Theme of the Issue: Glaucoma - Leading cause of Blindness
NPCB INDIA QUARTERLY
January - March 2013
From Editor's Desk National Programme for Control of Blindness (NPCB) was launched in the year 1976 as a 100% centrally sponsored scheme with the objective to reduce the prevalence of blindness to 0.3% population by 2020.
NEWSLETTER
The basic objective of the National Programme for Control of Blindness today still remain the same as planned initially since its inception. The new initiatives undertaken during the 11th Five Year Plan included prevention, screening and management of new emerging diseases including childhood blindness and glaucoma. These new initiatives under the 11th Five Year Plan have been incorporated into the 12th Five Year Plan with renewed vigour and massive IEC plans are on the anvil to educate the masses about the need to diagnose and manage these eye diseases at an early stage.
QUARTERLY
NPCB has taken a lead in addressing other issues of blindness in a comprehensive manner during the 12th Five Year Plan (2012-17) as well. All attempts shall be made to cover and address emerging eye diseases other than cataract like diabetic retinopathy, glaucoma, childhood blindness, low vision and corneal blindness in a mission mode through successful public private partnership. The endeavour of the NPCB programme is to treat successfully all persons suffering from avoidable blindness and to reach a annual sustainable level in terms of number of people treated well. Glaucoma is the third leading cause of blindness in India. According to NPCB-WHO survey (198689) glaucoma accounts for 5.80% of total blindness in India. Most epidemiological studies in India have concentrated on detection of primary open-angle glaucoma but it has been found that in oriental races including India, primary angle closure glaucoma accounts for nearly 30% of all cases of glaucoma. A look at the number of persons who are blind or heading towards blindness due to glaucoma in 50+ population gives an inkling of the gravity of this problem, as shown on next page. Late diagnosis is the main hindrance in preventing blindness due to glaucoma.Majority of the people, particularly in the rural and remote parts of country, come to know about it when vision in one eye has already been lost and there is significant diminution of vision in the other eye. Therefore, it becomes mandatory that the PMOAs, Medical Officers posted in the PHCs and the ophthalmologists working in district hospitals are able to pick up the patients suffering from glaucoma at early stages by looking at the fundus for optic disc changes, measuring intraocular pressure to find out any elevated levels and by doing visual field charting. Local drug treatment with eye drops should be started only when the diagnosis has been amply confirmed by an ophthalmologist working in the district hospital, better still in a medical college or tertiary level NGO eye hospital.
Statewise Blindness due to glaucoma in 50+ population
* Note: As per the National Survey 2001-02
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NATIONAL PROGRAMME FOR CONTROL OF BLINDNESS IN INDIA
Diagnosis Diagnosis of Glaucoma requires a comprehensive ophthalmic examination by an ophthalmologist that includes applanation tonometry (to measure IOP), shiotz tonometry and non contact tonometry being less reliable, slit lamp examination (evaluation of anterior chamber of the eye), ophthalmoscopy (examination of optic nerve), visual field testing (to know the functional status of nerve), pachymetry (thickness of cornea) and photograph of optic nerve with the help of fundus camera.
Normal
Abnormal
View of Optic Disc
Diagnostic Tests Following diagnostic tests are done to diagnose the disease. Tonometry: Is done to measure the pressure inside the eye. Normal pressure of eye ranges from 10-21 mm hg. Pressure recorded under general anesthesia is less than done without anesthesia because of the effect of the anesthesia. Corneal Measurement: Because of the increased eye pressure the corneal diameter may be increased from its birth diameter 10.5 mm. if corneal diameter is more than 12 mm in its first year of birth then that child should be investigated for congenital Glaucoma. Cornea may appear cloudy or hazy due to swelling of cornea. This haze usually clears when the pressure returns to normal. In advanced cases it may persist. Haab striae (tears in the Descemet membrane, which is the inner tissue layer of the cornea) may be seen as a result of elevated IOP. Gonioscopy: This is done to check whether angles are open or close. Ophthalmoscopy: Ophthalmoscopy is done to visualize changes in the optic nerve. Fundus photographs: May be taken to visualize changes and for future references. Pachymeter : Pachymetry is done to know the extent of corneal swelling. A- Scan: May be useful in knowing the length of eyeball.
Advancements in diagnostic tools HRT III (Heidelberg Retinal Tomogram): Optical Coherence Tomography (OCT): Anterior Segment OCT (Visante OCT): NPCB INDIA NEWSLETTER, JAN. - MAR. 2013
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Glaucoma Leading Cause of Blindness There are at least 12 million people in India affected with the Glaucoma, 1.5 million are blind from the disease2. In India various studies have reported prevalence of Glaucoma ranging from 1%-6%. A study conducted by National Programme for Control of Blindness, DGHS during the year 1999-2001 showed the prevalence of Glaucoma as 5.9% 1, in the blind people amongst 50+ age group. Glaucoma refers to a group of eye conditions that lead to damage to the optic nerve, the nerve that carries visual information from the eye to the brain. In many cases, damage to the optic nerve is due to increased pressure in the eye, also known as intraocular pressure (IOP).Glaucoma is also known as silent thief of sight. Types of Glaucoma ! ! ! !
