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Spontaneous Reattachment of the Retina Despite Proliferative Vitreoretinopathy
SPONTANEOUS REATTACHMENT OF THE RETINA DESPITE PROLIFERATIVE VITREORETINOPATHY EUGENE DE JUAN, JR., M.D., AND ROBERT MACHEMER, M.D.
Durham, North Carolina
In six cases of spontaneous retinal reattachment despite severe proliferative vitreoretinopathy, the retina was initially attached after a buckling procedure or vitreous surgery for proliferative vitreoretinopathy. However, each retina suddenly detached several weeks later. Surprisingly, the retinas settled slowly during the following weeks without further treatment. One case was marked by repeated episodes of detachment and reattachment. In none of the cases could an open retinal break be detected. In certain cases of proliferative vitreoretinopathy in which no open break is apparent and the detachment appears to be tractional, an observation period of several weeks may allow the retina to reattach spontaneously without further surgery. Spontaneous attachment of the retina in the presence of an untreated open break is rare. 1 Modern techniques have dramatically improved our ability to reattach the retina but failures still occur. These are most often the result of the development of proliferative vitreoretinopathy," Current techniques, particularly vitreous surgery, offer some hope but are still far from satisfactory." If treatment for proliferative vitreoretinopathy fails, the hope of reattachment is greatly reduced. Still, rare cases of late spontaneous reattachment despite proliferative vitreoretinopathy have been reported. 3-6 We have observed six cases of spontaneous retinal reattachment in patients with proliferative vitreoretinopathy. These
Accepted for publication Feb. 1, 1984. From the Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina. This study was supported by grant EY02903 from the National Eye Institute and by a grant from Research to Prevent Blindness, Inc. Dr. de Juan is a Heed Foundation Fellow (1983-1984). Reprint requests to Robert Machemer, M.D., Duke University Eye Center, Box 3802, Durham, NC 27710. 428
detachments occurred either after a scleral buckling procedure or after vitreous surgery techniques had produced initially successful retinal reattachment. Each of the detachments spontaneously settled during the next weeks. CASE REPORTS
Case I-A 73-year-old man had a total retinal detachment and proliferative vitreoretinopathy in his right eye. In August 1974 the patient underwent uncomplicated cataract surgery in this eye. He did well until three months later when a retinal detachment involving the macula developed. After surgical repair proliferative vitreoretinopathy and total retinal detachment (grade D2) developed. The patient underwent vitrectomy and membrane peeling in his right eye in January 1975. One month later the retina suddenly redetached and visual acuity decreased to hand motions. The retina was highly elevated and had a "morning-glory" appearance (grade D2) (Fig. 1, left). The eye was considered to be inoperable. During the next two months the retina spontaneously and completely settled. The patient's visual acuity improved to 15/200 without further treatment (Fig. 1, right). Case 2-A 35-year-old woman suffered a sudden loss of vision in her left eye. Examination disclosed a large retinal detachment and a scleral buckling procedure successfully reattached the retina. The detachment, however, recurred one month later. Visual acuity decreased to 2/200. There was heavy flare in the vitreous cavity with a moderate number of pigmented cells. Ophthalmoscopy disclosed an almost total retinal detachment with a starfold in the inferior
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Fig. 1 (de Juan and Machemer). Case 1. Left, Severe proliferative vitreoretinopathy after vitrectomy, Right, Spontaneous settling of the retina three months later.
