6BRIEF RESUME OF THE STUDY:

6.1NEED FOR THE STUDY :

Hypertensive retinopathy represents the ophthalmic findings of end organ damage secondary to systemic hypertension. Systemic hypertension is one of the most common disease in adult population and since it commences asymptomatically, its early detection and adequate treatment is very essential to reduce complications and thence quality of life. Hypertensive retinopathy is a relatively common condition in ophthalmic practice as ophthalmoscopy of a hypertensive patient forms an indispensable aid in its assessment and its prognosis but its value vis a vis general systemic complications is seldom noticed. Retinal vessels can be assessed because of their unique accessibility and inferences can be made as to the condition of vessels of similar size elsewhere in the body. Macroangiopathy in hypertensive patients affects vessels in retina, kidney and brain probably to a similar extent. It helps in its prognosis of other hypertensive and atherosclerotic changes and as well may give risk stratification for some of the ocular morbidities like Age related maculopathy and nuclear cataract.

6.2REVIEW OF THE LITERATURE:

1. Retinal vessels respond to elevations of systemic blood pressure by generalized arteriolar constriction. This can lead hypertensive retinopathic changes including arteriolar narrowing with focal irregularities, increased tone, increased arterial reflex, non-visualization of blood column, cotton wool spots, blot and superficial hemorrhages. J.B. Walsh during his study found that if the blood pressure is controlled, or slow rising, or if arteriolar sclerosis is present in the retinal arteries, then a picture of arteriolar irregularity will be noted and, depending upon the ability of the retinal vessels to contract, segmental constriction will be seen [1]. The fundal changes help in prognosis of systemic hypertensive complications as seen in the population based cross sectional study conducted by Tien Yen Ying et al; CHD (Odd’s Ratio 1.7), MI (OR 1.7), stroke (OR 2.0), carotid artery plaque (OR 1.9), glomerulosclerosis and silent brain infarction (defined as 3mm lesions in standard imaging of the brain tissue; p = 0.001) [4]. It as well may give a risk assessment of development of other ocular problems such as nuclear cataract and age related maculopathy.

2. Malignant hypertension defined as systolic blood pressure more than 240 mm of Hg or a diastolic BP of more than 140 mm of Hg, is more commonly seen secondary hypertension, examples including pheochromocytomas, kidney diseases, adrenal tumors. It can also be seen classically in accelerated hypertension. Here the sudden rise in blood pressure dynamics is met with minimal resistance from the relatively young vasculature. Retinal changes in accelerated hypertension are also called hypertensive neuropathy. It has three distinct categories – hypertensive retinopathy, choroidopathy and optic neuropathy. Mittal.B.V and Almeida A.F in a clinicopathological study on 43 cases found that the appearance of the retinopathy was significantly earlier than that of the choroidopathy or optic neuropathy (P less than 0.01)[6]. Cystoid macular edema, lipid deposits are more commonly seen in chronic malignant hypertensive retinopathy [9].

3. Hayreh.S.S and et al in their study suggested evidence indicating that it is due to choroidal ischemia, and that hypertensive choroidopathy and retinopathy are two independent and unrelated manifestations of renovascular malignant hypertension. Impaired circulation in choroidal vascular bed, extensive occlusion and ischemic changes in RPE can be seen in response to hypertension [3].

4. Fasternberg. D.M and et al studied 27 postpartum toxemic cases and found, the normal retinal, and predominantly abnormal choroidal vascular patterns provide evidence implicating choroidal vascular insufficiency as the primary basis for secondary retinal detachments seen in toxemia of pregnancy. Toxemia in pregnancy is a form of secondary hypertension and the choroidal vascular bed is the prime site of damage. There is non perfusion and the ischemic changes can lead to serous exudation independent of classical changes of hypertensive retinopathy without sclerosis. It occurs in the later stages of pregnancy and most commonly in the 9th month. Ocular findings can be very helpful in planning termination of pregnancy to prevent loss of vision or perhaps to save the life of mother or child [10].

5. Normal aging process of arteriolar attenuation poses problem in prognosis of group I cases. The inconsistency of correlation between duration, atherosclerotic changes in essential hypertension and magnitude of retinal changes mandates closer scrutinization for prognosis in this set of patients. Some local factors may have role to play as well. Rise in diastolic pressure has the best correaltion with the retinopathic changes. In separating hypertensives from nonhypertensives, the most consistent ophthalmoscopic finding is arteriolar narrowing with focal irregularity [2].

6. Strict BP monitored control is the mainstay of the treatment. There is evidence that endothelial dysfunction is characteristic of essential hypertension. Nitric Oxide Synthetase uncoupling and oxidative stress have been found to play pivotal role in the pathophysiology of vascular damage. This explains the insufficient role of BP reduction alone in prevention of vascular complications and calls for supplementation with antioxidant principles [5].

6.3 OBJECTIVES:

  1. To study the fundal changes in different categories of hypertension; essential, secondary, malignant, toxemia of pregnancy.
  2. To classify the fundal changes according to its severity and correlate the findings with magnitude and duration of hypertension and systemic hypertensive complications.
  3. To do a comprehensive ocular examination and correlate any significant persistent relation between severity of hypertensive retinopathy and ocular local factors.

7. MATERIALS AND METHODS:

7.1 SOURCE OF DATA:

1. Hypertensive patients who fulfill the inclusion and exclusion criteria, attending the outpatient section at the department of Ophthalmology, K.R.H, Mysore.