Open-angle (chronic) Glaucoma Angle-closure (acute) Glaucoma Secondary Glaucoma Congenital Glaucoma
Open - angle (Chronic) Glaucoma Open-angle Glaucoma occurs slowly as the drainage area in the eye becomes clogged. Fluid from inside of the eye is unable to drain outside of the eye resulting in to building up of Pressure. Peripheral vision is damaged gradually. Open-angle Glaucoma is the most common kind of Glaucoma. Angle - closure Glaucoma This is less common type and can leads to rapid loss of vision if not treated immediately. Rapid rise in intraocular pressure occurs due to sudden blockade of drainage system of eye. Blurry vision, rainbow halos around lights, headaches or severe pain may occur with closed-angle Glaucoma Secondary Glaucoma Secondary Glaucoma occur secondary to some other disease process in the eye like bleeding & inflammation in the eye, hypermature cataract and tumour etc. Main line of treatment is controlling and curing the primary cause. Usually secondary Glaucoma subsides after removal of primary cause but some times residual changes may persist. Congenital Glaucoma Primary congenital Glaucoma is present at birth. It is usually diagnosed at birth or shortly thereafter, and most cases are diagnosed during the first year of life. ! ! !
Inherited as autosomal dominant. In 75% of cases, primary congenital Glaucoma is bilateral. It occurs more often in boys than in girls.
Prevalence of Congenital Glaucoma: In contrast to a prevalence of1:10,000 in the West, prevalence is as high as 1:1250 among the Romany population of Slovakia, and 1:2500 in the Middle East, suggesting a genetic etiology. In the Indian state of Andhra Pradesh, the prevalence is 1:3300, and the disease accounts for 4.2% of all childhood blindness3.
Symptoms ! ! !
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Excessive tearing (called epiphora) Sensitivity to light (called photophobia). Spasms or squeezing of the eyelid (called blepharospasm)
NATIONAL PROGRAMME FOR CONTROL OF BLINDNESS IN INDIA
Treatment Glaucoma cannot be cured, but it can be controlled, Medications can lower the pressure enough to protect the optic nerve from future damage and possible loss of vision. Glaucomatous visual loss cannot be restored. But if the intraocular pressure is reduced substantially, progressive visual loss may be prevented in a majority of cases.
MedicalTreatment Anti-Glaucoma medicines are required for long period usually life long. Irregular application of antiGlaucoma eye drops hastens the optic nerve damage and hence patient has to adhere to strict regime under supervision.
LaserTreatment Laser Irodotomy: A small opening is made in the iris using the Nd: YAG Laser to facilitate easier circulation of aqueous humour within the eye. As the procedure is simple and doesn't have significant side effects, it may also be done as a preventive measure in patients having narrow angles but have not developed Glaucoma. Laser Iridoplasty: In some cases of narrow angle Glaucoma, the iris is bunched up to cause narrow angles.The Argon Laser can be used to reduce this bunching and cause angle re-opening. Selective Laser Trabeculoplasty: This procedure is useful in patients with primary open angle Glaucoma.This laser selectively modifies trabecular meshwork (drainage area) to increase drainage of eye fluid and decrease intra ocular pressure.The treatment however has a tendency to lose its beneficial effect over time.
Surgical treatment Surgery is done to create an alternative pathway for drainage of aqueous fluid outside of the eye. Prognosis of this surgery is usually good but some time its beneficial effects may be lost over a period of time. Hence patient is instructed to have a regular checkup even after successful surgery.
Glaucoma Looking beyond Intraocular Pressure Glaucoma is a group of eye diseases characterized by a progressive optic neuropathy (with multifactorial risk factors) characterized by recognizable patterns of optic disc and retinal nerve fiber structural and visual field functional damage.
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Glaucoma can occur despite Intra Ocular Pressure (IOP) being in the normal range and glaucoma patients often progress despite controlled IOP. There are three major theories regarding the pathogenesis of glaucoma:
! Mechanical (IOP related damage) ! Vascular (decrease in blood supply to optic nerve head) ! Biochemical (decrease in neurotrophic factors / increased levels of neurotoxins) Hence potential treatment options include decreasing IOP, increasing blood flow to optic nerve head and neuroprotection of retinal ganglion cells. Presently, IOP is the only risk factor which we treat. In clinical practice, most ophthalmologists rely mainly on sporadic measurements of IOP obtained during daytime office visits. Such sporadic determination of IOP in the office is somewhat akin to random blood sugar checks in the management of diabetes. Twenty-four–hour IOP behavior in glaucoma patients has implications for both disease pathogenesis and disease management as any single intraocular pressure measurement taken between 7 am and 9 pm has a higher than 75% chance to miss the highest point of a diurnal curve.
