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Bilateral Ocular Shotgun Injury
Bilateral Ocular Shotgun Injury Robert E. Morris, M.D., C. Douglas Witherspoon, M.D., Richard M. Feist, M.D., James B. Byrne, Jr., M.D., and Dennis E. Ottemiller, B.S.
We retrospectively studied 14 patients with bilateral ocular shotgun injury in order to determine overall visual prognosis and factors affecting individual prognosis. Although only eight of 28 eyes (29%) in this series recovered visual acuity of 20/100 or better, six of 14 patients (43%) recovered at least 20/100 and eight of 14 patients (57%) recovered visual acuity of at least 20/400. Tissue destruction in the form of severe ocular disorganization or direct injury of optic nerve or macula was the primary limiting factor to visual recovery in 16 of 20 eyes (80%) not recovering to 20/100, while retinal detachment was the limiting factor in only four of these 20 eyes (20%). While extensive ocular disorganization, direct optic nerve or macular injury, no light perception on initial examination, and multiple pellet injuries were predictive of poor outcome, retinal detachment and double perforating injury were not. ALTHOUGH there have been a few case reports of ocular shotgun injuries 1,2 and other cases have been included in discussions of doubleperforating injury, 3 few clinical series of ocular shotgun injuries have been reported. 4,s The visual prognosis in these patients has been described as generally poor, with both early sequelae (direct injury to vital visual tissue) and late sequelae (intraocular scarring a n d fibrosis with secondary retinal detachment) re sponsible for poor outcome. While present treatment does not allow reversal of the early sequelae of ocular shotgun injury, current sur gical techniques should be sufficient to de crease the morbidity from late retinal detach-
Accepted for publication Feb. 9, 1987. From the University of Alabama/Eye Foundation Hos pital Combined Program in Ophthalmology, and the Retinal Research Foundation of the South, Birmingham, Alabama. Reprint requests to Robert E. Morris, M.D., P.O. Box 55569, Birmingham, AL 35255.
ment in these cases. We retrospectively examined 14 patients with ocular shotgun inju ries treated between May 1979 and June 1986 to determine the patterns of injury and prognos tic factors involved in this severe form of ocular injury.
Subjects and Methods The Eye Injury Registry of Alabama reported that 8.8% of 882 reports of serious eye injuries gathered on a statewide basis over a four-year period concerned gunshot injuries. Of 78 eyes (58 patients) with gunshot injuries, 54 cases (34 patients) had notation on the Registry's report ing form regarding the type of gunshot respon sible for injury. Of these 34 patients, 32 (94%) had suffered shotgun injuries; 20 of the pa tients with shotgun injury (59%) had bilateral ocular involvement. Fourteen of these patients who were treated by us comprise this series (Table 1). These patients ranged in age from 16 to 64 years (mean, 26.7 years). Twelve (86%) of the injuries resulted from assault, and two (14%) resulted from hunting accidents. There were 12 men and two women. Initial visual acuity was no light perception in 13 eyes, light perception in 12 eyes, hand motions in one eye, 1/200 in one eye, and 4/200 in one eye. Twenty-two of the injuries were double-perforating, two were single-perforating, and four were nonperforating. Nineteen eyes were struck by one pellet, five by two or more pellets, and four eyes were struck by an indeterminate number of pellets. Our therapeutic strategy in patients with bilateral ocular shotgun injuries involved staged operations. Primary repair consisting of closure of entrance wounds and of surgically accessible exit wounds was carried out at the time of initial examination, which was the day of injury in 18 eyes, one day after injury in eight eyes, and seven days after injury in two
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the repair of secondary retinal detachments (four eyes).
TABLE 1 SUMMARY OF PATIENT DATA
PATIENT
INITIAL
FINAL
VISUAL
VISUAL
TYPE OF
NO. OF
NO., SEX EYE ACUITY* ACUITY* PERFORATION PELLETS VITRECTOMY
1,M 2, M 3, M 4, M 5, M 6, M 7, F 8, F 9, M 10, M 11, M 12, M 13, M 14, M
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R L R L R L R L R L R L R L R L R L R L R L R L R L R L
NLP NLP LP NLP LP NLP NLP 1/200 LP NLP NLP LP HM 4/200 NLP NLP NLP LP LP LP LP LP LP LP NLP NLP NLP LP
NLP NLP LP NLP 20/25 NLP NLP 20/200 HM NLP NLP 20/60 20/50 20/400 NLP 20/400 NLP 20/400 20/30 20/60 20/80 20/40 20/30 3/200 NLP NLP NLP LP
Double Double Double None Double None Double Double Double Double Double Double None Double Double None Single Double Double Double Double Single Double Double Double Double Double Double
2 1 1 1 1 1 Multiple Multiple 1 2 1 1 1 1 2 1 1 1 1 1 1 1 1 1 Multiple Multiple 2 4
4-
+ (x2)
+ (x2)
+ + (x2)
+ + + + +
+ + + + -
Results Nine eyes were severely disorganized with injury inconsistent with any chance of sight or satisfactory cosmesis; of these eyes, eight were enucleated (Fig. 1). The eye not enucleated was retained at the insistence of the patient. Visual acuity was maintained (five eyes) or improved (14 eyes) in the remaining 19 eyes. Of the 14 eyes with improvement in visual acuity, one was initially without light perception because of an optic nerve injury but improved to 20/100 before macular traction decreased final visual acuity to counting fingers. Of the 28 eyes, final visual acuity was no light perception in 12 eyes, light perception in two eyes, hand motions in one eye, counting fingers in one eye, 3/200 to 20/200 in four eyes, and better than 20/100 in eight eyes (Table 1). Three patients (21%) had an initial visual acuity of no light perception, nine patients (64%) had light perception only, and two pa tients (14%) had initial visual acuity of better than counting fingers. Two patients (14%) had a final visual acuity of no light perception, two patients (14%) had light perception, one pa tient (7%) had hand motions, one patient (7%)
+ (x2)
*NLP, no light perception; LP, light perception; HM, hand motions.
