CASE REPORT
Central Serous Chorioretinopathy Following Hypobaric Chamber Exposure William W. Ide IDE WW. Central serous chorioretinopathy following hypobaric eye (OS). He had previously completed an altitude chamchamber exposure. Aviat Space Environ Med 2014; 85:1053–5. ber exercise to 20,000 ft (6096 m) for a total of 14 min. Background: Hypobaric hypoxic exposures are associated with a Throughout the course of his simulated flight he was number of risks, most notably decompression sickness and various ophable to successfully equalize his ears by using yawning thalmologic disorders, including high altitude retinopathy. Central serous chorioretinopathy (CSCR) is an idiopathic condition that typically and Valsalva maneuvers. He denied any ear, sinus, or affects young males and is associated with several comorbidities and retro-orbital pain at any point during the exercise, which medications; however, an association with hypoxia or high altitude has he completed uneventfully. The patient reported he was not been identified. We present a case of CSCR in an aviator following a asymptomatic until roughly 1 h after exiting the altitude simulated flight in a hypobaric chamber. Case Report: A 30-yr-old male U.S. Navy pilot presented with complaints of painless unilateral scochamber, at which point he noticed a blue ring in his OS toma, micropsia, and blurred vision 1 h after completing a training exerDelivered by Publishing Technology to: Umea University Library when he closed his eyes and an orange ring in his OS cise in a hypobaric chamber. A dilated fundoscopic examination, macular IP: 130.239.20.174 On: Wed, 01 Apr 2015 19:55:16 when his eyes were open. The patient denied symptoms optical coherence tomography, and intravenous fluorescein angiography Copyright: Aerospace Medical Association in the right eye (OD), eye pain, fatigue, headache, neck confirmed a diagnosis of CSCR. The patient was restricted from flying duty and observed for a period of 1 mo, after which point his symptoms pain, vertigo, or nausea and exhibited no mental status spontaneously resolved and flight status was restored. Discussion: Comchanges. He reported his symptoms to the Aviation plaints of visual symptoms immediately following hypobaric exposure Survival Training Center staff who then contacted the should primarily trigger suspicion of decompression sickness; however, on-call Dive Medical Officer. The Dive Medical Officer once ruled out, patients should be referred to an eye specialist for detailed ocular examination. This case suggests a possible link between determined that the patient’s symptoms were not conCSCR and hypobaric hypoxia as a topic of further investigation. sistent with a presentation of DCS and, in consultation Keywords: CSCR, decompression, hypoxia, altitude, retinopathy, eye, with the flight surgeon, referred the patient to the eye visual changes, optical coherence tomography.
H
YPOBARIC CHAMBERS are used by the U.S. Navy to prepare aviators for operation in a high altitude, hypoxic environment by familiarization with the symptoms of hypoxia and its required emergency procedures once identified. There are a number of medical conditions considered to be risks of such exposure, most notably altitude decompression sickness (DCS) and sinus barotraumas (8). Additionally, ophthalmic conditions such as central vein occlusion and optic neuropathy have been reported (3,6,9). We describe a case of an aviator presenting with acute unilateral scotoma and metamorphopsia immediately following a simulated flight using a hypobaric chamber. Central serous chorioretinopathy (CSCR) is an idiopathic disorder characterized by serous neurosensory retinal detachment in the macular region (7). Although the pathogenesis of CSCR is not entirely understood, risk factors include type A personality, emotional stress, alcohol use, diabetes, pregnancy, hypertension, and medications such as corticosteroids, antibiotics, and antihistamines (2). There is no established association between CSCR and decompression or hypoxia. CASE REPORT A 30-yr-old male active duty U.S. Navy pilot presented with complaints of visual disturbance in his left
clinic for further evaluation. The patient’s past medical history, which was significant for successful photorefractive keratotomy 8 yr prior, was reviewed. He was normotensive, did not use tobacco, and drank socially. He took no medications chronically. A review of systems was unremarkable. An Amsler grid test was administered by the consulting optometrist and the results were within normal limits OD. The patient reported a wavy, orange-colored circle with Amsler grid OS. Intraocular pressure was measured at 17 mmHg OD and 19 mmHg OS. The anterior chamber, sclera, pupillary reactivity, and extraocular motility were normal. The patient’s uncorrected distance visual acuity was 20/20 in both eyes (OU), 20/30-1 (OD), and 20/20-1(OS). The patient’s medical record indicated a baseline uncorrected distance visual acuity of 20/25 OU. A fundoscopic examination performed after administration of cycloplegic drops revealed normal macular thickness and contour OD, confirmed by macular
