Increased Intraocular Pressure in Severely Burned Patients
L a w r e n c e S. E v a n s , M . D .
S i x e y e s of t i i r e e p a t i e n t s w i t h s e v e r e b o d y burns had intraocular pressure ranging from 37.2 to 8 1 . 7 m m H g . B e c a u s e o f e x t r e m e o r b i t a l congestion, lateral canthotomies were per formed, w h i c h caused abrupt d e c r e a s e in in traocular pressure (range, 17.6 to 49.0 m m Hg). None of the patients had a history of g l a u c o ma, narrow angles, or any precondition for a p u p i l l a r y b l o c k m e c h a n i s m . Two p a t i e n t s sur vived and neither had optic nerve d a m a g e or increased intraocular pressure after hospital d i s c h a r g e . T o n o m e t r y s h o u l d b e p e r f o r m e d in patients with severe tiurns and orbital conges t i o n , e s p e c i a l l y in t h o s e p a t i e n t s r e c e i v i n g l a r g e a m o u n t s o f i n t r a v e n o u s fluids. L a t e r a l c a n t h o t o m i e s m a y b e o f benefit t o r e l i e v e p o tentially damaging high intraocular pressure.
EYELID BURNS are the most c o m m o n ocular i n j u r i e s s e e n in s e r i o u s t h e r m a l b u r n a c c i d e n t s , w h i c h are m o s t f r e q u e n t l y h o u s e fires a n d flash fires of c o m b u s t i b l e v a p o r s a n d g a s e s . T h e g l o b e s t e n d to b e s p a r e d , a l t h o u g h m i n o r c o r n e al a b r a s i o n s a r e often s e e n . I t r e a t e d t h r e e patients with severe burns w h o had high intra ocular pressure. Lateral c a n t h o t o m i e s lowered the i n t r a o c u l a r p r e s s u r e i m m e d i a t e l y , w h i c h implicated swollen periocular tissues pressing on the g l o b e s as the m a i n r e a s o n for t h e i n t r a o c ular pressure increase.
Case Reports Case 1 A 5 9 - y e a r - o l d m a n w a s a d m i t t e d to t h e b u r n u n i t of L o y o l a U n i v e r s i t y M e d i c a l C e n t e r after
Accepted for publication Sept. 2 6 , 1 9 9 0 . From ttie Department of Ophthalmology, Stritch School of Medicine, Loyola University of Chicago, Maywood, Illinois. Reprint requests to Lawrence S. Evans, M.D., Depart ment of Ophthalmology, Stritch School of Medicine Loyola University of Chicago, 2 1 6 0 S. First Ave., Maywood, IL 6 0 1 5 3 .
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an e x p l o s i o n a n d flash fire in an i n d u s t r i a l accident. The patient had second- and thirddegree burns of the face, lower extremities, back, and forearms, totaling 5 5 % of the body surface. T h e eyes had clear corneas, moderately chemotic conjunctivae, normal pupillary light reflexes, partial-thickness eyelid burns, and singed eyelashes. Between the time of admis sion and the time of the follow-up examination (30 hours), the patient received 3 2 . 2 1 of intra v e n o u s fluids, 8 0 m l o f o r a l a n t a c i d s , w i t h 4 . 2 1 of u r i n e o u t p u t , for a m e a s u r e d e x c e s s i n p u t o v e r o u t p u t o f a p p r o x i m a t e l y 2 8 1 o f fluids. H i s b o d y w e i g h t w a s 7 7 . 3 kg at a d m i s s i o n a n d 9 3 . 0 kg at t h e t i m e o f t h e f o l l o w - u p e x a m i n a t i o n , for a g a i n o f 1 5 . 7 kg. T h i s g a i n w a s l e s s t h a n t h a t o f t h e fluid e x c e s s , b u t t h i s w a s e x p e c t e d b e c a u s e of the fluid l o s s t h r o u g h b u r n e d a r e a s . At t h i s t i m e , the face w a s g r e a t l y s w o l l e n a n d t h e eyelids were tight. S c h i ö t z tonometry measure ments were taken without pressing on the g l o b e s a n d w e r e f o u n d to b e 3 7 . 2 m m H g in each eye. The patient had no previous ocular p r o b l e m s , a n d t h e r e w a s n o r e a s o n to s u s p e c t a b i l a t e r a l p u p i l l a r y b l o c k m e c h a n i s m for t h e intraocular pressure increase. Permission was o b t a i n e d from the p a t i e n t ' s f a m i l y to p e r f o r m lateral c a n t h o t o m i e s . T h e lateral canthal areas were injected with 2 % lidocaine with epineph rine, and lateral c a n t h o t o m i e s were performed. Intraocular pressure, measured immediately, w a s R . E . ; 2 9 . 4 m m Hg a n d L . E . : 1 9 . 6 m m Hg. The patient had a lengthy convalescence and w a s fully a m b u l a t o r y w i t h o u t v i s u a l c o m p l a i n t s six m o n t h s after t h e a c c i d e n t . V i s u a l a c u i t y w a s R . E . : 2 0 / 2 0 w i t h r e f r a c t i o n o f +1.00 + 1.25 X 5 a n d L . E . : 2 0 / 2 0 w i t h r e f r a c t i o n o f -t-1.00 -1-0.75 X 2. R e s u l t s o f s l i t - l a m p e x a m i n a tion of the corneas, anterior c h a m b e r s , irides, and conjunctivae were normal. No canthotomy scars were discernible. T h e eyelid burns were healed entirely and the eyelashes had regrown without misdirection. Intraocular pressure was R . E . ; 13 m m Hg a n d L . E . : 1 7 m m Hg b y a p p l a nation tonometry. Results o f Goldmann visual field t e s t i n g w e r e full to Ij^ a n d I45. R e s u l t s o f examination of the optic nerves and the r e m a i n der of t h e fundus e x a m i n a t i o n w e r e n o r m a l .
