Int. Ophthal. 1,1: 5-8, 1978
Results of pars plana vitrectomy in penetrating ocular trauma* STEPHEN J. R Y A N , Los Angeles, USA
M.D.**
Keywords: Penetrating ocular trauma, Pars plana vitrectomy, Fibrous proliferation, Vitreous hemorrhage. Abstract Thirty-four severely injured eyes were operated with pars plana vitrectomy. The nine cases with involvement exclusively of the anterior segment alone were operated with success in all cases. However, the injuries of the posterior segment still reflect significant problems in that only 50 percent obtained successful visual results. This reflects, in great part, the degree of severity of the initial damage. The theoretical rationale for pars plana vitrectomy in penetrating ocular trauma is discussed. Because of the many variables from patient to patient and injury to injury, conflicting clinical impressions as to appropriate management prevail. In the abscence of a definitive clinical trial or suitable experimental model, our guidelines for the role and proper timing of pars plana vitrectomy for penetrating ocular trauma are presented.
Introduction Ocular trauma accounts for approximately three percent of the blindness in the United States (27), In some communities, 30 percent of all acute ocular cases are related to trauma (26) while Holland (15) reported that 12 percent of all ophthalmic cases requiring hospital admission are related to the sequelae of ocular trauma. Socioeconomic factors and geography, as well as expertise and referral patterns, determine the bias of ascertainment and, thus, the incidence of ocular trauma in a particular locale. Penetrating ocular trauma often occurs in the relatively From the Department of Ophthalmology, University of Southern California School of Medicine, and the Estelle Doheny Eye Foundation, Los Angeles, California, U.S.A. * This study was supported in part by the National Institutes of Health grant EY 02061 01. ** Dr. Ryan is recipient of the Louis B. Mayer Scholar Award from Research to Prevent Blindness, Inc., New York, New York.
young but otherwise healthy patient, so that it remains an important, if not the statistically leading, cause of blindness. The effects of bilateral ocular trauma are particularly devastating, since productive and frequently young individuals can be rendered economically dependent because of their visual handicap. Roper-Hall (33) stated that the recovery of an eye from injury depends on three factors: (1) the extent of the initial damage, (2) the efficiency of treatment, and (3) the satisfactory management of complications. In recent years, a much higher percentage of patients achieve good vision after penetrating ocular injury (32, 11, 12). This improvement largely reflects the better results obtained by repairing anterior segment injuries with microsurgical techniques (Neubauer 28, 29, Eagling 12 and Faulborn 13). By contrast, the visual prognosis after injuries of the posterior segment has shown little or no improvement, chiefly because of the complications of retinal detachment, vitreous hemorrhage, extensive choroidal hemorrhage, and cyclitic membrane formation (Eagling 13).
6 More recently, vitrectomy has been employed for many of the complications of penetrating ocular trauma (15) as a logical extension of the initial work and observations of open-sky vitrectomy (18). Pars plana vitrectomy provides a new approach to previously hopeless cases of ocular trauma (2 l, 22, 25, 16, 4). In the author's practice, trauma has become the second most frequent indication (exceeded only by diabetes) for pars plana vitrectomy. Histopathologic correlation with clinical findings have led to working hypotheses emphasizing the importance of vitreous hemorrhage and vitreous incarceration with subsequent vitreoretinal traction ( l 1). Condensation, organization, and traction of the vitreous on the retina can lead to retinal detachment, cyclitic membrane formation, recurrent vitreous hemorrhage, and ultimately loss of the eye with total retinal detachment and phthisis. Since vitreous hemorrhage seems to play an important role in the development of subsequent traction, there is a good rationale for vitrectomy, i.e., to remove the inciting hemorrhage. Also, removing the vitreous deprives the cellular fibrous ingrowth of a scaffolding upon which to grow and via which to cause traction on the return. Controversy continues as to the optimum time and appropriate indications for vitrectomy in the early phase after penetrating injury. The advocates of early pars plana vitrectomy in posterior segment trauma do not agree as just how early this operative intervention should be performed. Some favor early (within 48 hours) surgery (4), whereas others prefer to wait ten to fourteen days (Machemer--personal communication). The cases included here were studied to learn the results of vitrectomy for penetrating ocular injuries. This review is not based on a prospective, controlled trial. The clinical impressions, however, provide a basis for discussing guidelines in the management of penetrating ocular injuries. Methodology All cases included in this study were operated with pars plana vitrectomy for complications of penetrating ocular trauma. It should be noted that all cases are referred from other ophthalmologists, and, thus, these cases do not reflect primary surgery, including
