Isolated Unilateral Orbital Compression Syndrome in A 19-Year-Old Male With Homozygous Sickle Cell Disease

This study aimed to report a rare case of a rapidly progressive isolated unilateral orbital compression syndrome in a male with homozygous sickle cell disease, who presented with proptosis and optic nerve dysfunction. He neither had long bone pain crisis nor fever at the time of presentation that was managed surgically to preserve vision. Rapidly progressive left orbital swelling is observed in a 19-year-old homozygous sickle cell disease patient associated with severe pain, headache, and impaired vision. Computed tomography of the orbit confirmed the presence of a unilateral large superior sub-periosteal cystic mass. Surgical exploration via anterior orbitotomy revealed a large sub-periosteal hematoma occupying the superior orbit which was evacuated. The patient completely recovered within 14 days post-surgery and regained his vision. Orbital involvement in sickle cell disease is rare, however, it can occur as a sequela of vaso-occlusive crisis and bone marrow infarctions leading to bleeding and sub-periosteal hematomas in the orbit. Prompt diagnosis and management of orbital compression syndrome are crucial to prevent permanent optic nerve damage. Hence, cautious evaluation and close monitoring are important, especially in cases where surgical evacuation is indicated for quick recovery and prevention of visual loss.


Introduction
Sickle cell disease is a group of inherited monogenic hematological disorders that affect the red blood cells [1,2]. It is caused by the substitution of the amino acid valine for glutamic acid in the β-globin chain [3]. This mutation in gene coding creates inflexible sticky crescent-shaped RBCs; incapable to transverse the capillary bed, causing organs' ischemia-reperfusion injuries [4].
Sickle cell disease can be divided into five subtypes depending on the inherited genes from both parents [3]. The most common subtype worldwide is the hemoglobin SS, followed by hemoglobin SC disease and hemoglobin Sβ thalassemia. Hemoglobin SD and hemoglobin SE are the other subtypes that are less noticed [5].
Vaso-occlusive process in sickle cell disease comprises all the different systems of the body. People with sickle cell disease mainly experience anemia, bone pain, acute chest syndrome, ischemic stroke syndrome, and sudden death. Others can also suffer from chronic restrictive lung disease, pulmonary hypertension, dysrhythmias, hemorrhagic stroke, venous sinus thrombosis, silent cerebral infarction, cognitive impairment, avascular necrosis, leg ulceration, renal failure, nocturnal enuresis, priapism, cholelithiasis, or mesenteric vaso-occlusion [6].
Moreover, the eye also shows different sickling signs including corkscrew vessels and comma-shaped capillary segment involving the conjunctiva, iris ischemic atrophy, and cataract [7]. The posterior segment can exhibit non-proliferative changes such as tortuous veins, silver-wiring of arterioles, salmon patches, black sunbursts, macular depression sign, peripheral retinal holes, or angioid streaks, in addition to proliferative changes including peripheral arteriolar occlusion, arteriovenous anastomoses, sea-fan shaped neovascularization, auto-infarcted greyish fibrovascular lesions, vitreous hemorrhage, and retinal detachments either rhegmatogenous or tractional [8].
Although orbital involvement in sickle cell disease is rare, when it does occur, it could even be complicated by orbital compression syndrome; this develops when infarction of the microvasculature in the sphenoid bone marrow leads to inflammation and necrosis, which in turn cause subperiosteal hemorrhage [9]. This is either managed medically or surgically whenever there is optic nerve dysfunction or large hematomas [10]. In fact, 16 case reports exist in the literature describing orbital involvement in the last three decades and only four of them have been managed surgically [10,11]. In this study, we report a unilateral orbital compression syndrome in a homozygous sickle cell disease a 19-year-old man, in whom proptosis and eye pain were the only presenting symptoms. A 19-year-old man with sickle cell disease, cashier by profession, and a hookah smoker presented to the ophthalmic emergency department on June 25, 2021, with a one-day history of frontal headache followed by sudden left eye pain associated with increasing orbital swelling and decreasing vision. The patient denied any history of fever or bone pain at or prior to presentation. However, he reported a history of sudden hearing loss six years ago for which a cochlear implant surgery was performed.

Case Presentation
The patient was in severe pain but remained alert. His body temperature was 36.2°C, blood pressure was 126/90, heart rate was 88/min, and oxygen saturation was 98% on room air. Ocular examination showed a vision of 6/6 in the right eye, while examination of the left eye showed a vision of 1.5 m counting fingers, non-axial proptosis with a dystopia of 8 mm to the inferolateral side, vertical palpebral height was 16 mm, with periocular fullness, tenderness on palpation and resistance to retropulsion (Figures 1, 2). Moreover, extraocular muscles were restricted in all gazes with a 3-mm lagophthalmos ( Figure 3).   Although posterior segment and optic disc examination appeared completely normal, the pupil assessment revealed relative afferent pupillary light reflex defect grade 3 with positive color desaturation.
Laboratory results showed white blood cell count was 3.78 x 10 9 /L (normal range: 3.6-9.6), hemoglobin level was 10.   The patient was started on intravenous methylprednisolone 1 g once daily along with intravenous Coamoxiclav 1.2 g every 8 h. The decision was made to surgically intervene on the day of admission, so the patient was immediately prepped for surgical exploration under general anesthesia.
A sub-brow approach was performed through a 2-cm incision. When periosteum was incised, a large subperiosteal hematoma with blood clots was seen and entirely evacuated ( Figure 6). Immediate improvement of proptosis was noticed on the table and the globe was back to normal position (Figure 7). Hemostasis was achieved and the incision was sutured in two layers with interrupted 6-0 vicryl sutures. The evacuated material was sent for histopathology and confirmed blood products.  The patient had immediate resolution of proptosis, pain and visual acuity improved to 6/18 on the first post-operative day with mild lid edema. He regained full range of extraocular movements in all directions of gaze with no lagophthalmos. The patient received a total of three doses of daily intravenous methylprednisolone and was discharged home on oral antibiotics on the fourth post-operative day. He was advised of a followup visit to the outpatient department after one week. Two weeks later, the patient had a full recovery with the restoration of visual acuity to 6/6 in the affected eye (Figures 8-10).

Discussion
Orbital compression syndrome rarely presents as a complication of sickle cell disease. To the best of our knowledge, 16 previous case reports exist describing orbital compression syndrome in the last three decades. All previous articles reported having either acute pain crisis preceding the orbital compression event, documented fever, or a rise of white blood cells on admission (Tables 1-3) [10][11][12][13][14][15][16][17][18][19].

Case report
Curran et al. [    Unlike the previous case reports, detailed history taking, vital signs checking, and complete blood count workup all turned to be unremarkable, and proptosis and eye pain were the only presenting symptoms. Although the patient and his parents denied any previous significant sickling attacks, the necessity of undergoing both ears cochlear implantation following sensorineural hearing loss six years prior to the presentation can be explained by having a sickle cell crisis at that time.
Moreover, only four of the previously reported cases have required surgical intervention, while the rest improved with conservative management. Our case sets a good example of early recognition and prompt surgical intervention which proved crucial in regaining vision in cases with optic nerve dysfunction.

Conclusions
Orbital compression syndrome, although rare, can occur in patients with sickle cell disease. As shown in our case, prompt surgical management is crucial for successful resolution and recovery of vision, especially in those cases complicated by optic nerve dysfunction due to large sub-periosteal hematoma. We suggest that future studies should focus on comparing different sickle cell disease variants and their association with orbital compression syndrome occurs.

Additional Information Disclosures
Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work.