I could hardly sleep last night because I was just too anxious to hear the latest about glaucoma from my son, Debola who is a lecturer in Genetic Diseases in one of the leading universities in Canada. He had come from Canada to celebrate my 50th Birthday with me.
Yesterday, he had informed me that a glaucoma gene had been identified in his blood, his younger brother’s and mine. Considering the fact that my father (and probably his older brother and younger sister) had all gone blind from glaucoma, I was very worried we could end up having a whole house full of blind people. What a great burden that would be for my wife, the only one free of this terrible scourge?
“Not quite,” says Debola. “My brother, Desola and I have the gene, but we don’t have the disease yet. It is also erroneous to say that Mother is free of glaucoma because the gene was not found in her blood. Let us get this right.
Many different diseases affecting the eye can result in glaucoma, either alone or as part of a larger syndrome of ocular problems. Therefore, understanding its genetic foundations helps us better understand how and why it occurs.
The picture is undeniably murky as there are a number of identified genes that confer an increased risk of glaucoma on carriers. Desola and I are, strictly speaking, carriers. Having the gene makes us likely candidates to develop glaucoma but we may never do owing to the presence of gene modifiers. A gene modifier is a gene that modifies the effect produced by another gene.
“Dad, remember there are no easily recognisable symptoms and signs of glaucoma until the disease is advanced, so identifying the gene in my brother and I, long before the signs of glaucoma means damage due to the disease can be prevented. Daddy, please, note that some structural and functional damage must have been identified before you can say that a person has glaucoma!
“And even more intriguing is the fact that the major tool (perimetry) for measuring progression (whether we are doing well or not) rely on the evidence of the continuation of damage. In other words, you can only tell if you are winning or not by monitoring the increase in damage. Isn’t that absurd?
“Why must we wait for damage to occur before we know whether to increase the dosage or the frequency of use of the prescribed medication, change it completely or perhaps, intervene surgically? This has been the greatest challenge we faced with the treatment of this disease! And that is why glaucoma has been such a dreadful disease.
“That was several years ago. We are now in the year 2020, the year of the “Right to Sight.” Today, we are better equipped. In addition to knowing that I have the gene, the thickness and other features of the inner coat of my eyes (the retina) are measured at intervals to see if there are subtle structural changes suggestive of any disease, including glaucoma, before any characteristic functional damage occurs.
“Dad, you won’t believe this! I am wearing a “smart” contact lens that monitors my intraocular pressure (IOP) round the clock. You know that elevated IOP is often associated with the optic nerve damage that is characteristic of glaucoma. So, changes in the pressure inside my eyes are accurately assessed day and night.
“Added to this, the patient with glaucoma also has a computerised eye medication delivery system, inserted beneath the eye, that is automatically stimulated to discharge medications to bring the IOP to normal levels. Thus there is a precise and timely delivery of medications to keep the intraocular pressure at the desired level round the clock.
“The most exciting work we are doing now is on modifier genes. We have now identified some of these and in a position to manipulate them to increase the survival of the retinal ganglion cell layer (the inner coat of the eye). This will make it more resistant to damage from high intraocular pressure and other hazards.
“And if all fails and blindness ensues, we have now perfected the Bionic eye to restore sight to the blind. A bionic eye communicates images to the brain so we can distinguish what we see. These mechanical eyes are now being improved upon to provide enhanced sight so that it is possible to see even better than a normal eye! With all these new developments, Dad, would you agree with me that glaucoma is no longer such a dreadful disease?” Debola concluded.
I am completely speechless. What can I say? He has answered all my questions and allayed my fears, except one. There’s just one question. How do I put it? I summon up courage and ask, “When are you coming back home?” “Home?” He shook his head. I notice a tinge of sadness in his voice, “Dad, coming home will sound the death knell for my research – no water, no light and many hungry faces with loads of security challenges. I am sorry, Dad, certainly not now.”