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Factors influencing the urgency of repair of retinal detachment
209
CURRENTOPHTHALMOLOGY
rubeosis iridis, and one had raised intraocular pressure due to acute angle closure after retinal venous occlusion although there was no rubeosis. The ninth eye had neovascular glaucoma due to an old central retinal artery occlusion and the tenth eye had diabetic retinopathy and rubeosis iridis. All eyes had an ischemic response with extensive areas of retinal capillary loss. All eyes were treated by panretinal xenon arc photocoagulation, avoiding the macular area. In most cases more than 400 burns of 4.5” spot size were applied. The patients were followed for 6 to 19 months (mean 11 months) after photocoagulation. After treatment, rubeosis iridis decreased in all cases and disappeared in four eyes. Intraocular pressure, which was raised in eight cases (35 to 63 mmHg) decreased considerably in all but one eye. All eyes have been quiet and painless after treatment. Central visual acuity was poor and it did not improve in any of the eyes. The final vision varied from counting fingers to no light perception. These results support the hypothesis that retinal hypoxia is a cause of iris neovascularization and suggest that retinal photocoagulation may have a potential prophylactic and therapeutic role in rubeosis iridis and early neovascular glaucoma, as long as the ocular media are clear and the pupil can be dilated. (Abstract by L. Laatikainen)
Comment Those of us who were influenced by Meyer-Schwickerath’s treatment of diabetics with panretinal photocoagulation noted the beneficial effects in early cases of rubeosis iridis. It was only in borderline early cases that the rubeosis was noted to have disappeared without recurrence. The report by Laatikainen appears to be an important one, suggesting even better prognosis for the rubeosis and pain, albeit not for the visual acuity. The qualifications that the ocular media be clear and that the pupil be dilatable are important in choosing early cases, particularly since the pupil is affected very early in rubeosis. A recent report at the Wills Eye Hospital Conference by Rowley, Magargal and Goldbert (Ophthafmofogy Times 3:2, Aug. 1978) indicates a remarkably parallel result with panretinal photocoagulation. These authors also studied 10 patients, including eight with central vein occlusion, one with a superior branch vein occlusion and one with proliferative diabetic retinopathy. The follow-up period ranged from I to 10 months. SAUL SUGAR
Factors Influencing the Urgency of Repair of Retinal Detachment, by I. Kreissig. Klin Monatsbl Augenheilkd 171:530-538, 1977 This study reports on 266 retinal detachment patients with clear media who were operated using an episcleral sponge and cryotherapy. In 90 percent of cases, subretinal fluid was not drained. Factors influencing postoperative macular function are considered as they relate to five categories of detachment: Group 1 - Macula attached preoperatively Group 2 - Macula partially detached preoperatively Group 3 - Macula completely detached, but retina attached around the disc Group 4 - Macula completely detached, retina partly elevated at the disc Group 5 - Macula completely detached and detachment of the retina around the disc All 70 patients in Group 1 retained macular vision postoperatively as recorded 4 to 12 weeks after surgery. Those patients with the macula detached for under a week also had a good prognosis for macular vision. Patients whose maculas had been detached for more than one week had a poorer prognosis, and this poorer prognosis was similar whether the macula had been detached for one week or one year. Patients under 55 years of age showed no significant difference from those over 55 after two months but there was a significant difference after one year. In the younger group of patients, post-op vision was better after one year than in those over 55. Although only a small group of high myopes (over 6D) were in the study, they generally had a poorer return of macular function than nonmyopes. On the basis of this study, the author recommends immediate surgery 1) if the macula is not detached; 2) if the macula is partly detached; 3) if the macula is detached for less than one week; or 4) if the macula is detached in an elderly person or high myope. (Abstract by I. Kreissig)
Comment This interesting
paper helps to substantiate
the clinical impression that many of us harbor. The
210
SurvOphthalmol 23 (3) November-December 1978
CURRENTOPHTHALMOLOGY
importance of operating on a detached retina where the macula is not yet involved is self-evident. However, the author’s additional guidelines are helpful. The fact that macular function may return if the macula has been off only one week is good to know. For some time I too have felt that younger patients have a better prognosis for recovery of macular function than older patients, a finding borne out by the Kreissig study. Failure of macular vision to return immediately should not be an immediate cause for concern since, as the author and others have observed, slow improvement - even over a year’s time - may occur. One other indicator of visual prognosis that should be mentioned is whether or not the fovea1 xanthophyll pigment has been spilled. If the detached retina shows a yellow pigment spot in the central retina this, in my experience, is the kiss of death for return of macular function. WILLIAM TASMAN