temporal quadrant (Fig. 2, top left). Epiretinal membranes were present in the macula and temporally. No open retinal break was found. The detachment was considered to be tractional. No further surgery was recommended. Three months later the retina had flattened somewhat (Fig. 2, top right) and after nine months only a small remnant of epiretinal tissue was still visible (Fig. 2, bottom left). Visual acuity improved to 8/200. Case 3-This 52-year-old man had recurrent retinal detachments in his left eye. He had undergone uncomplicated intracapsular cataract extraction with placement of an anterior chamber intraocular lens in February 1981. Two years later, he developed an acute posterior vitreous detachment followed by a superior retinal detachment from a dialysis extending from the 11 to the 1 o'clock positions. Focal cryotherapy, scleral buckling, and air injection were performed. Progressive vitreoretinal traction unresponsive to additional laser photocoagulation developed. One month after surgery the eye had a total retinal detachment and proliferative vitreoretinopathy (grade D2). A vitrectomy with total fluid-gas exchange was performed and postoperative photocoagulation administered. The retina, however, again detached. An examination showed a total retinal detachment with proliferative vitreoretinopathy (grade D2) but no retinal break was found. One month later, the patient's visual acuity had improved from hand motions to 20/100 and the retina was largely attached except for some "dry" folds. Case 4-A 23-year-old woman with a retinal detachment and proliferative vitreoretinopathy had been the product of a twin birth and had received oxygen therapy for several days. Her right eye had been blind since birth. She had severe myopia and a pigmentary peripheral degeneration. In July 1975 an
inferior retinal detachment developed. It was repaired and the retina remained attached until six weeks later when proliferative vitreoretinopathy caused an almost total retinal detachment (grade C2). The patient underwent vitrectomy, lensectomy, and membrane peeling but the retina suddenly detached four weeks later. No retinal break was found. Without further treatment the retina slowly reattached during the next three months. The patient's visual acuity improved to 20/100 and remained stable until May 1980 when the retina again redetached. This time the patient underwent a scleral buckling procedure. The retina reattached but a pigmented macular pucker developed. This was removed surgically. At the last follow-up visit, the visual acuity was 20/80. Case 5--This 63-year-old man had a retinal detachment in his left eye which had a history of mild amblyopia. Cataract surgery in June 1980 had returned his visual acuity to 20/60. In August he noted decreased vision and an examination disclosed a retinal detachment involving the macula. He underwent focal cryotherapy and scleral buckling but the retina failed to flatten because of proliferative vitreoretinopathy. Two months after the operation the patient had a visual acuity of light perception and there was a total retinal detachment with preretinal membrane formation temporally. No open retinal breaks were seen. At a return visit seven weeks later, the retina was attached except in the inferior temporal quadrant. By December the retina was totally attached with some "dry" retinal folds and visual acuity had improved to 20/80. Case 6--This 55-year-old woman had a large traction retinal detachment in her right eye. Vision in her left eye had been lost 25 years earlier because of a retinal detachment. In 1965 she had undergone successful retinal surgery for a superior detachment
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Fig. 2 (de Juan and Machemer). Case 2. Top left, Moderate retinal elevation with proliferative vitreoretinopathy in the temporal retina. Top right, Three months later the retina has flattened somewhat and the starfold is less prominent. Bottom left, After nine months the retina is flat with a mild pucker (arrow).
in her right eye. In 1973, a cataract was removed without complication. Two years later a total retinal detachment developed. During the retinal reattachment procedure, spontaneous drainage of vitreous fluid occurred at a site of previous scleral dissection and a choroidal hemorrhage developed. Postoperatively, the retina developed a high traction detachment nasally (grade D2). The patient underwent vitrectomy and membrane peeling which allowed the retina to flatten. After three months an inferior retinal detachment again developed. No treatment was given but at a follow-up examination the retina had reattached and the visual acuity had improved to 20/160 (Fig. 3, left). During the next few months the retina detached and spontaneously reattached sever-
al times. With each detachment the visual acuity dramatically decreased and then slowly returned to the previous level of 20/200. A retinal break was never found. The iris developed rubeosis, totally closing the angle; intraocular pressure ranged from hypotony to increased levels depending on whether or not the retina was attached. A subtenon's injection of triamcinolone acetonide did not alter the course. In November 1975 the patient underwent a scleral resection because of persistent traction retinal detachment. The retina again attached and detached several times. In March 1976 the visual acuity had decreased to hand motions and there was a total retinal detachment (Fig. 3, right). A repeat scleral buckle was performed in May after which the retina
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Fig. 3 (de Juan and Machemer). Case 6. This patient had several episodes of repeated detachments and spontaneous reattachments. Left, Retina after spontaneous reattachment. Right, Retina during detachment. Note the moderate proliferative vitreoretinopathy.
