A concerned pet owner called to complain about the sight of her pet, she was worried that it could be a sign of blindness and she was so confused about what to do, but after some careful evaluation, it turned out to be that, the dog could be suffering from a corneal ulcer, upon hearing the word ulcer she was asking if it was related to the injury of the stomach often due to lack of food but this case was a different one as it had no business with the stomach but certainly with the eye.
Right before we begin to study what cornea is, permit me to describe quickly what the cornea is, it is the transparent shiny membrane that makes up the front of the eyeball. The cornea is made up of three layers that are made of highly specialized skin cells. The outermost layer is the epithelium, which is a very thin layer of cells, below the epithelium is where the stroma is found and the stroma is the major supportive tissue of the cornea. The deepest layer is Descemet's membrane, all the layers stated are very clear, and it is impossible to see them without a special strain that colors specific cells as well as highlight them after being observed under the microscope.
Corneal ulceration could happen for different reasons, it is important not to only treat the ulcer, but also to carry out other examinations to figure out the presence of any underlying cause of cancer, things that could trigger corneal ulceration including eyelid disease for example; ectropion, extra eyelashes, entropion, ectopic cilia, dry eyes, exposure to a foreign object, infection with Feline Herpes Virus, nerve paralysis, and trauma. The average size of the canine cornea is 0.62mm thick, corneal epithelium is made up of stratified, nonkeratinized squamous cells. The epithelium is 5-7 cell layers thick and could regenerate upon injury, and its purpose is to provide a barrier against water, chemicals, and microbes.
Corneal erosion or corneal abrasion is when there is an erosion of a few layers of the epithelium, and a corneal ulcer is a deeper erosion that cuts through the entire epithelium and into the stroma. With corneal ulcer, fluid begins to accumulate in the stroma, providing a cloudy appearance to the eye, and when erosion gets through the epithelium and stroma then into the deepest level of Descemet's membrane and then a DESCEMETOCLE is formed, which is a very serious condition. Upon the rupturing of the descemet's membrane, the liquid inside the eyeball would leak out, the eye would collapse and the liquid in the eyeball would leak out, when this happens, the eye would collapse and there would be irreplaceable damage.
At any point when there is a red or painful eye, or there is an ocular discharge, the cornea needs to be stained to look for the presence of an ulcer, once an ulcer is found and it has a stromal loss or a cellular infiltrate. Professionals highly recommend that canine patients with a corneal ulcer be fitted with an E-collar at least until the ulcer is healed. Different categories of E-collars are available, but something that will protect the eye is usually recommended, but the collars that are made of a soft cloth and 'donut' styles cannot protect the eyes.
Trauma is the most common cause of corneal cancer, an ulcer could proceed from blunt trauma, like rubbing the eye on the carpet, contact with a harp object or laceration, Chemical burn occurring due to an irritant shampoo, or when drywall dust enters into the eye. Viral infections, bacterial infections, and other diseases could also trigger corneal ulcers, although it is a very rare occurrence. A corneal ulcer is a very painful experience, most dogs when affected will begin to rub the affected eye with a paw or rub it on a carpet to relieve the intense pain felt, they also try to keep the lids tightly shut to protect the eye, sometimes the discharge collected will gather at a corner of the eye, and in some occasion, it would run down the face.
In the case of Descemetoceles, surgical treatment with a graft is advised, in a case where the pet owner is unable to afford surgery or the patient is not an ideal anesthetic candidate, some form of aggressive medical management could be attempted with the knowledge that the eye may be removed. A perforated eye could still be saved depending on the age and size of the perforation, but if the eye still has a form of positive dazzle response, vision could still be saved and a graft could be attempted. Surgical intervention is the best chance that can be used to save the globe of the pet, but pet owners must bear in mind that, the eye could be enucleated or shrink. At a point where a watertight seal cannot be accomplished, then the eye of the affected eye would continue to leak and be a source of pain and possible infection.
The treatment for corneal ulcers depends greatly on whether the condition is a corneal abrasion, corneal ulcer, or descemetocele. It takes corneal abrasions around 3-5 days to get healed, medications are usually taken to prevent bacterial infections and relieve spasms and pain. Antibiotics eye drop function for a short time and they need to be applied consistently and often, about every 4-6 hours depending on the prescription by the vet.
When corneal ulcer or descemetocele is the case, then necessary steps must be taken for healing. Surgery may be a required option to take out dead or poorly healing layers of corneal tissue to perform a corneal graft, your vet will choose the best option to help foster the healing for your pet. For pet owners who choose to use antibiotics for the treatment of their pet, please pay attention to your pet, and if they appear to be in pain, then discontinue the medication. Corneal ulcer on its own is a highly painful condition and highly kept tightly shut, Atropine helps to relieve pain but it also dilates the pupil widely, so bear in mind that the eye is sensitive to light and your pet may close his or her eye when exposed to bright light, the dilation of the eye could last for several days after the drug may have been discontinued.