![]() More specialised soft lenses, in both hydrogel and silicone hydrogel materials, can be custom-made for eyes that fall outside the usual range of sizes and shapes, or where the shape of the eye has been distorted through injury or keratoconus. Generally, soft lenses require more care in handling than their GP counterparts and, for that reason, moulded lenses are available in a disposable format for more frequent (including daily) disposal. Soft lenses used to be made mainly of hydrogel materials, but increasingly they are made using silicone hydrogel materials, which permit more oxygen to reach the cornea through the lens. Larger amounts of astigmatism may require a special type of lens, called a toric, in order to overcome this effect. ![]() This means that even small amounts of astigmatism may show through the lens and cause a reduction in vision. The softness of the lens means that it will wrap around any distortion in the shape of the cornea. Consequently, they’ll always work closely with specialist eye practitioners.įind the best specialist to treat your eye condition by contacting your local lens manufacturer. Speciality lens manufacturers are not just skilled at producing contact lenses tailored to your needs, but they often also have considerable experience in choosing the best lens materials to suit a specific condition. Gas permeable lenses are custom made by skilled practitioners and lens manufacturers, and can be designed to meet even the most complex prescriptions or eye shapes. Gas permeable lenses generally provide better vision than softer counterparts and generally last longer and are cheaper to maintain, but new wearers need to be prepared to build up wearing time. Within a week or so, most wearers can keep their lenses in all day in comfort. This awareness disappears gradually though, as you gradually build up wearing time across several days. Initially, you feel the edges of the lens under your eyelids as you blink, and so they may feel a little like an eyelash when you first wear them. The lenses are highly polished and generally provide very good vision. This gentle movement allows tears to flow around the lens and carry waste products away from under the lens. Soft lenses may be used in the early stages of the disease but as the condition develops gas permeable and scleral lenses tend to give better results. These “quadrant-specific” design lenses are available as regular gas permeable or scleral designs. Specialist manufacturers can now make lenses that are more curved in one meridian, to match this difference in curvature. These too can be difficult to fit as the bulge tends to occur lower down than in traditional keratoconus, which makes it difficult to fit a lens that bridges the bulge and still manages to rest on the white of the eye beneath. As the condition progresses it becomes more difficult to correct, and the best option is contact lenses. Because of the position, vision can sometimes be corrected quite well in the early stages with spectacles. The position of this arc of thinning means that the cornea tends to bulge out at the bottom, rather like a “beer-belly”. PMD is caused by a thinning of a narrow band of the cornea between 4 and 8 o’clock, approximately 2mm in from the edge of the cornea and the white of the eye. We look forward to helping you.Pellucid marginal degeneration, or PMD, is often confused with keratoconus, and indeed it is a type of irregularity affecting the cornea which results in visual impairment. If you have been diagnosed with keratoconus or pellucid marginal degeneration and would like to schedule a consultation, please use our online appointment request or call 33. Have you been diagnosed with Keratoconus or PMD? In addition, he uses only the best equipment on the market to successfully treat these eye conditions. Jon Scott is an expert in diagnosing and treating Keratoconus and PMD. Once again, highly specialized contact lenses can be used to treat these disorders.ĭr. While some of these patients actually had undiagnosed keratoconus or pellucid marginal degeneration prior to surgery, many cases are thought to be caused by the biomechanical effects of the surgery. While the majority of patients can be treated with contact lenses, in severe cases, both disorders can lead to the need for a corneal transplant.Įven in the hands of the most skilled physicians, ectasia can be induced by refractive surgery (LASIK, PRK, RK, etc.). While this doesn’t correct or reverse the condition it has been shown to significantly strengthen the cornea to keep it from getting worse. It involves placing vitamin-A drops in the eye and exposing it to a certain wavelength of ultraviolet light. FDA trials are currently underway for a procedure called corneal cross-linking.
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