remained flat but all vision was subsequently lost because of uncontrolled intraocular pressure. The patient refused further surgery. DISCUSSION
Spontaneous retinal reattachment is rare in the presence of an open retinal break. When the detachment is additionally complicated by extensive epiretinal membrane formation causing traction, the prognosis, even with surgery, is guarded. Several cases of spontaneous retinal reattachment despite proliferative vitreoretinopathy have been reported. Kokolakis, Bravo, and Chiqnell! studied the disappearance of sub retinal fluid as a criterion for late retinal reattachment and concluded that a spontaneous posterior vitreous detachment releasing anteroposterior traction was probably the associated event allowing the retina to attach spontaneously. The epiretinal membranes that had been present in several of their cases could no longer be identified once the retina was reattached. Tolentino, Schepens, and Freernan'' observed three cases in which spontaneous retinal
reattachment occurred in the presence of proliferative vitreoretinopathy. The mechanism by which this occurred appeared to be a posterior vitreous detachment that removed with it a semitransparent membrane that presumably was the preretinal membrane causing the retinal traction. Byer" reported a case of spontaneous disappearance of early postoperative preretinal traction in which the posterior vitreous surface became anteriorly displaced, allowing a small starshaped retinal fold to disappear. More recently, Cantrill! observed a spontaneously reattached retina despite preretinal and transvitreous membranes without surgical intervention. Again, in this case there was an anterior displacement of the posterior vitreous face. Cangemi, Pitta, and Schwartz! reported another case of spontaneous resolution of massive periretinal proliferation. The retina spontaneously settled two weeks after the appearance of proliferative vitreoretinopathy. Again, examination showed a broad equatorial membrane with a frag-
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mented central pigmented membrane just posterior to the iris surface, indicating an anteriorly displaced posterior vitreous detachment. Our Case 2 was similar to the previously reported cases, but our other five cases differed in that these patients had undergone total posterior vitrectomy so that release of anteroposterior traction by further separation of the posterior vitreous face could not explain the spontaneous reattachment. We believe that posterior vitreous detachment with release of anteroposterior traction was not the mechanism of reattachment even in our Case 2, but that release of tangential traction was more likely. The retinal reattachments in our patients all appeared to follow a common course. In all cases initial attachment of the retina was achieved after a scleral buckling procedure or vitreous surgery. This was usually followed by a sudden decrease in vision shown to be the result of recurrent retinal detachment with severe proliferative vitreoretinopathy. In none of the patients could a retinal break be identified as the cause of the detachment. The first patient in whom this was recognized (Case 1) was considered to be inoperable only to return three months later with his retina totally attached. Another patient (Case 6) was examined repeatedly by several retinal surgeons because of multiple episodes of sudden decrease in vision caused by recurrent retinal detachment that resolved slowly during a period of several weeks. Other patients had been scheduled for possible repeat surgery but by the time of the examination their retinas had flattened. After we became aware of this phenomenon, we tried to postpone surgery in some of these patients until the retina was given a chance to reattach without intervention. We have also observed the apparent disappearance of the epiretinal tissue as the retina spontaneously reattached. We
APRIL, 1984
believe that this does not represent a disappearance of the epiretinal membranes but only that the effects of the membranes-the starfolds-are not apparent. This was dramatically demonstrated by Case 6 in which repeated episodes of detachment occurred with starfold formation. Each time the retina slowly settled, and each time the starfolds flattened, vision improved, and there was little or no evidence of the epiretinal tissue. During scar formation certain active cells contain an increased amount of actin and myosin. These cells, called myofibroblasts, are thought to contribute to the tractional forces that develop during the scarring process" We do not understand fully what conditions determine whether a cell appears as a myofibroblast. However, we postulate that in cases of spontaneous reattachment of the retina despite proliferative vitreoretinopathy, the retina is first reattached by a combination of drainage of subretinal fluid, closure of open breaks, and release of traction on the retina either by scleral buckling or membrane peeling. After a short period (one to two weeks) there is either increased proliferation or the cells that are present become more contractile in character. This causes the retina to detach because the epiretinal tissue exerts moderate tangential traction resulting in a starfold formation. Once the retina detaches, the epiretinal membranes may slowly lose some of their contractile force, thereby allowing the retina to attach. Case 6, in which several detachments occurred, demonstrated the sometimes delicate balance between the tractional forces causing the retina to be detached and the forces generated by the retinal pigment epithelium causing the retina to reattach. In addition to relaxation of contraction of the preretinal tissue, there is another mechanism to eliminate the traction. This was demonstrated
