Optometry clinics : the official publication of the Prentice Society最新文献

Intracranial hypertension is not a definitive diagnosis, but rather a syndrome that may result from a number of neurologic and systemic disorders. Intracranial hypertension refers to prolonged elevation of intracranial pressure, generally above 200 mm H2O. This condition may be recognized by the various clinical signs and symptoms that are manifest in most patients, including headache, papilledema, transient visual obscurations, diplopia, ocular motor disorders, tinnitus, nausea, vomiting, and mental irregularities, as well as dysfunctions of the circulatory and respiratory systems. Thorough medical testing as well as a comprehensive ocular evaluation is indicated in these cases. Intracranial hypertension most commonly results from mass lesions, tension hydrocephalus, and pseudotumor cerebri. Other causes include disorders of venous outflow, such as dural sinus thromboses or arteriovenous malformations, and various encephalopathies. Management for intracranial hypertension may involve medical treatment, drug therapy, or surgical intervention. Typically, diuretics are used initially. Corticosteroids may be used as well, although they are not the first choice for treatment. Cerebrospinal fluid shunting procedures may be necessary if medical treatment fails. Optic nerve sheath decompression may also be attempted when chronic papilledema threatens visual function. It is important that the primary care optometrist recognize the manifestations of intracranial hypertension in order to make necessary referrals for management of the underlying etiologies.

This paper describes the diagnosis, analysis, and management of ophthalmic bacterial corneal infections, with emphasis on the various risk factors, culture techniques, relations to other pathologic states, prophylaxis, sensitivity trends, and treatment protocols associated with bacterial corneal ulcers. New antiinfective agents and their role in the management of current bacterial ophthalmic infections are also discussed.

Lasers are a key component of the vision practitioner's arsenal of care, and provide a wonderful new frontier of diagnostic and therapeutic options. In light of their expanded utilization, it is crucial that eye care practitioners have a thorough understanding of potential laser hazards and the regulations that establish guidelines for their safe application. This review describes the American National Standards Institute (ANSI) standards applicable to the safe use of lasers (Z 136.1) and the safe use of lasers in health care facilities (Z 136.3). Laser hazard classification, the organization of a laser safety program, and administrative and procedural controls are included.

Current ophthalmic laser treatment can be described on the basis of its effect on tissue. Laser variables such as wavelength, spot size, power, and mode of delivery are all controllable, but are dependent on the transparency, pigmentation, and water content of the tissue involved. This discussion introduces the clinician to these variables, while describing specific laser-tissue interactions.

The tear film is a complex physical and biochemical structure. It functions to lubricate and protect the ocular surface from a variety of insults. Disorders of the tear film can lead to patient complaints as well as observable clinical signs. Combining clinical observations with a knowledge of the dynamic interaction of the tear film and the ocular surface should allow the practitioner to develop a management plan for symptomatic patients. This article details the many tests available for assessing tear film and ocular surface integrity, and discusses means of managing complications.

The excimer laser will have a tremendous impact on the future of eye care. This article covers the basic concepts of photorefractive and phototherapeutic keratectomy. Preoperative, operative, and postoperative techniques are reviewed. Common postoperative complications are discussed. This article also reviews clinical data and future trends in excimer technology. A comparison of photorefractive keratectomy with radial keratotomy is also provided.

All forms of primary and secondary pupillary block angle-closure glaucoma result in an increased resistance to aqueous flow at the pupil margin. As the pressure in the posterior chamber increases, the iris bows forward until the trabecular meshwork is occluded and aqueous outflow is interrupted. Most pupillary block glaucomas are ocular urgencies and require immediate medical therapy to lower intraocular pressure. The definitive treatment for pupillary block is laser therapy. By creating a hole in the iris, the pressure in the anterior and posterior chambers is equalized, allowing the angle to remain open. This discussion reviews the indications, contraindications, and techniques involved in the laser management of angle-closure glaucomas.

Corneal vascularization is an important clinical event that requires careful management. Vessel penetration can serve to heal a threatening inflammatory process, cause opacification and loss of vision, induce graft rejection, or serve as a warning of corneal distress. The latter condition is particularly common in contact lens wearers. Practitioners should be aware of the subtle signs of early neovascularization, and work toward its remission. Acute vessel penetration is a difficult clinical situation to manage. Quiescent vessels in the cornea must be explained by history and managed with either monitoring or intervention.

High serum cholesterol levels have been accepted as a major risk factor for cardiovascular disease and arteriosclerosis. There are several corneal signs that potentially indicate abnormal cholesterol levels, thus altering the eye care practitioner to refer the patient for lipid evaluation. This article describes the corneal manifestations of abnormal cholesterol levels and offers guidelines for management.