World Keratoconus Day is a chance to raise extra awareness of the disease and this year falls on 10th November. Keratoconus is a disease of the cornea which is progressive but non-inflammatory. Keratoconus is caused by weakening of the collagen fibres which would normally maintain the cornea’s dome-like shape. With this disease the weakened cornea starts to thin, change shape and bulge outwards. This bulging and thinning causes the cornea to form a gradual cone shape which can severely affect vision.
An initial sign of keratoconus is often changes in prescription. Also, many patients experience visual disturbances such as glare, halos and double vision which is due to the cornea changing shape. Overtime patients with keratoconus notice their vision starts to become distorted and blurry, and as this is a progressive disease, these visual symptoms become worse. Many patients with keratoconus tend to be very near-sighted with a high level of astigmatism. Initially glasses and contact lenses may help with the visual changes but as the disease gets worse glasses and contact lenses lose their helpful effects. Opticians tend to refer a patient on to an ophthalmologist if these signs start to occur and worsen, the ophthalmologist will then diagnose the condition and devise a treatment plan.
Keratoconus can occur for many reasons, but the cause is still unknown. The disease can run in families and may develop from an early age, for this reason it is recommended getting children’s eyes checked by an ophthalmologist if the disease does run in the family. It may also develop at a later age due to; chronic eye rubbing or laser eye surgery (called ectasia) for example. There are also some other medical conditions where a patient may be more likely to develop keratoconus such as; retinitis pigmentosa, Ehlers-Danlos syndrome and Down’s syndrome.
Treatment for keratoconus varies due to the severity of the disease. As mentioned above glasses or soft contact lenses are initially recommended to help with the visual changes, but as the disease progresses switching to hard or other specialist contact lenses may be favourable to get better vision. These type of contact lenses must be correctly fitted and having follow ups to monitor the vision and status of the cornea is essential. If glasses and different types of contact lenses do not work, and as the disease continues to develop, a procedure called corneal collagen cross linking may be advised by a corneal doctor. This procedure, now recommended by the National Institute for Health and Care Excellence (NICE), helps to slow or stop disease progression. It works by using an ultraviolet light and riboflavin (vitamin B2), to help build and straighten the weakened collagen fibres by creating more cross linking between the fibres of the cornea, making it stronger and more ridged. Corneal collagen cross linking can be done on children and adults alike and is fast becoming ophthalmologists procedure of choice to treat keratoconus due to its safety and efficacy. Other options for treating keratoconus can also include corneal ring implants, which helps to support the cornea’s natural shape, and phototherapeutic keratoplasty (PTK) may also be suggested. If the disease is too advanced and severe the treatments above may not help, and the only option may be for the patient to have a corneal transplant, this can either be a partial or full thickness transplant and only used as a last resort if other treatments cannot help.
Keratoconus is a serious eye disease and can be blinding if not monitored and treated correctly. Currently there are no cures for the disease and the only treatment to help slow or stop keratoconus is corneal collagen cross linking. It is advised that patients, adults and children, with keratoconus or suspected keratoconus attend their follow up appointments and keep to the advice of their optician or eye doctor.
Source by Samer Hamada
Definition of Keratoconus: The word keratoconus is derived from Greek and Latin. Kerato means cornea and conus means cone shaped. It is a bilateral, progressive, asymmetric, non-inflammatory thinning and ectatic condition of the cornea, resulting in a high degree of irregular myopic astigmatism.
Prevalence: Keratoconus is estimated to occur in 1 out of every 2000 persons in the general population. There appears to be no significant preponderance with regards to either men or women.
What is the usual age of onset of keratoconus?
The onset of keratoconus is between the ages of 10 and 30. The changes in the shape of the cornea usually occur slowly over several years.
Symptoms: Symptoms depend on the severity of the disease. The most common symptoms include:
• Blurred vision.
• Distortion of vision.
• Eye Irritation and itching.
• Frequent spectacle power changes.
• Inability to wear contact lenses.
The cause of keratoconus remains unknown, although recent research seems to indicate the possible causes include:
• Keratoconus is thought to involve a defect in collagen, the tissue that makes up most of the cornea.
• Keratoconus have a genetic component and studies indicate that about 8% of patients have affected relatives.
• It happens more often in people with certain medical problems, including certain allergic conditions.