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by Case 2. As the retina began to settle the preretinal tissue began to peel, leaving a small fragment of partially peeled preretinal tissue. We admit that the ophthalmoscopic appearance of some of the detachments was not entirely tractional (that is, a concave retinal surface) and a small hole within a fold of retina-although never found--eould not be ruled out. An alternative explanation for the spontaneous reattachment, therefore, would be that the proliferative process closed a small hole that formed postoperatively, thus allowing the retina to settle. However, it is difficult to postulate this in the patient who had several spontaneous reattachments. Although spontaneous reattachment in the presence of proliferative vitreoretinopathy is rare, certain features appear to be common. They usually occur in patients in whom the retinal periphery is well seen and no retinal break is found. The degree of retinal elevation is on average less than expected for a rhegmatogenous retinal detachment after vitrectomy. The appearance overall is mostly tractional. Additionally, a history of
433
successful reattachment after retinal and vitreous surgery is helpful. Judging from our cases, four to six weeks of observation should be sufficient to determine whether the retina will settle spontaneously. This phenomenon does not prevent a good visual outcome. REFERENCES 1. Duke-Elder, S., and Dobree, J. H.: Diseases of the retina. In Duke-Elder, S. (ed.): System of Ophthalmology, vol. 10. St. Louis, C. V. Mosby, 1967, pp. 805-806. 2. Machemer, R.: Massive periretinal proliferation. A logical approach to therapy. Trans. Am. Ophthalmol. Soc. 125:556, 1977. 3. Cantrill, H. L.: Spontaneous retinal reattachment. Retina 1:216, 1981. 4. Koklakis, S. N., Bravo, L., and Chiqnell, A. H.: Late retinal reattachment. Br. J. Ophthalmol. 65:142, 1981. 5. Cangemi, F. E., Pitta, C. B., and Schwartz, P. L.: Spontaneous resolution of massive periretinal proliferations. Am. J. Ophthalmol. 93:92, 1982. 6. Tolentino, F.!., Schepens, C. L., and Freeman, H. M.: Vitreoretinal Disorders. Diagnosis and Management. Philadelphia, W. B. Saunders, 1976, pp. 483-485. 7. Byer, N. E.: Spontaneous disappearance of early postoperative preretinal retraction. Arch. Ophthalmol. 90:133, 1973. 8. Gabbiani, G., Hirschel, B. J., and Ryan, G. B.: Granulation tissue as a contractile organ. A study of structure and function. J. Exp. Med. 135:719, 1972.
Durham, North Carolina
In six cases of spontaneous retinal reattachment despite severe proliferative vitreoretinopathy, the retina was initially attached after a buckling procedure or vitreous surgery for proliferative vitreoretinopathy. However, each retina suddenly detached several weeks later. Surprisingly, the retinas settled slowly during the following weeks without further treatment. One case was marked by repeated episodes of detachment and reattachment. In none of the cases could an open retinal break be detected. In certain cases of proliferative vitreoretinopathy in which no open break is apparent and the detachment appears to be tractional, an observation period of several weeks may allow the retina to reattach spontaneously without further surgery. Spontaneous attachment of the retina in the presence of an untreated open break is rare. 1 Modern techniques have dramatically improved our ability to reattach the retina but failures still occur. These are most often the result of the development of proliferative vitreoretinopathy," Current techniques, particularly vitreous surgery, offer some hope but are still far from satisfactory." If treatment for proliferative vitreoretinopathy fails, the hope of reattachment is greatly reduced. Still, rare cases of late spontaneous reattachment despite proliferative vitreoretinopathy have been reported. 3-6 We have observed six cases of spontaneous retinal reattachment in patients with proliferative vitreoretinopathy. These
Accepted for publication Feb. 1, 1984. From the Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina. This study was supported by grant EY02903 from the National Eye Institute and by a grant from Research to Prevent Blindness, Inc. Dr. de Juan is a Heed Foundation Fellow (1983-1984). Reprint requests to Robert Machemer, M.D., Duke University Eye Center, Box 3802, Durham, NC 27710. 428
detachments occurred either after a scleral buckling procedure or after vitreous surgery techniques had produced initially successful retinal reattachment. Each of the detachments spontaneously settled during the next weeks. CASE REPORTS
Case I-A 73-year-old man had a total retinal detachment and proliferative vitreoretinopathy in his right eye. In August 1974 the patient underwent uncomplicated cataract surgery in this eye. He did well until three months later when a retinal detachment involving the macula developed. After surgical repair proliferative vitreoretinopathy and total retinal detachment (grade D2) developed. The patient underwent vitrectomy and membrane peeling in his right eye in January 1975. One month later the retina suddenly redetached and visual acuity decreased to hand motions. The retina was highly elevated and had a "morning-glory" appearance (grade D2) (Fig. 1, left). The eye was considered to be inoperable. During the next two months the retina spontaneously and completely settled. The patient's visual acuity improved to 15/200 without further treatment (Fig. 1, right). Case 2-A 35-year-old woman suffered a sudden loss of vision in her left eye. Examination disclosed a large retinal detachment and a scleral buckling procedure successfully reattached the retina. The detachment, however, recurred one month later. Visual acuity decreased to 2/200. There was heavy flare in the vitreous cavity with a moderate number of pigmented cells. Ophthalmoscopy disclosed an almost total retinal detachment with a starfold in the inferior
© AMERICAN JOURNAL OF OPHTHALMOLOGY 97:428-433, 1984
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Fig. 1 (de Juan and Machemer). Case 1. Left, Severe proliferative vitreoretinopathy after vitrectomy, Right, Spontaneous settling of the retina three months later.