©AMERICAN JOURNAL OF OPHTHALMOLOGY 1 1 1 : 5 6 - 5 8 , JANUARY, 1 9 9 1
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Intraocular Pressure in Burned Patients
Case 2 A 72-year-old man received burns over 3 0 % of h i s b o d y s u r f a c e a n d i n h a l a t i o n a l i n j u r i e s in a h o u s e fire. T h e p a t i e n t h a d p a r t i a l - t h i c k n e s s b u r n s of the f o r e a r m s , left u p p e r a r m a n d s h o u l d e r , t h e a n t e r i o r s u r f a c e o f t h e e n t i r e left leg, a n d of t h e b a c k of t h e h e a d . H e h a d a f u l l - t h i c k n e s s b u r n o f t h e f a c e . T h e f a m i l y stat ed that h e h a d d i a b e t e s m e l l i t u s a n d h y p e r t e n sion but no previous ocular problems. T h e pa tient was c o m a t o s e and p h a r m a c o l o g i c a l l y p a r a l y z e d for m e c h a n i c a l r e s p i r a t o r y v e n t i l a tion w h e n e x a m i n e d t h r e e h o u r s after a d m i s s i o n for o p h t h a l m i c a s s e s s m e n t . B o t h c o r n e a s were cloudy, and a central epithelial defect was n o t e d o n t h e r i g h t e y e . T h e left c o n j u n c t i v a w a s c h e m o t i c . P u p i l s w e r e 1.5 m m in s i z e a n d u n r e a c t i v e in b o t h e y e s . W h e n r e - e x a m i n e d 2 0 h o u r s later, t h e e y e l i d s w e r e s w o l l e n a n d t i g h t . I n t r a o c u l a r p r e s s u r e w a s R . E . : 7 4 . 0 m m Hg a n d L . E . : 7 2 . 0 m m Hg. L a t e r a l c a n t h o t o m i e s w e r e p e r formed. Intraocular pressure, measured i m m e d i a t e l y , w a s R . E . : 3 5 . 0 m m Hg a n d L . E . : 3 0 . 0 m m Hg. By the t i m e t h e c a n t h o t o m i e s w e r e p e r f o r m e d , the p a t i e n t r e c e i v e d 2 3 1 o f i n t r a v e n o u s fluids a n d h a d a u r i n e o u t p u t o f 2 1 for a m e a s u r e d fluid g a i n o f 2 1 1 in 2 3 h o u r s . T h e patient's condition deteriorated, and he died six days later. Case 3 A 27-year-old man received high-voltage e l e c t r i c b u r n s in a h i g h w a y c o n s t r u c t i o n a c c i d e n t . O c u l a r e x a m i n a t i o n in t h e e m e r g e n c y room showed a central epithelial defect on the right c o r n e a a n d a t o t a l e p i t h e l i a l d e f e c t on t h e left c o r n e a . B o t h c o r n e a s w e r e h a z y , a n d m o d e r a t e Chemosis w a s n o t e d in b o t h e y e s . T h e p u p i l s w e r e n o t d i l a t e d at t h e r e q u e s t o f t h e admitting service. Upon admission the patient w a s t a k e n to the o p e r a t i n g r o o m for f a s c i o t o m i e s on all e x t r e m i t i e s . At t h i s t i m e , a p p r o x i m a t e l y four h o u r s after a d m i s s i o n , i n t r a o c u l a r pressure, measured by S c h i ó t z t o n o m e t r y , was R.E.; 8 1 . 7 m m H g a n d L . E . : 5 0 . 2 m m H g . Lateral canthotomies were performed, and intraocular pressure, measured immediately afterward, w a s R . E . : 3 2 . 2 m m Hg a n d L . E . : 2 4 . 4 m m Hg. W h e n the c a n t h o t o m i e s were performed, the patient received approximately 7.6 1 of intrave n o u s fluids a n d h a d a u r i n e o u t p u t o f 1.9 1, for a m e a s u r e d g a i n o f 5 . 7 1. T h e s e v e r i t y o f t h e injury n e c e s s i t a t e d a m p u t a t i o n o f b o t h a r m s , total skin grafting to t h e f a c e , a n d s e v e r a l r e c o n s t r u c t i v e p r o c e d u r e s o f the e y e l i d s , w i t h further s u r g i c a l p r o c e d u r e s f o r e s e e n . Five
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m o n t h s after t h e i n j u r y , i n t r a o c u l a r p r e s s u r e w a s 1 6 . 0 m m Hg in e a c h e y e . T h e p a t i e n t developed bilateral cataracts with best-correct ed v i s u a l a c u i t y o f 2 0 / 6 0 in e a c h e y e . T h e o p t i c n e r v e s a p p e a r e d to h a v e a n o r m a l m y o p i c c o n figuration, c o r r e s p o n d i n g to t h e p a t i e n t ' s r e fractive e r r o r . S e v e n t e e n m o n t h s after t h e i n j u ry w h e n t h e e y e l i d s h a d h e a l e d sufficiently, t h e left c a t a r a c t w a s r e m o v e d a n d a p o s t e r i o r c h a m ber intraocular lens was implanted, which re s u l t e d in 2 0 / 2 0 v i s u a l a c u i t y .