eyes. At the time of primary repair nonviable incarcerated uveal tissue was excised, viable prolapsed uveal tissue was reinserted, and subconjunctival, topical, and intravenous antibiot ics were begun. Eyes believed to be salvageable underwent secondary reconstruction nine days to 13 weeks after initial examination. Timing of reconstructive surgery was a compromise be tween waiting for inflammation to subside and operating before intraocular scarring added ir reparable retinal damage. Persistent vitreous hemorrhage was removed, damaged tissues were repaired or replaced (one cornea, eight lenses), and detached retinas were repaired (12 eyes). Six eyes required additional surgery after the initial reconstructive operation for the removal of traumatic cataracts (two eyes) and
Fig. 1 (Morris and associates). Patient 13. This patient had multiple pellet, double-perforating inju ry to both eyes with complete disorganization, no light perception, and retinal prolapse through the entrance wounds of both eyes. Early enucleation of both eyes resulted.
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TABLE 2 EYES WITH POOR VISUAL OUTCOME FINAL PATIENT NO.
1 2 3 4 5 6 7 8 9 12 13 14
EYE
VISUAL ACUITY*
CAUSE OF POOR VISUAL OUTCOME
R L R L L R L R L R L R L R L L R L R L
NLP NLP LP NLP NLP NLP 20/200 HM NLP NLP 20/400 NLP CF NLP 20/400 3/200 NLP NLP NLP LP
Severe ocular disorganization Optic nerve damage Retinal detachment Optic nerve damage Optic nerve damage Severe ocular disorganization Macular damage Macular damage Severe ocular disorganization Severe ocular disorganization Macular damage Severe ocular disorganization Retinal detachment Severe ocular disorganization Retinal detachment Macular damage Severe ocular disorganization Severe ocular disorganization Severe ocular disorganization Retinal detachment
*NLP, no light perception; LP, light perception; HM, hand motions; CF, counting fingers.
had counting fingers, and eight patient's (57%) had better than counting fingers. All 11 pa tients with initial visual acuity of light percep tion or better maintained (two patients) or im proved (nine patients) their visual acuity during the course of treatment. Of 14 patients, six (43%) regained visual acuity of better than 20/100 in at least one eye, and eight (57%) regained visual acuity of 20/400 or better in at least one eye (Table 2). While the overall rate of recovery to 20/100 was 27% (eight of 28 eyes), 42% of salvageable eyes (eight of the 19 eyes not disorganized at initial examination) reached this level of visual acuity. Of the 19 salvageable eyes, four (21%) sus tained direct optic nerve damage. All of these eyes were without light perception on initial examination, and only one of these eyes re gained vision. That eye reached a visual acuity of 20/100 before retinal detachment dropped it to counting fingers. An additional four of the salvageable eyes (21%) suffered direct macular damage as part of the initial injury. Initial visual acuity in these eyes ranged from light
Fig. 2 (Morris and associates). Patient 4, left eye. This eye suffered a double-perforating injury with exit wound through the macula. Initial visual acuity was 1/200. Final visual acuity improved to 20/200 after vitrectomy, scleral buckle with encircling band, and lensectomy. perception to 4/200; final visual acuity ranged from 20/200 to hand motions (Fig. 2). The re maining 11 salvageable eyes (58%) did not have direct damage to the optic nerve or macula from the initial injury. Initial visual acuity ranged from light perception (ten eyes) to hand motions (one eye). All but two of these eyes had an improvement in visual acuity. Final visual acuity was 20/100 or better in eight of these eyes (73%) and 20/50 or better in five of these eyes (45%) (Fig. 3). Of the 28 eyes in the series, 19 suffered injury from a single pellet, five suffered injury from multiple (two or more) pellets, and four suf fered injury from an undetermined number of pellets (Table 1). Of the 19 eyes struck by a single pellet, two underwent enucleation and four suffered optic nerve damage. Visual out come in the remaining 13 eyes with a single pellet injury ranged from light perception to 20/25. Of the 19 eyes with a single pellet injury, eight (42%) had a visual recovery to 20/100 or better. Four of the five eyes struck by multiple pellets underwent enucleation; visual outcome in the remaining eye was light perception. Three of the four eyes struck by an undeter mined number of pellets underwent enuclea tion; visual outcome in the remaining eye was 20/200. Of the 22 eyes with a double-perforating injury, seven (32%) were enucleated, one suf-