temporal quadrant (Fig. 2, top left). Epiretinal membranes were present in the macula and temporally. No open retinal break was found. The detachment was considered to be tractional. No further surgery was recommended. Three months later the retina had flattened somewhat (Fig. 2, top right) and after nine months only a small remnant of epiretinal tissue was still visible (Fig. 2, bottom left). Visual acuity improved to 8/200. Case 3-This 52-year-old man had recurrent retinal detachments in his left eye. He had undergone uncomplicated intracapsular cataract extraction with placement of an anterior chamber intraocular lens in February 1981. Two years later, he developed an acute posterior vitreous detachment followed by a superior retinal detachment from a dialysis extending from the 11 to the 1 o'clock positions. Focal cryotherapy, scleral buckling, and air injection were performed. Progressive vitreoretinal traction unresponsive to additional laser photocoagulation developed. One month after surgery the eye had a total retinal detachment and proliferative vitreoretinopathy (grade D2). A vitrectomy with total fluid-gas exchange was performed and postoperative photocoagulation administered. The retina, however, again detached. An examination showed a total retinal detachment with proliferative vitreoretinopathy (grade D2) but no retinal break was found. One month later, the patient's visual acuity had improved from hand motions to 20/100 and the retina was largely attached except for some "dry" folds. Case 4-A 23-year-old woman with a retinal detachment and proliferative vitreoretinopathy had been the product of a twin birth and had received oxygen therapy for several days. Her right eye had been blind since birth. She had severe myopia and a pigmentary peripheral degeneration. In July 1975 an
inferior retinal detachment developed. It was repaired and the retina remained attached until six weeks later when proliferative vitreoretinopathy caused an almost total retinal detachment (grade C2). The patient underwent vitrectomy, lensectomy, and membrane peeling but the retina suddenly detached four weeks later. No retinal break was found. Without further treatment the retina slowly reattached during the next three months. The patient's visual acuity improved to 20/100 and remained stable until May 1980 when the retina again redetached. This time the patient underwent a scleral buckling procedure. The retina reattached but a pigmented macular pucker developed. This was removed surgically. At the last follow-up visit, the visual acuity was 20/80. Case 5--This 63-year-old man had a retinal detachment in his left eye which had a history of mild amblyopia. Cataract surgery in June 1980 had returned his visual acuity to 20/60. In August he noted decreased vision and an examination disclosed a retinal detachment involving the macula. He underwent focal cryotherapy and scleral buckling but the retina failed to flatten because of proliferative vitreoretinopathy. Two months after the operation the patient had a visual acuity of light perception and there was a total retinal detachment with preretinal membrane formation temporally. No open retinal breaks were seen. At a return visit seven weeks later, the retina was attached except in the inferior temporal quadrant. By December the retina was totally attached with some "dry" retinal folds and visual acuity had improved to 20/80. Case 6--This 55-year-old woman had a large traction retinal detachment in her right eye. Vision in her left eye had been lost 25 years earlier because of a retinal detachment. In 1965 she had undergone successful retinal surgery for a superior detachment
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Fig. 2 (de Juan and Machemer). Case 2. Top left, Moderate retinal elevation with proliferative vitreoretinopathy in the temporal retina. Top right, Three months later the retina has flattened somewhat and the starfold is less prominent. Bottom left, After nine months the retina is flat with a mild pucker (arrow).
