Conjunctiva

NHCOCH3. White crystals, m.p. 18l-l83"C. Soluble sulphacetamide is the sodium salt which is soluble in water. Il is prepared by acetylating sulphanilamide and hydrolysing one acetyl group. Being more soluble than most of the sulphonamides it is used in treating infections of the urinary tract and of the conjunctiva. 

Acrolein vapor is highly irritating to the eyes, causing pain or discomfort in the eye, profuse lacrimation, involuntary blinking, and marked reddening of the conjunctiva. Splashes of Hquid acrolein will produce a severe injury to the eyeHds and conjunctiva and chemical bums of the cornea. 

In humans, cases of dermatitis have been described after contact with DHBs. Combined exposure to hydroquinone and quinone airborne concentrations causes eye irritation, sensitivity to light, injury of the corneal epithelium, and visual disturbances (126). Cases with an appreciable loss of vision have occurred (127). Long-term exposure causes staining due to irritation or allergy of the conjunctiva and cornea and also opacities. Resorcinol and catechol are also irritants for eyes. 

Magnesium vanadates, as vanadium compounds in general, are known irritants of the respiratory tract and conjunctiva. The threshold limit value (TLV) for vanadium compounds in air recommended by the National Institute of Occupational Safety and Health is 0.05 mg/m based on a typical 8-h workday and 40-h workweek (7,147). Chronic inhalation can lead to lung diseases such as bronchitis, bronchopneumonia, and lobar pneumonia. These dust-related effects can be avoided by use of individual respirators in areas where exposure is likely. 

Vision is vital for human activities, and eyes are very sensitive to a number of toxic insults induced by chemical compounds. The most serious outcome is permanent eye damage which may be so severe as to cause loss of vision. The eye consists of the cornea and conjunctiva, the choroid, the iris, and the ciliary body. It also contains the retina, which is of neural origin, and the optic nerve. The retina contains photoreceptors, a highly specific light-sensitive type of neural tissue. The eye also contains the lens and a small cerebrospinal fluid system, the aqueous humor system, that is important for the maintenance of the steady state of hydration of the lens and thus the transparency of the eye. 

Augapfel, m. eyeball, "apple of the eye. bindehaut, /. ocular conjunctiva, -gef ss-haut, /. chorioid membrane, chorioid. haut, /. sclerotic coat, sclera. 

Augen. eye. visual, ocular, optic. achat, m. Min.) cat s-eye. -arzt, m. oculist, -binde-haut, /. ocular conjunctiva. -blick, m. moment, instant. 

Vereinigung, /. union, combination 2iasocia-tion, society, club agreement. Vereinigungs-haut, /. (Anat.) conjunctiva. 

Panthenol is frequently used in ointments and solutions for the treatment of burns, anal fissures, and inflammation of the conjunctiva. The vitamin has to be substituted in patients on total parenteral nutrition and in those who regularly undergo dialysis. Hypervitamin-osis has not been observed for doses up to 5 g/d (22). Furthermore, the administration of pantothenic acid leads to improved surgical wound healing due to its antiinflammatory properties. 

The effect on the eyes was more noticeable. A single application of the solution mentioned above produced moderate redness and short and minor swelling of conjunctiva. Radiotracer studies with Hostapur SAS [102] revealed that after oral (up to 50 mg/kg) and dermal application on rats, the product and its metabolites were very quickly excreted either in completely oxidized form as carbon dioxide or in the urine and feces. Residues in organs and tissues after 7 days were well below 1 ppm. 

The cornea is the first structure of the eye to be in contact with incident light. It is composed of five distinct layers lying parallel to its surface the outer epithelium, which is continuous with the epithelial layers of the conjunctiva the epithelial basal lamina the keratocyte-containing stroma, which is a collagen structure arranged so that it is transparent Descemet s membrane and, finally, the endothelium adjacent to the aqueous humour. 

While no exact numbers are available, conjunctivitis, which is also known as red eye, is one of the most common ophthalmic complaints seen by general clinicians. An inflamed conjunctiva is the most common cause of red eye.10 Use the differential diagnosis algorithm shown in Fig. 60-1 to determine the proper treatment or need for referral. 

Petechiae are very small (usually less than 3 mm) pinpoint flat red spots beneath the skin surface caused by microhem-orrhaging. They occur in 20% to 40% of chronic IE, often found on the buccal mucosa, conjunctivae (Fig. 71-3A) and extremities1 (Fig. 71-3B). 

Chemosis Edema of the bulbar conjunctiva, forming a swelling around the cornea. 

Keratoconjunctivitis sicca Dryness of conjunctiva and cornea a component of Sjogren s syndrome. 

The potential of diisopropyl methylphosphonate to cause eye irritation was evaluated with the Draize Test (Hart 1976). The compound was directly applied to the conjunctival sac of one eye in each of nine New Zealand White rabbits. Significant irritation of the conjunctivae was observed in all rabbits, and the comeal surface was characterized by a diffuse opacity. The opacity was temporary and cleared within 8 days. Irrigation with lukewarm water following application of diisopropyl methylphosphonate reduced but did not prevent irritation (Hart 1976). 

In-depth discussions of the anatomy of the eye and adnexa have been adequately covered elsewhere in the pharmaceutical literature [13-17] and in recent texts on ocular anatomy. Here a brief overview is presented of the critical anatomical features that influence the nature and administration of ophthalmic preparations. In this discussion, consideration will be given primarily to drugs applied topically, that is, onto the cornea or conjunctiva or into the palpebral fornices. Increasingly, drugs are being developed for administration by parenteral-type dosage forms subconjunctivally, into the anterior and posterior chambers, the vitreous chamber, Tenon s capsule, or by retrobulbar injection. 

---