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Fig. 3 (Morris and associates). Patient 11, right eye. This eye suffered a single pellet, double-perforating injury with exit wound distant from the macula. Initial visual acuity was light perception only with a final visual acuity of 20/80 after vitrectomy, lensectomy, air-fluid exchange, and cryoablation of the exit site. fered direct optic nerve injury, and four (18%) suffered direct macular injury. Final visual acu ity in the 15 eyes with a double-perforating injury that were not enucleated ranged from no light perception (one eye) to 20/25 (one eye). The rate of visual recovery to 20/100 in eyes with double-perforating injury was 27% (four of 15 eyes). One of the two eyes with a single-perforating injury was enucleated and the other eye had a final visual acuity of 20/40. None of the four eyes with nonperforating injuries were enucleated, but three of these eyes suffered direct optic nerve injury. Two of these eyes remained without light perception, one recovered counting fingers, and one recov ered to 20/50. Sixteen of the 19 eyes in the series not severe ly disorganized on initial examination under went some type of reconstructive surgery. Two of the three eyes that did not undergo recon structive surgery had suffered nonperforating injuries of the globe with direct optic nerve damage incompatible with light perception; the other eye had a nonperforating injury and im proved from a visual acuity of hand motions to 20/50. Of 15 eyes that underwent vitrectomy, seven (47%) recovered to a visual acuity of better than
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20/100. Twelve of these eyes had retinal detach ment as an indication for vitrectomy (six eyes recovered to better than 20/100). Four eyes underwent air-fluid exchange at the time of first vitrectomy (two eyes recovered to better than 20/100). Four eyes underwent a second vitrectomy for recurrent retinal detachment (one eye recov ered to better than 20/100). Two of these eyes underwent air-fluid exchange as well (final vis ual acuity was light perception and 20/25), and one eye received retinal tacks and silicone oil at reoperation (final visual acuity was light per ception). Of 28 eyes, 12 developed traumatic cataracts (six eyes recovered to better than 20/100); ten of these 12 eyes underwent trans pars plana lensectomy at the time of vitrectomy, one eye un derwent trans pars plana lensectomy at a later time, and one eye, not requiring vitrectomy, underwent extracapsular cataract extraction. Intraoperative cryotherapy was performed at the time of first vitrectomy in three eyes (two eyes recovered to better than 20/100), and at the time of second vitrectomy in three eyes (one eye recovered to better than 20/100). Timing of reconstructive surgery ranged from nine days to 13 weeks in the 14 eyes undergoing reconstructive surgery. Fourteen of the eyes underwent definitive surgery with in one month of injury, and seven of these eyes (50%) recovered visual acuity of 20/100 or bet ter. Of the 16 eyes, three had macular injuries and one eye had optic nerve injury, but all eyes had final visual acuity of light perception or better. Two eyes underwent definitive surgery more than a month after injury, and neither of these eyes recovered to 20/100. One of these eyes belonged to a patient whose other eye was atrophied. Vitrectomy was offered to this pa tient although the eye had been without light perception since the initial injury and there was little hope for visual recovery. Surgery was performed five weeks after injury in this case, and after vitreous hemorrhage had been re moved through an exit wound the optic nerve was observed. The other eye undergoing de layed surgery was the only remaining eye in an indigent patient. Initial visual acuity had been 1/200 but dense vitreous hemorrhage precluded any view of the posterior pole. Vitrectomy was finally performed 13 weeks after injury. Al though there was no exit wound through the posterior pole, extensive contusion to the pos-
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terior pole was seen at the time of surgery. Visual acuity was 20/200 at last examination, ten months after injury.