in her right eye. In 1973, a cataract was removed without complication. Two years later a total retinal detachment developed. During the retinal reattachment procedure, spontaneous drainage of vitreous fluid occurred at a site of previous scleral dissection and a choroidal hemorrhage developed. Postoperatively, the retina developed a high traction detachment nasally (grade D2). The patient underwent vitrectomy and membrane peeling which allowed the retina to flatten. After three months an inferior retinal detachment again developed. No treatment was given but at a follow-up examination the retina had reattached and the visual acuity had improved to 20/160 (Fig. 3, left). During the next few months the retina detached and spontaneously reattached sever-
al times. With each detachment the visual acuity dramatically decreased and then slowly returned to the previous level of 20/200. A retinal break was never found. The iris developed rubeosis, totally closing the angle; intraocular pressure ranged from hypotony to increased levels depending on whether or not the retina was attached. A subtenon's injection of triamcinolone acetonide did not alter the course. In November 1975 the patient underwent a scleral resection because of persistent traction retinal detachment. The retina again attached and detached several times. In March 1976 the visual acuity had decreased to hand motions and there was a total retinal detachment (Fig. 3, right). A repeat scleral buckle was performed in May after which the retina
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Fig. 3 (de Juan and Machemer). Case 6. This patient had several episodes of repeated detachments and spontaneous reattachments. Left, Retina after spontaneous reattachment. Right, Retina during detachment. Note the moderate proliferative vitreoretinopathy.
remained flat but all vision was subsequently lost because of uncontrolled intraocular pressure. The patient refused further surgery. DISCUSSION
Spontaneous retinal reattachment is rare in the presence of an open retinal break. When the detachment is additionally complicated by extensive epiretinal membrane formation causing traction, the prognosis, even with surgery, is guarded. Several cases of spontaneous retinal reattachment despite proliferative vitreoretinopathy have been reported. Kokolakis, Bravo, and Chiqnell! studied the disappearance of sub retinal fluid as a criterion for late retinal reattachment and concluded that a spontaneous posterior vitreous detachment releasing anteroposterior traction was probably the associated event allowing the retina to attach spontaneously. The epiretinal membranes that had been present in several of their cases could no longer be identified once the retina was reattached. Tolentino, Schepens, and Freernan'' observed three cases in which spontaneous retinal
reattachment occurred in the presence of proliferative vitreoretinopathy. The mechanism by which this occurred appeared to be a posterior vitreous detachment that removed with it a semitransparent membrane that presumably was the preretinal membrane causing the retinal traction. Byer" reported a case of spontaneous disappearance of early postoperative preretinal traction in which the posterior vitreous surface became anteriorly displaced, allowing a small starshaped retinal fold to disappear. More recently, Cantrill! observed a spontaneously reattached retina despite preretinal and transvitreous membranes without surgical intervention. Again, in this case there was an anterior displacement of the posterior vitreous face. Cangemi, Pitta, and Schwartz! reported another case of spontaneous resolution of massive periretinal proliferation. The retina spontaneously settled two weeks after the appearance of proliferative vitreoretinopathy. Again, examination showed a broad equatorial membrane with a frag-
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mented central pigmented membrane just posterior to the iris surface, indicating an anteriorly displaced posterior vitreous detachment. Our Case 2 was similar to the previously reported cases, but our other five cases differed in that these patients had undergone total posterior vitrectomy so that release of anteroposterior traction by further separation of the posterior vitreous face could not explain the spontaneous reattachment. We believe that posterior vitreous detachment with release of anteroposterior traction was not the mechanism of reattachment even in our Case 2, but that release of tangential traction was more likely. The retinal reattachments in our patients all appeared to follow a common course. In all cases initial attachment of the retina was achieved after a scleral buckling procedure or vitreous surgery. This was usually followed by a sudden decrease in vision shown to be the result of recurrent retinal detachment with severe proliferative vitreoretinopathy. In none of the patients could a retinal break be identified as the cause of the detachment. The first patient in whom this was recognized (Case 1) was considered to be inoperable only to return three months later with his retina totally attached. Another patient (Case 6) was examined repeatedly by several retinal surgeons because of multiple episodes of sudden decrease in vision caused by recurrent retinal detachment that resolved slowly during a period of several weeks. Other patients had been scheduled for possible repeat surgery but by the time of the examination their retinas had flattened. After we became aware of this phenomenon, we tried to postpone surgery in some of these patients until the retina was given a chance to reattach without intervention. We have also observed the apparent disappearance of the epiretinal tissue as the retina spontaneously reattached. We