From the Naval Health Clinic Patuxent River, Patuxent River, MD. This manuscript was received for review in May 2014. It was accepted for publication in July 2014. Address correspondence and reprint requests to: William W. Ide, 47149 Buse Rd., Patuxent River, MD 20670; [email protected]. mil. Reprint & Copyright © by the Aerospace Medical Association, Alexandria, VA. DOI: 10.3357/ASEM.4073.2014
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CSCR AFTER HYPOBARIC EXPOSURE—IDE optical coherence tomography (OCT) (Fig. 1) with an elevated macula OS located inferior/temporal to the fovea, which was also demonstrated by OCT (Fig. 2). Optic discs and vitreous humor were unremarkable. A color vision and visual field test, including the Glaucoma Hemifield, were within normal limits OU. A diagnosis of CSCR OS was made; the patient was counseled and referred to Ophthalmology and restricted from duty involving flying. The patient was evaluated by an ophthalmologist the following day and underwent repeat OCT and fundoscopic examination, which confirmed the diagnosis. He was observed for a period of 1 mo and on return to the ophthalmology clinic reported complete resolution of symptoms. Corrected visual acuity was 20/20 OU. Macular OCT, intravenous fluorescein angiography, and dilated fundoscopic examination demonstrated complete resolution of CSCR with a small pigment epithelial detachment OS (Fig. 3). An Amsler grid test was repeated and findings were normal. The patient was submitted for a waiver of aeromedical standards and cleared to return to flying. Delivered by Publishing Technology to: Umea University Library IP: 130.239.20.174 On: Wed, 01 Apr 2015 19:55:16 DISCUSSION Copyright: Aerospace Medical Association Central serous chorioretinopathy typically affects individuals ages 20-50 yr, with a 6 to 10 fold higher
Fig. 2. Optical coherence tomography of the left eye showing accumulation of subretinal fluid at the time of initial presentation.
Fig. 1. Optical coherence tomography of the normal right eye at time of initial presentation.
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incidence in men than in women (5). The condition is characterized by accumulation of subneural retinal fluid in the macular region which originates from the choroid (7). Though the cause of the retinal pigment epithelium leak is not fully understood, a number of medications and systemic conditions have been identified as risk factors (2). There is no current evidence to suggest a causal relationship between CSCR and prior keratorefractive surgery (4). The most common presenting symptoms are unilateral blurred vision, micropsia, metamorphopsia, and scotoma. Changes in visual acuity are variable, but the readings average 20/30 (7). The diagnosis of CSCR is clinical, but may be confirmed by intravenous fluorescein angiography, fundus autofluorescence, and OCT. The visual prognosis of CSCR is typically favorable and, in most cases, symptoms resolve spontaneously within several months. Accordingly, the recommended treatment is observation and discontinuance of medications known to be causal (7). In patients who have persistent or recurrent symptoms, or who require restored visual acuity to return to work, treatment options include laser photocoagulation or photodynamic therapy (5). In the setting of recent high altitude exposure, reports of visual changes should primarily trigger suspicion of altitude DCS. In this case, DCS may have been a
Aviation, Space, and Environmental Medicine x Vol. 85, No. 10 x October 2014
CSCR AFTER HYPOBARIC EXPOSURE—IDE In addition to DCS, ophthalmological conditions, including high-altitude retinopathy, retinal hemorrhage, optic neuropathy, and central retinal vein occlusion, have been reported following hypobaric chamber and high altitude exposures (3,9). One study noted an incidence of retinal vessel leakage in 50% of participants exposed to altitude. In contrast to the typical presentation of CSCR, which unilaterally affects the macula, altitude retinopathy is usually bilateral, occurs in a temporalinferior pattern, and reverses completely after descent. Of note, both CSCR and altitude retinopathy are pathogenically linked to abnormal choroidal circulation. In the latter condition, the effect is proposed to be secondary to a hypoxic retinal capillary bed (10). The author suggests that a potential link between hypoxia and CSCR should prompt further investigation. Furthermore, in the setting of recent hypobaric exposure, any aircrew member complaining of unilateral visual symptoms should undergo a detailed ocular examination provided this does not delay hyperbaric oxygen treatment if DCS is suspected. Delivered by Publishing Technology to: Umea University Library ACKNOWLEDGMENTS IP: 130.239.20.174 On: Wed, 01 2015 19:55:16 The Apr author wishes to thank Christina M. Ide, PA-C, Drs. Jenine Copyright: Aerospace Medical Association Melko, Frederick McDonald, Amanda Jimenez, and Chris DeAngelis for all your guidance and support. Author and affiliation: William W. Ide, M.D., B.S., Naval Health Clinic Patuxent River, Naval Air Station Patuxent River, Patuxent River, MD.
