- Email: [email protected]
New England Ophthalmological Society
SOCIETY PROCEEDINGS N E W ENGLAND OPHTHALMOLOGICAL SOCIETY 448th meeting, March 18, 1959 HENRY L. BIRGE, M.D.,
presiding
SYMPOSIUM ON STRABISMUS
MODERATOR: Hermann M. Burian, M.D. Frank D. Costenbader, M.D., Philip Knapp, M.D., Edmond L. Cooper, M.D., and Harold Whaley Brown, M.D.
DISCUSSORS:
Do you ever do a recession of one lateral rectus? If so, when? DR. K N A P P : I used to do single recessions on the lateral rectus for deviations under 20 diopters but I was disappointed in the re sults and now I do less surgery on both lat eral recti. Either that, or, if the deviation is low enough, I don't operate. If the deviation is small enough, antisuppression followed by fusion training will usually be helpful. Discuss recession of one medial rectus. When? DR. COOPER: I insist that surgery should be symmetrical whenever possible. I would say that the only time I would recess one me dial rectus is if the amount of recession I want to do is so small that it can't be divided between two eyes. If I am planning to do a two-mm. recession, I can't do a one mm. on each eye. I don't think I can accurately measure a two-mm. recession. I will say that I have sometimes done a two or a two and one-half-mm. recession. Is an eso deviation which is greater on looking up than on looking straight ahead an "A" phenomenon? DR. COOPER: The question is, is this an "A" or a "V" phenomenon? I think it would be an "A." I would call this an "A" phe nomenon if the eso deviation is greater up by 15 degrees than it is on looking down. Now I notice that Dr. Costenbader judges his "A" and "V" by a difference of 10 looking up and down. Dr. Knapp judges his "A" and "V" by a difference of 15 looking up and straight ahead. I choose 15 but I choose the
503
difference of 15 between the measurements up and down. So it depends on what the measurement is whether this is an "A" or not according to our definition. Please elaborate on the value of plus and minus lenses in the treatment of squint. DR. COSTENBADER: That is a large order. I don't think I can elaborate on it other than to say that plus lenses tend to minimize the accommodation necessary and thus the ac commodative effort involved and then, pre sumably, the accommodative convergence that results. Minus lenses tend to increase the amount of accommodative effort neces sary and thus the amount of accommodative convergence which results therefrom. This is not on a one to one ratio by any means. Some persons get much more convergence from a given amount of presumed accom modation expended than others. / had an adult patient with a monocular esotropia of 20 to 25 degrees, with a slight amblyopia and, after operation, the eye tended to go back to the original angle of squint. How could this have been pre vented? DR. COOPER : I suppose that after the op eration the eye was straight for a while and then iater tended to go back. I must say I can't explain this and I am not sure I be lieve it. I would think your surgery was not adequate and the only way I could say how to prevent this result would be to have your surgery adequate. If it isn't, then go back and do more surgery based on your findings. / / after recession of a medial rectus an exotropia is produced which is greater for distance than for near but with a limitation of adduction of the affected eye, would you still recess the lateral rectus? DR. COOPER : I think that in limited adduc tion of the affected eye one wouldn't ex pect to find the resulting exotropia greater for distance than for near. If there was definite limitation of the adduction of the eye that had the recession of the medial rectus, one would expect, and one would find, the exotropia to be greater for near than for distance ; in that case I would read-
504
SOCIETY PROCEEDINGS
vance the recessed medial. If the situation as described here actually did exist,—a weak ness of adduction as well as greater devia tion for distance than for near—and provid ing the resulting exotropia was large enough, I would probably consider recessing the lateral and readvancing the recessed me dial. Comment on bimedial recessions. DR. BURIAN : Bimedial recessions have been done a great deal over the past 15 to 20 years and are highly recommended by some of our best surgeons. We have done a considerable number over the past seven years and I am still not too happy over them. Not only do overeffects occur but there is also the possibility of undereffects occurring. At the present time I am putting together a few hundred cases and I will be a little more intelligent on the subject in a couple of months when I know just what our results have been. Are many cases of unsuccessfully oper ated esotropia due to the blindspot relation ship, the optic disc relationship? DR. COSTENBADER : I can't tell if many are ; I know some are. I also know that some patients who don't have the blindspot rela tionship also get unsuccessful or poor re sults. I have noticed two things as a result of a well-defined blindspot relationship. If I can have a youngster sit down and give him the Lancaster or similar type of projector test and place my head directly over the child's head and have him put on the red and green specs and presumably put the red light on the green light and if I close one eye and fixate one light and the other light falls on my blindspot, I know that it must fall on his blindspot unless his eyeball is different from mine. If there is a well-defined blindspot re lationship in a given individual, I have the definite feeling that if you undercorrect his esotropia he has a much greater tendency to restore toward or to that same relationship than if he did not have the relationship in the first place. I cannot say how many do that, I can simply say that I have cases in which this has happened.
