|Year : 1983 | Volume
| Issue : 7 | Page : 1025-1026
Pan retinal photo coagulation in diabetic retinopathy
Institute of Ophthalmology & Sarojini Devi Eye Hospital, Hyderabad, India
Institute of Ophthalmology & Sarojini Devi Eye Hospital, Hyderabad, A.P.
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Satpathi M. Pan retinal photo coagulation in diabetic retinopathy. Indian J Ophthalmol 1983;31, Suppl S1:1025-6
Diabetes with retinopathy develop proliferative changes in 5% of 10%. These occur in the presence of severe microvascular abnorlities, particularly capillary non perfusion which results in retinal ischemia. It is postulated that vaso-formation substances are released which stimulates the growth of the new vessels. These usually occur at the edge of the areas of the capillary non perfusion in the peripheral retina and at the optic disc. New vessels leak plasma components and may bleed resulting in pre-retinal and vitreous haemorrhage. The vitreous body contracts away from the retinal surface pulling the fragile new vessels with it. The mechanical traction on the blood vessels increases the tendency to haemorrhage and formation of fibrous band results in detachment of the retina.
Early treatment of all the areas of retinal ischemic by peripheral retinal ablation prevents blindness in the majority of cases. The aim of the treatment is to protect the foveal vision by destroying all the peripheral retina as far as the equator. Areas of ischemic retina at the posterior pole, as noted by nonperfusion of capillaries on fluorascein angiorgaphy must be destroyed.
| Material and methods|| |
Those patients on routine screening to have diabetic retinopathy were referred from eye specialists and diabetic clinics are selected for this study.
Patients entering the record were subjected to full ophthalmic assessment including refraction, tonometry. Visual fields, fundus photography and fluorescein angiography. Every attempt was made to achieve a good diabetic controll.
The Criteria for inclusion were that 1) the patient affected with proliferative diabetic retinopathy process involving the retina and optic disc. 2) that the visual acuity at initial assessment is not less than 6/24 in the proposed eye for treatment.
Exclusion of cases from the study was made 1) advanced stage of proliferative retinopathy 2) Visual acuity was adversely effected by opacities of the media 3) Cases with nephropathy and extra ocular complications 4) in cases of Maculopathy.
| Technique|| |
All treated eyes were subjected to peripheral retinal photocoagulation by means of a Log 3 Xenon light coagulator. The procedure was well tolerated after instillation of local anesthetic drops and retrobulbar xylocaine.
Photocoagulation burns were applied within the vascular arcades above and below the macula but an approximately circular area of ardius 2½ disc diameters, with the fovea at its centre and including the papi lomacular bundle. In the nasal fundus photocoagulation was extended centrally to the edge of the optic disc and involved any new vessels arising from the margin.
Individual burns are made with an image field aperture 2° to 3° (.6 mm to 0.9 m.m.) and an exposure time 1 second so that uniform grey colour is seen over the treated ares. A white coagulam is considered as exessive energy to complete the treatment over 300 burns in 6 sittings in a period of 3 weeks to the most of our patients. During the subsequent visits, photo-coagulation was applied to cover up the ara left in earlier sittings.
Patients were reviewed at an itervals of 1 month and 6 months after cmpletion of peripheral retinal ablation.
| Observation and conclusion|| |
More number of cases are presented with peripheral retinal Neo-vascularisation.
Evaluation of treatment was done basing on four main criteria. 1. Visual acuity. 2. Appearanc of Optic disc and peripheral retina often 6 months. 3. Any other complications.
Visual acutiy was maintained as before and there was no deteroration of vision in 46 (60%) of the cases and there was regression of teh neo vascularisation botn in the optic disc and over the peripheral retina.
2. There was no complication encountered during photocoagulation.
3. 20 (25%) cases have developed fresh vitreo-retinal haemorrhage during the follow up of 2 years.
4. 12 (15%) of the cases have developed optic atirophy and deterioration of vision from the level during the follow up period.
| References|| |
Constable San J. 1981, Monogram. Laser its clinical uses in eye diseases.
[Table - 1], [Table - 2], [Table - 3], [Table - 4]