Healthy eyes are happy eyes.

Whilst many of us overlook our vision because we're not experiencing any problems, it doesn't mean that subtle changes aren't already happening. Like any medical condition, early detection and intervention can be vital. If you suspect for any reason that your vision is deteriorating or that eye strain and discomfort is holding you back, or you can't remember when your last eye test was, then it's time to book an appointment and get your eyes tested. It only takes an hour and the benefits are enormous.

Below are just a few examples of conditions which can be identified in a routine eye examination at Christensen Harbison Optometrists. Most of these can be treated successfully if identified in time, so don't put off that eye examination!


Glaucoma is a condition in which the nerve cells that transmit information from the eye to the brain become damaged. This prevents visual information from getting from the retina in the eye to the brain. Glaucoma is often associated with a build-up of pressure in the eye. The eye is normally filled with fluid that is constantly being replaced. If excessive amounts of fluid are produced or if it cannot drain away properly, the pressure inside the eye can increase. In some forms of glaucoma, the pressure inside the eye can become extremely high, while in other forms the pressure may remain normal. 


Normal optic nerve head, with healthy pink neural rim. Optic nerve head in early glaucoma with the cup (the white bit in the middle) extending downward due to damage to the neural rim. Optic nerve head in advanced glaucoma where most of the neural rim has died leaving the large white cup in the middle.

Normal Visual Field. The damage to the bottom of the optic nerve head (top picture) causes damage to the top half of the visual field. A large proportion of peripheral (side) vision is missing in advanced glaucoma.

Macular Degeneration

The macula is the central part of the retina, the light sensitive tissue at the back of the eye. The retina processes all visual images. It is responsible for your ability to read, recognise faces, drive and see colours clearly. You are reading this sentence using your macula. Macular degeneration causes progressive macular damage resulting in loss of central vision but the peripheral (side) vision is not affected. There are two main types. Dry macula degeneration causes a gradual deterioration to the central vision due to the macula tissue slowly dying. Wet macula degeneration causes a more sudden vision loss caused by swelling from abnormal blood vessels under the retina. Prompt medical treatment is required. 


 Normal retina showing healthy macula (the red spot in the middle).  Normal macula OCT scan. The retina has ten layers which can be
viewed in cross-section with the OCT scan.

 Retina photo with some subtle changes at the macula
Diagnosis uncertain.
OCT scan of the same macula reveals swelling (the dark area in the middle) from wet macula degeneration. Prompt treatment required.

 Wet macular degeneration. The red spot in the middle is a
haemorrhage and the circular yellow area surrounding it
is fluid/swelling.
 Disciform (circular) scar from advanced wet macular degeneration.

 Early dry macula degeneration. The yellow spots are drusen which are deposits of fatty proteins. They are basically waste product that 
the light receptors have failed to dispose of. 
 Drusen distorting some of the layers of the retina causing a slight
reduction in vision in dry macula degeneration. It is said to be 
"dry" because there are no dark areas representing fluid such as in 
the image earlier up the page. 

 Moderately advanced dry macular degeneration. The macula region has a "moth eaten" appearance due to the tissue slowly dying.  Dry macular degeneration in the fellow eye.

Diabetic Retinopathy

Background or "simple" diabetic retinopathy. Diabetes can cause damage to the blood vessel walls allowing leaks such as the haemorrhages in the above photo. This requires monitoring.   Background diabetic retinopathy. Because the blood vessels are leaky, the retinal tissue can be starved of oxygen leading to proliferative diabetic retinopathy, where the retina grows new blood vessels. These new vessels can haemorrhage and cause serious complications. 


 Laser burns for proliferative diabetic retinopathy. Because the retina is being deprived of oxygen making it "sick", the aim of the laser is to turn sick retina into dead retina. This does affect peripheral (side) vision to an extent but preserves central vision and reduces the risk of serious consequences such as damage to the macula or retinal detachment.  Laser burns for diabetic retinopathy, or "pan-retinal photocoagulation".



Other conditions


 Vitreo-macular traction. Difficult to see from a 
retinal photo alone.
Vitreo-macula traction. Strands of vitreous (the jelly inside the
eye) are adhering to the macula and pulling it apart. It's easy
to see why this would be affecting vision.


Epi-retinal membrane. It's like a clear skin growing over the 
retina, causing the retina to bunch up so that it appears wrinkled in this photo. This can distort vision. Epi-retinal membranes can be removed surgically if the reduction in vision warrants it.
OCT of an epi-retinal membrane which is pulling the macula out of
shape. The epi-retinal membrane is the white line on the top-right
of the image and the retina is bunching up immediately beneath it.

Macula hole. Well defined red circle in the middle surrounded by an orange circular/annular region or "cuff". These can cause a significant decrease in vision, and surgery is usually recommended if the condition is identified in a timely manner.  OCT of a macula hole showing the break/gap in all the layers down to the bottom layer or retinal pigment epithelium. 


 Before cataract surgery. Our view of the retina is obscured by cataract, as is this person's view of the world. Cataract is a clouding of the lens of the eye. During cataract surgery the lens of the eye is removed and an artificial lens put in its place. Cataract surgery nowadays has a very high success rate.   After cataract surgery. Our view of the retina is greatly improved, as is the patient's eyesight. 


Retinal detachment. The retina is lifting up towards the observer making it appear out of focus. Urgent surgery is usually required.  Another example of wet macular degeneration.