Stephen 3. Ryan wound closure, by the author. The anterior segment cases were those in which penetrating injury involved the anterior corneoscleral coat of the eye, uvea, and lens; but there was no involvement of the vitreous, choroid, or retina. The anterior segment reconstruction in these cases in which there was not damage to the vitreous frequently necessitated only removal of the lens or pupillary membrane. The penetrating injuries of the posterior segment included those with involvement of the vitreous, retina, or choroid, i.e., trauma posterior to the lens. Those cases with anterior segment as well as posterior segment involvement were included in this posterior group, since the common denominators of severity and poor prognosis were the degree of the posterior segment involvement. This group included cases with intraocular foreign bodies. It should be noted that this series is biased by the ascertainment of cases. Thus, the cases that could be closed in a more straightforward fashion by the referring ophthalmologists were not referred. On the other hand, there are also many hopeless cases that were managed locally, even so severe as to require early enucleation, and again without referral. The common denominator of the cases reported remains that the indications for pars plana vitrectomy were present.
Results Anterior Segment Injury Of the nine cases in which cataract extraction, excision of pupillary membranes, or anterior segment reconstruction were required, all nine obtained improvement in vision. Seven of the nine cases had 20]40 or better visual acuity, and the remaining two cases had 20]100 or better visual acuity. One patient did require a scleral buckling procedure for a retinal detachment, which was a complication of surgery. However, the retina was successfully reattached, and the patient has doen well postoperatively.
Posterior Segment Injury Of 25 penetrating injuries to the posterior segement, nine cases with intraocular foreign bodies are included. Successful visual results were achieved in four
Results of pars plana vitrectomy in penetrating ocular trauma
7
of the nine intraocular foreign bodies. F o u r failures lost vision on the basis primarily of inoperable retinal detachment, while one case had uncontrollable hemorrhage. Of the 16 penetrating injuries without foreign bodies, eight achieved visual acuity of 20/100 or better. The cases with good prognosis were those in which the retina was and remained attached. Scleral buckling procedures were performed in 14 of the total 25 cases. When one adds the four cases that were" inoperable, it is apparent that 18 out of the 25 cases had severe retinal involvement by the initial injury (versus subsequent traction). It is felt that surgery did not cause, but rather may have hastened, the loss of an eye, i.e., those patients without visual recovery had severe ocular damage and would not have recovered sight in any event.
antibiotics can significantly alter the course of endophthalmitis (13). Intraocular fibrosis with subsequent retinal detachment is also a major cause of blindness following intraocular trauma. Vitreous hemorrhage, injury to the lens, injury to the ciliary body, and the response of the vitreous to injury are all stimuli for fibrotic overgrowth and membrane formation (5, 6, 7, 36). The rationale for vitrectomy is the removal of vitreous, which acts as a scaffold for fibrous proligeration from the ciliary epithelial wound and scleral wound leading to traction and subsequent retinal detachment. In addition, blood and its breakdown products have a significant contributing role and should be removed as an inciting factor. If necessary, one may remove a cataractous lens as well as the hemorrhagic vitreous. By clearing the media, one may identify posterior retinal tears and detachments and treat them p r o m p t l y under direct visualization. Since the onset of massive periretinal proliferation is related to the length of time the retina is detached (24) and massive periretinal proliferation is also a cause of failure in traumatized eyes with retinal detachments treated by later vitrectomy (2, 17), it seems logical to assume that early surgical reattachment of the retina might decrease the incidence of massive periretinal proliferation. Thus, early removal of the vitreous hemorrhage and retinal repair may be quite important in reducing the incidence of