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Show /. Clin. Neuro-ophthamol. 5:273-276, 1985 © 1985 Raven Press, New York Vision Loss Following Transurethral Resection of the Prostate MARILYN C. KAY, M.D. JONATHAN KAY, M.D. FRANK BEGUN, M.D. JOE E. YEUNG, M.D., Ph.D. Abstract Transi~nt.blindness is an uncommonly reported complicatIon of transurethral resection of the prostate ITURP). We report three cases and discuss the possible etiologies of this complaint, which is a symptom of the "TURP syndrome." The transurethral resection of the pfostate (TURP) reaction, consisting of headache, nausea, vomiting, cardiac arrhythmias, disorientation, and/or seizures, occurs when large amounts of hypotonic bladder irrigation solution are systemically absorbed.! It has been attributed to cerebral edema resulting from a hyponatremic, hypervolemic state. 2- 6 Transient blindness as a feature of this syndrome has been infrequently reported in the urologic and anesthetic literature. 2- 6 To our knowledge, the occurrence of blindness after TURP has not been reported previously in the ophthalmologic literature. We report here three patients with visual complications of this syndrome, and discuss a new theory of its etiology. Case 1 A 79-year-old male underwent transurethral prostate resection for prostatic hypertrophy under general anesthesia. His blood pressure was stable during the procedure. Bladder irrigation with 1.5% glycine solution was performed for adequate visualization during the surgery. The patient was uneventfully extubated post- From the Departments of Ophthalmology, Urology, Anesthesiology, and Internal Medicine, Medical College of Wisconsin and Surgical Service, Veterans Administration Medical Center, Milwaukee, WI, U.S.A. Write for reprints to: Dr. M. C. Kay, Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, WI 53226, U.S.A. December 1985 operatively and an electrocardiogram showed normal sinus rhythm. Serum sodium was 122 mEq/L (preoperative level was 139 mEq/L), so 500 cc of 3% sodium chloride solution was infused intravenously. The patient was initially restless but rapidly became oriented; he first complained that he was blind 1!12 h after entering the recovery room. Serum sodium was then 130 mEq/L. The patient's pupils were noted to be briskly reactive to flashlight. His blood pressure at this time was 110/60, no different from preoperative status. Ophthalmic examination showed visual acuity of counting fingers at 1 foot in both eyes. Eye movements were full and conjugate. Both pupils were directly reactive. The media was clear and the optic nerveheads in both eyes were flat, with unremarkable posterior poles. Normal saline was again administered intravenously. The patient remained oriented and, except for some nausea, remained medically stable. Upon discharge from recovery he noted his vision was improving. A serum sodium drawn 4 h after return to the ward was 134 mEq/L. Eye examination at the bedside the following morning showed visual acuity at near of 20/50/ 20/70 (with a +3 sphere lens). Cataracts were judged accountable for the decreased near vision. The rest of his examination was unchanged from the night before. The patient was examined again 2 weeks later and had distance visual acuity of 20/25, 20/20 with his own glasses. Goldmann perimetry was ~ormal and his pupils were briskly reactive to hght. The rest of his eye examination was unremarkable. Case 2 A 75-year-old male underwent a TURP under general anesthesia for benign prostatic hypertr~ phy. The patient was aphakic. His preoperative laboratory evaluation was essentially 273 Vision Loss After TURP within normal limits, including a serum sodium of 133 mEq/L (normal 135-145 mEq/L). Surgery proceeded uneventfully with glycine irrigation of the bladder to facilitate visualization and concluded after 1 h with no episodes of hypotension or hypertension. While in the recovery area, the patient became nauseated. A serum sodium performed at this time was 117 mEqlL, and blood pressure was 110/60. The patient complained that he was blind. This complaint lasted for more than an hour, despite intravenous infusion of 3% sodium chloride solution and an elevation of the serum sodium to 125 mEq/L. When examined at the bedside 2 h after first complaining of blindness, the patient's vision with his glasses varied from 20/30 to 20/400 OU. Pupillary reactions and fundoscopy were normal. His confrontation visual fields appeared constricted bilaterally. The serum sodium was approximately 129 mEq/L. Three hours after the initial complaint the patient noted his vision was much improved (serum sodium stable at 129 mEqlL). Case 3 A 76-year-old male underwent transurethral resection of the prostate under spinal anesthesia for urinary retention. He was a diabetic controlled with oral medication. Preoperative electrolytes were within normal limits, including a serum sodium of 137 mEqlL. One hour into the resection, which was done with the aid of 1.5% glycine irrigation, the patient complained of some subcostal discomfort, numbness of his mouth, and loss of vision