Discussion T h e a d m i n i s t r a t i o n o f l a r g e q u a n t i t i e s o f in t r a v e n o u s fluids t o m a i n t a i n b l o o d p r e s s u r e is t h e k e y t h e r a p e u t i c m e a s u r e in t r e a t m e n t o f t h e severely burned patient, and this contributes to t h e o r b i t a l c o n g e s t i o n . In t h e p a t i e n t in C a s e 3 , for e x a m p l e , 3 1 1 o f fluids w a s g i v e n w i t h i n 2 4 hours of the injury. C o n t i n u o u s cardiovascular m o n i t o r i n g , i n c l u d i n g t h e u s e of i n t r a c a r d i a c c a t h e t e r s , is n e c e s s a r y to p r o v i d e c l o s e p h a r m a cologic support. All three patients had massive periorbital swelling, and because each eye s h o w e d a m a r k e d d e c r e a s e in i n t r a o c u l a r p r e s s u r e w h e n l a t e r a l c a n t h o t o m y w a s p e r f o r m e d , it is e v i d e n t t h a t o r b i t a l p r e s s u r e t r a n s m i t t e d to t h e e y e w a s t h e p r i m a r y m e c h a n i s m for t h e h i g h intraocular pressure. That n o n e of the eyes had n o r m a l i n t r a o c u l a r p r e s s u r e after c a n t h o t o m y m a y b e a t t r i b u t e d , at l e a s t in p a r t , to i n c o m pleteness of the c a n t h o t o m i e s and residual high o r b i t a l p r e s s u r e . Two p a t i e n t s r e c e i v e d l a r g e a m o u n t s o f i n t r a v e n o u s fluids, a n d t h e t h i r d patient received a moderate amount. Therefore, fluid l o a d i n g d o e s n o t a p p e a r to b e t h e s o l e r e a s o n for t h e h i g h o r b i t a l p r e s s u r e . A n o t h e r p l a u s i b l e m e c h a n i s m to c o n s i d e r for t h e i n t r a o c u l a r p r e s s u r e i n c r e a s e is p u p i l l a r y b l o c k c a u s e d b y o r b i t a l p r e s s u r e o n the g l o b e , d i s placing the lens anteriorly. Electric burns, such as t h o s e s e e n in t h e p a t i e n t i n C a s e 3 , a r e a l s o t h e r m a l b u r n s b e c a u s e b o d y r e s i s t a n c e to e l e c t r i c c u r r e n t c o n v e r t s e l e c t r i c e n e r g y i n t o heat." Small controlled electric currents, however, s u c h as t h o s e u s e d for e l e c t r o s h o c k therapy^ a n d c a r d i o v e r s i o n , ' h a v e b e e n r e p o r t e d to c a u s e increased intraocular pressure. A g e n e r a l f e a t u r e o f s e v e r e b u r n i n j u r y is t h e shift o f w a t e r from t h e i n t r a v a s c u l a r s p a c e to the extravascular space, particularly to the peri ocular extravascular space, which can cause s w e l l i n g a n d t i g h t n e s s o f t h e e y e l i d s . W a t e r is
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a l s o lost t h r o u g h b u r n e d b o d y s u r f a c e s . T h e s e p r o c e s s e s may l e a d to d a n g e r o u s h y p o t e n s i o n and hemoconcentration. Administration of large volumes of sodium-containing intrave n o u s fluids is n e c e s s a r y to m a i n t a i n h e m o d y n a m i c s a n d to c o r r e c t e l e c t r o l y t e i m b a l a n c e s . ' S e v e r a l f a c t o r s c o n t r i b u t e to t h e e x t r a c e l l u l a r e d e m a , i n c l u d i n g t h e follow^ing: i n c r e a s e d c a p illary e n d o t h e l i a l l e a k a g e , w h i c h p e r m i t s w a t e r a n d p l a s m a p r o t e i n s to e n t e r t h e e x t r a c e l l u l a r s p a c e ; r e d u c t i o n in c a p i l l a r y c o l l o i d o s m o t i c p r e s s u r e from d e c r e a s e d p l a s m a p r o t e i n c o n centration; increased capillary hydrostatic p r e s s u r e from v a s o c o n s t r i c t i o n o r c a p i l l a r y b l o c k a g e b y p l a t e l e t s or c e l l s ; a n d i m p a i r e d l y m p h a t i c d r a i n a g e from duct b l o c k a g e b y p l a t e l e t s , c e l l s , or b o t h . ' S e v e r e d e r a n g e m e n t s of fluid a n d e l e c t r o l y t e i m b a l a n c e u s u a l l y o c cur, g e n e r a l l y c a u s e d b y s y s t e m i c i m p a i r m e n t of t h e c e l l u l a r s o d i u m - p o t a s s i u m p u m p . ' E n d o crine responses to burn injury include high levels of antidiuretic h o r m o n e and aldosterone, w h i c h p r o m o t e fluid r e t e n t i o n , p o s s i b l y p o t e n tiating o r b i t a l c o n g e s t i o n . ' Typically t h e s e v e r e l y b u r n e d p a t i e n t d o e s n o t d e v e l o p p e r i o r b i t a