Lubricants ocular

Although usually considered to be inactive ingredients in ophthalmic formulations added because they impart viscosity, many of these polymers function as ocular lubricants. They are marketed as the active ingredients in OTC ocular lubricants used to provide relief from dry eye conditions. The regulatory requirements for these OTC products are found in the FDA Code of Federal Regulations (21CFR349.12), and their formulations are presented in the Twelfth Edition of the APhA Handbook of Nonprescription Drugs. 

The carbomer polymeric gel base itself has been used successfully to treat moderate to severe cases of dry eye (keratoconjunctivitis sicca) [282]. The dry eye syndrome is usually characterized by deficiency of tear production and, therefore, requires frequent instillation of aqueous artificial tear eyedrops to keep the corneal epithelium moist. The gel base applied in a small amount provides a prolonged lubrication to the external ocular tissues, and some patients have reduced the frequency of dosing to control their symptoms to three times a day or fewer. 

An erodible insert developed as a potential ocular drug-delivery system is marketed as a prescription drug for the lubricant properties of the polymer base. Lacrisert is a sterile ophthalmic insert used in the treatment of moderate to severe dry eye syndrome and is usually recommended for patients unable to obtain symptomatic relief with artificial tear solutions. The insert is composed of 5 mg of hydroxypropylcellulose in a rod-shaped form about 1.27 mm diameter by about 3.5 mm long. No preservative is used, since it is essentially anhydrous. The quite rigid cellulose rod is placed in the lower conjunctival sac and first imbibes water from the tears and after several hours forms a... 

Artificial Tears (Tears Naturale) [OTC] [Ocular Lubricant]... 

Topically administered ophthalmic preparations can affect visual acuity. Examples are lubricating gels and ointments for dry eye, antimicrobial ointments for ocular infections, and gel-forming solutions for glaucoma. Although acuity is only slightly reduced and is only temporary, this effect can be annoying to patients and may lead to noncompliance. 

In addition to moistening the corneal and conjunctival surfeces and providing lubrication for the eyelids, the tear film provides nutrients and oxygen to the ocular surfece... 

Polymer-based artificial tears are the most common tear supplementation product used in dry eye treatment. In addition to dry eye, ocular lubricants are used in the treatment of corneal abrasions, ultraviolet keratitis, herpes simplex and zoster keratitis, phlyctenular disease, giant papillary conjunctivitis, superior limbic keratoconjimc-tivitis, vernal disease, adenoviral infections, and other ocular surfece conditions. 

The beneficial effects of sodimn hyaluronate follow from its viscoelastic properties, which lubricate as well as protect the ocular surface. A study foimd a 0.2% solution of sodium hyaluronate had a significantly longer ocular residence time than did 0.3% HPMC or 1.4% PVA. Most patients achieve control of symptoms with topical instillation up to four times daily. Subjective relief of symptoms such as burning and grittiness usually occurs immediately after drug instillation, and these effects can last 60 minutes or longer. 

Nonmedicated ointments are indicated for moderate to severe dry eye, especially with lagophthalmos, persistent inferior corneal stippling, or severe epithelial compromise. Esters of latty acids with long-chain alcohols, such as petrolatum, mineral oil, lanolin, and lanolin alcohols, serve as lubricants and create a lipid layer, retarding evaporation. Although these preparations (Table 14-2) melt at the temperature of the ocular tissue and disperse with the tear fluid, they appear to be retained longer than other ophthalmic vehicles. Because of their molecular... 

All patients with blepharospasm should receive dry eye testing, because dry eye can exacerbate the spasms. Appropriate dry eye therapy with ocular lubricants or lacrimal occlusion should accompany any other treatment for blepharospasm. The clinician should search for and correct other treatable problems that may exacerbate the disease, such as corneal erosion, fiareign bodies, acute glaucoma, uveitis, entropion, eyelash abnormalities, and blepharitis. Emotional problems and neurosis usually are not a significant precipitating cause of blepharospasm in adults but may play a prominent role in affected younger individuals. 

Treatment consists of ocular lubrication for symptoms or signs of dry eye and treating any secondary bacterial infection with an appropriate topical antibiotic. Topical lubricants alone usually cannot control the symptoms of FES or LES. Preventing lid eversion generally requires lid taping or use of nocturnal eye shields.The definitive treatment, however, is surgical tightening of the eyelid and therefore requires an oculoplastics consult. 

Systane (Alcon) Polyethylene glycol 400, propylene glycol, HP-Guar Balances pH forms a lubricating gel on contact with ocular surface and reported to reduce ocular inflammatory changes. Longer lasting formulation as compared with traditional formulations and can be dosed every 8 hours. 

Pregnant and lactating women and children younger than 8 years should avoid oral doxycycline therapy. In these patients erythromycin base, 500 mg four times daily for 7 days, or amoxicillin, 500 mg three times daily for 7 days, is an alternative to doxycycline. Once systemic therapy has been initiated, topical treatment with lubricants, rasoconstrictors, or a combination antibiotic-steroid may help to relieve the patient s ocular symptoms. 

The management of dry eye associated with SJS can be accomplished in an aggressive feshion with the use of nonpreserved lubricant solutions and bland ointments. Unfortimately, patients with SJS or OCR frequently have chronic severe dry eye. The challenge in managing this condition is to provide the best environment and visual performance possible in the face of rather severe compromise of the ocular surface.The best approach may entail using a variety of mechanisms to preserve lacrimal function, such as moisture chambers, lacrimal occlusion,... 

Pingueculae may become inflamed, resulting in so-called pingueculitis. The most common causes of such inflammation are mechanical irritation or ocular surface disease. Irritation by the edge of a contact lens is a frequent cause (Figure 25-34).Treatment includes elimination of the causal fector, increased lubrication, and a short course of topical steroids when inflammation is significant. 

In mild cases of allergic conjunctivitis, the use of cold compresses, nonpreserved ocular lubricants, and vasoconstrictors provide symptomatic relief Nonpreserved lubricants dilute and flush the precorneal tear film and wash away the allergens. 

Treatment of VKC depends on the severity of symptoms and the clinical presentation. In mild cases the use of cool compresses, ocular lubricants, decongestant-antihistamine combinations, and mast cell stabilizers may be sufficient. Environmental controls include maintaining a cool moist environment, for example, with air conditioning. 

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