this dreaded complication. However, the advocates of early vitrectomy in posterior segment trauma do not agree on the proper timing of operative intervention. Surgery is recommended by some (4) within the first 48 hours. Yet, others (20) advocate delayed surgery for seven to fourteen days because of the problem of intraocular bleeding. Secondary hemorrhage was also a major complication in a series of 72 severely injured eyes treated by primary vitrectomy as a prophylactic surgical procedure (12). We now propose, after the primary repair and, in part, depending on the facilities available, that certain patients be referred or managed in the early phase (within four to seven days after injury) for a combined surgical procedure, i.e., removal of vitreous and other tissue incarcerated in the wound, removal of vitreous hemorrhage, and reattachment of the retina in one procedure. Among the patients to be
Discussion
In the past, valiant, but for the most part futile, attempts have been made to salvage severely traumatized eyes by primarily suturing the wound, removing intraocular magnetic foreign bodies, if present, and waiting for the vitreous hemorrhage to clear. Unfortunately, as the hemorrhage cleared, the injured eye often reveated an inoperable retinal detachment due, in part, to epithelial and stromal ingrowth (1,5), as well as components of massive periretinal proliferation (22). In the past five years, much attention has been given to the role of pars plana vitrectomy in penetrating ocular trauma (21, 22, 8, 9, 19, 25, 31, 26, 17, 14, 34). There is general agreement that the vitrectomy technique offers new approaches to these complex and hitherto almost hopeless trauma cases. The results of delayed vitrectomy in ocular trauma have been gratifying in anterior segment injuries (31). Clinical experience with vitrectomy in trauma, as well as laboratory experiments, supports the concept that early vitrectomy can salvage a greater number of eyes than standard techniques (5, 4). However, patients with posterior segment trauma have a 50 percent or less chance of improvement with delayed vitrectomy (2, 30, 17). Infection is always a potential problem in ocular trauma, but laboratory experiments have shown that early vitrectomy in combination with intracameral
8 managed in this way are those with vitreous hemorrhage with retinal detachment, retained reactive intraocular foreign body, double-perforating injuries, and as part of severe intraocular inflammation, e.g., admixed vitreous and disrupted lens material. These clinical impressions have no supportive data at present due to the inability of trauma centers, including our own, to isolate and control the many variables in the often complex clinical setting. For this reason, a primate model is needed to obtain experimental evidence for the role of timing of vitrectomy after trauma (3). Guidelines and rationale for the management of penetrating ocular injuries are provided in more detail in a subsequent companion manuscript (35). References
1. Allen, J.C. Epithelial and stromal ingrowth. Amer J Ophthalmol 65:179 (1968). 2. Benson, W.E. and Machemer, R.W. Severe perforating injuries treated with pars plana vitrectomy. Amer J Ophthalmol 81 : 728 (1976). 3. Cleary, P.E. Personal communication (1977). 4. Coleman, D.J. Role of vitrectomy in trauma in Current Concepts of the Vitreous including Vitrectomy, Gitter, K.A. (ed.). C.V. Mosby Company, St. Louis, Missouri, pp. 236-243 (1976). 5. Coles, W.H. and Haik, G.M. Vitrectomy in intraocular trauma: Its rationale and its indications and limitations. Arch Ophthalmol 87:621 (1972). 6. Constable, I.J., Oguri, M., Chesney, C.M., Swann, D.A., and Coleman, R.E. Platelet-induced vitreous membrane formation. Invest Ophthalmol 12:680 (1973). 7. Constable, l.J. Pathology of vitreous membranes and the effect of hemorrhage and new vessels on the vitreous. Trans Ophthalmol Soc U.K. 95:382 (1975). 8. Douvas, N.G. The cataract rotoextractor. Trans Amer Acad Oph thalmol Otolaryngol 77:792 (1973). 9. Douvas, N.G. Microsurgicalpars plana vitrectomy. Trans Amer Acad Ophthalmol Otolaryngol 81:371 (1976). 10. Eagling,E.M. Perforating injuries involving the posterior segment. Trans Ophthalmol Soc U.K. 95:335 (1975). 11. Eagling, E.M. Perforating injuries of the eye. Brit J Ophthalmol 60:723 (1976). 12. Faulborn, J., Atkinson, A., and Olivier, D. Primary vitrectomy as a preventive surgical procedure in the treatment of severely injured eyes. Brit J Ophthalmol 61:202 (1977). 13. Forester, R.K. Experimental endophthalmitis. Presented at the Retina and Vitreous Symposium, Bascom Palmer Eye Institute Dedication Meeting, Miami, Florida, January (1976). 14. Gitter, K.A. Current Concepts of the Vitreous including Vitrectomy. C.V. Mosby Company, St. Louis, Missouri (1976). 15. Holland, G. Klinische Monatsbldtter far Augenheilkunde 145:915 (1964).