Discussion Despite the severity of ocular shotgun inju ries the prognosis is favorable for those eyes with visual acuity of light perception or better at first examination. Of these 15 eyes, two (13%) maintained initial visual acuity and 13 (87%) improved with treatment. The factors involved with poor visual out come in this series were severe ocular disorgan ization by the initial injury, anatomic involve ment of the optic nerve or macula by the initial injury, and no light perception on initial exami nation. By contrast, neither retinal detachment nor double-perforating injury was associated with a prognosis poorer than that of the series as a whole. Of 20 eyes in this series that failed to recover visual acuity of at least 20/100, the limiting factor in visual recovery was the anatomic pat tern of the initial injury in 16 eyes (severe ocular disorganization in nine eyes, optic nerve injury in three eyes, and macular injury in three eyes). Of the 19 eyes that were not initial ly disorganized, 13 developed retinal detach ments, including four eyes that required repeat vitrectomy for retinal detachment. Only four eyes failed to reach a visual acuity of at least 20/100 on the basis of retinal detachment second ary to the initial injury. While eyes with double-perforating injuries were more likely to require enucleation, there was no trend toward better visual outcome in eyes with nonperforating injuries since these eyes were more likely to suffer optic nerve injury. Conversely, the involvement of multi ple pellets in an injury was associated with a poorer visual prognosis and a higher rate of severe ocular injury requiring enucleation. Current treatment modalities allow for the repair of most of the tissues damaged in pene trating ocular injuries. Corneas, lenses, and even sclera can be replaced by eye bank tissue or prosthetic devices. Vitreous hemorrhages and opacities can be removed mechanically, and retinal detachments can be repaired. The only limits to repair of these eyes are total disorganization of the globe and irreparably damaged retina or optic nerve.
699
Before vitrectomy was available, Drummond and Kielar4 described a series of 20 patients (20 eyes) with double-perforating shotgun injuries that received primary closure only. The rate of return to visual acuity of 20/400 was only 15% (three of 20 eyes) in that series vs nine of 22 eyes (41%) with double-perforating injury in this series. At that time Drummond and Kielar predicted that vitrectomy would improve the visual outcome of eyes with vitreous hemor rhage and limited or no retinal detachment. In our series eight of 11 eyes fitting this descrip tion that were without direct injury to the optic nerve or macula recovered final visual acuity of at least 20/100. In contrast to the increased rate of recovery to a visual acuity of 20/400, we did not find a significant drop in the rate of light perception loss in eyes with double-perforating injury. The rate of no light perception in eyes with double-perforating injury was 45% (nine of 20 eyes) in Drummond and Kielar's 4 series, 54% (seven of 13 eyes) in Kutschera and Kosmath's 5 series, and 43% (eight of 22 eyes) in our series. We believe that improvements in the preven tion and treatment of retinal detachment, as represented by closed microsurgical vitrec tomy, are responsible for the observed im provement in the salvage rate of useful vision. It is the direct tissue damage of the initial injury that determines the visual prognosis of these eyes, and there is unfortunately nothing that can be done at present to reverse visual loss from destruction of the retina or optic nerve. This limit to the effectiveness of any treatment for ocular shotgun injury under scores the vital role that prevention must play as ophthalmologists attempt to limit this source of visual morbidity. Because the majority of these injuries result from intentional assault, prevention will be difficult. Hunting, though, is an activity in which the potential for ocular injury can be anticipated. The destructive potential of a shot gun can be appreciated by considering that a single number 6 shotgun pellet has 1.08 foot pounds of kinetic energy at 65 yards, while 0.4 foot pound is the amount of kinetic energy required to penetrate the skin and feathers of birds. 6 ' 7 Safety glasses have been shown to be of some value in past reports, 8 and recent advanc es, such as new polycarbonate materials, prom ise further improvement in our ability to pre vent these injuries. 9 Unfortunately, safety glasses are only of value when worn, and their
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u s e f u l n e s s will d e p e n d u p o n public e d u c a t i o n . O u r e x p e r i e n c e h a s b e e n t h a t ocular s h o t g u n injuries are e x t r e m e l y s e v e r e injuries, b u t ag gressive surgical i n t e r v e n t i o n can r e s t o r e u s e ful vision in m a n y eyes t h a t h a v e n o t s u s t a i n e d d e s t r u c t i o n of the retina or optic n e r v e .
References 1. Mclntyre, M. W.: Bilateral gunshot perforations with retention of useful vision. A case report. Eye, Ear, Nose, and Throat Monthly 48:33, 1969. 2. Kennedy, K. S., and Izenberg, R. A.: Facial and ocular shotgun blast injury. A report of a case. J. Am. Osteopath. Assoc. 85:586, 1985. 3. Ramsay, R. C , Cantrill, H. L., and Knobloch,
May, 1987
W. H.: Vitrectomy for double penetrating ocular in juries. Am. J. Ophthalmol. 100:586, 1985. 4. Drummond, J., and Kielar, R. A.: Perforating ocular shotgun injuries. Relationship of ocular findings to pellet ballistics. South. Med. J. 69:1066, 1976. 5. Kutschera, E., and Kosmath, B.: Augenverletzungen bei Jagdunfallen. Klin. Monatsbl. Augenheilkd. 153:808, 1968. 6. Butler, D. F.: The American Shotgun. New York, Winchester Press, 1973, pp. 197-198. 7. Rice, F. P.: Outdoor Life Gun Data Book. New York, Harper & Row, 1975, pp. 378-385. 8. Robertson, D. M.: Safety glasses as protection against shotgun pellets. Am. J. Ophthalmol. 81:671, 1976. 9. Simmons, S. T., Kroehl, G. B., and Hay, P. B.: Prevention of ocular gunshot injuries using polycar bonate lenses. Ophthalmology 91:977, 1984.