Fig. 3. Optical coherence tomography of the left eye 1 mo after presentation showing resolution of central serous chorioretinopathy with a small pigment epithelial detachment.
consideration in the absence of an identifiable lesion which correlated with his reported visual changes. The majority of altitude-induced DCS cases have been reported at altitudes above 25,000 ft (7620 m), although any exposure above 18,000 ft (5486 m) is considered to be a risk factor. Additional factors such as duration of exposure and previous exposures to altitude will increase the likelihood of developing DCS (1). While 65– 80% of altitude DCS cases present with pain, typically in large joints, visual symptoms such as scotoma, diplopia, blurred vision, and loss of vision are reported manifestations of neurological DCS, for which emergent hyperbaric oxygen therapy is indicated (9). In this case, the patient reported unilateral symptoms unaccompanied by additional central or peripheral nervous system manifestations that did not arise until 1 h after the exposure. Although in rare cases symptoms have not been reported until hours after descent, the majority of cases occur during or shortly after descent (1).
REFE.RENCES 1. Davis JR, Johnson R, Stepanek J, Fogarty JA, eds. Fundamentals of aerospace medicine, 4th ed. Philadelphia: Lippincott Williams & Wilkins; 2008:51–69. 2. Haimovici R, Koh S, Gagnon DR, Lehrfeld T, Wellik S. Central serous chorioretinopathy case-control study group. Risk factors for central serous chorioretinopathy: a case-control study. Ophthalmology 2004; 111:244–9. 3. Lee KM, Yoo SJ, Woo SJ. Central retinal vein occlusion following hypobaric chamber exposure. Aviat Space Environ Med 2013; 84:986–9. 4. Moshirfar M, Hsu M, Schulman J, Armenia J, Sikder S, Hartnett ME. The incidence of central serous chorioretinopathy after photorefractive keratectomy and laser in situ keratomileusis. J Ophthalmol 2012; 2012:904215. 5. Pare JR, Guo Y, Schechter-Perkins EM. The evaluation of acute vision loss: central serous chorioretinopathy. Am J Emerg Med 2014; 32:396.e3-4. 6. Pokroy R, Barenboim E, Carter D, Assa A, Alhalel A. Unilateral optic disc swelling in a fighter pilot. Aviat Space Environ Med 2009; 80:894–7. 7. Pulido JS, Kitzmann AS, Wirostko WJ. Central serous chorioretinopathy. In: Yanoff M, Duker JS, eds. Ophthalmology, 4th ed. Philadelphia: Saunders; 2014:605–9. 8. Rainford DJ, Gradwell D, eds. Ernsting’s aviation medicine, 4th ed. London: Hodder Arnold; 2006:129–36. 9. Steigleman A, Butler F, Chhoeu A, O'Malley T, Bower E, Giebner S. Optic neuropathy following an altitude exposure. Aviat Space Environ Med 2003; 74:985–9. 10. Willmann G, Fischer MD, Schatz A, Schommer K, Gekeler F. Retinal vessel leakage at high altitude [letter]. JAMA 2013; 309:2210–2.
