Netherlands Ophthalmological Society, 167th Meeting, Vlissingen 1972 Ophthalmologica, Basel 171: 309-311 (1975)
Treatment of Diabetic Retinopathy with Photocoagulation at Advanced Age
When considering the indications for photocoagulation in a diabetic retinopathy, we should always wonder what influence the photocoagulation will exert on the further course of the diabetic retinopathy of our patient. It is often difficult to predict whether the clinical picture will deteriorate faster without treatment than with treatment. This problem is complicated by the fact that the fundus picture and the visual acuity need not have a parallel development after treatment with photocoagulation. The fundus picture may show a marked improvement with simultaneous deterioration of the visual acuity. The difference in the development of fundus picture and visual acuity occurs rather frequently in diabetics of higher age. We compared the course of fundus picture and visual acuity of 95 photocoagulation-trcated eyes and 57 non-treated eyes. The average observation time was 2 years. The fundus picture of 47 out of the 95 treated eyes improved, whereas in the 57 non-treated eyes an improvement was observed in only five cases. However, this was not so favorable for the visual acuity in the treated eyes: only in seven cases was an improvement observed, in 55 eyes the visual acuity remained unchanged and in 33 eyes it had deteriorated. Almost the same ratio was found in the 57 non-treated eyes: the visual acuity regressed in almost one third (17 eyes); it remained unchanged in two thirds (38 eyes) and improved in two eyes. However, it is to be expected that after a long observation period the less favorable development of the fundus picture in the untreated eyes will also show greater deterioration of the visual acuity. A more detailed analysis of the clinical picture of diabetic retinopathy in patients over 60 years of age shows that the nonproliferative form of diabetic retinopathy clearly predominates over the proliferative type. Of our 75 patients, 45 had a nonproliferative form and 30 a proliferative
Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 3/5/2018 9:23:13 AM
S. R ia sk o ff
R iaskoff
retinopathy. 19 eyes had a visual acuity less than 1/60. The causes were hemorrhage in eleven cases and degeneration of the macular region in eight cases. 31 eyes had a visual acuity of 0.1-0.02 at the first examination. The causes were hemorrhage in four cases and degeneration of the macula in 27 cases. It is striking to what high degree the bad condition of the macula constitutes a decisive cause for the bad visual acuity. After photocoagulation, 33 eyes showed a loss of visual acuity. The causes were hemorrhage for seven, retinal detachment for two, a secondary glaucoma for one and macular degeneration for 23 eyes. We are not dealing here with a postcoagulative maculopathy but with an increase of the diabetic changes at the posterior pole, namely accumulation of lipoid exudates, marked edema formation with cystic macular degeneration, or finally intraretinal hemorrhages in the macular region. It is of great importance for the application of photocoagulation to be able to predict whether the posterior pole will respond favorably or un favorably. According to our experience, the following signs and symptoms lead one to expect deterioration of the macular region, in spite of the photo coagulation: (1) Massive storage of lipoid exudates in the form of large plates lying against the macula. (2) Diffuse edema at the posterior pole with many patch-like intraretinal hemorrhages and incipient cystoid degen eration of the macula. (3) Very narrow or already obliterated arteriolar branches around the posterior pole. (4) Markedly changed veins in the region of the posterior pole. (5) A fluorescence angiogram showing ex tensive occlusion zones or extensive leakage. (6) Electro-ophthalmologic findings pointing towards a serious circulatory disturbance in the retina. (7) A short interval between the occurrence of diabetic retinopathy and the diagnosis of diabetes, in which serious abnormalities have been present right from the beginning. The more prognostically bad symptoms, as mentioned here, arc present, the more careful we have to be in accepting the indication for treatment with photocoagulation. Reserve is also warranted in incipient diabetic retinopathy, because, when the first symptoms develop, we do not yet know how fast this retinopathy will progress and/or whether it will threaten the visual acuity at all. In these dubious cases the patient’s life expectation is an important factor in the decision for treatment. In particular in cases in which a photocoagulation would appear to be sensible only in the long run, we should request the family doctor and internist to inform us in more detail of the patient's life expectation. For it is highly probable that in the end, for example after 4-5 or more years, the favorable influence of the
Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 3/5/2018 9:23:13 AM
310
Treatment of Retinopathy with Photocoagulation at Advanced Age
311
photocoagulation on the fundus picture will also work out in favor of the visual acuity, because then less serious complications can arise. If the prognosis quo ad vitam is good, we would carry out photocoagulation also in dubious cases, but if it is bad it is wiser to refrain. Dr. S. R iaskoff, Willemsplein 13d. Rotterdam (The Netherlands)