We retrospectively studied 14 patients with bilateral ocular shotgun injury in order to determine overall visual prognosis and factors affecting individual prognosis. Although only eight of 28 eyes (29%) in this series recovered visual acuity of 20/100 or better, six of 14 patients (43%) recovered at least 20/100 and eight of 14 patients (57%) recovered visual acuity of at least 20/400. Tissue destruction in the form of severe ocular disorganization or direct injury of optic nerve or macula was the primary limiting factor to visual recovery in 16 of 20 eyes (80%) not recovering to 20/100, while retinal detachment was the limiting factor in only four of these 20 eyes (20%). While extensive ocular disorganization, direct optic nerve or macular injury, no light perception on initial examination, and multiple pellet injuries were predictive of poor outcome, retinal detachment and double perforating injury were not. ALTHOUGH there have been a few case reports of ocular shotgun injuries 1,2 and other cases have been included in discussions of doubleperforating injury, 3 few clinical series of ocular shotgun injuries have been reported. 4,s The visual prognosis in these patients has been described as generally poor, with both early sequelae (direct injury to vital visual tissue) and late sequelae (intraocular scarring a n d fibrosis with secondary retinal detachment) re sponsible for poor outcome. While present treatment does not allow reversal of the early sequelae of ocular shotgun injury, current sur gical techniques should be sufficient to de crease the morbidity from late retinal detach-
Accepted for publication Feb. 9, 1987. From the University of Alabama/Eye Foundation Hos pital Combined Program in Ophthalmology, and the Retinal Research Foundation of the South, Birmingham, Alabama. Reprint requests to Robert E. Morris, M.D., P.O. Box 55569, Birmingham, AL 35255.
ment in these cases. We retrospectively examined 14 patients with ocular shotgun inju ries treated between May 1979 and June 1986 to determine the patterns of injury and prognos tic factors involved in this severe form of ocular injury.
Subjects and Methods The Eye Injury Registry of Alabama reported that 8.8% of 882 reports of serious eye injuries gathered on a statewide basis over a four-year period concerned gunshot injuries. Of 78 eyes (58 patients) with gunshot injuries, 54 cases (34 patients) had notation on the Registry's report ing form regarding the type of gunshot respon sible for injury. Of these 34 patients, 32 (94%) had suffered shotgun injuries; 20 of the pa tients with shotgun injury (59%) had bilateral ocular involvement. Fourteen of these patients who were treated by us comprise this series (Table 1). These patients ranged in age from 16 to 64 years (mean, 26.7 years). Twelve (86%) of the injuries resulted from assault, and two (14%) resulted from hunting accidents. There were 12 men and two women. Initial visual acuity was no light perception in 13 eyes, light perception in 12 eyes, hand motions in one eye, 1/200 in one eye, and 4/200 in one eye. Twenty-two of the injuries were double-perforating, two were single-perforating, and four were nonperforating. Nineteen eyes were struck by one pellet, five by two or more pellets, and four eyes were struck by an indeterminate number of pellets. Our therapeutic strategy in patients with bilateral ocular shotgun injuries involved staged operations. Primary repair consisting of closure of entrance wounds and of surgically accessible exit wounds was carried out at the time of initial examination, which was the day of injury in 18 eyes, one day after injury in eight eyes, and seven days after injury in two
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the repair of secondary retinal detachments (four eyes).
TABLE 1 SUMMARY OF PATIENT DATA
PATIENT
INITIAL
FINAL
VISUAL
VISUAL
TYPE OF
NO. OF
NO., SEX EYE ACUITY* ACUITY* PERFORATION PELLETS VITRECTOMY
1,M 2, M 3, M 4, M 5, M 6, M 7, F 8, F 9, M 10, M 11, M 12, M 13, M 14, M
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R L R L R L R L R L R L R L R L R L R L R L R L R L R L
NLP NLP LP NLP LP NLP NLP 1/200 LP NLP NLP LP HM 4/200 NLP NLP NLP LP LP LP LP LP LP LP NLP NLP NLP LP
NLP NLP LP NLP 20/25 NLP NLP 20/200 HM NLP NLP 20/60 20/50 20/400 NLP 20/400 NLP 20/400 20/30 20/60 20/80 20/40 20/30 3/200 NLP NLP NLP LP
Double Double Double None Double None Double Double Double Double Double Double None Double Double None Single Double Double Double Double Single Double Double Double Double Double Double
2 1 1 1 1 1 Multiple Multiple 1 2 1 1 1 1 2 1 1 1 1 1 1 1 1 1 Multiple Multiple 2 4
4-
+ (x2)
+ (x2)
+ + (x2)
+ + + + +
+ + + + -
Results Nine eyes were severely disorganized with injury inconsistent with any chance of sight or satisfactory cosmesis; of these eyes, eight were enucleated (Fig. 1). The eye not enucleated was retained at the insistence of the patient. Visual acuity was maintained (five eyes) or improved (14 eyes) in the remaining 19 eyes. Of the 14 eyes with improvement in visual acuity, one was initially without light perception because of an optic nerve injury but improved to 20/100 before macular traction decreased final visual acuity to counting fingers. Of the 28 eyes, final visual acuity was no light perception in 12 eyes, light perception in two eyes, hand motions in one eye, counting fingers in one eye, 3/200 to 20/200 in four eyes, and better than 20/100 in eight eyes (Table 1). Three patients (21%) had an initial visual acuity of no light perception, nine patients (64%) had light perception only, and two pa tients (14%) had initial visual acuity of better than counting fingers. Two patients (14%) had a final visual acuity of no light perception, two patients (14%) had light perception, one pa tient (7%) had hand motions, one patient (7%)
+ (x2)
*NLP, no light perception; LP, light perception; HM, hand motions.
