Objective To evaluate the accuracy of the biometry using immersion B scan and partial coherence interferometry (Lenstar LS900) for the axial length (AL) of silicone oil-filled eyes respectively. Methods Thirty-five silicone oil-filled eyes (38 patients) were included in the study. All of these eyes underwent silicone oil removal, cataract extraction and intraocular lenses implantation. The AL of all the silicone oil-filled eyes was measured with A/B-scan ultrasound and Lenstar LS900 before operation and with Lenstar LS900 after operation. The measured distance was compared respectively. The method of immersion B-scan guided with respective sonic velocity. AL was the sum of corneal thickness, anterior chamber depth, lens thickness, the apparent length of oil bubble (velocity values 996 m/s), the depth of the water layer beneath the oil bubble. Results Thirty-one eyes were measured with Lenstar LS900 before silicone oil removal, and the mean AL was (24.12±1.70) mm, 7 eyes failed to get the results before the operation; 36 eyes were measured with Lenstar LS900 after silicone oil removal, and the mean AL was (24.45±1.89) mm. All eyes were measured with B-scan before silicone oil removal, and the mean AL was (24.87±2.52) mm. The difference (31 eyes) of AL measurement before silicone oil removal by two methods was (−0.00±0.09) mm; the difference (31 eyes) between pre- and post-surgical AL measurement with Lenstar LS900 was (0.02±0.07) mm; the difference (36 eyes) between pre-surgical AL measured with B-scan and post-surgical AL measured with Lenstar LS900 was (−0.02±0.11) mm. All the differences were not statistically significant (t=−0.205, 1.752, −1.280; P＞0.05). The consistency of the results measured by two methods was well in Bland-Ahamn analysis. Conclusions Measurement results of AL between immersion B-scan guided with respective sonic velocity and Lenstar LS900 are high repeatability on silicone oil-filled eyes. The AL of silicone oil-filled eyes can be measured reliably by immersion B-scan guided with respective sonic velocity.
Objective To observe the multimodal imaging features of retinal diseases associated with COVID-19. MethodsA retrospective case study. Sixteen patients (30 eyes) of retinal diseases associated with COVID-19 admitted to the Ophthalmology Department of the Second People's Hospital of Zhengzhou in December 2022 were included in the study. There were 5 males and 11 females, with the mean age of (26.69±9.88) years; 14 patients were bilateral and 2 patients were unilateral. The time of ocular symptoms after the diagnosis of COVID-19 was (2.63±0.89) days. All patients underwent the examinations of best corrtected visual acuity (BCVA), fundus color photography (FP), infrared fundus photography (IR), optical coherence tomography (OCT). Fluorescein fundus angiography (FFA) was performed in 2 patients (4 eyes). There were 20 eyes with acute macular neuroretinopathy (AMN), including 6 eyes with cotton wool spots; 10 eyes with Purtscher-like retinopathy (PLR). The BCVA of the patients was 0.1-1.0. No obvious abnormality was found in anterior segment examination. The features of FP, IR and OCT were analyzed retrospectively. ResultsIn 20 eyes of AMN, irregular reddish brown lesions in the central or paracentral area of the macula in 14 eyes; FP showed no obvious abnormality in 6 eyes; IR showed irregular map like low reflection in the central or paracentral area of macular in all eyes; OCT showed hyperreflectivity in outer plexiform layer and outer nuclear layer, hyporeflectivity in the ellipsoid zone and photoreceptor layers in all eyes; no abnormal fluorecence was observed in 2 eyes examined by FFA. In 10 eyes with PLR, cotton wool spots and retinal hemorrhage were observed in the posterior pole and/or peripapillary area, and the peripheral retina was generally normal, Purtscher spot was found in 5 eyes and macular edema in 4 eyes; OCT showed strong reflex signal in neuroepithelial layers, edema in neuroepithelial layers in 6 eyes; in the 2 eyes examined by FFA, fluorescein leakage from the retinal vein wall was observed, the posterior pole and peripapillary area retinal arteriole occlusions showed patchy hypofluorescence, the fluorescence was obscured by retinal hemorrhage below at inferior retina. ConclusionsFor AMN associated with COVID-19, IR can show the lesion contour , OCT shows lesions in the outer retina. PLR associated with COVID-19 are usually at the posterior pole and/or peripapillary area in FP, OCT shows neurocortical edema.