• Some think that chronic excessive eye rubbing can cause of keratoconus.
(A)Based on keratometry reading:
- Mild: Keratometric readings are less than 45D in both meridians.
Moderate: Keratometric readings are between 45D and 52D in both meridians.
Advanced: Keratometric readings are between 53D and 62D in both meridians.
Severe: keratometric readings are in both meridians more than 62D.
(B)Based on morphologic shape:
- Nipple Cones: Characterized by their small size (5 mm) and steep curvature. The optical centre is often either central or para-central and displaced inferonasally.
Oval Cones: Which are larger (5-6 mm), ellipsoid and commonly displaced inferonasally.
Globus Cones: Which are largest more than 6mm and may involve over 75% of the cornea.
- In early stage, impaired vision in one eye caused by progressive Irregular myopic astigmatism with steep keratometry reading.
Scissor reflex on retinoscopy.
Ophthalmoscopically shows an “Oil droplet reflex”.
Munson sign-Bulging of lower lid in down gaze.
Fleischer Ring-Epithelial iron deposits at the base of the cornea. Mechanism of iron deposition is not clear understood. It may be uneven distribution of tears.
Progressive Central or paracentral stromal thinning with inferior apical protrusion.
Vogt striae-Fine deep vertical stromal folds which temporarily disappear on digital pressure.
Rizutti sign-conical reflection on the nasal cornea when light is shone from the temporal side.
Prominent corneal nerves.
Acute Hydropes-Corneal edema resulting from tears Due to ruptures of the descemet`s membrane and acute seepage of the aqueous humor into the corneal stroma and epithelium. These breaks usually heal within 6-10 weeks and the edema gradually clears.
Variable corneal scarring, depending on severity of the disease.
Associations: The ocular and systemic associations of the keratoconus include:
• Vernal conjunctivitis.
• Blue sclera.
• Ectopia Lentis.
• Retinitis Pigmentosa.
• Leber congenital amaurosis.
• Down syndrome.
• Ehlers-Danols syndrome.
• Marfan syndrome.
• Atopic dermatitis.
• Osteogenesis imperfecta.
Exams and Tests:
• Visual acuity testing: Visual acuity is an indication of the clarity or clearness of one’s vision. It is a measurement of how well a person sees.
• Refraction: The refraction test is an eye exam that measures a person’s prescription for eye glasses or contact lenses.
• Slit Lamp examination: The slit lamp is an instrument consisting of a high-intensity light source that can be focused to shine a thin sheet of light into the eye. The slit lamp examination provides a stereoscopic magnified view of the eye structures in detail, enabling anatomical diagnoses to be made for a variety of eye conditions like keratoconus.
• Corneal topography: Corneal topography, also known as photokeratoscopy or video-keratography, is a non invasive imaging technique for mapping the surface curvature of the cornea. The three-dimensional map is a valuable aid. It is also used in the diagnosis and treatment of a number of conditions; in planning refractive surgery such as LASIK and evaluation of its results; or in assessing the fit of contact lenses or to diagnose keratoconus.
Spectacles: In the early stages of the keratoconus, spectacles are usually successful in correcting the myopia astigmatism associated with the keratoconus. But in severe cases it does not give good quality of vision due to high amount of corneal toricity.
- Soft contact lenses: In the early stages of the keratoconus soft contact lens is helpful. Because soft contact lens give good comfort. But in advanced stages soft contact lenses cannot correct irregular astigmatism. So, soft contact lenses are not useful in advanced stages of keratoconus.
2. Rigid Gas Permeable contact lenses (RGP): As the condition advances, the cornea becomes highly irregular and vision is no longer adequately corrected with spectacles and soft contact lenses. Rigid gas permeable contact lenses are then required to provide optimal visual acuity. Rigid gas permeable lenses enables to vault over the cornea, replacing cornea`s irregularities by filling tears between cornea (front surface of the eye) and back surface of the RGP lenses with a smooth, uniform refracting surface to improve vision.
3. Piggy back contact lenses: Ideal fitting of a rigid gas permeable contact lens over a cone-shaped cornea can sometimes is not possible. To get good fitting and good visual outcome some practitioner use piggyback contact lens. This method involves placing a soft contact lens, such as one made of silicone hydrogel, over the eye and then fit a RGP lens over the soft contact lens.