APRIL, 1984
believe that this does not represent a disappearance of the epiretinal membranes but only that the effects of the membranes-the starfolds-are not apparent. This was dramatically demonstrated by Case 6 in which repeated episodes of detachment occurred with starfold formation. Each time the retina slowly settled, and each time the starfolds flattened, vision improved, and there was little or no evidence of the epiretinal tissue. During scar formation certain active cells contain an increased amount of actin and myosin. These cells, called myofibroblasts, are thought to contribute to the tractional forces that develop during the scarring process" We do not understand fully what conditions determine whether a cell appears as a myofibroblast. However, we postulate that in cases of spontaneous reattachment of the retina despite proliferative vitreoretinopathy, the retina is first reattached by a combination of drainage of subretinal fluid, closure of open breaks, and release of traction on the retina either by scleral buckling or membrane peeling. After a short period (one to two weeks) there is either increased proliferation or the cells that are present become more contractile in character. This causes the retina to detach because the epiretinal tissue exerts moderate tangential traction resulting in a starfold formation. Once the retina detaches, the epiretinal membranes may slowly lose some of their contractile force, thereby allowing the retina to attach. Case 6, in which several detachments occurred, demonstrated the sometimes delicate balance between the tractional forces causing the retina to be detached and the forces generated by the retinal pigment epithelium causing the retina to reattach. In addition to relaxation of contraction of the preretinal tissue, there is another mechanism to eliminate the traction. This was demonstrated
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by Case 2. As the retina began to settle the preretinal tissue began to peel, leaving a small fragment of partially peeled preretinal tissue. We admit that the ophthalmoscopic appearance of some of the detachments was not entirely tractional (that is, a concave retinal surface) and a small hole within a fold of retina-although never found--eould not be ruled out. An alternative explanation for the spontaneous reattachment, therefore, would be that the proliferative process closed a small hole that formed postoperatively, thus allowing the retina to settle. However, it is difficult to postulate this in the patient who had several spontaneous reattachments. Although spontaneous reattachment in the presence of proliferative vitreoretinopathy is rare, certain features appear to be common. They usually occur in patients in whom the retinal periphery is well seen and no retinal break is found. The degree of retinal elevation is on average less than expected for a rhegmatogenous retinal detachment after vitrectomy. The appearance overall is mostly tractional. Additionally, a history of
433
successful reattachment after retinal and vitreous surgery is helpful. Judging from our cases, four to six weeks of observation should be sufficient to determine whether the retina will settle spontaneously. This phenomenon does not prevent a good visual outcome. REFERENCES 1. Duke-Elder, S., and Dobree, J. H.: Diseases of the retina. In Duke-Elder, S. (ed.): System of Ophthalmology, vol. 10. St. Louis, C. V. Mosby, 1967, pp. 805-806. 2. Machemer, R.: Massive periretinal proliferation. A logical approach to therapy. Trans. Am. Ophthalmol. Soc. 125:556, 1977. 3. Cantrill, H. L.: Spontaneous retinal reattachment. Retina 1:216, 1981. 4. Koklakis, S. N., Bravo, L., and Chiqnell, A. H.: Late retinal reattachment. Br. J. Ophthalmol. 65:142, 1981. 5. Cangemi, F. E., Pitta, C. B., and Schwartz, P. L.: Spontaneous resolution of massive periretinal proliferations. Am. J. Ophthalmol. 93:92, 1982. 6. Tolentino, F.!., Schepens, C. L., and Freeman, H. M.: Vitreoretinal Disorders. Diagnosis and Management. Philadelphia, W. B. Saunders, 1976, pp. 483-485. 7. Byer, N. E.: Spontaneous disappearance of early postoperative preretinal retraction. Arch. Ophthalmol. 90:133, 1973. 8. Gabbiani, G., Hirschel, B. J., and Ryan, G. B.: Granulation tissue as a contractile organ. A study of structure and function. J. Exp. Med. 135:719, 1972.