|Year : 1981 | Volume
| Issue : 3 | Page : 269-275
Anticoagulant therapy in branch vein occlusion
HK Tewari, PK Khosla, SP Garg
Dr. Rajendra Prasad Centre for Ophthalmic Sciences A.I.I.M.S., New Delhi, India
H K Tewari
Dr. Rajendra Prasad Centre for Ophthalmic Sciences A.I.I.M.S., New Delhi-110029
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Tewari H K, Khosla P K, Garg S P. Anticoagulant therapy in branch vein occlusion. Indian J Ophthalmol 1981;29:269-75
|How to cite this URL:|
Tewari H K, Khosla P K, Garg S P. Anticoagulant therapy in branch vein occlusion. Indian J Ophthalmol [serial online] 1981 [cited 2021 Jun 21];29:269-75. Available from: https://www.ijo.in/text.asp?1981/29/3/269/30900
There has been increased awareness of the visual morbidity associated wiih retinal vein occlusion - believed to be the second largest cause of retinal vascular disease (after diabetic retinopathy). Since the first description there has been no disagreement as to the clinical ophthalmoscopic picture, however, there is lot of disagreement as to its management and is still controversial, apart from cases where systemic treatment for arterial disease or appropriate measures for inflammatory pathology can be of avail.
The anticoagulation therapy has its proponents and also who have recorded absence of benefit from this. We studied the natural history of branch vein occlusions in our environments and thought it worthwhile to compare it with the results of anticoagulant therapy on various parameters to find out its role although it is not a randomised study but is comparable due to similar circumstances.
| Methods and material|| |
30 cases of branch vein occlusion on anticoagulant therapy have been followed up in this study. Although we started the series with 50 cases to compare it with our previous study but because of complications and other factors 20 cases had to be dropped from this study. All consecutive cases were put on anticoagulant treatment after a detailed systemic (including cardiovascular) check up.
Cases with systemic disease as diabetic retinopathy or local disease (e.g. Eales' disease) were excluded. Cases, where there was contraindication to anticoagulant therapy were also dropped. The cases were grouped as Hemisphere, Main Branch and Small branch blocks. The parameters (visual acuity and findings on fluorescein angiography as intactress of perifoveal arcade, number of capillary non perfusion areas with special reference to macular area and areas of leakage in the macular region) in this study have been compared with our previous study which was taken as a control group. The regime of anticoagulant therapy was as follows:- Tab. Sintrom (4mg) 4 Tabs 1st day, 3 tabs 2nd day, 2 tabs 3rd day, 1 tab 4th day. The prothrombin time was done on 4th day and was kept at 2 times that of normal. A maintenance dose was Given for 3 months and prothrombin time was repeated every : weeks. The follow tip was done every month for three months and every 3 months upto one year.
| Observations|| |
[Table - 1] shows age and sex distribution in various types of branch blocks in treated (30 cases) and controls (50 cases from previous series).
[Table - 2] shows average improvement in lines in visual acuity as seen after 3 months from the time of presentation in treated and control group. The visual outcome was better in small branch blocks in the treated group while it was about the same in other two groups in both series although the averages were better in treated group.
[Table - 3] shows various signs present on fluorescein angiography in treated and control groups at presentation and after 3 months. The selected signs (intactness of macular arcade, number of areas of capillary nonperfusion and leak in macular area) which influence the final visual outcome, were specifically compared [Figure - 1][Figure - 2][Figure - 3][Figure - 4][Figure - 5][Figure - 6][Figure - 7]. However there were difficulties in studying these signs in all cases because of retinal haemorrhages, overlying retinal oedema, poor contrast etc. We could only study 12 cases in treated series which were compared to 20 in control series.
| Perifoveal arcade intactness|| |
At the onset out of 12 cases in treated group 5 cases had intact arcade while in seven cases it was broken. After the therapy for 3 months the perifoveal arcade was found to be intact only in 6 cases indicating that only one case improved who initially had a broken arcade. In the control series out of 20 cases 11 cases had intact arcade while at the conclusion of study 12 patients had intact arcade indicating that only one patient improved in this series also. Hence there does not seem to be significant difference in revival of intactness on anticoagulant therapy. Interestingly both cases in which the improvement was seen were small branch blocks.
| Capillary non perfusion areas|| |
These were studie specifically in relation to the macular area. In treated group at the beginning of the study there was only I patient in whom there were minimal areas of capillary non perfusion while at the completion of the treatment there were 5 cases i.e. 4 patients during this period improved and came into the category of good prognosis. On the other hand in control series at the onset there were 7 cases with minimal or no areas of capillary non perfusion & 10 at the end of the study. This clearly shows that anticoagulant therapy significantly alters the areas of non perfusion.
| Leakage in macular area|| |
At the onset leakage in macular area was seen in 7 cases in the treated group and after therapy it was seen in 6 patients i.e. only I patient improved. All these cases had large number of capillary non perfusion areas and broken perifoveal arcade. In the control group it was seen in 13 cases initially and 10 cases at the end of three months. It seems that anticoagulants do not have significant beneficial effect on leakage in the macular area.