Aviation, Space, and Environmental Medicine x Vol. 85, No. 10 x October 2014
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Central Serous Chorioretinopathy Following Hypobaric Chamber Exposure William W. Ide IDE WW. Central serous chorioretinopathy following hypobaric eye (OS). He had previously completed an altitude chamchamber exposure. Aviat Space Environ Med 2014; 85:1053–5. ber exercise to 20,000 ft (6096 m) for a total of 14 min. Background: Hypobaric hypoxic exposures are associated with a Throughout the course of his simulated flight he was number of risks, most notably decompression sickness and various ophable to successfully equalize his ears by using yawning thalmologic disorders, including high altitude retinopathy. Central serous chorioretinopathy (CSCR) is an idiopathic condition that typically and Valsalva maneuvers. He denied any ear, sinus, or affects young males and is associated with several comorbidities and retro-orbital pain at any point during the exercise, which medications; however, an association with hypoxia or high altitude has he completed uneventfully. The patient reported he was not been identified. We present a case of CSCR in an aviator following a asymptomatic until roughly 1 h after exiting the altitude simulated flight in a hypobaric chamber. Case Report: A 30-yr-old male U.S. Navy pilot presented with complaints of painless unilateral scochamber, at which point he noticed a blue ring in his OS toma, micropsia, and blurred vision 1 h after completing a training exerDelivered by Publishing Technology to: Umea University Library when he closed his eyes and an orange ring in his OS cise in a hypobaric chamber. A dilated fundoscopic examination, macular IP: 130.239.20.174 On: Wed, 01 Apr 2015 19:55:16 when his eyes were open. The patient denied symptoms optical coherence tomography, and intravenous fluorescein angiography Copyright: Aerospace Medical Association in the right eye (OD), eye pain, fatigue, headache, neck confirmed a diagnosis of CSCR. The patient was restricted from flying duty and observed for a period of 1 mo, after which point his symptoms pain, vertigo, or nausea and exhibited no mental status spontaneously resolved and flight status was restored. Discussion: Comchanges. He reported his symptoms to the Aviation plaints of visual symptoms immediately following hypobaric exposure Survival Training Center staff who then contacted the should primarily trigger suspicion of decompression sickness; however, on-call Dive Medical Officer. The Dive Medical Officer once ruled out, patients should be referred to an eye specialist for detailed ocular examination. This case suggests a possible link between determined that the patient’s symptoms were not conCSCR and hypobaric hypoxia as a topic of further investigation. sistent with a presentation of DCS and, in consultation Keywords: CSCR, decompression, hypoxia, altitude, retinopathy, eye, with the flight surgeon, referred the patient to the eye visual changes, optical coherence tomography.
H
YPOBARIC CHAMBERS are used by the U.S. Navy to prepare aviators for operation in a high altitude, hypoxic environment by familiarization with the symptoms of hypoxia and its required emergency procedures once identified. There are a number of medical conditions considered to be risks of such exposure, most notably altitude decompression sickness (DCS) and sinus barotraumas (8). Additionally, ophthalmic conditions such as central vein occlusion and optic neuropathy have been reported (3,6,9). We describe a case of an aviator presenting with acute unilateral scotoma and metamorphopsia immediately following a simulated flight using a hypobaric chamber. Central serous chorioretinopathy (CSCR) is an idiopathic disorder characterized by serous neurosensory retinal detachment in the macular region (7). Although the pathogenesis of CSCR is not entirely understood, risk factors include type A personality, emotional stress, alcohol use, diabetes, pregnancy, hypertension, and medications such as corticosteroids, antibiotics, and antihistamines (2). There is no established association between CSCR and decompression or hypoxia. CASE REPORT A 30-yr-old male active duty U.S. Navy pilot presented with complaints of visual disturbance in his left
clinic for further evaluation. The patient’s past medical history, which was significant for successful photorefractive keratotomy 8 yr prior, was reviewed. He was normotensive, did not use tobacco, and drank socially. He took no medications chronically. A review of systems was unremarkable. An Amsler grid test was administered by the consulting optometrist and the results were within normal limits OD. The patient reported a wavy, orange-colored circle with Amsler grid OS. Intraocular pressure was measured at 17 mmHg OD and 19 mmHg OS. The anterior chamber, sclera, pupillary reactivity, and extraocular motility were normal. The patient’s uncorrected distance visual acuity was 20/20 in both eyes (OU), 20/30-1 (OD), and 20/20-1(OS). The patient’s medical record indicated a baseline uncorrected distance visual acuity of 20/25 OU. A fundoscopic examination performed after administration of cycloplegic drops revealed normal macular thickness and contour OD, confirmed by macular