Stephen J. Ryan 16. Hutton, W.C., Snyder, M.D., and Vaiser, A. Vitreetomy in the treatment of ocular perforating injuries. Amer J Ophthalmol 81:733 (1976). 17. Irvine, A.R. and Stone, R.D. Indications for the newer vitrectomy techniques in ocular trauma. Trans Pac Coast Otolaryngol-Ophthalmol Soc., pp. 117-127 (1974). 18. Kasner, D. Highlights of Ophthalmology 11:306 (1968). 19. Kreiger, A.E., Straatsma, B.R., and Griffin, J.R. A vitrectomy instrument in stereotaxis intraocular surgery. Amer J Ophthalmol 76:572 (1973). 20. Machemer, R.W.: Personal communication. 21. Machemer, R.W., Buettner, H., and Norton, E.W.D. Vitrectomy: A pars plana approach. Trans Amer Acad Oph thalmol Otolaryngol 75:813 (1971). 22. Machemer, R.W. Surgical management of non-magnetic intraocular foreign bodies. Arch Ophthalmol 93:1003 (1975). 23. Machemer, R.W. Vitrectomy: A Pars Plana Approach. Grune & Stratton, New York, New York. (1975). 24. Machemer, R.W. and Laqua, H. Pigment epithelium proliferation in retinal detachment (massive periretinal proliferation). Amer J Ophthalmol 80:1 (1975). 25. Michels, R.G., Machemer, R.W. and Muller-Jensen, K. Vitreous surgery: Past, present, and future. Advances in Ophthalmol 29:22 (1974). 26, Minton, J. Occupational eye diseases and injuries. London, Heinemann (1949). 27. National Health Education Committee, Inc. New York, N.Y., Blindness, Facts on the Major Killing and Crippling Diseases in the United States Today pp. 4 - 5 (1971). 28. Neubauer, H. Mierosurgery in ocular trauma. Advances in Ophthalmol 22:246 (1970). 29. Neubauer, H. Treatment of perforating injuries with intraocular foreign bodies. Presented at the Retina and Vitreous Symposium, Bascom Palmer Eye Insitute Dedication Meeting, Miami, Florida, January (1976). 30. Okun, E. Pars plana vitrectomy for conditions other than advanced diabetic retinopathy. In Current Concepts of the Vitreous including Vitrectomy, Gitter, K.A. (ed.). C.V. Mosby Company, St. Louis, Missouri, pg. 244-252 (1976). 31. Peyman, G.A. and Diamond, J.G. The vitreophage in ocular reconstruction following trauma. Canadian Y Ophthalmol 10:419 (1975). 32. Roper-Hall, M.J. (1959): Trans Ophthalmol Soc U.K. 79:57 (1959). 33. Roper-Hall, M.J. Ophthalmologica (Basel) 1 5 8 : 1 2 (1969). 34. Ryan, S.J. Pars plana vitrectomy: Principles of instrumentation. Trans Amer Acad Ophthalmol Otolaryngol 81:352 (1976). 35. Ryan, S.J.: Guidelines in the management of penetrating ocular trauma with emphasis on the role and timing of pars plana vitrectomy. International Ophthalmology. (In press.) 36. Tolentino, F.I., Donovan, R.H., and Schepens, C.L. Retina Congress, Chapter 19. Pruett, R.C. and Reagan, C.D.L. (eds.). Appleton, Century Crofts, New York, New York (1974). Stephen J. Ryan, M.D., Estelle Doheny Eye Foundation, 1355 San Pablo Street, Los Angeles, California 90033
Results of pars plana vitrectomy in penetrating ocular trauma* STEPHEN J. R Y A N , Los Angeles, USA
M.D.**
Keywords: Penetrating ocular trauma, Pars plana vitrectomy, Fibrous proliferation, Vitreous hemorrhage. Abstract Thirty-four severely injured eyes were operated with pars plana vitrectomy. The nine cases with involvement exclusively of the anterior segment alone were operated with success in all cases. However, the injuries of the posterior segment still reflect significant problems in that only 50 percent obtained successful visual results. This reflects, in great part, the degree of severity of the initial damage. The theoretical rationale for pars plana vitrectomy in penetrating ocular trauma is discussed. Because of the many variables from patient to patient and injury to injury, conflicting clinical impressions as to appropriate management prevail. In the abscence of a definitive clinical trial or suitable experimental model, our guidelines for the role and proper timing of pars plana vitrectomy for penetrating ocular trauma are presented.