eyes. At the time of primary repair nonviable incarcerated uveal tissue was excised, viable prolapsed uveal tissue was reinserted, and subconjunctival, topical, and intravenous antibiot ics were begun. Eyes believed to be salvageable underwent secondary reconstruction nine days to 13 weeks after initial examination. Timing of reconstructive surgery was a compromise be tween waiting for inflammation to subside and operating before intraocular scarring added ir reparable retinal damage. Persistent vitreous hemorrhage was removed, damaged tissues were repaired or replaced (one cornea, eight lenses), and detached retinas were repaired (12 eyes). Six eyes required additional surgery after the initial reconstructive operation for the removal of traumatic cataracts (two eyes) and
Fig. 1 (Morris and associates). Patient 13. This patient had multiple pellet, double-perforating inju ry to both eyes with complete disorganization, no light perception, and retinal prolapse through the entrance wounds of both eyes. Early enucleation of both eyes resulted.
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TABLE 2 EYES WITH POOR VISUAL OUTCOME FINAL PATIENT NO.
1 2 3 4 5 6 7 8 9 12 13 14
EYE
VISUAL ACUITY*
CAUSE OF POOR VISUAL OUTCOME
R L R L L R L R L R L R L R L L R L R L
NLP NLP LP NLP NLP NLP 20/200 HM NLP NLP 20/400 NLP CF NLP 20/400 3/200 NLP NLP NLP LP
Severe ocular disorganization Optic nerve damage Retinal detachment Optic nerve damage Optic nerve damage Severe ocular disorganization Macular damage Macular damage Severe ocular disorganization Severe ocular disorganization Macular damage Severe ocular disorganization Retinal detachment Severe ocular disorganization Retinal detachment Macular damage Severe ocular disorganization Severe ocular disorganization Severe ocular disorganization Retinal detachment
*NLP, no light perception; LP, light perception; HM, hand motions; CF, counting fingers.
had counting fingers, and eight patient's (57%) had better than counting fingers. All 11 pa tients with initial visual acuity of light percep tion or better maintained (two patients) or im proved (nine patients) their visual acuity during the course of treatment. Of 14 patients, six (43%) regained visual acuity of better than 20/100 in at least one eye, and eight (57%) regained visual acuity of 20/400 or better in at least one eye (Table 2). While the overall rate of recovery to 20/100 was 27% (eight of 28 eyes), 42% of salvageable eyes (eight of the 19 eyes not disorganized at initial examination) reached this level of visual acuity. Of the 19 salvageable eyes, four (21%) sus tained direct optic nerve damage. All of these eyes were without light perception on initial examination, and only one of these eyes re gained vision. That eye reached a visual acuity of 20/100 before retinal detachment dropped it to counting fingers. An additional four of the salvageable eyes (21%) suffered direct macular damage as part of the initial injury. Initial visual acuity in these eyes ranged from light
Fig. 2 (Morris and associates). Patient 4, left eye. This eye suffered a double-perforating injury with exit wound through the macula. Initial visual acuity was 1/200. Final visual acuity improved to 20/200 after vitrectomy, scleral buckle with encircling band, and lensectomy. perception to 4/200; final visual acuity ranged from 20/200 to hand motions (Fig. 2). The re maining 11 salvageable eyes (58%) did not have direct damage to the optic nerve or macula from the initial injury. Initial visual acuity ranged from light perception (ten eyes) to hand motions (one eye). All but two of these eyes had an improvement in visual acuity. Final visual acuity was 20/100 or better in eight of these eyes (73%) and 20/50 or better in five of these eyes (45%) (Fig. 3). Of the 28 eyes in the series, 19 suffered injury from a single pellet, five suffered injury from multiple (two or more) pellets, and four suf fered injury from an undetermined number of pellets (Table 1). Of the 19 eyes struck by a single pellet, two underwent enucleation and four suffered optic nerve damage. Visual out come in the remaining 13 eyes with a single pellet injury ranged from light perception to 20/25. Of the 19 eyes with a single pellet injury, eight (42%) had a visual recovery to 20/100 or better. Four of the five eyes struck by multiple pellets underwent enucleation; visual outcome in the remaining eye was light perception. Three of the four eyes struck by an undeter mined number of pellets underwent enuclea tion; visual outcome in the remaining eye was 20/200. Of the 22 eyes with a double-perforating injury, seven (32%) were enucleated, one suf-
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Fig. 3 (Morris and associates). Patient 11, right eye. This eye suffered a single pellet, double-perforating injury with exit wound distant from the macula. Initial visual acuity was light perception only with a final visual acuity of 20/80 after vitrectomy, lensectomy, air-fluid exchange, and cryoablation of the exit site. fered direct optic nerve injury, and four (18%) suffered direct macular injury. Final visual acu ity in the 15 eyes with a double-perforating injury that were not enucleated ranged from no light perception (one eye) to 20/25 (one eye). The rate of visual recovery to 20/100 in eyes with double-perforating injury was 27% (four of 15 eyes). One of the two eyes with a single-perforating injury was enucleated and the other eye had a final visual acuity of 20/40. None of the four eyes with nonperforating injuries were enucleated, but three of these eyes suffered direct optic nerve injury. Two of these eyes remained without light perception, one recovered counting fingers, and one recov ered to 20/50. Sixteen of the 19 eyes in the series not severe ly disorganized on initial examination under went some type of reconstructive surgery. Two of the three eyes that did not undergo recon structive surgery had suffered nonperforating injuries of the globe with direct optic nerve damage incompatible with light perception; the other eye had a nonperforating injury and im proved from a visual acuity of hand motions to 20/50. Of 15 eyes that underwent vitrectomy, seven (47%) recovered to a visual acuity of better than