l e d e m a u n t i l a few h o u r s after t h e i n j u r y . I m m e d i a t e e x a m i n a t i o n facili tates e v a l u a t i o n o f any o c u l a r i n j u r i e s . T h i s e x a m i n a t i o n m a y p r e c e d e an i n t r a o c u l a r p r e s sure i n c r e a s e , s o it is i m p o r t a n t to p e r f o r m t o n o m e t r y after p e r i o r b i t a l e d e m a e n s u e s . P e r i o r b i t a l e d e m a m a y o c c u r e v e n w h e n t h e face is s p a r e d from a direct b u r n . O n arrival at t h e h o s p i t a l , m a n y s e v e r e l y b u r n e d p a t i e n t s are a b l e to c o o p e r a t e for o c u l a r e x a m i n a t i o n , p o s s i b l y to r e l a t e p r e v i o u s o c u l a r p r o b l e m s a n d to permit m e a s u r e m e n t of visual acuity with a n e a r - v i s i o n test c a r d . S e v e r e l y b u r n e d p a t i e n t s are u s u a l l y p h a r m a c o l o g i c a l l y p a r a l y z e d a n d given m e c h a n i c a l p u l m o n a r y v e n t i l a t i o n w i t h e n d o t r a c h e a l i n t u b a t i o n s h o r t l y after a r r i v a l , w h i c h l i m i t s c o o p e r a t i o n for e x a m i n a t i o n , e v e n t h o u g h t h e y m a y b e fully c o n s c i o u s a n d a w a r e . The eyelids and conjunctival sacs should be i r r i g a t e d to r e m o v e p a r t i c u l a t e m a t e r i a l . S i n g e d eyelashes may be removed with a moist sponge to p r e v e n t t h e m from e n t e r i n g a n d i r r i t a t i n g t h e e y e s . E y e l i d r e t r a c t i o n is n e c e s s a r y for e x a m i nation if p e r i o r b i t a l edema has already d e v e l o p e d . After the c o r n e a is e x a m i n e d , t o
n o m e t r y is p e r f o r m e d w i t h r e t r a c t i o n r e l a x e d to permit a more accurate reading. Topical anes thesia should be used because the patient may h a v e full s e n s a t i o n e v e n t h o u g h u n a b l e t o c o m m u n i c a t e . I f h i g h i n t r a o c u l a r p r e s s u r e is f o u n d with severe periocular edema and canthotomy is to b e p e r f o r m e d , l o c a l a n e s t h e s i a s h o u l d b e i n j e c t e d t h r o u g h u n b u r n e d s k i n if p o s s i b l e . A n ophthalmic antibiotic ointment should be ap p l i e d to t h e g l o b e s a n d c a n t h o t o m y s i t e s . S i l v e r s u l f a d i a z i n e is c o m m o n l y u s e d to treat b u r n e d skin w h e n t h e r e is n o k n o w n a l l e r g y to s u l f o n a mides. Sulfacetamide 1 0 % ophthalmic oint m e n t m a y a l s o b e u s e d w i t h o u t i n c r e a s e d risk o f allergic reaction. Aminoglycoside antibiotics s h o u l d b e a v o i d e d to l e s s e n t h e c h a n c e o f e m e r g e n c e of r e s i s t a n t s t r a i n s o f b a c t e r i a . Fuchs'' r e p o r t e d t h a t a c u t e t r a n s i t o r y g l a u c o m a c a n o c c u r w i t h t h e r m a l b u r n s , b u t t h i s refers to direct b u r n s o f t h e e y e a n d a d n e x a . In 11 previously described patients with blindness after m a j o r b u r n s w i t h v a r i a b l e d e g r e e s o f r e c o v e r y in four p a t i e n t s , R e s c h a n d Sullivan^ r e m a r k e d that in five o f t h e six a d u l t p a t i e n t s t h e o p t i c n e r v e s w e r e e i t h e r p a l e or e d e m a t o u s . T h e y did n o t m e n t i o n i n c r e a s e d i n t r a o c u l a r p r e s s u r e as a p o s s i b l e f a c t o r . A l l p a t i e n t s h a d other significant o p h t h a l m i c and neurologic s i g n s . S a l z a n d Donin* a n d W a l s h a n d H o y t ' have also described similar patients.
References 1. Davies, J. W. L.: Physiological Responses to Burn Injury. London, Academic Press, 1982, pp. 13; 46; 212; 2 1 5 ; 5 3 2 ; and 537. 2. Arstikaitis, M., and Hodgson, H.: The effect of lobotomy and electroshock on intraocular pressure. Am. J. Ophthalmol. 35:1625, 1 9 5 2 . 3. Berger, R. O.: Ocular complications of cardio version. Ann. Ophthalmol. 10:161, 1978. 4. Fuchs, Η. Ε.: Textbook of Ophthalmology, ed. 7. Philadelphia,). B. Lippincott, 1923, pp. 498 and 7 8 5 . 5. Resch, C. S., and Sullivan, W. G.: Unexplained blindness after a major burn. Burns 14:225, 1 9 8 8 . 6. Salz, J. J . , and Donin, J. F.: Blindness after burns. Can. J. Ophthalmol. 7:243, 1 9 7 2 . 7. Walsh, F. B., and Hoyt, W. F.: Clinical NeuroOphthalmology, ed. 3. Baltimore, Williams and Wilkins, 1969, pp. 2 4 8 0 - 2 4 8 2 .
