One review has found that eye drops to numb the surface of the eye such as tetracaine improve pain; however, their safety is unclear. Another review did not find evidence of benefit and concluded there was not enough data on safety. Topical nonsteroidal anti-inflammatory drugs (NSAIDs) are useful to reduce the pain caused by corneal abrasions. Diclofenac and ketorolac are the most used, one drop four times a day. It is worth noting, however, that diclofenac may delay wound healing and ketorolac should be avoided in people who wear contact lenses. Some studies do not recommend using topical NSAIDs due to the risk of corneal toxicity. There is no direct evidence regarding the use of oral analgesics, but because pain relief is the main concern for people with corneal abrasions, these are prescribed according to individuals characteristics. Topical antibiotics are used to prevent concomitant infections, which result in slower healing of corneal abrasions. Ointments are considered the first-line treatment, as they are more lubricating than drops. If the person uses contact lenses, an antibiotic with anti-pseudomonal activity is preferred (ciprofloxacin, gentamicin or ofloxacin), and the use of contact lenses should be discontinued until the abrasion has healed and the antibiotic treatment has ended. This is because contact lens wearers are often colonized with Pseudomonas aeruginosa, which may cause corneal perforations and subsequent permanent vision loss.
The flukes can also reach other organs and tissues, such as the brain and skeletal muscles. However, when this takes place completion of the life cycles is not achieved, because the eggs laid cannot exit these sites. Time from infection to laying of eggs is 65 to 90 days. Infections may persist for 20 years in humans. Animals such as pigs, dogs, and a variety of feline species can also harbor P. westermani. For other species, rodents and deer are also additional (paratenic) hosts. By consuming infected animals of these reservoir species, even animals and humans that do not eat crustaceans directly can become infected. Background
The first human case was seen in 1879 in Taiwan. An autopsy was done and adult trematodes were found in the lungs. The adult flukes have a reddish-brown in color with an ovoid shape. They have two muscular suckers, the first an oral sucker located anteriorly and the second a ventral sucker located mid-body. The adult flukes can live up to 20 years. The eggs are golden brown in color and are asymmetrically ovoid. They have a very thick shell. As seen above, these trematodes have a very complex life cycle with seven distinct phases involving intermediate hosts and humans. These seven phases are outlined as follows: eggs reach fresh water where they develop into miracidia. These penetrate many species of aquatic snails (first intermediate host) where they go through three distinct stages: first sporocysts, then rediae, and finally cercariae, also referred to as the larvae.