4. Rose-K Lens: Rose-k lens was introduced by Dr Paul rose in 1995. This lens is world’s most frequently prescribed gas permeable lens for keratoconus. This lens has complex geometric design. Here six different curves at back surface of the lens and decreasing optic zone as base curve steepens. The material of the lens is Boston.
5. Boston sclera contact lens: In advance case of keratoconus to delay the surgery Boston sclera contact lens is very helpful. It is made of material that allows oxygen to pass through to the eye, larger diameters (15 to 24mm), edges rest on the sclera or white portion of the eye and the central optic zone (12mm) is designed to completely vaults over the irregularly shaped cornea. These larger lenses also are more stable than conventional gas permeable contact lenses.
Penetrating Keratoplasty: In about 15% of cases, the keratoconus progresses to the stage where corneal transplantation is required to achieve better vision.
Corneal Collagen Cross-linking with Riboflavin (C3-R): A new, minimally invasive procedure called Corneal Collagen Cross-linking with Riboflavin (vitamin B) and ultraviolet-A (UVA 365nm) is called C3-R.
The treatment is performed in operation theatre under complete sterile conditions. Usually one eye is treated in one sitting. The treatment is performed using anesthetic eye drops. The surface of the eye (cornea) is treated with application of Riboflavin eye drops for 30 minutes. The eye is then exposed to UVA light for 30 minutes. The combination of Riboflavin drops and ultra violet light that react with the tissues in the cornea, strengthening them by creating more ‘cross-linking’ among them. The resulting increased stiffness and rigidity of the cornea, stabilizes corneal ectasia. Hence, the treatment takes about an hour per eye. After the treatment, antibiotic eye drops are applied; a bandage contact lens may be applied, which will be removed after few days.
However one need to understand that Collagen cross-linking treatment is not a cure for keratoconus, rather, it aims to slow the progression of the condition. However following the cross-linking treatment it makes the patient more comfortable to wear contact lens.
Complications of keratoconus:
• Patients with even borderline keratoconus should not have laser vision correction. Corneal topography is done before laser vision correction to rule out people with this condition.
• There is a risk of rejection after corneal transplantation, but the risk is much lower than with other organ transplants.
When to Contact a Medical Professional?
Young persons whose vision cannot be corrected to 20/20 or 6/6 with glasses should be evaluated by an eye doctor experienced with keratoconus.
Does keratoconus affect both eyes?
Yes, keratoconus generally affects both eyes. Keratoconus is basically a bilateral condition; the degree of progression for the two eyes is often unequal.
Does keratoconus cause blindness?
Keratoconus does not cause total blindness. However it can lead to significant vision impairment resulting in legal blindness.
There are no preventive measures. Some specialists believe that patients with keratoconus should have their eye allergies aggressively treated and should be instructed not to rub their eyes.
Source by Subrata Roy
For people with vision problems, vision insurance can be a real life saver. When you consider that one has to spend anywhere from a few hundred to a few thousand dollars every year on prescription glasses, contact lenses, and regular eye visits, it makes a lot of sense to get insured and drastically cut down these costs.
Individual vision insurance can be easily obtained through your employer. Most companies offer individual as well as group packages to insure not just yourself but also your family. This is a great plan for families that have more than one person with vision problems.
There have been cases when insurance providers haven’t lived up to their promises and charged people hundreds of dollars through some clause in the fine print of the contract. Therefore, it is recommended that you carefully go through your policy and comb out any suspicious clause that may have you pay hundreds of dollars extra for treatment.
Points like the one mentioned above make many people think whether individual vision insurance is even a justified expense. After all, a policy costs around $15-20 each month. If you have just mild vision problems, can take care of your contact lenses/prescription glasses (i.e. you can manage not to break/lose them), then your total expenses for treatment every year might be just around the expenses on an insurance policy. For such people, it may make financial sense to not purchase such a policy.
But for others who have severe vision problems or keep on losing/breaking their prescription glasses and contact lenses, individual insurance can cut down the costs drastically. You can literally save hundreds of dollars, especially on prescription glasses and contact lenses, which usually cost hundreds of dollars.
In the end, you have to sit down and analyze your total expenses every year on vision related problems. If it is more than $150, then by all means, go for a vision insurance policy.