L a w r e n c e S. E v a n s , M . D .
S i x e y e s of t i i r e e p a t i e n t s w i t h s e v e r e b o d y burns had intraocular pressure ranging from 37.2 to 8 1 . 7 m m H g . B e c a u s e o f e x t r e m e o r b i t a l congestion, lateral canthotomies were per formed, w h i c h caused abrupt d e c r e a s e in in traocular pressure (range, 17.6 to 49.0 m m Hg). None of the patients had a history of g l a u c o ma, narrow angles, or any precondition for a p u p i l l a r y b l o c k m e c h a n i s m . Two p a t i e n t s sur vived and neither had optic nerve d a m a g e or increased intraocular pressure after hospital d i s c h a r g e . T o n o m e t r y s h o u l d b e p e r f o r m e d in patients with severe tiurns and orbital conges t i o n , e s p e c i a l l y in t h o s e p a t i e n t s r e c e i v i n g l a r g e a m o u n t s o f i n t r a v e n o u s fluids. L a t e r a l c a n t h o t o m i e s m a y b e o f benefit t o r e l i e v e p o tentially damaging high intraocular pressure.
EYELID BURNS are the most c o m m o n ocular i n j u r i e s s e e n in s e r i o u s t h e r m a l b u r n a c c i d e n t s , w h i c h are m o s t f r e q u e n t l y h o u s e fires a n d flash fires of c o m b u s t i b l e v a p o r s a n d g a s e s . T h e g l o b e s t e n d to b e s p a r e d , a l t h o u g h m i n o r c o r n e al a b r a s i o n s a r e often s e e n . I t r e a t e d t h r e e patients with severe burns w h o had high intra ocular pressure. Lateral c a n t h o t o m i e s lowered the i n t r a o c u l a r p r e s s u r e i m m e d i a t e l y , w h i c h implicated swollen periocular tissues pressing on the g l o b e s as the m a i n r e a s o n for t h e i n t r a o c ular pressure increase.
Case Reports Case 1 A 5 9 - y e a r - o l d m a n w a s a d m i t t e d to t h e b u r n u n i t of L o y o l a U n i v e r s i t y M e d i c a l C e n t e r after
Accepted for publication Sept. 2 6 , 1 9 9 0 . From ttie Department of Ophthalmology, Stritch School of Medicine, Loyola University of Chicago, Maywood, Illinois. Reprint requests to Lawrence S. Evans, M.D., Depart ment of Ophthalmology, Stritch School of Medicine Loyola University of Chicago, 2 1 6 0 S. First Ave., Maywood, IL 6 0 1 5 3 .
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an e x p l o s i o n a n d flash fire in an i n d u s t r i a l accident. The patient had second- and thirddegree burns of the face, lower extremities, back, and forearms, totaling 5 5 % of the body surface. T h e eyes had clear corneas, moderately chemotic conjunctivae, normal pupillary light reflexes, partial-thickness eyelid burns, and singed eyelashes. Between the time of admis sion and the time of the follow-up examination (30 hours), the patient received 3 2 . 2 1 of intra v e n o u s fluids, 8 0 m l o f o r a l a n t a c i d s , w i t h 4 . 2 1 of u r i n e o u t p u t , for a m e a s u r e d e x c e s s i n p u t o v e r o u t p u t o f a p p r o x i m a t e l y 2 8 1 o f fluids. H i s b o d y w e i g h t w a s 7 7 . 3 kg at a d m i s s i o n a n d 9 3 . 0 kg at t h e t i m e o f t h e f o l l o w - u p e x a m i n a t i o n , for a g a i n o f 1 5 . 7 kg. T h i s g a i n w a s l e s s t h a n t h a t o f t h e fluid e x c e s s , b u t t h i s w a s e x p e c t e d b e c a u s e of the fluid l o s s t h r o u g h b u r n e d a r e a s . At t h i s t i m e , the face w a s g r e a t l y s w o l l e n a n d t h e eyelids were tight. S c h i ö t z tonometry measure ments were taken without pressing on the g l o b e s a n d w e r e f o u n d to b e 3 7 . 2 m m H g in each eye. The patient had no previous ocular p r o b l e m s , a n d t h e r e w a s n o r e a s o n to s u s p e c t a b i l a t e r a l p u p i l l a r y b l o c k m e c h a n i s m for t h e intraocular pressure increase. Permission was o b t a i n e d from the p a t i e n t ' s f a m i l y to p e r f o r m lateral c a n t h o t o m i e s . T h e lateral canthal areas were injected with 2 % lidocaine with epineph rine, and lateral c a n t h o t o m i e s were performed. Intraocular pressure, measured immediately, w a s R . E . ; 2 9 . 4 m m Hg a n d L . E . : 1 9 . 6 m m Hg. The patient had a lengthy convalescence and w a s fully a m b u l a t o r y w i t h o u t v i s u a l c o m p l a i n t s six m o n t h s after t h e a c c i d e n t . V i s u a l a c u i t y w a s R . E . : 2 0 / 2 0 w i t h r e f r a c t i o n o f +1.00 + 1.25 X 5 a n d L . E . : 2 0 / 2 0 w i t h r e f r a c t i o n o f -t-1.00 -1-0.75 X 2. R e s u l t s o f s l i t - l a m p e x a m i n a tion of the corneas, anterior c h a m b e r s , irides, and conjunctivae were normal. No canthotomy scars were discernible. T h e eyelid burns were healed entirely and the eyelashes had regrown without misdirection. Intraocular pressure was R . E . ; 13 m m Hg a n d L . E . : 1 7 m m Hg b y a p p l a nation tonometry. Results o f Goldmann visual field t e s t i n g w e r e full to Ij^ a n d I45. R e s u l t s o f examination of the optic nerves and the r e m a i n der of t h e fundus e x a m i n a t i o n w e r e n o r m a l .