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20/100. Twelve of these eyes had retinal detach ment as an indication for vitrectomy (six eyes recovered to better than 20/100). Four eyes underwent air-fluid exchange at the time of first vitrectomy (two eyes recovered to better than 20/100). Four eyes underwent a second vitrectomy for recurrent retinal detachment (one eye recov ered to better than 20/100). Two of these eyes underwent air-fluid exchange as well (final vis ual acuity was light perception and 20/25), and one eye received retinal tacks and silicone oil at reoperation (final visual acuity was light per ception). Of 28 eyes, 12 developed traumatic cataracts (six eyes recovered to better than 20/100); ten of these 12 eyes underwent trans pars plana lensectomy at the time of vitrectomy, one eye un derwent trans pars plana lensectomy at a later time, and one eye, not requiring vitrectomy, underwent extracapsular cataract extraction. Intraoperative cryotherapy was performed at the time of first vitrectomy in three eyes (two eyes recovered to better than 20/100), and at the time of second vitrectomy in three eyes (one eye recovered to better than 20/100). Timing of reconstructive surgery ranged from nine days to 13 weeks in the 14 eyes undergoing reconstructive surgery. Fourteen of the eyes underwent definitive surgery with in one month of injury, and seven of these eyes (50%) recovered visual acuity of 20/100 or bet ter. Of the 16 eyes, three had macular injuries and one eye had optic nerve injury, but all eyes had final visual acuity of light perception or better. Two eyes underwent definitive surgery more than a month after injury, and neither of these eyes recovered to 20/100. One of these eyes belonged to a patient whose other eye was atrophied. Vitrectomy was offered to this pa tient although the eye had been without light perception since the initial injury and there was little hope for visual recovery. Surgery was performed five weeks after injury in this case, and after vitreous hemorrhage had been re moved through an exit wound the optic nerve was observed. The other eye undergoing de layed surgery was the only remaining eye in an indigent patient. Initial visual acuity had been 1/200 but dense vitreous hemorrhage precluded any view of the posterior pole. Vitrectomy was finally performed 13 weeks after injury. Al though there was no exit wound through the posterior pole, extensive contusion to the pos-
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Binocular Shotgun Injury
terior pole was seen at the time of surgery. Visual acuity was 20/200 at last examination, ten months after injury.
Discussion Despite the severity of ocular shotgun inju ries the prognosis is favorable for those eyes with visual acuity of light perception or better at first examination. Of these 15 eyes, two (13%) maintained initial visual acuity and 13 (87%) improved with treatment. The factors involved with poor visual out come in this series were severe ocular disorgan ization by the initial injury, anatomic involve ment of the optic nerve or macula by the initial injury, and no light perception on initial exami nation. By contrast, neither retinal detachment nor double-perforating injury was associated with a prognosis poorer than that of the series as a whole. Of 20 eyes in this series that failed to recover visual acuity of at least 20/100, the limiting factor in visual recovery was the anatomic pat tern of the initial injury in 16 eyes (severe ocular disorganization in nine eyes, optic nerve injury in three eyes, and macular injury in three eyes). Of the 19 eyes that were not initial ly disorganized, 13 developed retinal detach ments, including four eyes that required repeat vitrectomy for retinal detachment. Only four eyes failed to reach a visual acuity of at least 20/100 on the basis of retinal detachment second ary to the initial injury. While eyes with double-perforating injuries were more likely to require enucleation, there was no trend toward better visual outcome in eyes with nonperforating injuries since these eyes were more likely to suffer optic nerve injury. Conversely, the involvement of multi ple pellets in an injury was associated with a poorer visual prognosis and a higher rate of severe ocular injury requiring enucleation. Current treatment modalities allow for the repair of most of the tissues damaged in pene trating ocular injuries. Corneas, lenses, and even sclera can be replaced by eye bank tissue or prosthetic devices. Vitreous hemorrhages and opacities can be removed mechanically, and retinal detachments can be repaired. The only limits to repair of these eyes are total disorganization of the globe and irreparably damaged retina or optic nerve.