The other group of which I am conscious are the overcorrected exotropes. About 50 percent of these cases, and they do exist, have, when I have overcorrected them inad vertently, hit the blindspot relationship and this has been a well-defined blindspot rela tionship. Explain the mechanism of horror fusionis. DR. BURIAN : By horror fusionis we do not mean that the patient does not fuse or cannot be made to fuse, we mean that, in general, patients with esotropia, for in stance, dislike macular stimulation more than anything else. They can avoid stimula tion by suppression, by establishing anoma lous correspondence, and by changing the an gle of squint. The horror fusionis phenom enon is this latter phenomenon. You have a patient and you are using perhaps a rotary prism and a red glass and you try to bring the double images closer together and then suddenly they go apart again. There is no suppression involved. There is a change in the angle of squint. The orthoptists know about this and they call it "chasing" when ever they come to the objective angle and the patient changes again so they don't quite catch up with him. This is horror fusionis. STRABISMIC AMBLYOPIA DR. HERMANN M. BURIAN, Iowa City: So far as the treatment of strabismic amblyopia is concerned there would seem to be agree ment that the method of occlusion supported by adequate exercises is still the treatment of choice. It is mainly for the treatment of patients with eccentric fixation that pleoptics was devised. There is considerable difference between the attitude and the approach of the two founders of pleoptics, Bangerter and Cup pers. Bangerter believes that eccentric fixa tion is simply an extreme degree of ambly opia and that it is our job in this case as in all cases of amblyopia to break through the extreme suppression of the foveal area. Once this break through is achieved the path is open to the improvement of the visual acuity of the amblyopic eye. All of Bangert-
SOCIETY PROCEEDINGS er's instruments attempt to direct by visual, acoustic, or tactile stimuli the patient's atten tion to his fovea and to acceptance of mac ular stimulation. Cuppers believes that eccentric fixation is the result of a change in spatial localization such that the eccentric retinal area, which the patient uses for fixation, carries the fovea in a straight-ahead visual direction. My experience with pleoptics have been restricted to the methods advocated by Cup pers. Regardless of theoretic considerations there can be no doubt that Cuppers' methods represent a great advance and we must ac cept the happy pragmatic formula that it works. I mean that one can change the fixa tion pattern of eccentric fixaters by means of the Euthyscope. There is no patching ex cept of the amblyopic eye between treat ments. The Euthyscope is something of a modi fied ophthalmoscope. It is used in this fash ion: After the macula of the amblyopic pa tient is located, a disc of appropriate size is placed in the path of light of the instrument to shield the macular area. The intensity of the light is then stepped up and the fundus is illuminated for about 20 seconds. The result is that the patient sees a doughnut-shaped after-image when the instrument's light is turned off. The center of the doughnut should correspond to the fovea of the eye. This after-image lasts from three to four minutes and, during that period, the patient is asked to watch single symbols, or other means are used to bring the fovea to the at tention of the patient. When the after-image fades, the process is repeated again and again and again. The poor therapist is ex hausted after half an hour and so is the pa tient. Cuppers does this for an hour twice a day. The Euthyscope treatment simply means that you repeat and repeat and repeat the after-image until you finally make the pa tient aware of his fovea; until you get him to see an object straight-ahead and not over
505
there. I personally believe this is not a change of localization but of attention being drawn to the fovea. However, there is no question that it works, occasionally in a few sessions. In all cases time and patience are required before central fixation is carried over into the ordinary art of vision. How practical is this method that requires two daily sessions of an hour each extend ing over two weeks, six weeks, or three months? It is strenuous for the therapist who must have infinite patience and it is strenuous for the patient. I do not believe any. ophthalmologist could possibly afford the time or want to carry out the treatment himself. Therefore especially trained help is required. It is mandatory also that there be some arrangement whereby the amblyopic children may be in one place and cared for all day. In other words, some sort of pleop tics school of the type Bangerter has. There is no reason why this should not be feasible in the United States. Let me conclude with two thoughts. Once the visual acuity of the amblyopic eye has been normalized and securely established our job is not finished. To maintain full function, the amblyopic eye must be used in binocular vision. Results will be maintained only if the patient keeps using the eye. The second thought—pleoptics can only be given to children old enough to co-op erate with the therapists, about six years of age. Pleoptics has also increased the age limit at which amblyopia can be successfully treated. It is remarkable that 18-year-old pa tients and even adults can now be success fully treated. No treatment is, however, ever as good as the absence of need for treatment. Preven tion of amblyopia should remain our fore most goal. Let the ophthalmologist be con stantly aware of the fact that he can by ade quate treatment prevent the development of deep-seated amblyopia in every child. Charles Snyder, Recorder.
presiding
SYMPOSIUM ON STRABISMUS
MODERATOR: Hermann M. Burian, M.D. Frank D. Costenbader, M.D., Philip Knapp, M.D., Edmond L. Cooper, M.D., and Harold Whaley Brown, M.D.