©AMERICAN JOURNAL OF OPHTHALMOLOGY 1 1 1 : 5 6 - 5 8 , JANUARY, 1 9 9 1
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Intraocular Pressure in Burned Patients
Case 2 A 72-year-old man received burns over 3 0 % of h i s b o d y s u r f a c e a n d i n h a l a t i o n a l i n j u r i e s in a h o u s e fire. T h e p a t i e n t h a d p a r t i a l - t h i c k n e s s b u r n s of the f o r e a r m s , left u p p e r a r m a n d s h o u l d e r , t h e a n t e r i o r s u r f a c e o f t h e e n t i r e left leg, a n d of t h e b a c k of t h e h e a d . H e h a d a f u l l - t h i c k n e s s b u r n o f t h e f a c e . T h e f a m i l y stat ed that h e h a d d i a b e t e s m e l l i t u s a n d h y p e r t e n sion but no previous ocular problems. T h e pa tient was c o m a t o s e and p h a r m a c o l o g i c a l l y p a r a l y z e d for m e c h a n i c a l r e s p i r a t o r y v e n t i l a tion w h e n e x a m i n e d t h r e e h o u r s after a d m i s s i o n for o p h t h a l m i c a s s e s s m e n t . B o t h c o r n e a s were cloudy, and a central epithelial defect was n o t e d o n t h e r i g h t e y e . T h e left c o n j u n c t i v a w a s c h e m o t i c . P u p i l s w e r e 1.5 m m in s i z e a n d u n r e a c t i v e in b o t h e y e s . W h e n r e - e x a m i n e d 2 0 h o u r s later, t h e e y e l i d s w e r e s w o l l e n a n d t i g h t . I n t r a o c u l a r p r e s s u r e w a s R . E . : 7 4 . 0 m m Hg a n d L . E . : 7 2 . 0 m m Hg. L a t e r a l c a n t h o t o m i e s w e r e p e r formed. Intraocular pressure, measured i m m e d i a t e l y , w a s R . E . : 3 5 . 0 m m Hg a n d L . E . : 3 0 . 0 m m Hg. By the t i m e t h e c a n t h o t o m i e s w e r e p e r f o r m e d , the p a t i e n t r e c e i v e d 2 3 1 o f i n t r a v e n o u s fluids a n d h a d a u r i n e o u t p u t o f 2 1 for a m e a s u r e d fluid g a i n o f 2 1 1 in 2 3 h o u r s . T h e patient's condition deteriorated, and he died six days later. Case 3 A 27-year-old man received high-voltage e l e c t r i c b u r n s in a h i g h w a y c o n s t r u c t i o n a c c i d e n t . O c u l a r e x a m i n a t i o n in t h e e m e r g e n c y room showed a central epithelial defect on the right c o r n e a a n d a t o t a l e p i t h e l i a l d e f e c t on t h e left c o r n e a . B o t h c o r n e a s w e r e h a z y , a n d m o d e r a t e Chemosis w a s n o t e d in b o t h e y e s . T h e p u p i l s w e r e n o t d i l a t e d at t h e r e q u e s t o f t h e admitting service. Upon admission the patient w a s t a k e n to the o p e r a t i n g r o o m for f a s c i o t o m i e s on all e x t r e m i t i e s . At t h i s t i m e , a p p r o x i m a t e l y four h o u r s after a d m i s s i o n , i n t r a o c u l a r pressure, measured by S c h i ó t z t o n o m e t r y , was R.E.; 8 1 . 7 m m H g a n d L . E . : 5 0 . 2 m m H g . Lateral canthotomies were performed, and intraocular pressure, measured immediately afterward, w a s R . E . : 3 2 . 2 m m Hg a n d L . E . : 2 4 . 4 m m Hg. W h e n the c a n t h o t o m i e s were performed, the patient received approximately 7.6 1 of intrave n o u s fluids a n d h a d a u r i n e o u t p u t o f 1.9 1, for a m e a s u r e d g a i n o f 5 . 7 1. T h e s e v e r i t y o f t h e injury n e c e s s i t a t e d a m p u t a t i o n o f b o t h a r m s , total skin grafting to t h e f a c e , a n d s e v e r a l r e c o n s t r u c t i v e p r o c e d u r e s o f the e y e l i d s , w i t h further s u r g i c a l p r o c e d u r e s f o r e s e e n . Five
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m o n t h s after t h e i n j u r y , i n t r a o c u l a r p r e s s u r e w a s 1 6 . 0 m m Hg in e a c h e y e . T h e p a t i e n t developed bilateral cataracts with best-correct ed v i s u a l a c u i t y o f 2 0 / 6 0 in e a c h e y e . T h e o p t i c n e r v e s a p p e a r e d to h a v e a n o r m a l m y o p i c c o n figuration, c o r r e s p o n d i n g to t h e p a t i e n t ' s r e fractive e r r o r . S e v e n t e e n m o n t h s after t h e i n j u ry w h e n t h e e y e l i d s h a d h e a l e d sufficiently, t h e left c a t a r a c t w a s r e m o v e d a n d a p o s t e r i o r c h a m ber intraocular lens was implanted, which re s u l t e d in 2 0 / 2 0 v i s u a l a c u i t y .