Source by John Newcomb
If you have vision problems, and you have been prescribed to use corrective prescription eyewear, you need to wear a lens/glass as per that. And once you have started wearing prescribed eyeglasses or contact lenses, then it is impossible for you to go out without them. Well, in such cases, if your friends are planning an adventurous vacation on the beach, will you join them?
Look, if you are wearing an eyeglass or contact lens, it will be very difficult for you to enjoy the vacation on the beach. When you are wearing a prescribed contact lens, you need to stay away from the water drops, or else eyes will start to itch. Again, you cannot wear sunglasses over the power eyeglasses on the beach.
In such cases, the best option is to wear the power sunglasses. These are also known as Prescription sunglasses, as a certified Optometrist prescribes these. These sunglasses are designed with power lenses to ensure you a clear vision on a bright sunny day. So, instead of wearing those eyeglasses or contact lenses, you can simply wear the power sunglasses.
Benefits of Using Power Sunglasses
These unique and innovative sunglasses are highly appreciated by the customers worldwide. You will find some benefits of using prescription sunglasses.
It is necessary to wear power lens, for the people with vision problems. With the introduction of prescribed sunglasses, it is now comfortable for the individuals, to enjoy their outdoor activities more fluently. You can simply order the prescription sunglasses online from the reputed online lens stores.
Now you don’t need to wear an eyeglass when you are going out. This power sunglasses will effectively do the work of the eyeglass. Again, it seems to be a smarter and stylish choice to grab the prescription sunglasses instead of those traditional eyeglasses.
The UV rays can affect the eye-sight. Thus individuals prefer to wear sunglasses on bright sunny days. It is recommended to use prescribed sunglasses, as it offers both UV protection and vision improvement. These kinds of sunglasses are designed with power lenses with 100% UV protection and glare reduction property.
These sunglasses come in different colour, as the tinted material is used over the power lenses. The light bouncing back from the concrete pavement, water, sand, and snow is highly restricted by the reflective surface of the sunglasses.
Starting from cheap sunglasses to designer prescription sunglasses, every type of power sunglasses is available on the internet. When you are buying sunglasses online, go for the wraparound and large sunglasses.
It is necessary to ensure that the radiations are not leaking in around the corner edges. Some popular styles of wraparound sunglasses include Aviator, Cat Eye, Clubmaster style, WayFarer style, Oversized, and Round. You can choose any of the above styles, as per your convenience.
Power Sunglasses Prevent Ageing Issues
If you are using your eyeglass and spending hours on the beach, then it’s obvious the UV radiations are highly affecting your eyes and skin. Mainly, the UV rays cause severe sunburn, which directly promotes the wrinkle and premature ageing.
The skins around the eyes are very sensitive; you need to protect them from the UV lights. The men’s prescription sunglasses cover them fully and restrict the passage of UV rays. Thus, the ageing and wrinkles issues on the face are highly reduced with the use of prescription sunglasses.
The designer prescription sunglasses enhance the vision of eye and also reduce the glare reflections on the eye. Thus, now a clear and crisp vision is effectively ensured to you, without putting any strain on the eyes. The headaches and the blurred vision issues are also greatly resolved. Indeed, these sunglasses are probably the best accessories for the people with vision issues.
You don’t need to visit the physical stores to grab the men’s prescription sunglasses. Simply browse through the reputed online stores, which deal with eyeglasses, frames and lens. It is recommended to order both prescribed eyeglass along with sunglasses to avail attractive discounts from the online stores.
Some reputed online stores offer power sunglasses for free on ordering the prescription sunglasses. So, you need to check all the offers and discounts, before buying the prescription sunglasses online. Again, don’t forget to check the frame material and tinted glasses of the power sunglasses.
Source by Sanjay Patel
Among the current selection of soft contacts, the Acuvue Oasys family of lenses is taking their place in the ‘neighborhood’ and is rapidly growing in popularity. They have stepped to the forefront, becoming a leading brand prescribed by eye doctors.
Acuvue Oasys, for Astigmatism, and for Presbyopia all share features that contribute to the ongoing improvement in comfort and extended wear desired by contact users.
The trademarked Hydraclear Plus technology approximates the way eyes naturally stay wet, with a delivery of moisture that lasts all day even in environments and conditions that rapidly produce dryness. The use of senofilcon A (a silicone hydrogel material) facilitates a high flow of oxygen through the lens–a necessary process to maintain eye health. This unbeatable combination gets you as close to that feeling of ‘not wearing any contacts at all’ as any soft lens can.