2. Hypertensive patients who fulfill the inclusion and exclusion criteria, referred from other departments to the Department of Ophthalmology, K.R.H, Mysore.

7.2 METHODS OF COLLECTION OF DATA:

SAMPLE SIZE : A minimum of 200 patients.

SAMPLING METHOD : Simple Random Sampling.

The data will be collected using a piloted performa meeting the objective of the study by means of personal interview with the patient after informed consent. The data will be collected from the fore mentioned sources using the following inclusion and exclusion criteria.

Inclusion criteria:

  1. Essential hypertension – Systolic BP >140 mm of Hg; Diastolic BP > 90 mm of Hg.

Malignant hypertension – Systolic BP > 240 mm of Hg; diastolic BP > 140 mm of Hg.

Pregnancy induced hypertension – In pregnancies more than 20 weeks gestation; Systolic BP > 140 mm of Hg; Diastolic BP > 90 mm of Hg.

  1. Hypertensive retinopathic changes.
  2. Elevated BP associated with retinal venous obstruction, neovascularisation, arterial emboli.

Exclusion Criteria:

  1. Diabetic retinopathy.
  2. Ocular ischemic syndrome.
  3. Bilateral CRVO
  4. Collagen vascular disease; Hyperviscosity syndrome.
  5. Anaemic retinopathy, sickle cell retinopathy, Radiation retinopathy.

Duration of the study: Cases fulfilling the inclusion and exclusion criteria will be studies for a period of 20 months - Dec.2007 to Sept. 2009.

PROCEDURE :

After proper selection of the patients, their informed consent will be obtained for the study. A detailed medical history will be taken from every patient and evidence of any systemic complications of hypertension will be noted. This will be followed by detailed medical examination including physical examination. Patients presenting with any of the exclusion criterion will be excluded from the purview of the study. Routine ocular work up will be carried out including visual acuity and refraction, IOP measurement, slit lamp examination. Detailed fundus examination will be carried out and recorded after full dilatation of the pupils. Patient will be subjected to investigations where in appropriate. The patient will be advised appropriate management in consultation with concerned departments and followed up for response to treatment for a minimum period of 6 months, at an interval of 2 weeks in the first month and monthly there after. The changes noted will be recorded.

STATISTICAL METHHOD USED: Chi – Square test.

7.5 Does the study require any investigation / intervention to be

conducted on patients / human / animals ? If so, describe briefly.

Investigations:

In all patients -

  • B.P measurement
  • Visual acuity and refraction
  • Tonometry
  • Fundus examination
  • Gonioscopy
  • B-Scan examination
  • Renal profile, lipid profile
  • Blood sugar measurement

Where required -

  • Fundus flourescein angiography
  • Visual field analysis
  • Immunological blood
  • Cardiac status assessment
  • Imaging studies (CT, MRI, IVP, Ultrasound)
  • Renal biopsy
  • Urine VMA

7.6 Has ethical clearance been obtained from your institution ?

YES.

8. LIST OF REFERENCES:

8.1 Journal references:

  1. LalSK, Jain IS, GuptaSD, Wahi PL.“Role of local factors in hypertensive retinopathy.”Indian J Ophthalmol 1974;22:1-5.
  1. J.B. Walsh. “Hypertensive retinopathy. Description, classification, and prognosis” Ophthalmology- October 1982; Vol. 89, Issue 10, p 1127-1131.
  1. S.S. Hayreh , G.E. Servais , P.S. Virdi. ‘Fundus lesions in malignant hypertension. VI. Hypertensive choroidopathy’, Ophthalmology- November 1986 Vol. 93, Issue 11, p 1383-1400.
  1. Tien Yin Wong , Ronald Klein , A.Richey Sharrett , Teri A Manolio , Larry D Hubbard , Emily K Marino and et al. “The prevalence and risk factors of retinal microvascular abnormalities in older persons” Ophthalmology- 2003 April; Vol. 110, Issue 4, p 658-666.
  1. P. Ferroni , S. Basili , V. Paoletti , G. Davì. “Endothelial dysfunction and oxidative stress in arterial hypertension” 2006 April; Vol. 16, Issue 3, p 222-233.
  1. Mittal BV, Almeida AF. “Malignant hypertension (a clinico-pathologic study of 43 cases)” J Postgrad Med 2007 oct; vol 33: p 49-54.

8.2 Text references:

  1. System of Ophthalmology, Sir Stewart Duke Elder volume X, Diseases of the retina, Jaypee brothers. Chapter IV, retinopathies associated with general disease. I. the vascular diseases. Pg. no. 277 – 355.
  1. Retina, second edition, Editor in chief Stephan J. Ryan, M.D. vol-2 Medical retina, Edited by Andrew P. Schachat, M.D., Robert T. Murphy, M.D. Mosby. Section 5 Retinal Vascular disease, chapter 79-81. pg no. 1393 – 1420.
  1. Ophthalmology, second edition, Myron Yanoff, Jay S. duker, Mosby, Part 8: retina and vitreous. section 5: Vascular disorders 849-856.
  1. Sihota R, Tandon R. editors.Diseases of the retina. Chap 20 In: Parson’s Diseases of the Eye, 20th ed. New Delhi, Elsevier; 2003. p. 293-294.