False Diagnosis of Orbital Apex Tumor by CAT Scan in Thyroid Eye Disease, by J.O. Susac, A.N. Martins, B. Robinson, and D.F. Corrigan. Ann Neural 2:397-398, 1977 Computerized axial tomography (CAT) is the diagnostic procedure of choice in the evaluation of patients with exophthalmos. As with any laboratory test, however, caution must be exercised in interpreting the results. Correlation with the clinical picture is also a “must” as exemplified by the patient reported here. A 37-year-old man developed slowly progressive exophthalmos of his right eye and diplopia over a sixmonth period. An ophthalmologist found exophthalmos and limited upgaze of the right eye, and entertained the diagnosis of thyroid eye disease. When the process worsened and thyroid function tests were reported as normal, he obtained a CAT scan. This was interpreted as showing an orbital apex tumor, most likely a meningioma of the optic nerve. With that diagnosis, the patient was referred to a neurosurgery service where neuroophthalmological evaluation revealed vision of 20/20 in both eyes, normal pupils and visual fields. Downward displacement of the proptotic right eye was associated with lid retraction of that eye. Overlying the right lateral rectus muscle were dilated episcleral vessels. Total inability to elevate the right eye was associated with a positive forced ductions test. Mild limitation of abduction and adduction was present, but downgaze was full. Funduscopic examination was normal. Review of the CAT scan revealed a normal contour of the optic nerve in horizontal sections above the “apex tumor,” which represented a markedly enlarged inferior rectus muscle. Although routine thyroid function tests were normal, the Werner Cytomel (triiodothyronine) suppression test was abnormal. In addition, the failure of TSH to rise after TRH stimulation gave additional evidence of autonomous thyroid function as seen in Graves’ disease. This patient clinically had classical thyroid eye disease, including what J. Lawton Smith has termed, the “tight inferior rectus syndrome.” In this condition, the swollen inferior rectus muscle mechanically restricts the globe from elevating. In our patient, the swollen inferior rectus muscle appeared as an orbital apex tumor on CAT. When this patient was reported, coronal sections of the orbit were not available. Coronal sections would undoubtedly have shown the enlarged inferior rectus muscle lying below the normal optic nerve. (Abstract by J.O. Susac)
Comment New diagnostic techniques are subject to misinterpretation in the early years of their use. Computerized tomography of the orbit has not been spared this. The opportunity for error is increased because interpretation is generally in the hands of neuroradiologists who are not familiar with the many causes of exophthalmos, particularly the massive swelling of the extraocular muscles which can occur. As this case report shows, in the axial section there are enlarged inferior rectus muscles which produce an image which has been confused with a tumor by the unwary. Clinical suspicion that Graves’ disease may be present alerts one to this possibility. The presence of a normal optic nerve in sections above the large muscle is further evidence that the observed mass is a swollen muscle rather than neoplasia. However, in some difficult cases coronal sections or thin layer high resolution CT technique may be necessary to distinguish the image formed by an enlarged extraocular muscle from that of a strategically located neoplasm (i.e. lymphoma or meningioma). STEPHEN L. TROKEL
CURRENTOPHTHALMOLOGY
rubeosis iridis, and one had raised intraocular pressure due to acute angle closure after retinal venous occlusion although there was no rubeosis. The ninth eye had neovascular glaucoma due to an old central retinal artery occlusion and the tenth eye had diabetic retinopathy and rubeosis iridis. All eyes had an ischemic response with extensive areas of retinal capillary loss. All eyes were treated by panretinal xenon arc photocoagulation, avoiding the macular area. In most cases more than 400 burns of 4.5” spot size were applied. The patients were followed for 6 to 19 months (mean 11 months) after photocoagulation. After treatment, rubeosis iridis decreased in all cases and disappeared in four eyes. Intraocular pressure, which was raised in eight cases (35 to 63 mmHg) decreased considerably in all but one eye. All eyes have been quiet and painless after treatment. Central visual acuity was poor and it did not improve in any of the eyes. The final vision varied from counting fingers to no light perception. These results support the hypothesis that retinal hypoxia is a cause of iris neovascularization and suggest that retinal photocoagulation may have a potential prophylactic and therapeutic role in rubeosis iridis and early neovascular glaucoma, as long as the ocular media are clear and the pupil can be dilated. (Abstract by L. Laatikainen)
Comment Those of us who were influenced by Meyer-Schwickerath’s treatment of diabetics with panretinal photocoagulation noted the beneficial effects in early cases of rubeosis iridis. It was only in borderline early cases that the rubeosis was noted to have disappeared without recurrence. The report by Laatikainen appears to be an important one, suggesting even better prognosis for the rubeosis and pain, albeit not for the visual acuity. The qualifications that the ocular media be clear and that the pupil be dilatable are important in choosing early cases, particularly since the pupil is affected very early in rubeosis. A recent report at the Wills Eye Hospital Conference by Rowley, Magargal and Goldbert (Ophthafmofogy Times 3:2, Aug. 1978) indicates a remarkably parallel result with panretinal photocoagulation. These authors also studied 10 patients, including eight with central vein occlusion, one with a superior branch vein occlusion and one with proliferative diabetic retinopathy. The follow-up period ranged from I to 10 months. SAUL SUGAR