DISCUSSORS:
Do you ever do a recession of one lateral rectus? If so, when? DR. K N A P P : I used to do single recessions on the lateral rectus for deviations under 20 diopters but I was disappointed in the re sults and now I do less surgery on both lat eral recti. Either that, or, if the deviation is low enough, I don't operate. If the deviation is small enough, antisuppression followed by fusion training will usually be helpful. Discuss recession of one medial rectus. When? DR. COOPER: I insist that surgery should be symmetrical whenever possible. I would say that the only time I would recess one me dial rectus is if the amount of recession I want to do is so small that it can't be divided between two eyes. If I am planning to do a two-mm. recession, I can't do a one mm. on each eye. I don't think I can accurately measure a two-mm. recession. I will say that I have sometimes done a two or a two and one-half-mm. recession. Is an eso deviation which is greater on looking up than on looking straight ahead an "A" phenomenon? DR. COOPER: The question is, is this an "A" or a "V" phenomenon? I think it would be an "A." I would call this an "A" phe nomenon if the eso deviation is greater up by 15 degrees than it is on looking down. Now I notice that Dr. Costenbader judges his "A" and "V" by a difference of 10 looking up and down. Dr. Knapp judges his "A" and "V" by a difference of 15 looking up and straight ahead. I choose 15 but I choose the
503
difference of 15 between the measurements up and down. So it depends on what the measurement is whether this is an "A" or not according to our definition. Please elaborate on the value of plus and minus lenses in the treatment of squint. DR. COSTENBADER: That is a large order. I don't think I can elaborate on it other than to say that plus lenses tend to minimize the accommodation necessary and thus the ac commodative effort involved and then, pre sumably, the accommodative convergence that results. Minus lenses tend to increase the amount of accommodative effort neces sary and thus the amount of accommodative convergence which results therefrom. This is not on a one to one ratio by any means. Some persons get much more convergence from a given amount of presumed accom modation expended than others. / had an adult patient with a monocular esotropia of 20 to 25 degrees, with a slight amblyopia and, after operation, the eye tended to go back to the original angle of squint. How could this have been pre vented? DR. COOPER : I suppose that after the op eration the eye was straight for a while and then iater tended to go back. I must say I can't explain this and I am not sure I be lieve it. I would think your surgery was not adequate and the only way I could say how to prevent this result would be to have your surgery adequate. If it isn't, then go back and do more surgery based on your findings. / / after recession of a medial rectus an exotropia is produced which is greater for distance than for near but with a limitation of adduction of the affected eye, would you still recess the lateral rectus? DR. COOPER : I think that in limited adduc tion of the affected eye one wouldn't ex pect to find the resulting exotropia greater for distance than for near. If there was definite limitation of the adduction of the eye that had the recession of the medial rectus, one would expect, and one would find, the exotropia to be greater for near than for distance ; in that case I would read-
504
SOCIETY PROCEEDINGS
vance the recessed medial. If the situation as described here actually did exist,—a weak ness of adduction as well as greater devia tion for distance than for near—and provid ing the resulting exotropia was large enough, I would probably consider recessing the lateral and readvancing the recessed me dial. Comment on bimedial recessions. DR. BURIAN : Bimedial recessions have been done a great deal over the past 15 to 20 years and are highly recommended by some of our best surgeons. We have done a considerable number over the past seven years and I am still not too happy over them. Not only do overeffects occur but there is also the possibility of undereffects occurring. At the present time I am putting together a few hundred cases and I will be a little more intelligent on the subject in a couple of months when I know just what our results have been. Are many cases of unsuccessfully oper ated esotropia due to the blindspot relation ship, the optic disc relationship? DR. COSTENBADER : I can't tell if many are ; I know some are. I also know that some patients who don't have the blindspot rela tionship also get unsuccessful or poor re sults. I have noticed two things as a result of a well-defined blindspot relationship. If I can have a youngster sit down and give him the Lancaster or similar type of projector test and place my head directly over the child's head and have him put on the red and green specs and presumably put the red light on the green light and if I close one eye and fixate one light and the other light falls on my blindspot, I know that it must fall on his blindspot unless his eyeball is different from mine. If there is a well-defined blindspot re lationship in a given individual, I have the definite feeling that if you undercorrect his esotropia he has a much greater tendency to restore toward or to that same relationship than if he did not have the relationship in the first place. I cannot say how many do that, I can simply say that I have cases in which this has happened.