The Acuvue Oasys family has also forged ahead in the area of UV protection, blocking 96% of UV-A radiation and 99% of UV-B radiation from reaching the covered portion of the eye*. These numbers put Acuvue Oasys at the top of the list in this regard, gaining seals of acceptance for ultraviolet absorbing contact lenses from both the American Optometric Association and the World Council of Optometry.
In addition to the comfort and UV protection, the Astigmatism version of this lens delivers constant, crisp vision due to its four-point Accelerated Stabilization Design that keeps the lens from rotating (and causing a loss of focus). The Presbyopia version of the lens employs Stereo Precision Technology to achieve clear sight at all distances.
Many contact users who are introduced to the Acuvue Oasys family are happy with the results, and there are others who are switching from their prior contacts to get this same satisfaction. One such individual, age 60, has spent much of her forty-four ‘contact years’ settling for just three hours of comfortable lens wear a day. After recently discovering Acuvue Oasys, she now experiences several days of wear without discomfort. Another turned away from ‘old’ Acuvue Oasys after an initial trial only to come back and embrace the improved brand.
Acuvue Oasys is FDA approved for two-week daily wear or six nights of extended wear. Ask your eye doctor about the Acuvue Oasys family member best suited for you.
*All other areas of the eye still need to be protected from ultraviolet radiation. These lenses are no substitute for UV-protecting eyewear such as sunglasses, goggles, etc.
UV-A radiation damages collagen fibers (which support cell structure) and destroys Vitamin A in the skin.
UV-B radiation does direct DNA damage that leads to skin cancer.
Source by Chelsea Francis
All contact lens wearers have experienced dry eyes at some point. The irritation, the burning and heavy squinting make getting through the day unbearable. One of the steps to take is to observe the situations you are in when this occurs, as a lot of the time dry eyes may be prevented when the appropriate steps are taken. Here are 7 helpful tips to avoid dry eyes:
~Set your computer screen below your eye level: When your screen is above your eye level you tend to open your eyes more to see the screen better. When your screen is lower you relax your eyes, which helps reduce the dehydration of the tears in your eyes.
~Be mindful of your surroundings: Whether you live in the mountains, in the desert or are catching the next flight home, the air in these and many other areas can be very dry. Try closing your eyes more often to decrease the amount of moisture loss in your eyes. You can also carry an extra bottle of solution to rewet your lenses if they are drying out.
~Try wearing a disposable moist contact lens: Theses lenses contain more water content than traditional lenses, so they provide longer lasting comfort throughout the day, and since they are disposable they require no maintenance. Just toss out the dry lenses and pop in a fresh pair. Moist contact lenses are also available for both astigmatic and multifocal wearers.
~Think about wearing sunglasses: Consider wearing sunglasses, even when you wouldn’t normally, if you find your eyes are drying out more often than you’d like. Blocking the suns scorching rays and the winds blustery gust will go a long way to keeping your eyes moist throughout the day.
~Avoiding smoke or smoking: Not only is smoking bad for your lungs, it is also extremely bad for your eyes. You may find that smoke causes your contact lenses to rest uncomfortably in your eyes, causing them to become red, scratchy and irritating. This is because smoke extracts moisture from the surrounding air, thus drying out your contacts and your eyes at the same time. Smoking also can cause harmful long term consequences to your eyes such as glaucoma, cataracts and even blindness.
~Prevent air blowing directly into your eyes: Fans, air conditioners, car heaters, and hair dryers. Each of these, among many others, can dry your lenses and your eyes out in minutes making for a really unpleasant rest of your day.
~Use eye drops regularly: If you have persistent dry eyes be sure to use rewetting drops even when you’re not dried out. This will keep you ahead of the game and avoid any unnecessary discomfort later. Consider using rewetting drops prior to removing your lenses. This will ensure that the lenses are well hydrated and therefore become easier and safer to remove.
Proper eyecare maintenance is critical for healthy vision. Although the above are great suggestions as to how to avoid dry eyes please make sure to consult your eye care doctor for appropriate instructions and correct eyeglass and contact lens fittings.
Source by Chelsea Francis