O osterhuis : The differentiation of the various forms of macular changes and their significance for the visual prognosis in diabetic retinopathy is very important. The reduction of the lipoid-containing exudates in the retina after photocoagulation may also be related to the better maintenance of the diet by the diabetic patient, if he is aware that blindness is threatening. An evaluation with respect to the course of the other untreated eye acting as a control therefore seems absolutely necessary. R iaskoff: It is beyond doubt that the non-treated eye offers a very good control for the efficacy of a treatment with photocoagulation. However, this control is not an ideal one, because complete right-left symmetry is the exception rather than the rule in the evolution of diabetic retinopathy. Another possibility of finding out whether the disappearance of exudates should be attributed to the photocoagulation or to other factors is the follow-up of lipoid exudates at various sites in the treated eye. Sometimes the wreath of lipoid exudates is seen to disappear entirely after the coagu lation of microaneurysms and hemorrhages in the center of a circinate focus, while, at another site, where the source of exudation had not been coagulated, the lipoid accumulations remain intact. Observation of such a nature most probably constitute arguments in favor of the positive effect of photocoagulation. M anschot: The fluorescence angiograms of diabetics shown by you now and also formerly [D ublin , 1972] show a remarkable diminution of areas with obliterate capillary circulation. Morphologically, we find in trypsin digestion preparations of such a retina entirely ‘dead’ capillaries, only consisting of basal membrane without endothelium or pericytes. Do you believe that these ‘dead’ capillaries can become functional again? R iaskoff: I do not believe that the blood circulation can be restored in the areas with histologically ‘dead’ capillaries, after treatment with photocoagulation. The remarkable extension of the ‘filling capillary network’ in the fluorescence angiograms shown is most probably based on the use of different absorption filters. In the be ginning of fluorescence angiography we used an absorption filter with which the capillary vascular net did not become well visible. The visualization of the capillary net on the later photos should therefore not be regarded as a result of the intervening photocoagulations. Reopening of small zones, however, might be possible if the occlusive process has not been of too long duration, i.e. if obliteration of the pre capillaries has not yet taken place. As a matter of fact, this phenomenon has indeed be described by Koiinf.r as a spontaneous event (without treatment by photo coagulation).
Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 3/5/2018 9:23:13 AM
Discussion
Treatment of Diabetic Retinopathy with Photocoagulation at Advanced Age
When considering the indications for photocoagulation in a diabetic retinopathy, we should always wonder what influence the photocoagulation will exert on the further course of the diabetic retinopathy of our patient. It is often difficult to predict whether the clinical picture will deteriorate faster without treatment than with treatment. This problem is complicated by the fact that the fundus picture and the visual acuity need not have a parallel development after treatment with photocoagulation. The fundus picture may show a marked improvement with simultaneous deterioration of the visual acuity. The difference in the development of fundus picture and visual acuity occurs rather frequently in diabetics of higher age. We compared the course of fundus picture and visual acuity of 95 photocoagulation-trcated eyes and 57 non-treated eyes. The average observation time was 2 years. The fundus picture of 47 out of the 95 treated eyes improved, whereas in the 57 non-treated eyes an improvement was observed in only five cases. However, this was not so favorable for the visual acuity in the treated eyes: only in seven cases was an improvement observed, in 55 eyes the visual acuity remained unchanged and in 33 eyes it had deteriorated. Almost the same ratio was found in the 57 non-treated eyes: the visual acuity regressed in almost one third (17 eyes); it remained unchanged in two thirds (38 eyes) and improved in two eyes. However, it is to be expected that after a long observation period the less favorable development of the fundus picture in the untreated eyes will also show greater deterioration of the visual acuity. A more detailed analysis of the clinical picture of diabetic retinopathy in patients over 60 years of age shows that the nonproliferative form of diabetic retinopathy clearly predominates over the proliferative type. Of our 75 patients, 45 had a nonproliferative form and 30 a proliferative
Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 3/5/2018 9:23:13 AM
S. R ia sk o ff
R iaskoff