New vessel formation on the surface of retina was seen in 2 cases in this study during 1 year follow up however no case showed thrombotic glaucoma though there were 3 patients who were earlier diagnosed cases of glaucoma and were already on treatment. We cannot conclude but it seems thrombotic glaucoma may not occur while patients are under anticoagulant therapy.
| Discussion|| |
There seems to be an inherent bias in the treatment of branch vein occlusion as patients with visual problems only present themselves and we do not know how many recover after remaining asymptomatic or show resolution even after complications. Evaluation may, however, be difficult as quite a lot of cases show spontaneous regression. No medication has been documented to be beneficial so it is imperative that a prospective statistical study be undertaken using adequately matched untreated control group.
Anticoagulant therapy has been tried most but we do not know whether it helps in the process of natural history by preventing thrombosis at the site of obstructive lesion or affects the thrombus itself. It seems logical that anticoagulants may be helping in avoiding the thrombotic process hence aid the process of recanalisation or may benefit in i ncipient cases by preventing its development. Anticoagulants must be used under the close supervision of a physician particularly, in arteriosclerotic hypertensive subjects after ruling out systemic infective lesions. There seems to be little effective difference between short course of heparin or heparin followed by one of oumorin derivatives or administration of coumorin derivatives alone and equivocal results are reported with or without anticoagulants.
We believe that visual symptoms alone are a poor parameter for assessment. Visual acuity and fluorescein angiographic findings (integrity of perifoveal arcade, capillary nonperfusion areas and leakage in macular area) together were taken as parameter for progress in this study.
We classified our cases into hemisphere blocks, main branch blocks and small branch blocks [Table - 1]. Evaluating the distribution of cases confirms our previous study that the small branch blocks are common in the younger age group, the hemisphere blocks in older while the main branch blocks are seen equally in all age groups above 40 years of age. The males and females are equally affected.
Good visual acuity was seen in 15% of untreated group and 28% of treated group while Larson and Nord reported good vision in 32% of 131 untreated cases and 46 of 100 treated cases. In our study the final visual acuity results after three months of treatment were shad better than in untreated group [Table - 2] and were best reflected in small branch blocks. There was no significant difference in main branch and hemisphere group. The visual results in cases who were assessed early cases by fluoroscein angiography were better than those who were assessed as established cases so value of fluorescein angiography for assessment of age of block and hence for putting the patient on treatment seems to be very important.
Intactness of perifoveal arcade signifies normal functioning of central area of retina subserving visual acuity hence definitely indicative of good visual outcome, although it is difficult to study it in early stages due to oedema or haemorrhage. The visual results were excellent in all the cases which showed intact arcade indicating that anticoagulants may help in keeping the functional integrity of arcade. It is surmised that anticoagulant therapy may be responsible for better capillary perfusion allowing better integrity of arcades i.e. not allowing its further breaking up leading to better visual acuity in the long run. Intact foveal arcade upto 3 months seems to be an important factor in prognosticating visual outcome on any type of treatment.
Presence of small and few capillary nonperfusion areas or their total absence at the end of 3 months indicates good visual prognosis. There was suggestive difference in the disappearance of big capillary nonperfusion areas in the treated and control groups. It indicates that whatever difference is seen in the visual outcome in control and treated series may be related to better perfusion due to anticoagulant therapy.
The leakage in the macular area was not significantly different in the control and treated group as seen after 3 months of treatment. It is surmised that macular oedema as shown by fluoresein leakage is a later development than the capillary nonperfusion areas with consequent functional and anatomical break in the integrity of perifoveal arcade. The role of anticoagulants in cases where there is macular leakage would be less significant as most of these cases are associated with large capillary nonperfusion areas and anatomically broken perifoveal arcades.
| Summary|| |
The anticoagulants do not significantly affect the natural history of branch vein occlusion. The visual outcome in a case of branch vein block with or without treatment is better if (i) there are no or small capillary nonperfusion areas. (ii) capillary nonperfusion areas reduce in size and number (iii) Presence of intact perifoveal arcade (iv) Absence of leakage in macular area and oedema in case a patient maintains good visual acuity for 3 months after the presentation the over all outcome is very favourable.
| References|| |
Vannas S. and Raitta C., 1966, Amer. J. Ophthalmol. 62 : 874.
Rodriguez and dall 'Borgo, 1961, Arch. Chil,Ophthalmol. 18: 29.
Tewari H.K. & Khosla P.K., 1978, Proc. Ind. Ophthalmol, Soc. Hyderabad Session.
Duff I.F.; Falls, H.F. and Linman J.W. T, 1951, Arch. Ophthalmol. 46: 601.
Larson and Nord, 1950, Acta Ophthalmol. (Kbh) 28 : 187.
Clemett R.S., Kohner E.M., and Hamilton, A.M., 1973 Trans. Ophth. Soc. U.K. 93 : 523.
[Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4], [Figure - 5], [Figure - 6], [Figure - 7]
[Table - 1], [Table - 2], [Table - 3]