From the Naval Health Clinic Patuxent River, Patuxent River, MD. This manuscript was received for review in May 2014. It was accepted for publication in July 2014. Address correspondence and reprint requests to: William W. Ide, 47149 Buse Rd., Patuxent River, MD 20670; [email protected]. mil. Reprint & Copyright © by the Aerospace Medical Association, Alexandria, VA. DOI: 10.3357/ASEM.4073.2014
Aviation, Space, and Environmental Medicine x Vol. 85, No. 10 x October 2014
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CSCR AFTER HYPOBARIC EXPOSURE—IDE optical coherence tomography (OCT) (Fig. 1) with an elevated macula OS located inferior/temporal to the fovea, which was also demonstrated by OCT (Fig. 2). Optic discs and vitreous humor were unremarkable. A color vision and visual field test, including the Glaucoma Hemifield, were within normal limits OU. A diagnosis of CSCR OS was made; the patient was counseled and referred to Ophthalmology and restricted from duty involving flying. The patient was evaluated by an ophthalmologist the following day and underwent repeat OCT and fundoscopic examination, which confirmed the diagnosis. He was observed for a period of 1 mo and on return to the ophthalmology clinic reported complete resolution of symptoms. Corrected visual acuity was 20/20 OU. Macular OCT, intravenous fluorescein angiography, and dilated fundoscopic examination demonstrated complete resolution of CSCR with a small pigment epithelial detachment OS (Fig. 3). An Amsler grid test was repeated and findings were normal. The patient was submitted for a waiver of aeromedical standards and cleared to return to flying. Delivered by Publishing Technology to: Umea University Library IP: 130.239.20.174 On: Wed, 01 Apr 2015 19:55:16 DISCUSSION Copyright: Aerospace Medical Association Central serous chorioretinopathy typically affects individuals ages 20-50 yr, with a 6 to 10 fold higher
Fig. 2. Optical coherence tomography of the left eye showing accumulation of subretinal fluid at the time of initial presentation.
Fig. 1. Optical coherence tomography of the normal right eye at time of initial presentation.
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incidence in men than in women (5). The condition is characterized by accumulation of subneural retinal fluid in the macular region which originates from the choroid (7). Though the cause of the retinal pigment epithelium leak is not fully understood, a number of medications and systemic conditions have been identified as risk factors (2). There is no current evidence to suggest a causal relationship between CSCR and prior keratorefractive surgery (4). The most common presenting symptoms are unilateral blurred vision, micropsia, metamorphopsia, and scotoma. Changes in visual acuity are variable, but the readings average 20/30 (7). The diagnosis of CSCR is clinical, but may be confirmed by intravenous fluorescein angiography, fundus autofluorescence, and OCT. The visual prognosis of CSCR is typically favorable and, in most cases, symptoms resolve spontaneously within several months. Accordingly, the recommended treatment is observation and discontinuance of medications known to be causal (7). In patients who have persistent or recurrent symptoms, or who require restored visual acuity to return to work, treatment options include laser photocoagulation or photodynamic therapy (5). In the setting of recent high altitude exposure, reports of visual changes should primarily trigger suspicion of altitude DCS. In this case, DCS may have been a
Aviation, Space, and Environmental Medicine x Vol. 85, No. 10 x October 2014
CSCR AFTER HYPOBARIC EXPOSURE—IDE In addition to DCS, ophthalmological conditions, including high-altitude retinopathy, retinal hemorrhage, optic neuropathy, and central retinal vein occlusion, have been reported following hypobaric chamber and high altitude exposures (3,9). One study noted an incidence of retinal vessel leakage in 50% of participants exposed to altitude. In contrast to the typical presentation of CSCR, which unilaterally affects the macula, altitude retinopathy is usually bilateral, occurs in a temporalinferior pattern, and reverses completely after descent. Of note, both CSCR and altitude retinopathy are pathogenically linked to abnormal choroidal circulation. In the latter condition, the effect is proposed to be secondary to a hypoxic retinal capillary bed (10). The author suggests that a potential link between hypoxia and CSCR should prompt further investigation. Furthermore, in the setting of recent hypobaric exposure, any aircrew member complaining of unilateral visual symptoms should undergo a detailed ocular examination provided this does not delay hyperbaric oxygen treatment if DCS is suspected. Delivered by Publishing Technology to: Umea University Library ACKNOWLEDGMENTS IP: 130.239.20.174 On: Wed, 01 2015 19:55:16 The Apr author wishes to thank Christina M. Ide, PA-C, Drs. Jenine Copyright: Aerospace Medical Association Melko, Frederick McDonald, Amanda Jimenez, and Chris DeAngelis for all your guidance and support. Author and affiliation: William W. Ide, M.D., B.S., Naval Health Clinic Patuxent River, Naval Air Station Patuxent River, Patuxent River, MD.