Introduction Ocular trauma accounts for approximately three percent of the blindness in the United States (27), In some communities, 30 percent of all acute ocular cases are related to trauma (26) while Holland (15) reported that 12 percent of all ophthalmic cases requiring hospital admission are related to the sequelae of ocular trauma. Socioeconomic factors and geography, as well as expertise and referral patterns, determine the bias of ascertainment and, thus, the incidence of ocular trauma in a particular locale. Penetrating ocular trauma often occurs in the relatively From the Department of Ophthalmology, University of Southern California School of Medicine, and the Estelle Doheny Eye Foundation, Los Angeles, California, U.S.A. * This study was supported in part by the National Institutes of Health grant EY 02061 01. ** Dr. Ryan is recipient of the Louis B. Mayer Scholar Award from Research to Prevent Blindness, Inc., New York, New York.
young but otherwise healthy patient, so that it remains an important, if not the statistically leading, cause of blindness. The effects of bilateral ocular trauma are particularly devastating, since productive and frequently young individuals can be rendered economically dependent because of their visual handicap. Roper-Hall (33) stated that the recovery of an eye from injury depends on three factors: (1) the extent of the initial damage, (2) the efficiency of treatment, and (3) the satisfactory management of complications. In recent years, a much higher percentage of patients achieve good vision after penetrating ocular injury (32, 11, 12). This improvement largely reflects the better results obtained by repairing anterior segment injuries with microsurgical techniques (Neubauer 28, 29, Eagling 12 and Faulborn 13). By contrast, the visual prognosis after injuries of the posterior segment has shown little or no improvement, chiefly because of the complications of retinal detachment, vitreous hemorrhage, extensive choroidal hemorrhage, and cyclitic membrane formation (Eagling 13).
6 More recently, vitrectomy has been employed for many of the complications of penetrating ocular trauma (15) as a logical extension of the initial work and observations of open-sky vitrectomy (18). Pars plana vitrectomy provides a new approach to previously hopeless cases of ocular trauma (2 l, 22, 25, 16, 4). In the author's practice, trauma has become the second most frequent indication (exceeded only by diabetes) for pars plana vitrectomy. Histopathologic correlation with clinical findings have led to working hypotheses emphasizing the importance of vitreous hemorrhage and vitreous incarceration with subsequent vitreoretinal traction ( l 1). Condensation, organization, and traction of the vitreous on the retina can lead to retinal detachment, cyclitic membrane formation, recurrent vitreous hemorrhage, and ultimately loss of the eye with total retinal detachment and phthisis. Since vitreous hemorrhage seems to play an important role in the development of subsequent traction, there is a good rationale for vitrectomy, i.e., to remove the inciting hemorrhage. Also, removing the vitreous deprives the cellular fibrous ingrowth of a scaffolding upon which to grow and via which to cause traction on the return. Controversy continues as to the optimum time and appropriate indications for vitrectomy in the early phase after penetrating injury. The advocates of early pars plana vitrectomy in posterior segment trauma do not agree as just how early this operative intervention should be performed. Some favor early (within 48 hours) surgery (4), whereas others prefer to wait ten to fourteen days (Machemer--personal communication). The cases included here were studied to learn the results of vitrectomy for penetrating ocular injuries. This review is not based on a prospective, controlled trial. The clinical impressions, however, provide a basis for discussing guidelines in the management of penetrating ocular injuries. Methodology All cases included in this study were operated with pars plana vitrectomy for complications of penetrating ocular trauma. It should be noted that all cases are referred from other ophthalmologists, and, thus, these cases do not reflect primary surgery, including
