Contact Lens Problems part 2

The problems associated with the use of contact lenses can be:

• Related to the contact lens itself
• Associated problems with conjunctival
• Associated with cornea problems

Contact lenses problems

• Poor lens fit5 - both tight and loose lens can also cause damage. Tight lenses normally feel comfortable at first and then become increasingly uncomfortable for a period of hours. With continued use, Tight Lens can develop the syndrome (see below). Loose lenses result in decentration lens: the patient complains of a greater awareness of the lens and diverse vision with each blink.
• Poor lens care - not clean the lenses properly can result in the accumulation of protein and fat deposits in the lens. These can cause irritation of the cornea and problems of visual acuity. The bacteria, protozoa and fungi can form a film on the lens and the strands of fungi can invade the same lens. Deposits in, or damage to the surface of the lens can also occur due to other substances that may come into contact with hair like spray, makeup, smoke and hand cream. It is important to ensure that the patient is using the lenses properly in order to prevent the formation of future reservoir.
• Lens damage - damage or deterioration of the contact lens is more common with soft lenses that rigid gas permeable (RGP) lenses. Damage can occur in the form of tears, cracks and chips. These can cause local irritation of the cornea. The objective then is also an increased risk of colonization of pathogens that lead to conjunctivitis and keratitis. Deformation of the lens can occur if too much is squeezed during the cleaning process, or if kept in conditions that are too hot (for example, wash in hot water or keep them in a case in the dashboard of the car). Deformation of the lens can lead to distortions induced by the cornea and the difficulty in correcting an error of refraction that can take months to resolve.
• Lens drying - an appearance of "eyes" or reducing the rate of flashing is common in contact lens wearers and may result in drying of the lens with the formation of deposits on their surface. It can also lead to hypoxia corneal.

Problems conjunctival

• Allergic conjunctivitis - arises because of the sensitivity thiomersal, a preservative used in contact lens care solutions. This is presented with redness, burning and itching that is worse in the insertion of lenses and reduces with time. But diagnosis is difficult and conjunctivitis can only occur gradually days or months after the initial exposure. There will be evidence of perilimbal injection (redness that is, around the cornea). The treatment is avoidance of thiomersal; advise patients to visit their contact lenses-provider options for lens care solutions.
• Conjunctivitis papillary giant - this allergic condition arises as a direct consequence of the lens itself and presents itself as the intolerance associated with the lens of the eye irritation and redness. The closer inspection, papillae large (> 3.0mm) can be seen from the upper tarsal conjunctiva. These are considered due to chronic irritation and therefore immune mediated and mechanical means. The treatment involves removing the lens until the condition has been resolved.
• Idiopathic higher limbic keratoconjunctivitis - arises from time to time in hydrogel lens wearers, especially among women aged between 20 and 60 and especially with abnormal thyroid function (30-50%). Again, this is done with the lens intolerance, redness and irritation of the eyes and is associated with fine papillae higher education in the tarsal conjunctiva. Treatment is by removing the lens until the condition has been resolved.
• Toxic conjunctivitis - can occur as a result of cleaning solutions used for the lens due to absorption through the lens of preservatives. This is more of a problem when using soft lenses. The lenses can also be coated with other substances that may be on the side of the user to insert the lens for example, perfume or hand cream. The eye was red and may develop corneal abrasions ± infiltrators and a fine exceeding limbic keratoconjunctivitis. Once again, treatment is removal of the lens until the condition has been resolved. If they are serious ocular lubricants may be needed along with a short course of topical steroids.

The cornea problems

• Superficial punctate keratitis (KPS) - this is the most common problem associated with contact lenses and wear may occur as a result of dry eye. It is then usually seen in the lower half of the cornea as little scattered fluorescein points when the cornea is seen with cobalt blue light from a slit lamp. The dry eye can be aggravated by competing factors such as smoke, dust, air-conditioned rooms and medication (for example, antihistamines, diuretics and psychotropic agents). KPS may also arise in association with any of the conditions described below.
• Mechanical injury - because of cracked or damaged lenses or trauma to insert or remove the lens. You can also arise from the friction of debris accumulated on the lens.
• Tight Lens Syndrome - primarily relate RGP lenses and, especially if used lenses overnight: the lens does not move to blink and it seems stuck in the cornea. Generalised corneal edema is viewed with particular damage seen at 3 pm and 9 am in the position that there can be erosions in epithelial and neovascularization. Compounded by the decline in the rate of blinking and relieved by improving the adjustment of the lens along with the use of lubricants.
• Hypoxia corneal - due to a decrease of oxygen produced by the spread of the lens. This is rare these days because of the quality of lenses, but can occur when individuals do not replace the lenses or use beyond the recommended time. In the acute phase, this will cause corneal ulceration and pain. The chronic hypoxia can be asymptomatic, but the results to changes in the structure of the cornea and neovascularization. The latter feature is more common in hydrogel lens wearers, but can occur with RGP lenses. Neovascularización surface (1-2mm) can be monitored more profound, but growth can lead to bleeding Intracorneal and vision problems. The treatment in a unit of the eyes is by removing the lens and the treatment of corneal ulcers with antibiotics and topical cycloplegic agents. Topical steroids, may also be needed if serious. Patients should be equipped with RGP lenses if they wish to continue using contact lenses and educated in regard to the use healthy.
• CLARE (Contact lens induced red eye) - comes in the wake of a contact lens wear and is associated with an acute onset of red eyes associated with infiltrators. Trying to remove lenses to complete the resolution has occurred. Recurrence is common use long lenses if they are used once again.
• Microbial keratitis

1. Essence: this is the most serious (and most common2) complication of the use of contact lenses and can cause vision problems. It is most common in soft lens wearers wear their lenses on a broad basis when it occurs in 20 per 10000 per year, compared with 1.1 per 10000 per year in people using RGP lenses on a daily basis.
2. Aetiology: The most common cause is infection by Pseudomonas and Klebsiella, although other bacteria and fungi can also cause the problem. In particular, the agency Acanthamoeba spp. can cause a rare but potentially devastating endangering keratitis view (this suspect in the patient that nothing in the pits).
3. Presentation: The patient is presented with pain, watery eyes, irritation and photophobia.
4. Management: Patients must start at the topical antibiotic therapy: vancomycin, gentamicin, tobramycin or a fluoroquinolone urgently and referred to a specialist opinion. The lenses and cleaning solution must accompany the patient and must be cultivated.
5. Prognosis: corneal scarring is a common complication and some patients requiring cornea transplants as a result.