Factors Influencing the Urgency of Repair of Retinal Detachment, by I. Kreissig. Klin Monatsbl Augenheilkd 171:530-538, 1977 This study reports on 266 retinal detachment patients with clear media who were operated using an episcleral sponge and cryotherapy. In 90 percent of cases, subretinal fluid was not drained. Factors influencing postoperative macular function are considered as they relate to five categories of detachment: Group 1 - Macula attached preoperatively Group 2 - Macula partially detached preoperatively Group 3 - Macula completely detached, but retina attached around the disc Group 4 - Macula completely detached, retina partly elevated at the disc Group 5 - Macula completely detached and detachment of the retina around the disc All 70 patients in Group 1 retained macular vision postoperatively as recorded 4 to 12 weeks after surgery. Those patients with the macula detached for under a week also had a good prognosis for macular vision. Patients whose maculas had been detached for more than one week had a poorer prognosis, and this poorer prognosis was similar whether the macula had been detached for one week or one year. Patients under 55 years of age showed no significant difference from those over 55 after two months but there was a significant difference after one year. In the younger group of patients, post-op vision was better after one year than in those over 55. Although only a small group of high myopes (over 6D) were in the study, they generally had a poorer return of macular function than nonmyopes. On the basis of this study, the author recommends immediate surgery 1) if the macula is not detached; 2) if the macula is partly detached; 3) if the macula is detached for less than one week; or 4) if the macula is detached in an elderly person or high myope. (Abstract by I. Kreissig)
Comment This interesting
paper helps to substantiate
the clinical impression that many of us harbor. The
210
SurvOphthalmol 23 (3) November-December 1978
CURRENTOPHTHALMOLOGY
importance of operating on a detached retina where the macula is not yet involved is self-evident. However, the author’s additional guidelines are helpful. The fact that macular function may return if the macula has been off only one week is good to know. For some time I too have felt that younger patients have a better prognosis for recovery of macular function than older patients, a finding borne out by the Kreissig study. Failure of macular vision to return immediately should not be an immediate cause for concern since, as the author and others have observed, slow improvement - even over a year’s time - may occur. One other indicator of visual prognosis that should be mentioned is whether or not the fovea1 xanthophyll pigment has been spilled. If the detached retina shows a yellow pigment spot in the central retina this, in my experience, is the kiss of death for return of macular function. WILLIAM TASMAN
False Diagnosis of Orbital Apex Tumor by CAT Scan in Thyroid Eye Disease, by J.O. Susac, A.N. Martins, B. Robinson, and D.F. Corrigan. Ann Neural 2:397-398, 1977 Computerized axial tomography (CAT) is the diagnostic procedure of choice in the evaluation of patients with exophthalmos. As with any laboratory test, however, caution must be exercised in interpreting the results. Correlation with the clinical picture is also a “must” as exemplified by the patient reported here. A 37-year-old man developed slowly progressive exophthalmos of his right eye and diplopia over a sixmonth period. An ophthalmologist found exophthalmos and limited upgaze of the right eye, and entertained the diagnosis of thyroid eye disease. When the process worsened and thyroid function tests were reported as normal, he obtained a CAT scan. This was interpreted as showing an orbital apex tumor, most likely a meningioma of the optic nerve. With that diagnosis, the patient was referred to a neurosurgery service where neuroophthalmological evaluation revealed vision of 20/20 in both eyes, normal pupils and visual fields. Downward displacement of the proptotic right eye was associated with lid retraction of that eye. Overlying the right lateral rectus muscle were dilated episcleral vessels. Total inability to elevate the right eye was associated with a positive forced ductions test. Mild limitation of abduction and adduction was present, but downgaze was full. Funduscopic examination was normal. Review of the CAT scan revealed a normal contour of the optic nerve in horizontal sections above the “apex tumor,” which represented a markedly enlarged inferior rectus muscle. Although routine thyroid function tests were normal, the Werner Cytomel (triiodothyronine) suppression test was abnormal. In addition, the failure of TSH to rise after TRH stimulation gave additional evidence of autonomous thyroid function as seen in Graves’ disease. This patient clinically had classical thyroid eye disease, including what J. Lawton Smith has termed, the “tight inferior rectus syndrome.” In this condition, the swollen inferior rectus muscle mechanically restricts the globe from elevating. In our patient, the swollen inferior rectus muscle appeared as an orbital apex tumor on CAT. When this patient was reported, coronal sections of the orbit were not available. Coronal sections would undoubtedly have shown the enlarged inferior rectus muscle lying below the normal optic nerve. (Abstract by J.O. Susac)
Comment New diagnostic techniques are subject to misinterpretation in the early years of their use. Computerized tomography of the orbit has not been spared this. The opportunity for error is increased because interpretation is generally in the hands of neuroradiologists who are not familiar with the many causes of exophthalmos, particularly the massive swelling of the extraocular muscles which can occur. As this case report shows, in the axial section there are enlarged inferior rectus muscles which produce an image which has been confused with a tumor by the unwary. Clinical suspicion that Graves’ disease may be present alerts one to this possibility. The presence of a normal optic nerve in sections above the large muscle is further evidence that the observed mass is a swollen muscle rather than neoplasia. However, in some difficult cases coronal sections or thin layer high resolution CT technique may be necessary to distinguish the image formed by an enlarged extraocular muscle from that of a strategically located neoplasm (i.e. lymphoma or meningioma). STEPHEN L. TROKEL