Stephen 3. Ryan wound closure, by the author. The anterior segment cases were those in which penetrating injury involved the anterior corneoscleral coat of the eye, uvea, and lens; but there was no involvement of the vitreous, choroid, or retina. The anterior segment reconstruction in these cases in which there was not damage to the vitreous frequently necessitated only removal of the lens or pupillary membrane. The penetrating injuries of the posterior segment included those with involvement of the vitreous, retina, or choroid, i.e., trauma posterior to the lens. Those cases with anterior segment as well as posterior segment involvement were included in this posterior group, since the common denominators of severity and poor prognosis were the degree of the posterior segment involvement. This group included cases with intraocular foreign bodies. It should be noted that this series is biased by the ascertainment of cases. Thus, the cases that could be closed in a more straightforward fashion by the referring ophthalmologists were not referred. On the other hand, there are also many hopeless cases that were managed locally, even so severe as to require early enucleation, and again without referral. The common denominator of the cases reported remains that the indications for pars plana vitrectomy were present.
Results Anterior Segment Injury Of the nine cases in which cataract extraction, excision of pupillary membranes, or anterior segment reconstruction were required, all nine obtained improvement in vision. Seven of the nine cases had 20]40 or better visual acuity, and the remaining two cases had 20]100 or better visual acuity. One patient did require a scleral buckling procedure for a retinal detachment, which was a complication of surgery. However, the retina was successfully reattached, and the patient has doen well postoperatively.
Posterior Segment Injury Of 25 penetrating injuries to the posterior segement, nine cases with intraocular foreign bodies are included. Successful visual results were achieved in four
Results of pars plana vitrectomy in penetrating ocular trauma
7
of the nine intraocular foreign bodies. F o u r failures lost vision on the basis primarily of inoperable retinal detachment, while one case had uncontrollable hemorrhage. Of the 16 penetrating injuries without foreign bodies, eight achieved visual acuity of 20/100 or better. The cases with good prognosis were those in which the retina was and remained attached. Scleral buckling procedures were performed in 14 of the total 25 cases. When one adds the four cases that were" inoperable, it is apparent that 18 out of the 25 cases had severe retinal involvement by the initial injury (versus subsequent traction). It is felt that surgery did not cause, but rather may have hastened, the loss of an eye, i.e., those patients without visual recovery had severe ocular damage and would not have recovered sight in any event.
antibiotics can significantly alter the course of endophthalmitis (13). Intraocular fibrosis with subsequent retinal detachment is also a major cause of blindness following intraocular trauma. Vitreous hemorrhage, injury to the lens, injury to the ciliary body, and the response of the vitreous to injury are all stimuli for fibrotic overgrowth and membrane formation (5, 6, 7, 36). The rationale for vitrectomy is the removal of vitreous, which acts as a scaffold for fibrous proligeration from the ciliary epithelial wound and scleral wound leading to traction and subsequent retinal detachment. In addition, blood and its breakdown products have a significant contributing role and should be removed as an inciting factor. If necessary, one may remove a cataractous lens as well as the hemorrhagic vitreous. By clearing the media, one may identify posterior retinal tears and detachments and treat them p r o m p t l y under direct visualization. Since the onset of massive periretinal proliferation is related to the length of time the retina is detached (24) and massive periretinal proliferation is also a cause of failure in traumatized eyes with retinal detachments treated by later vitrectomy (2, 17), it seems logical to assume that early surgical reattachment of the retina might decrease the incidence of massive periretinal proliferation. Thus, early removal of the vitreous hemorrhage and retinal repair may be quite important in reducing the incidence of this dreaded complication. However, the advocates of early vitrectomy in posterior segment trauma do not agree on the proper timing of operative intervention. Surgery is recommended by some (4) within the first 48 hours. Yet, others (20) advocate delayed surgery for seven to fourteen days because of the problem of intraocular bleeding. Secondary hemorrhage was also a major complication in a series of 72 severely injured eyes treated by primary vitrectomy as a prophylactic surgical procedure (12). We now propose, after the primary repair and, in part, depending on the facilities available, that certain patients be referred or managed in the early phase (within four to seven days after injury) for a combined surgical procedure, i.e., removal of vitreous and other tissue incarcerated in the wound, removal of vitreous hemorrhage, and reattachment of the retina in one procedure. Among the patients to be