retinopathy. 19 eyes had a visual acuity less than 1/60. The causes were hemorrhage in eleven cases and degeneration of the macular region in eight cases. 31 eyes had a visual acuity of 0.1-0.02 at the first examination. The causes were hemorrhage in four cases and degeneration of the macula in 27 cases. It is striking to what high degree the bad condition of the macula constitutes a decisive cause for the bad visual acuity. After photocoagulation, 33 eyes showed a loss of visual acuity. The causes were hemorrhage for seven, retinal detachment for two, a secondary glaucoma for one and macular degeneration for 23 eyes. We are not dealing here with a postcoagulative maculopathy but with an increase of the diabetic changes at the posterior pole, namely accumulation of lipoid exudates, marked edema formation with cystic macular degeneration, or finally intraretinal hemorrhages in the macular region. It is of great importance for the application of photocoagulation to be able to predict whether the posterior pole will respond favorably or un favorably. According to our experience, the following signs and symptoms lead one to expect deterioration of the macular region, in spite of the photo coagulation: (1) Massive storage of lipoid exudates in the form of large plates lying against the macula. (2) Diffuse edema at the posterior pole with many patch-like intraretinal hemorrhages and incipient cystoid degen eration of the macula. (3) Very narrow or already obliterated arteriolar branches around the posterior pole. (4) Markedly changed veins in the region of the posterior pole. (5) A fluorescence angiogram showing ex tensive occlusion zones or extensive leakage. (6) Electro-ophthalmologic findings pointing towards a serious circulatory disturbance in the retina. (7) A short interval between the occurrence of diabetic retinopathy and the diagnosis of diabetes, in which serious abnormalities have been present right from the beginning. The more prognostically bad symptoms, as mentioned here, arc present, the more careful we have to be in accepting the indication for treatment with photocoagulation. Reserve is also warranted in incipient diabetic retinopathy, because, when the first symptoms develop, we do not yet know how fast this retinopathy will progress and/or whether it will threaten the visual acuity at all. In these dubious cases the patient’s life expectation is an important factor in the decision for treatment. In particular in cases in which a photocoagulation would appear to be sensible only in the long run, we should request the family doctor and internist to inform us in more detail of the patient's life expectation. For it is highly probable that in the end, for example after 4-5 or more years, the favorable influence of the
Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 3/5/2018 9:23:13 AM
310
Treatment of Retinopathy with Photocoagulation at Advanced Age
311
photocoagulation on the fundus picture will also work out in favor of the visual acuity, because then less serious complications can arise. If the prognosis quo ad vitam is good, we would carry out photocoagulation also in dubious cases, but if it is bad it is wiser to refrain. Dr. S. R iaskoff, Willemsplein 13d. Rotterdam (The Netherlands)
O osterhuis : The differentiation of the various forms of macular changes and their significance for the visual prognosis in diabetic retinopathy is very important. The reduction of the lipoid-containing exudates in the retina after photocoagulation may also be related to the better maintenance of the diet by the diabetic patient, if he is aware that blindness is threatening. An evaluation with respect to the course of the other untreated eye acting as a control therefore seems absolutely necessary. R iaskoff: It is beyond doubt that the non-treated eye offers a very good control for the efficacy of a treatment with photocoagulation. However, this control is not an ideal one, because complete right-left symmetry is the exception rather than the rule in the evolution of diabetic retinopathy. Another possibility of finding out whether the disappearance of exudates should be attributed to the photocoagulation or to other factors is the follow-up of lipoid exudates at various sites in the treated eye. Sometimes the wreath of lipoid exudates is seen to disappear entirely after the coagu lation of microaneurysms and hemorrhages in the center of a circinate focus, while, at another site, where the source of exudation had not been coagulated, the lipoid accumulations remain intact. Observation of such a nature most probably constitute arguments in favor of the positive effect of photocoagulation. M anschot: The fluorescence angiograms of diabetics shown by you now and also formerly [D ublin , 1972] show a remarkable diminution of areas with obliterate capillary circulation. Morphologically, we find in trypsin digestion preparations of such a retina entirely ‘dead’ capillaries, only consisting of basal membrane without endothelium or pericytes. Do you believe that these ‘dead’ capillaries can become functional again? R iaskoff: I do not believe that the blood circulation can be restored in the areas with histologically ‘dead’ capillaries, after treatment with photocoagulation. The remarkable extension of the ‘filling capillary network’ in the fluorescence angiograms shown is most probably based on the use of different absorption filters. In the be ginning of fluorescence angiography we used an absorption filter with which the capillary vascular net did not become well visible. The visualization of the capillary net on the later photos should therefore not be regarded as a result of the intervening photocoagulations. Reopening of small zones, however, might be possible if the occlusive process has not been of too long duration, i.e. if obliteration of the pre capillaries has not yet taken place. As a matter of fact, this phenomenon has indeed be described by Koiinf.r as a spontaneous event (without treatment by photo coagulation).
Downloaded by: Univ. of California Santa Barbara 128.111.121.42 - 3/5/2018 9:23:13 AM
Discussion
