Purpose: We report a case of visual impairment due to circulatory failure in the central retinal artery during blow-out fracture repair.Case summary: A 16-year-old male with no underlying disease was diagnosed with a trapdoor type medial orbital wall blow-out fracture after a motorcycle accident and underwent blow-out fracture repair. During the surgery, his left eye was nearly completely dilated. Postoperatively, the visual acuity in the left eye was hand motion and there was ptosis of the left upper eyelid. Concerned with the possibility of orbital implant compression, computed tomography was performed immediately and a second operation was performed. However, there was no direct compression originating from the intraocular implant or any signs of active bleeding. The following day, optical coherence tomography and fluorescein angiography revealed a cherry-red spot on the central fovea with edema of the inner retinal layer and delayed arterial circulation. Under a diagnosis of incomplete central retinal artery occlusion, the patient was treated with intraocular pressure-lowering eye drops and intravenous mannitol. Despite prompt intervention, the visual acuity of the left eye did not improve beyond 0.04 at the 2-year follow-up. Conclusions When there is visual impairment and pupillary dilation after blow-out fracture repair, we should consider not only compressive factors but also the possibility of central retinal artery occlusion or circulatory failure. In such cases, retinal examinations should be done to assess the retinal blood flow and enable early detection of any complications allowing prompt appropriate intervention.

Background: This study aimed to evaluate the effects of hypercarbia on arterial oxygenation during one-lung ventilation (OLV). Methods: Fifty adult patients undergoing elective video-assisted thoracoscopic lobectomy or pneumonectomy were enrolled. Group I patients (n = 25) were first maintained at normocarbia (PaCO2: 38‒42 mmHg) for 30 min and then at hypercarbia (45‒50 mmHg). In Group II patients (n = 25), PaCO2 was maintained in the reverse order. Arterial oxygen partial pressure (PaO2), respiratory variables, hemodynamic variables, and hemoglobin concentration were compared during normocarbia and hypercarbia. Arterial O2 content and O2 delivery were calculated. Results: PaO2 values during normocarbia and hypercarbia were 66.5 ± 10.6 and 79.7 ± 17.3 mmHg, respectively (mean difference: 13.2 mmHg, 95% CI for difference of means: 17.0 to 9.3, P < 0.001). SaO2 values during normocarbia and hypercarbia were 92.5 ± 4.8% and 94.3 ± 3.1% (P = 0.009), respectively. Static compliance of the lung (33.0 ± 5.4 vs. 30.4 ± 5.3 ml/cmH2O, P < 0.001), arterial O2 content (15.4 ± 1.4 vs. 14.9 ± 1.5 ml/dl, P < 0.001) and O2 delivery (69.9 ± 18.4 vs. 65.1 ± 18.1 ml/min, P < 0.001) were significantly higher during hypercarbia than during normocarbia. Conclusions Hypercarbia increases PaO2 and O2 carrying capacity and improves pulmonary mechanics during OLV, suggesting that it may help manage oxygenation during OLV. Therefore, permissive hypercarbia may be a simple and valuable modality to manage arterial oxygenation during OLV.

Background: This study aimed to evaluate the effects of hypercarbia on arterial oxygenation during one-lung ventilation (OLV). Methods: Fifty adult patients undergoing elective video-assisted thoracoscopic lobectomy or pneumonectomy were enrolled. Group I patients (n = 25) were first maintained at normocarbia (PaCO2: 38‒42 mmHg) for 30 min and then at hypercarbia (45‒50 mmHg). In Group II patients (n = 25), PaCO2 was maintained in the reverse order. Arterial oxygen partial pressure (PaO2), respiratory variables, hemodynamic variables, and hemoglobin concentration were compared during normocarbia and hypercarbia. Arterial O2 content and O2 delivery were calculated. Results: PaO2 values during normocarbia and hypercarbia were 66.5 ± 10.6 and 79.7 ± 17.3 mmHg, respectively (mean difference: 13.2 mmHg, 95% CI for difference of means: 17.0 to 9.3, P < 0.001). SaO2 values during normocarbia and hypercarbia were 92.5 ± 4.8% and 94.3 ± 3.1% (P = 0.009), respectively. Static compliance of the lung (33.0 ± 5.4 vs. 30.4 ± 5.3 ml/cmH2O, P < 0.001), arterial O2 content (15.4 ± 1.4 vs. 14.9 ± 1.5 ml/dl, P < 0.001) and O2 delivery (69.9 ± 18.4 vs. 65.1 ± 18.1 ml/min, P < 0.001) were significantly higher during hypercarbia than during normocarbia. Conclusions Hypercarbia increases PaO2 and O2 carrying capacity and improves pulmonary mechanics during OLV, suggesting that it may help manage oxygenation during OLV. Therefore, permissive hypercarbia may be a simple and valuable modality to manage arterial oxygenation during OLV.