NPCB INDIA NEWSLETTER, JAN. - MAR. 2013
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Factors other than IOP: i)
Perfusion Pressure
Mean Ocular Perfusion Pressure (OPP) is defined as the mean arterial pressure minus IOP. Systolic and diastolic OPP can also be calculated using systolic and diastolic blood pressure values, respectively, minus IOP. Several studies have shown that cardiovascular disease, low BP, low perfusion pressures are predictors for long term progression in Glaucoma. Quigley and colleagues have shown in a study that subjects with a diastolic ocular perfusion pressure lower than 50 mmHg had a 4 times greater risk of OAG than those with a perfusion pressure of 80 mmHg. It has also been shown that, lower systolic perfusion pressure more than doubled the relative risk (RR) and lower diastolic perfusion pressure (DPP) ( 70 yrs). Glaucoma patients with significant visual field defects on automated perimetry should be counselled against driving and encouraged to use public trnasport or ask somebody to drive them to work/hospital. viii) Ocular surface health: Atleast 45% to 60% of patients instilling topical glaucoma medications are reported to have ocular surface disease (OSD). Changes in the ocular surface, conjunctiva, and trabecular meshwork are known to occur because of long-term exposure to glaucoma eyedrops and also to preservatives, active ingredients, or both. The coexistence of OSD and the use of BAK-containing medications may impact vision-related quality of life in this patient population. ix) Drug instillation technique: In a recent study done by the authors, it was found that nearly 90% of glaucoma patients were unable to instill glaucoma eye drops correctly. This is an important concern while treating glaucoma as this may be a cause of non-compliance and non response to glaucoma therapy. So, there should be proper demonstration of drug instillation technique by the treating doctor and this should be checked during follow up visits. Since Glaucoma can be treated and vision preserved if diagnosed at an early stage, if a patient is diagnosed to have glaucoma, the treating ophthalmologist must counsel the family of the patient regarding the life long treatment and follow up and screen the rest of the family members for Glaucoma. A systemic evaluation by a physician and treatment of associated systemic conditions is essential for ensuring a good quality of life in Glaucoma patients Tanuj Dada, Parul Ichhpujani, Reetika Sharma
NPCB INDIA NEWSLETTER, JAN. - MAR. 2013
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Observation of World Glaucoma Day As part of the Glaucoma Week, a Glaucoma Walk was flagged off on 13th March, 2013 from Civil Hospital, Shillong premises to Shillong club by Ms. Sujaya Krishnan, Joint Secretary, Government of India , Ministry of Health & Family Welfare. The walk was organized by the Meghalaya Blindness Control Society in collaboration with the NGO Bansara Eye Care for the North East Region. On the occasion, a workshop on the role of the media and civil society in eliminating avoidable blindness with special focus on Glaucoma was inaugurated by Shri R.S. Mooshahary, Governor, Meghalaya. “Let us dispel ignorance not just by visiting eye specialists but by creating an aware society because most people choose to be blind even with their eyes open”. Mooshahary exhorted the audience. The occasion also saw release of booklet the “Glaucoma Awareness for the General Public”, by the Governor, alongwith Ms. Krishnan and Shri D.P. Wahlong, Commissioner and Secretary (Health & FW), Government of Meghalaya. The week also saw hands on training by Dr. Tanuj Dada to all eye surgeons in the State.
To create awareness about Glaucoma amongst people, Delhi Ophthalmology Society organized a walk from Siriforts Sports Complex to AIIMS auditorium. A large number of eminent ophthalmologists and glaucoma specialists gathered at the venue and spoke about the need for creating awareness about the blinding effect of glaucoma and the problem of late diagnosis of this disease due to inability on the part of the public to seek medical attention at an early stage. Dr. N.K. Agarwal, Deputy Director General (NPCB), Nirman Bhawan participated in the meet and walk. He apprised all those present about the inclusion of glaucoma in the group of eye diseases for which NPCB issues funds to the NGOs and Govt. facilities, so that the low income group persons suffering from glaucoma are rendered free services, both diagnostic as well as medical on March 10, 2013 and surgical treatment.
INBOX Good magazine - provides latest information. Dr. M.H. Khan Mohammadia Hospital, MoH : Chawni - Banda (U.P.) Pin - 2010001 E mail.:
[email protected] The newsletter is very informative and update. Dr. Suresh Prasad H.o.D. (Eye), J.L.N.M. College Hospital, Bhagalpur, (Bihar) 812001 E mail.:
[email protected]
Mr. Ashok Parmar,
FEEDBACK / RESPONSE The material in the quarterly news letter is prepared meticulously and is informative, not only to the community but also to practitioners. Dr. Suresh Chandra Pant Senior Eye Surgeon (Joint Director) S.S. Jina Base Hospital, Haldwani, (Nanital) Uttarakhand E mail.:
[email protected]
