from the lens and exposure to the eye. These lenses can be devised for continuous wear for up to a month. These lenses can be worn to heal glaucoma as well as other eye disorders such as cataract and dry eye. Not only will these lenses extend distribution to the eye, but also they should reduce systemic absorption and thus systemic side effects that can be seen with anti-glaucoma treatments. Vitamin E is a recognised nutraceutical that in trivial quantities is beneficial for the eye. This Vitamin also stops UV light without any decrease in transparency, making this Vitamin not only advantageous for treatment of disease, but prevention as well. While these lenses are not presently on the market since further clinical trials are required, this technology will be something to watch out for in years to come.
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Figure 11: Vitamin E immersed contact lense
TearScan from Advanced Tear Diagnostics offers a one-step ocular diagnostic exam by measuring tear lactoferrin. It is the only obtainable analytical biomarker to determine aqueous deficiency. The company who developed this product believes that tear fluid holds the source material needed to classify aqueous lacking dry eye, assist in diagnostic differentiation between aqueous-deficient and evaporative dry eye, and improve effective treatments. TearScan also provides infornation that allows the provider to rank the level of dry eye strictness and observe the usefulness of the treatment. This test uses reflectance photometry and takes roughly four minutes and provides measurements with 98% specificity.
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Figure 12: TearScan
The computerized Smart System contrast sensitivity testing function provides comparable contrast sensitivity amounts to the Pelli-Robson chart, according to a new study at the University of Toronto. The researchers also found that the computerized Smart System contrast sensitivity function provides precise, reproducible and reliable outcomes.
M&S Chart
Figure 13: Contrast Sensitivity Testing
By recognizing these minuscule alterations in color sensitivity, the ColorTrac anomaloscope can aid opticians discover early eye disease, observe changes over time and manage disease for useful enhancement. This convenient and portable device can be easily carried from one exam room to another. It does not need any special training. ColorTrac shows the patient an collection of seven match points simultaneously, and the patient is requested to select the vertical pair that is the closest color match. The match-range is fixed on the normal point, and is segmented into increments of just noticeable differences, which allow positive, accurate responses in less than 60 seconds.
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Figure 14: Anomaloscope
This test offers a series of simple geometric shapes, a circle, square or diamond, each camouflaged by a random pattern of dots of fluctuating size and brightness. The color of the dots is the only visual indication that allows users to recognize the shape.
When the test starts, the hidden shapes are very easy to see because there is a blunt variance between the front and background colors.
As the test ensues, the plates get more puzzling. At the end, the app provides users with an assessment of their color vision including the type and extent of the deficiency, if there is any.
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Figure 15: Color Blindness Test App
8. Conclusion
From this paper it is clear that technologies have enhanced greatly within the optometry industry. From a simple eye test to Laser eye surgery there are many instruments that have evolved thanks to the developments in technology throughout the years. These technologies have clearly had a positive impact on the lives of those who require visionary aid, myself included. I Personally took the plunge and underwent Laser Eye Surgery. I suffer from shortsightedness and underwent the LASIK wavefront intralase procedure. The procedure was quick and painless and I would highly recommend it. From a personal experience I can say that the developments in technology within the Optometry industry are amasing and no doubt they will continue to rapidly change and benefit this industry.