bilaterally. He was alert and oriented. Serum sodium had been 122 mEq/.L an? serum glucose ha? been 125 mEqlL 15 mm prIor to the onset of his complaints. His blood pressure was 160/80, unchanged from his preoperative and intraoperative measurements. Intravenous furosemide (10 mg) was administered and surgery was completed rapidly. In the recovery a~ea, 25 min after the initial complaint, serum sodIUm was 114 mEqlL. The patient remained alert and responsive. After receiving 1 U of packed red blood cells, the patient reported he could count fingers at 12 inches. One hour after the onset of blindness, SOO cc of 3% sodium chloride solution was administered intravenously. Upon discharge from the recovery area 3. ~ after termination of surgery, the patient's vIsion had reverted to "normal" and his serum sodium was 126 mEq/L. A postoperative electrocardiogram was unremarkable. Discussion An early case report of TURP syndrome stressed the association of symptoms with the 274 occurrence of hyponatremia during irrigation of the bladder with Cytal, a solution of sorbitol and mannitol with no electrolytes added.! Congestive heart failure, convulsions, or death occurred in five patients, all of whom demonstrated decreased serum sodium and hypervolemic state. In these patients, the serum sodium reduction coincided with the rise in serum Cytal level. Glycine in a 1.5% solution in water is also a nonelectrolyte solution with optical properties similar to Cytal. It is usually used for irrigation of the bladder during transurethral resection of the prostate because it is less expensive than Cytal. The TURP syndrome has been reported with its use also. Transient blindness has only been reported as a complication of prostate sur· gery when glycine irrigation of the bladder has been performed.2- 6 Cerebral edema resulting in cortical blindness was implicated in three cases of transient blindness occurring after transurethral resection of the prostate during which large amounts of glycine solution were irrigated through the bladder. 2•3 One patient lost his vision 6 h after TURP under spinal anesthesia and suffered a grand mal seizure. His serum sodium at this time was 107 mEqlL. After treatment with fluid restriction and intravenous hypertonic saline, the vision recovered over several hours. The s~cond patient complained of blindness during hIS surgery. After surgery was completed, his serum ~odium was 106 mEqlL. After his hyponatremia was corrected, his vision recovered within. 5 h. The.pupil reactions and fundoscopy and VIsual acuity were not recorded in these case reports. The third patient reported blindness ?uring his surgery, but pupil reactions and fun~! .were reported as normal. Without any speCIfic treatment, with an initial serum sodium of 110 mEqlL, the patient recovered his vision completely over 2 h. The authors reporting the third case. suggested that perhaps segmental vasc~.t1ardisease of the occipital cortex made this portion of the brain more likely to develop problems from hyponatremia.3 A c~s~ of b~dness reported by Wong in 1984 was slmllar, With the exception that the pupils reacted sluggishly to light in the presence of a normal fundus exam.4 In addition, the patient reported paresthesias of his jaws and shoulders. Serum sodium was 122 mEqlL at this time. This patient's vision recovered totally within 24 h after surgery. Five additional cases of visual loss during tr~nsurethral resection of the prostate under spmal anesthesia associated with intraoperativ~ hypo~atremia were reported in the anestheslol~gy hterature in 1982.~ All patients recovered VISIon, from light perception only in Journal of Clinical Neuro-ophthaImology four, to a normal level 4-48 h after the initial loss. The authors felt that the unreactive pupils and paresthesias occurring in one of their patients were due to some other problem than occipital lobe edema. The other four patients reported did not have pupillary examination mentioned. The authors postulated (as did Wong) that glycine, when it reaches higher levels in the serum due to absorption of irrigation fluid through surgically opened venous channels, may act as an inhibitory transmitter in the central nervous system. Although these authors postulated that retinal function must have been compromised to account for one of their patients having fixed pupils during visual loss, most case reports (as does ours) stress the normality of the pupil reflexes. Sluggish pupil reactions occurring with paresthesias and nausea could represent brain stem dysfunction in addition to occipital cortex depression. Glycine acts as an inhibitory neurotransmitter in the spinal cord and brain stem and is normally present in small levels in the cortex as well. 7 Furthermore, elevation of serum glycine has been demonstrated to cause nausea, headache, and vomiting.8 The only study of the effects of high serum glycine on visual system function was reported in 1984 when dogs underwent visual evoked potential testing following intravenous infusion of glycine.9 The evoked potentials became markedly diminished. No