Discussion T h e a d m i n i s t r a t i o n o f l a r g e q u a n t i t i e s o f in t r a v e n o u s fluids t o m a i n t a i n b l o o d p r e s s u r e is t h e k e y t h e r a p e u t i c m e a s u r e in t r e a t m e n t o f t h e severely burned patient, and this contributes to t h e o r b i t a l c o n g e s t i o n . In t h e p a t i e n t in C a s e 3 , for e x a m p l e , 3 1 1 o f fluids w a s g i v e n w i t h i n 2 4 hours of the injury. C o n t i n u o u s cardiovascular m o n i t o r i n g , i n c l u d i n g t h e u s e of i n t r a c a r d i a c c a t h e t e r s , is n e c e s s a r y to p r o v i d e c l o s e p h a r m a cologic support. All three patients had massive periorbital swelling, and because each eye s h o w e d a m a r k e d d e c r e a s e in i n t r a o c u l a r p r e s s u r e w h e n l a t e r a l c a n t h o t o m y w a s p e r f o r m e d , it is e v i d e n t t h a t o r b i t a l p r e s s u r e t r a n s m i t t e d to t h e e y e w a s t h e p r i m a r y m e c h a n i s m for t h e h i g h intraocular pressure. That n o n e of the eyes had n o r m a l i n t r a o c u l a r p r e s s u r e after c a n t h o t o m y m a y b e a t t r i b u t e d , at l e a s t in p a r t , to i n c o m pleteness of the c a n t h o t o m i e s and residual high o r b i t a l p r e s s u r e . Two p a t i e n t s r e c e i v e d l a r g e a m o u n t s o f i n t r a v e n o u s fluids, a n d t h e t h i r d patient received a moderate amount. Therefore, fluid l o a d i n g d o e s n o t a p p e a r to b e t h e s o l e r e a s o n for t h e h i g h o r b i t a l p r e s s u r e . A n o t h e r p l a u s i b l e m e c h a n i s m to c o n s i d e r for t h e i n t r a o c u l a r p r e s s u r e i n c r e a s e is p u p i l l a r y b l o c k c a u s e d b y o r b i t a l p r e s s u r e o n the g l o b e , d i s placing the lens anteriorly. Electric burns, such as t h o s e s e e n in t h e p a t i e n t i n C a s e 3 , a r e a l s o t h e r m a l b u r n s b e c a u s e b o d y r e s i s t a n c e to e l e c t r i c c u r r e n t c o n v e r t s e l e c t r i c e n e r g y i n t o heat." Small controlled electric currents, however, s u c h as t h o s e u s e d for e l e c t r o s h o c k therapy^ a n d c a r d i o v e r s i o n , ' h a v e b e e n r e p o r t e d to c a u s e increased intraocular pressure. A g e n e r a l f e a t u r e o f s e v e r e b u r n i n j u r y is t h e shift o f w a t e r from t h e i n t r a v a s c u l a r s p a c e to the extravascular space, particularly to the peri ocular extravascular space, which can cause s w e l l i n g a n d t i g h t n e s s o f t h e e y e l i d s . W a t e r is
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a l s o lost t h r o u g h b u r n e d b o d y s u r f a c e s . T h e s e p r o c e s s e s may l e a d to d a n g e r o u s h y p o t e n s i o n and hemoconcentration. Administration of large volumes of sodium-containing intrave n o u s fluids is n e c e s s a r y to m a i n t a i n h e m o d y n a m i c s a n d to c o r r e c t e l e c t r o l y t e i m b a l a n c e s . ' S e v e r a l f a c t o r s c o n t r i b u t e to t h e e x t r a c e l l u l a r e d e m a , i n c l u d i n g t h e follow^ing: i n c r e a s e d c a p illary e n d o t h e l i a l l e a k a g e , w h i c h p e r m i t s w a t e r a n d p l a s m a p r o t e i n s to e n t e r t h e e x t r a c e l l u l a r s p a c e ; r e d u c t i o n in c a p i l l a r y c o l l o i d o s m o t i c p r e s s u r e from d e c r e a s e d p l a s m a p r o t e i n c o n centration; increased capillary hydrostatic p r e s s u r e from v a s o c o n s t r i c t i o n o r c a p i l l a r y b l o c k a g e b y p l a t e l e t s or c e l l s ; a n d i m p a i r e d l y m p h a t i c d r a i n a g e from duct b l o c k a g e b y p l a t e l e t s , c e l l s , or b o t h . ' S e v e r e d e r a n g e m e n t s of fluid a n d e l e c t r o l y t e i m b a l a n c e u s u a l l y o c cur, g e n e r a l l y c a u s e d b y s y s t e m i c i m p a i r m e n t of t h e c e l l u l a r s o d i u m - p o t a s s i u m p u m p . ' E n d o crine responses to burn injury include high levels of antidiuretic h o r m o n e and aldosterone, w h i c h p r o m o t e fluid r e t e n t i o n , p o s s i b l y p o t e n tiating o r b i t a l c o n g e s t i o n . ' Typically t h e s e v e r e l y b u r n e d p a t i e n t d o e s n o t d e v e l o p p e r i o r b i t a