Discussion
In the past, valiant, but for the most part futile, attempts have been made to salvage severely traumatized eyes by primarily suturing the wound, removing intraocular magnetic foreign bodies, if present, and waiting for the vitreous hemorrhage to clear. Unfortunately, as the hemorrhage cleared, the injured eye often reveated an inoperable retinal detachment due, in part, to epithelial and stromal ingrowth (1,5), as well as components of massive periretinal proliferation (22). In the past five years, much attention has been given to the role of pars plana vitrectomy in penetrating ocular trauma (21, 22, 8, 9, 19, 25, 31, 26, 17, 14, 34). There is general agreement that the vitrectomy technique offers new approaches to these complex and hitherto almost hopeless trauma cases. The results of delayed vitrectomy in ocular trauma have been gratifying in anterior segment injuries (31). Clinical experience with vitrectomy in trauma, as well as laboratory experiments, supports the concept that early vitrectomy can salvage a greater number of eyes than standard techniques (5, 4). However, patients with posterior segment trauma have a 50 percent or less chance of improvement with delayed vitrectomy (2, 30, 17). Infection is always a potential problem in ocular trauma, but laboratory experiments have shown that early vitrectomy in combination with intracameral
8 managed in this way are those with vitreous hemorrhage with retinal detachment, retained reactive intraocular foreign body, double-perforating injuries, and as part of severe intraocular inflammation, e.g., admixed vitreous and disrupted lens material. These clinical impressions have no supportive data at present due to the inability of trauma centers, including our own, to isolate and control the many variables in the often complex clinical setting. For this reason, a primate model is needed to obtain experimental evidence for the role of timing of vitrectomy after trauma (3). Guidelines and rationale for the management of penetrating ocular injuries are provided in more detail in a subsequent companion manuscript (35). References
1. Allen, J.C. Epithelial and stromal ingrowth. Amer J Ophthalmol 65:179 (1968). 2. Benson, W.E. and Machemer, R.W. Severe perforating injuries treated with pars plana vitrectomy. Amer J Ophthalmol 81 : 728 (1976). 3. Cleary, P.E. Personal communication (1977). 4. Coleman, D.J. Role of vitrectomy in trauma in Current Concepts of the Vitreous including Vitrectomy, Gitter, K.A. (ed.). C.V. Mosby Company, St. Louis, Missouri, pp. 236-243 (1976). 5. Coles, W.H. and Haik, G.M. Vitrectomy in intraocular trauma: Its rationale and its indications and limitations. Arch Ophthalmol 87:621 (1972). 6. Constable, I.J., Oguri, M., Chesney, C.M., Swann, D.A., and Coleman, R.E. Platelet-induced vitreous membrane formation. Invest Ophthalmol 12:680 (1973). 7. Constable, l.J. Pathology of vitreous membranes and the effect of hemorrhage and new vessels on the vitreous. Trans Ophthalmol Soc U.K. 95:382 (1975). 8. Douvas, N.G. The cataract rotoextractor. Trans Amer Acad Oph thalmol Otolaryngol 77:792 (1973). 9. Douvas, N.G. Microsurgicalpars plana vitrectomy. Trans Amer Acad Ophthalmol Otolaryngol 81:371 (1976). 10. Eagling,E.M. Perforating injuries involving the posterior segment. Trans Ophthalmol Soc U.K. 95:335 (1975). 11. Eagling, E.M. Perforating injuries of the eye. Brit J Ophthalmol 60:723 (1976). 12. Faulborn, J., Atkinson, A., and Olivier, D. Primary vitrectomy as a preventive surgical procedure in the treatment of severely injured eyes. Brit J Ophthalmol 61:202 (1977). 13. Forester, R.K. Experimental endophthalmitis. Presented at the Retina and Vitreous Symposium, Bascom Palmer Eye Institute Dedication Meeting, Miami, Florida, January (1976). 14. Gitter, K.A. Current Concepts of the Vitreous including Vitrectomy. C.V. Mosby Company, St. Louis, Missouri (1976). 15. Holland, G. Klinische Monatsbldtter far Augenheilkunde 145:915 (1964).