pupillary or retinal examination or retinal electrophysiology was performed on the animal subjects. The authors made no conclusion as to whether the optic nerves or occipital cortex were affected. We were unable to find a case of TURP syndrome, with or without blindness, unless serum sodium was below normal. However, the intraoperative serum sodium is not routinely checked if the patient is asymptomatic. Since loss or recovery of vision does not seem to linearly follow restoration of serum sodium to normal, as noted in our cases and in the report by Defalque and Miller,3 the mechanism of visualloss may be a function both of CNS toxicity from glycine and hyponatremia resulting in cerebral edema. Although cerebral edema could result from hyponatremia, none of our patients had signs or symptoms of intracranial pressure elevation. The few other case reports including eye examinations noted no fundus abnormalities such as papilledema. The association of hyponatremia with vision loss may possibly be fortuitous or it might be a result of the high absorption of glycine solution. However, glycine absorption is not always followed by hyponatremia. In Zucker and Bull's series of 17 patients undergoing transurethral resection of the pros- December 1985 Kay et al. tate, only two patients had hyponatremia result when serum glycine levels were elevated at the end of the case. to Elevated serum glycine levels and hyponatremia may be independently responsible for different manifestations of the TURP syndrome. Some reports have suggested that systemic glycine conversion to ammonia might account for the occurrence of the TURP syndrome. l1 ,12 However, those cases were different clinically from our and other reports of transient blindness. Hyperammonemia resulted in delayed awakening from general anesthesia for up to 12 h or progression to coma after surgery was completed. None of these patients had visual symptoms when alert. They regained alertness when ammonia levels reverted to normal. Since serum glycine levels are not routinely measured during prostatic surgery, a reasonable management choice to avoid such visual loss and other neurological sequelae would be to regularly check the serum sodium level and maintain it as close as possible to normal. Careful monitoring of the volume of glycine solution infused is indicated. If the ophthalmologist is confronted with a patient complaining of blindness after undergoing transurethral resection of the prostate, the first step to take would be to check the serum sodium. Fortunately, none of the cases reported has resulted in permanent blindness and this can be used to reassure the concerned patient and surgeon. References 1. Norris, H. T., Aasheim, G. M., Sherrard, D. J., and Tremann, J. A.: Symptomatology, pathophysiology and treatment of the transurethral resection of the prostate syndrome. Br. J. Urol. 45: 420-427, 1973. 2. Appelt, G. L., Benson, G. 5., and Corriere, J. N.: Transient blindness. Urology 13: 402-404, 1979. 3. Defalque, R. J., and Miller, D. W.: Visual disturbances during transurethral resection of the prostate. Can. Anaesth. Soc. J. 22: 620-621, 1975. 4. Wong, K. c.: Transurethral resection of the prostate: Anesthetic implications. In: Review course lectures. Cleveland: International Anesthesia Research Society, 1984: 191-197. 5. Ovassapian, A., Joshi, C. W., and Brunner, E. A.: Visual disturbances: An unusual symptom of transurethral prostatic resection reaction. Anesthesiology 57: 332-334, 1982. 6. Peters, K. R., Murr, J., and Wingard, D. W.: Intraocular pressure after transurethral prostatic surgery. Anesthesiology 55: 327-329, 1981. 7. Aprison, M. H., and Daly, E. c.: Biochemical aspects of transmission at inhibitory synapses: The role of glycine. In: Agranoff, B. W., and Aprison, M. H., eds. Advances in Neurochemistry, Vol. 3. New York: Plenum Press, 1978: 203-294. 275 Vision Loss After TURP 8. Doolan, P. D., Harper, H., Hutchin, M. E., and Alpen, E. L.: The renal tubular response to amino acid loading. ,. Clin. lill'est. 35: 888-896, 1956. 9. Wang, J. M., Creel, D., Clark, W., and Wong, K. c.: Effects of glycine infusion on homodynamic responses and visual evoked potentials in dogs. Al/t'stltes;o!oS!I 61, A348, 1984. 10. Zucker, J. R., and Bull, A. P.: Independent plasma levels of sodium and glycine during transurethral resection of the prostate. Can. AI/aestil. Soc. ,. 31: 307-313,1984. 11. Roesch, R. P., Stoelting, R. K., Lingeman, J. E., "7(, Kahnoski, R. J., Backes, D. J., and Gephardt, S. A: Ammonia toxicity resulting from glycine absorption during transurethral resection of the prostate. Anesthesiology 58: 577-579, 1983. 12. Hoekstra, P. T., Kahnoski, R. L McCamish, M. A, Bergen, W., and Heetderks, D. R.: Transurethral prostatic resection syndrome-A new perspective: Encephalopathy with associated hyperammonemia. f. Ural. 130: 704-707, 1983. 13. Thomas, D., and Hales, P.: Overhydration during transurethral resection of the prostate using glycine as an irrigation solution. Anesth. Inlens. Care 12: 366-369, 1984. Journal of Clinical Neuro-ophthalmology |