Fig. 3. Optical coherence tomography of the left eye 1 mo after presentation showing resolution of central serous chorioretinopathy with a small pigment epithelial detachment.
consideration in the absence of an identifiable lesion which correlated with his reported visual changes. The majority of altitude-induced DCS cases have been reported at altitudes above 25,000 ft (7620 m), although any exposure above 18,000 ft (5486 m) is considered to be a risk factor. Additional factors such as duration of exposure and previous exposures to altitude will increase the likelihood of developing DCS (1). While 65– 80% of altitude DCS cases present with pain, typically in large joints, visual symptoms such as scotoma, diplopia, blurred vision, and loss of vision are reported manifestations of neurological DCS, for which emergent hyperbaric oxygen therapy is indicated (9). In this case, the patient reported unilateral symptoms unaccompanied by additional central or peripheral nervous system manifestations that did not arise until 1 h after the exposure. Although in rare cases symptoms have not been reported until hours after descent, the majority of cases occur during or shortly after descent (1).
REFE.RENCES 1. Davis JR, Johnson R, Stepanek J, Fogarty JA, eds. Fundamentals of aerospace medicine, 4th ed. Philadelphia: Lippincott Williams & Wilkins; 2008:51–69. 2. Haimovici R, Koh S, Gagnon DR, Lehrfeld T, Wellik S. Central serous chorioretinopathy case-control study group. Risk factors for central serous chorioretinopathy: a case-control study. Ophthalmology 2004; 111:244–9. 3. Lee KM, Yoo SJ, Woo SJ. Central retinal vein occlusion following hypobaric chamber exposure. Aviat Space Environ Med 2013; 84:986–9. 4. Moshirfar M, Hsu M, Schulman J, Armenia J, Sikder S, Hartnett ME. The incidence of central serous chorioretinopathy after photorefractive keratectomy and laser in situ keratomileusis. J Ophthalmol 2012; 2012:904215. 5. Pare JR, Guo Y, Schechter-Perkins EM. The evaluation of acute vision loss: central serous chorioretinopathy. Am J Emerg Med 2014; 32:396.e3-4. 6. Pokroy R, Barenboim E, Carter D, Assa A, Alhalel A. Unilateral optic disc swelling in a fighter pilot. Aviat Space Environ Med 2009; 80:894–7. 7. Pulido JS, Kitzmann AS, Wirostko WJ. Central serous chorioretinopathy. In: Yanoff M, Duker JS, eds. Ophthalmology, 4th ed. Philadelphia: Saunders; 2014:605–9. 8. Rainford DJ, Gradwell D, eds. Ernsting’s aviation medicine, 4th ed. London: Hodder Arnold; 2006:129–36. 9. Steigleman A, Butler F, Chhoeu A, O'Malley T, Bower E, Giebner S. Optic neuropathy following an altitude exposure. Aviat Space Environ Med 2003; 74:985–9. 10. Willmann G, Fischer MD, Schatz A, Schommer K, Gekeler F. Retinal vessel leakage at high altitude [letter]. JAMA 2013; 309:2210–2.
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