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Before vitrectomy was available, Drummond and Kielar4 described a series of 20 patients (20 eyes) with double-perforating shotgun injuries that received primary closure only. The rate of return to visual acuity of 20/400 was only 15% (three of 20 eyes) in that series vs nine of 22 eyes (41%) with double-perforating injury in this series. At that time Drummond and Kielar predicted that vitrectomy would improve the visual outcome of eyes with vitreous hemor rhage and limited or no retinal detachment. In our series eight of 11 eyes fitting this descrip tion that were without direct injury to the optic nerve or macula recovered final visual acuity of at least 20/100. In contrast to the increased rate of recovery to a visual acuity of 20/400, we did not find a significant drop in the rate of light perception loss in eyes with double-perforating injury. The rate of no light perception in eyes with double-perforating injury was 45% (nine of 20 eyes) in Drummond and Kielar's 4 series, 54% (seven of 13 eyes) in Kutschera and Kosmath's 5 series, and 43% (eight of 22 eyes) in our series. We believe that improvements in the preven tion and treatment of retinal detachment, as represented by closed microsurgical vitrec tomy, are responsible for the observed im provement in the salvage rate of useful vision. It is the direct tissue damage of the initial injury that determines the visual prognosis of these eyes, and there is unfortunately nothing that can be done at present to reverse visual loss from destruction of the retina or optic nerve. This limit to the effectiveness of any treatment for ocular shotgun injury under scores the vital role that prevention must play as ophthalmologists attempt to limit this source of visual morbidity. Because the majority of these injuries result from intentional assault, prevention will be difficult. Hunting, though, is an activity in which the potential for ocular injury can be anticipated. The destructive potential of a shot gun can be appreciated by considering that a single number 6 shotgun pellet has 1.08 foot pounds of kinetic energy at 65 yards, while 0.4 foot pound is the amount of kinetic energy required to penetrate the skin and feathers of birds. 6 ' 7 Safety glasses have been shown to be of some value in past reports, 8 and recent advanc es, such as new polycarbonate materials, prom ise further improvement in our ability to pre vent these injuries. 9 Unfortunately, safety glasses are only of value when worn, and their
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u s e f u l n e s s will d e p e n d u p o n public e d u c a t i o n . O u r e x p e r i e n c e h a s b e e n t h a t ocular s h o t g u n injuries are e x t r e m e l y s e v e r e injuries, b u t ag gressive surgical i n t e r v e n t i o n can r e s t o r e u s e ful vision in m a n y eyes t h a t h a v e n o t s u s t a i n e d d e s t r u c t i o n of the retina or optic n e r v e .
References 1. Mclntyre, M. W.: Bilateral gunshot perforations with retention of useful vision. A case report. Eye, Ear, Nose, and Throat Monthly 48:33, 1969. 2. Kennedy, K. S., and Izenberg, R. A.: Facial and ocular shotgun blast injury. A report of a case. J. Am. Osteopath. Assoc. 85:586, 1985. 3. Ramsay, R. C , Cantrill, H. L., and Knobloch,
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W. H.: Vitrectomy for double penetrating ocular in juries. Am. J. Ophthalmol. 100:586, 1985. 4. Drummond, J., and Kielar, R. A.: Perforating ocular shotgun injuries. Relationship of ocular findings to pellet ballistics. South. Med. J. 69:1066, 1976. 5. Kutschera, E., and Kosmath, B.: Augenverletzungen bei Jagdunfallen. Klin. Monatsbl. Augenheilkd. 153:808, 1968. 6. Butler, D. F.: The American Shotgun. New York, Winchester Press, 1973, pp. 197-198. 7. Rice, F. P.: Outdoor Life Gun Data Book. New York, Harper & Row, 1975, pp. 378-385. 8. Robertson, D. M.: Safety glasses as protection against shotgun pellets. Am. J. Ophthalmol. 81:671, 1976. 9. Simmons, S. T., Kroehl, G. B., and Hay, P. B.: Prevention of ocular gunshot injuries using polycar bonate lenses. Ophthalmology 91:977, 1984.