“Consanguineous marriage increase the risk of more prevalence of congenital glaucoma” – Dr Anil Mandal, Consultant – VST Centre for Glaucoma Care – LV Prasad Eye Institute, Hyderabad

In India, the prevalence of congenital glaucoma is more common compared to Western countries. Dr Anil Mandal, Consultant – VST Centre for Glaucoma Care – LV Prasad Eye Institute, Hyderabad speaks about its growing prevalence in India and
the treatment options available, in an interaction with
Raelene Kambli

How do you define primary congenital glaucoma?
Primary congenital glaucoma may be defined as a type of developmental glaucoma which occurs because of embryological abnormality in the trabecular meshwork i.e. the drainage system of the eye. There is no other abnormality in the other structures of the eye or body.

How does primary congenital glaucoma affect the eye?
Usually the affected eye is enlarged in size with increase in corneal diameter and the total volume of the eye is also increased. The axial length of the eye is increased and that leads to myopia as the common refractory error in such children. The affected eye may be having intolerance to light, excessive watering and inability to open the eye even in normal lighting condition indoors. The appearance of the eye may be whitish or bluish because of water logging within the layers of cornea.

What is the prevalence of primary congenital glaucoma in India, and how often do you see it in your practice?
The prevalence of primary congenital glaucoma is one in 10 – 15 thousand live births in western world. In India the prevalence of congenital glaucoma is more common and occurs in 1 in 3300 live births according to the population based study conducted by LV Prasad Eye Institute in the Indian state of Andhra Pradesh. We, at LV Prasad Eye Institute, see congenital glaucoma much more frequently than an average ophthalmologist working in solo practice or an ophthalmologist working in other tertiary eye care centres. This is because of referral nature of the practice and personal interest to pursue good integrated management of children afflicted with congenital glaucoma. In our practice in LV Prasad Eye Institute, we see one or two referred patients in the OPD every day. In my twenty five years of practice I have operated more than 2000 children with congenital glaucoma.

In which area of India do you see a high prevalence
and why?
The prevalence of congenital glaucoma is high in few southern Indian states where consanguineous marriage is a socially-accepted norm. In other geographical areas in India as well as other parts of the world wherever marriage within the close relatives for e.g. uncle to niece or between second cousins is a socially accepted norm, there could be an increase in the prevalence of inherited disorders for e.g. congenital glaucoma.

How is primary congenital glaucoma treated?
Primary congenital glaucoma is a surgical disease and medical therapy has only a supportive role to reduce the pressure of the eye before the surgical intervention is done. The surgical technique involves incisional surgery at the junction of cornea and sclera at the 12 o’ clock position of the eye and the technique involves creating special channel or pathway for the fluid to be drained out of the eye, so that pressure within the eye is maintained in the normal range. Sometimes repeat surgery is required in the advanced stage of the disease.

What are the possible complications from surgery?
The surgery involves general anaesthesia for small children. Naturally, anaesthesia-related risk and complications are always there. Surgical complications include excessive lowering of pressure as well as high pressure within the eye in spite of surgery and both are harmful for the normal functioning of the eye. The aim of our surgery is to maintain the pressure of the eye at a normal range for the proper functioning of the cornea, optic nerve, retina and other structures of the eye.

What is the current state of research in this field?
Current state of research involves genetic study to understand the underlying genetic basis of the disease. Consanguineous marriage i.e. marriage with in the close relatives increase the risk of more prevalence of congenital glaucoma. In certain geographic areas, consanguineous marriages is accepted as a social norm and is one of the important reason for increased prevalence of this disease. Other research areas are surgical technique, exploration for the development newer anti-glaucoma medications and rehabilitation approach.

Tell us about your research in the field of clinical and genetic aspects of glaucoma?
Our research in this field includes clinical research in which we are looking at the long-term surgical outcome of the afflicted children, the affect of low vision assessment and it’s management as well as genetic study. In collaboration with our geneticist, we are looking into the basic molecular mechanism of the disease, genotype-phenotype correlation and identification of new mutations in the gene which are responsible for congenital glaucoma in Indian population patients. We have reported several novel mutations in our patient population in different top-tier journals of the world. We have developed an integrated approach which includes medical, surgical, genetic and rehabilitation approaches for the holistic care of the afflicted children and their families.

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