The other group of which I am conscious are the overcorrected exotropes. About 50 percent of these cases, and they do exist, have, when I have overcorrected them inad vertently, hit the blindspot relationship and this has been a well-defined blindspot rela tionship. Explain the mechanism of horror fusionis. DR. BURIAN : By horror fusionis we do not mean that the patient does not fuse or cannot be made to fuse, we mean that, in general, patients with esotropia, for in stance, dislike macular stimulation more than anything else. They can avoid stimula tion by suppression, by establishing anoma lous correspondence, and by changing the an gle of squint. The horror fusionis phenom enon is this latter phenomenon. You have a patient and you are using perhaps a rotary prism and a red glass and you try to bring the double images closer together and then suddenly they go apart again. There is no suppression involved. There is a change in the angle of squint. The orthoptists know about this and they call it "chasing" when ever they come to the objective angle and the patient changes again so they don't quite catch up with him. This is horror fusionis. STRABISMIC AMBLYOPIA DR. HERMANN M. BURIAN, Iowa City: So far as the treatment of strabismic amblyopia is concerned there would seem to be agree ment that the method of occlusion supported by adequate exercises is still the treatment of choice. It is mainly for the treatment of patients with eccentric fixation that pleoptics was devised. There is considerable difference between the attitude and the approach of the two founders of pleoptics, Bangerter and Cup pers. Bangerter believes that eccentric fixa tion is simply an extreme degree of ambly opia and that it is our job in this case as in all cases of amblyopia to break through the extreme suppression of the foveal area. Once this break through is achieved the path is open to the improvement of the visual acuity of the amblyopic eye. All of Bangert-
SOCIETY PROCEEDINGS er's instruments attempt to direct by visual, acoustic, or tactile stimuli the patient's atten tion to his fovea and to acceptance of mac ular stimulation. Cuppers believes that eccentric fixation is the result of a change in spatial localization such that the eccentric retinal area, which the patient uses for fixation, carries the fovea in a straight-ahead visual direction. My experience with pleoptics have been restricted to the methods advocated by Cup pers. Regardless of theoretic considerations there can be no doubt that Cuppers' methods represent a great advance and we must ac cept the happy pragmatic formula that it works. I mean that one can change the fixa tion pattern of eccentric fixaters by means of the Euthyscope. There is no patching ex cept of the amblyopic eye between treat ments. The Euthyscope is something of a modi fied ophthalmoscope. It is used in this fash ion: After the macula of the amblyopic pa tient is located, a disc of appropriate size is placed in the path of light of the instrument to shield the macular area. The intensity of the light is then stepped up and the fundus is illuminated for about 20 seconds. The result is that the patient sees a doughnut-shaped after-image when the instrument's light is turned off. The center of the doughnut should correspond to the fovea of the eye. This after-image lasts from three to four minutes and, during that period, the patient is asked to watch single symbols, or other means are used to bring the fovea to the at tention of the patient. When the after-image fades, the process is repeated again and again and again. The poor therapist is ex hausted after half an hour and so is the pa tient. Cuppers does this for an hour twice a day. The Euthyscope treatment simply means that you repeat and repeat and repeat the after-image until you finally make the pa tient aware of his fovea; until you get him to see an object straight-ahead and not over
505
there. I personally believe this is not a change of localization but of attention being drawn to the fovea. However, there is no question that it works, occasionally in a few sessions. In all cases time and patience are required before central fixation is carried over into the ordinary art of vision. How practical is this method that requires two daily sessions of an hour each extend ing over two weeks, six weeks, or three months? It is strenuous for the therapist who must have infinite patience and it is strenuous for the patient. I do not believe any. ophthalmologist could possibly afford the time or want to carry out the treatment himself. Therefore especially trained help is required. It is mandatory also that there be some arrangement whereby the amblyopic children may be in one place and cared for all day. In other words, some sort of pleop tics school of the type Bangerter has. There is no reason why this should not be feasible in the United States. Let me conclude with two thoughts. Once the visual acuity of the amblyopic eye has been normalized and securely established our job is not finished. To maintain full function, the amblyopic eye must be used in binocular vision. Results will be maintained only if the patient keeps using the eye. The second thought—pleoptics can only be given to children old enough to co-op erate with the therapists, about six years of age. Pleoptics has also increased the age limit at which amblyopia can be successfully treated. It is remarkable that 18-year-old pa tients and even adults can now be success fully treated. No treatment is, however, ever as good as the absence of need for treatment. Preven tion of amblyopia should remain our fore most goal. Let the ophthalmologist be con stantly aware of the fact that he can by ade quate treatment prevent the development of deep-seated amblyopia in every child. Charles Snyder, Recorder.