Stephen J. Ryan 16. Hutton, W.C., Snyder, M.D., and Vaiser, A. Vitreetomy in the treatment of ocular perforating injuries. Amer J Ophthalmol 81:733 (1976). 17. Irvine, A.R. and Stone, R.D. Indications for the newer vitrectomy techniques in ocular trauma. Trans Pac Coast Otolaryngol-Ophthalmol Soc., pp. 117-127 (1974). 18. Kasner, D. Highlights of Ophthalmology 11:306 (1968). 19. Kreiger, A.E., Straatsma, B.R., and Griffin, J.R. A vitrectomy instrument in stereotaxis intraocular surgery. Amer J Ophthalmol 76:572 (1973). 20. Machemer, R.W.: Personal communication. 21. Machemer, R.W., Buettner, H., and Norton, E.W.D. Vitrectomy: A pars plana approach. Trans Amer Acad Oph thalmol Otolaryngol 75:813 (1971). 22. Machemer, R.W. Surgical management of non-magnetic intraocular foreign bodies. Arch Ophthalmol 93:1003 (1975). 23. Machemer, R.W. Vitrectomy: A Pars Plana Approach. Grune & Stratton, New York, New York. (1975). 24. Machemer, R.W. and Laqua, H. Pigment epithelium proliferation in retinal detachment (massive periretinal proliferation). Amer J Ophthalmol 80:1 (1975). 25. Michels, R.G., Machemer, R.W. and Muller-Jensen, K. Vitreous surgery: Past, present, and future. Advances in Ophthalmol 29:22 (1974). 26, Minton, J. Occupational eye diseases and injuries. London, Heinemann (1949). 27. National Health Education Committee, Inc. New York, N.Y., Blindness, Facts on the Major Killing and Crippling Diseases in the United States Today pp. 4 - 5 (1971). 28. Neubauer, H. Mierosurgery in ocular trauma. Advances in Ophthalmol 22:246 (1970). 29. Neubauer, H. Treatment of perforating injuries with intraocular foreign bodies. Presented at the Retina and Vitreous Symposium, Bascom Palmer Eye Insitute Dedication Meeting, Miami, Florida, January (1976). 30. Okun, E. Pars plana vitrectomy for conditions other than advanced diabetic retinopathy. In Current Concepts of the Vitreous including Vitrectomy, Gitter, K.A. (ed.). C.V. Mosby Company, St. Louis, Missouri, pg. 244-252 (1976). 31. Peyman, G.A. and Diamond, J.G. The vitreophage in ocular reconstruction following trauma. Canadian Y Ophthalmol 10:419 (1975). 32. Roper-Hall, M.J. (1959): Trans Ophthalmol Soc U.K. 79:57 (1959). 33. Roper-Hall, M.J. Ophthalmologica (Basel) 1 5 8 : 1 2 (1969). 34. Ryan, S.J. Pars plana vitrectomy: Principles of instrumentation. Trans Amer Acad Ophthalmol Otolaryngol 81:352 (1976). 35. Ryan, S.J.: Guidelines in the management of penetrating ocular trauma with emphasis on the role and timing of pars plana vitrectomy. International Ophthalmology. (In press.) 36. Tolentino, F.I., Donovan, R.H., and Schepens, C.L. Retina Congress, Chapter 19. Pruett, R.C. and Reagan, C.D.L. (eds.). Appleton, Century Crofts, New York, New York (1974). Stephen J. Ryan, M.D., Estelle Doheny Eye Foundation, 1355 San Pablo Street, Los Angeles, California 90033