l e d e m a u n t i l a few h o u r s after t h e i n j u r y . I m m e d i a t e e x a m i n a t i o n facili tates e v a l u a t i o n o f any o c u l a r i n j u r i e s . T h i s e x a m i n a t i o n m a y p r e c e d e an i n t r a o c u l a r p r e s sure i n c r e a s e , s o it is i m p o r t a n t to p e r f o r m t o n o m e t r y after p e r i o r b i t a l e d e m a e n s u e s . P e r i o r b i t a l e d e m a m a y o c c u r e v e n w h e n t h e face is s p a r e d from a direct b u r n . O n arrival at t h e h o s p i t a l , m a n y s e v e r e l y b u r n e d p a t i e n t s are a b l e to c o o p e r a t e for o c u l a r e x a m i n a t i o n , p o s s i b l y to r e l a t e p r e v i o u s o c u l a r p r o b l e m s a n d to permit m e a s u r e m e n t of visual acuity with a n e a r - v i s i o n test c a r d . S e v e r e l y b u r n e d p a t i e n t s are u s u a l l y p h a r m a c o l o g i c a l l y p a r a l y z e d a n d given m e c h a n i c a l p u l m o n a r y v e n t i l a t i o n w i t h e n d o t r a c h e a l i n t u b a t i o n s h o r t l y after a r r i v a l , w h i c h l i m i t s c o o p e r a t i o n for e x a m i n a t i o n , e v e n t h o u g h t h e y m a y b e fully c o n s c i o u s a n d a w a r e . The eyelids and conjunctival sacs should be i r r i g a t e d to r e m o v e p a r t i c u l a t e m a t e r i a l . S i n g e d eyelashes may be removed with a moist sponge to p r e v e n t t h e m from e n t e r i n g a n d i r r i t a t i n g t h e e y e s . E y e l i d r e t r a c t i o n is n e c e s s a r y for e x a m i nation if p e r i o r b i t a l edema has already d e v e l o p e d . After the c o r n e a is e x a m i n e d , t o
n o m e t r y is p e r f o r m e d w i t h r e t r a c t i o n r e l a x e d to permit a more accurate reading. Topical anes thesia should be used because the patient may h a v e full s e n s a t i o n e v e n t h o u g h u n a b l e t o c o m m u n i c a t e . I f h i g h i n t r a o c u l a r p r e s s u r e is f o u n d with severe periocular edema and canthotomy is to b e p e r f o r m e d , l o c a l a n e s t h e s i a s h o u l d b e i n j e c t e d t h r o u g h u n b u r n e d s k i n if p o s s i b l e . A n ophthalmic antibiotic ointment should be ap p l i e d to t h e g l o b e s a n d c a n t h o t o m y s i t e s . S i l v e r s u l f a d i a z i n e is c o m m o n l y u s e d to treat b u r n e d skin w h e n t h e r e is n o k n o w n a l l e r g y to s u l f o n a mides. Sulfacetamide 1 0 % ophthalmic oint m e n t m a y a l s o b e u s e d w i t h o u t i n c r e a s e d risk o f allergic reaction. Aminoglycoside antibiotics s h o u l d b e a v o i d e d to l e s s e n t h e c h a n c e o f e m e r g e n c e of r e s i s t a n t s t r a i n s o f b a c t e r i a . Fuchs'' r e p o r t e d t h a t a c u t e t r a n s i t o r y g l a u c o m a c a n o c c u r w i t h t h e r m a l b u r n s , b u t t h i s refers to direct b u r n s o f t h e e y e a n d a d n e x a . In 11 previously described patients with blindness after m a j o r b u r n s w i t h v a r i a b l e d e g r e e s o f r e c o v e r y in four p a t i e n t s , R e s c h a n d Sullivan^ r e m a r k e d that in five o f t h e six a d u l t p a t i e n t s t h e o p t i c n e r v e s w e r e e i t h e r p a l e or e d e m a t o u s . T h e y did n o t m e n t i o n i n c r e a s e d i n t r a o c u l a r p r e s s u r e as a p o s s i b l e f a c t o r . A l l p a t i e n t s h a d other significant o p h t h a l m i c and neurologic s i g n s . S a l z a n d Donin* a n d W a l s h a n d H o y t ' have also described similar patients.
References 1. Davies, J. W. L.: Physiological Responses to Burn Injury. London, Academic Press, 1982, pp. 13; 46; 212; 2 1 5 ; 5 3 2 ; and 537. 2. Arstikaitis, M., and Hodgson, H.: The effect of lobotomy and electroshock on intraocular pressure. Am. J. Ophthalmol. 35:1625, 1 9 5 2 . 3. Berger, R. O.: Ocular complications of cardio version. Ann. Ophthalmol. 10:161, 1978. 4. Fuchs, Η. Ε.: Textbook of Ophthalmology, ed. 7. Philadelphia,). B. Lippincott, 1923, pp. 498 and 7 8 5 . 5. Resch, C. S., and Sullivan, W. G.: Unexplained blindness after a major burn. Burns 14:225, 1 9 8 8 . 6. Salz, J. J . , and Donin, J. F.: Blindness after burns. Can. J. Ophthalmol. 7:243, 1 9 7 2 . 7. Walsh, F. B., and Hoyt, W. F.: Clinical NeuroOphthalmology, ed. 3. Baltimore, Williams and Wilkins, 1969, pp. 2 4 8 0 - 2 4 8 2 .
