Eye injuries in auto accident cases can be devastating. The eye is a very special mechanism.
The purpose of this article is to explain the function of the eye and what the role is of different physicians in terms of treating the eye.
The eye is basically broken into 2 segments. There is the anterior segment. That anterior segment includes the conjunctiva, the cornea, the anterior chamber, the iris, the pupil and the lens. The lens itself is inside a capsule. Everything that is behind that lens is referred to as the posterior chamber. That posterior chamber is comprised of the vitreous body, the retina, the choroid, the macula and the optic nerve.
Let’s talk about those various structures and what they’re composed of.
Auto Crash Eye Injuries-Structures
The conjunctiva is a thin layer of tissue that surrounds approximately 5/6 of the eye. You may be familiar with the term “conjunctivitis”. That is simply a condition that develops when the conjunctiva becomes slightly infected and generates a type of pus.
The outermost structure in the center of the eye is called the “cornea”. It is very thin but it consists of several different layers. The stroma comprises about 90% of the cornea. Sometimes the cornea can become cloudy or swollen. In particular it may develop tiny little cysts which may be called “microcystic edema”. If that is the case, then not only is the cornea cloudy but it is also swollen.
Auto Crash Eye Injuries-Pressure
Pressure in the eye is measured by putting an instrument against the cornea to measure the force of the fluid inside the eye pressing outward. That pressure is referred to as “intraocular pressure”. It may be important in terms of evaluating the overall condition of the eye. The high normal of pressure readings typically is in the range of 21.
Inside of the cornea is what is called an anterior chamber. That chamber is filled with water which is called “aqueous humor”. Sometimes that chamber can become cloudy because of any insult to the eye itself.
The next structure is the iris which is the structure in the eye that gives the eye its color. The iris also has the function of controlling the pupil. That is, the pupil gets bigger i.e., dilates and gets smaller as a result of the movement of the iris.
Auto Crash Eye Injuries-Pupil
The pupil itself might be referred to as a donut hole. It is not literally a hole. It is an area in the center of the eye that is filled with fluid that allows light to pass through it.
The next structure is the lens itself. The lens is comprised of basically 3 elements. The nucleus of the lens is the center which is quite hard. As you move away from the center, the lens itself becomes a bit softer and graduates into an area called the “cortex”. The third portion of the lens is the capsule which is the bag or envelope that contains the lens. The capsule is a very thin fiber, thinner than a human hair, that surrounds the entire lens.
Behind the lens is what is called posterior segment or posterior chamber of the eye. Four-fifths of the eye consists of what is called “vitreous body” which is comprised of vitreous fluid. Vitreous literally means glass. This vitreous fluid is a jelly-like substance essentially the same consistency as egg whites. It is sticky and stringy.
If a foreign body gets into the vitreous area, it may be necessary to remove all of that vitreous along with the foreign matter.
Retinal Tear or Retinal Detachment
Likewise if there is a retinal tear or retinal detachment, then the surgeon may perform a vitrectomy to remove all of that vitreous fluid and then cauterize the retina back to the structure behind it.
The surgeons who perform this type of posterior segment surgery are referred to as retina specialists. There is a very distinct divide between surgeons who deal with the anterior segment or chamber of the eye and those surgeons who deal with the posterior segment or chamber of the eye. The surgeons who deal with the anterior segment are referred to as anterior segment surgeons. The surgeons who deal with the back of the eye are referred to as posterior segment surgeons or retina specialists.
The Retina
Other structures within the back of the eye are the retina which is similar to the film that existed years ago in cameras. That retina should be flat against the back wall of the eye and it absorbs the light and sends signals to the optic nerve which then sends signals to the brain creating the picture that we see. An easy way to think of this process is that the retina is like a film which absorbs the light, interprets the light in analog fashion and then sends a message to the optic nerve which converts the message to a digital message which is then conveyed to the brain which then creates the pixels that constitute the picture.
The retina itself consists of two areas. The center of the retina is referred to as the macula. That is where your fine or focused vision is. The edges of the retina are referred to as the periphery and that is where your peripheral vision is. The optic nerve is right below the macula in the back of the eye.
Behind the retina is a wall called the “choroid”. That choroid is blood-rich. It supplies the blood to the retina.
Behind the choroid is what is called the “sclera” which is the white of the eye. That white of the eye encircles approximately 5/6 of the entire globe of the eye.
Like a Balloon
You can think of the eye as being like a balloon. It is about 1 inch in diameter. The eye is mostly filled with fluid but it also does have solid structures. It obviously is very sensitive.
The most sensitive of those structures is probably the optic nerve. The way that an optic nerve is evaluated by an ophthalmologist is based upon what is called the “cup to disk ratio”. What that means is that the center of the optic nerve, as visible to an ophthalmologist, should be approximately 30% i.e., 0.3 of the total circumference of the disk that surrounds the central cup.
A surgeon looking at the optic nerve can also tell by the overall condition of it whether or not it appears healthy. Damage to the optic nerve however may not manifest itself for months after an actual injury. As such these readings as referenced above may be somewhat misleading in terms of defining the overall condition of the optic nerve since the optic nerve is a very sensitive structure and there are a number of components to determine the overall health of the optic nerve.
Auto Crash Eye Injuries-Optic Nerve
Of all the injuries to the eye, the most devastating typically is an injury to the optic nerve. It is the optic nerve that conveys the signal to the brain which allows sight.
If any of the structures referenced herein are seriously injured, then they may require repair. That repair can be painful, extensive and sometimes sight-limiting.
Call, or contact us for a free consult. Also for more info on eye injuries see the Wikipedia pages. Also see the post on this site dealing with auto crash issues.