Purpose: We report a case of neuroretinitis combined with external ophthalmoplegia in a patient who developed a cerebral venous sinus thrombosis after administration of a SARS-CoV-2 vaccine.Case summary: A 26-year-old woman who was on oral contraceptives was diagnosed with a cerebral venous sinus thrombosis 1 month after the first injection of a SARS-CoV-2 vaccine (BNT162b2, Pfizer-BioNTech). The levels of factors 8 and 9 were elevated on the blood test. The corrected visual acuities were 0.3 in both eyes. A complete limitation of abduction and esotropia were evident in the left eye. Both eyes exhibited optic disc swelling and hemorrhage and retinal nerve fiber layer swelling. Subretinal fluid was apparent in the right eye. Three weeks later, the optic disc swellings and hemorrhages had worsened and both eyes evidenced macular stars. After 10 months, the corrected visual acuities improved to 0.9 in both eyes. Ocular motor function and the esotropia also improved. However, the overall contraction of the visual field did not. Conclusions SARS-CoV-2 vaccination can trigger cerebral venous sinus thrombosis, neuroretinitis, and external ophthalmoplegia. In patients with risk factors for such thrombosis, the possibility of ophthalmic complications should be considered after administration of a SARS-CoV-2 vaccine.

Purpose: We report an atypical case of ischemic oculomotor palsy occurring sequentially in both eyes and then improving, followed by a new abducens palsy in a diabetic patient with poor blood sugar control.Case summary: A 51-year-old woman presented with diplopia, dizziness, and pain in the right eye and was diagnosed with oculomotor palsy in the right eye. Magnetic resonance imaging of her brain was normal but glycated hemoglobin concentration was 13.4%. After 2 months, the third nerve palsy in the right eye had recovered completely but a new third nerve palsy occurred in the left eye. 1 month later, the symptoms had improved, and the patient did not return to our clinic until 18 months later, when she returned with new diplopia. This time, she was diagnosed with a sixth nerve palsy in the left eye and was observed while controlling her blood sugar. She recovered after 4 months. Conclusions Generally, cranial nerve palsies occur unilaterally in situations that can cause ischemia, such as diabetes, high blood pressure, and hyperlipidemia. Rarely, they occur bilaterally, or two or more cranial nerve palsies occur simultaneously. However, it is very rare that cranial nerve palsy occurs sequentially in both eyes under the same systemic blood sugar control. Diabetic patients with poor blood sugar control require long-term monitoring, considering the possibility of symptoms developing in both eyes with a time lag or other forms of ischemic cranial nerve palsy.

Purpose: To analyze the incidence of vitreous floaters after intravitreal antivascular endothelial growth factor injection and the effectiveness of the inverse tapping technique, which involves tapping the syringe with the needle downwards to prevent the entry of air bubbles during injection. Methods: The study enrolled patients undergoing their first intravitreal injection for exudative age-related macular degeneration or diabetic macular edema. The patients were divided into two groups: those who received an injection after inverse tapping (IT group) and controls who received the injection without tapping. Patients who consented to the study were randomly assigned to the IT group and the control group through block randomization. One week after injection, a questionnaire was used to assess the presence of vitreous floaters; those who reported them were examined via optical coherence tomography and wide fundus photography. Results: Of the 39 patients in the IT group, two (5.1%) reported floaters 1 week after injection. By contrast, eight (20.5%) of the 39 controls reported them, with a significant difference (p = 0.042). Patients with floaters were significantly younger. Posterior vitreous detachment, as evaluated by pre-injection optical coherence tomography, was observed in 10.0% of those with floaters and 76.5% of those without them. Conclusions The occurrence of vitreous floaters after intravitreal injection is related to age and the presence of posterior vitreous detachment. The use of the inverse tapping technique may help reduce these after intravitreal injection.