PMC10227508_01
Anterior segment photography and FFA examination at the initial visit suggest OT. Using the diffuse illumination method, the posterior synechiae of the iris (white arrow) was visible with a slit lamp (A). Cortical opacification of the lens (white arrow) was observed using a slit lamp with a narrow light band (B). The refractive stroma was unclear, with a large area of subretinal hyperfluorescence and prepapillary membranous hyperfluorescence extending below the retina (white arrowhead). The small image in the upper right corner is the enlarged view of the posterior pole of the right eye (C). FFA image of the left eye showed no retinal fluorescence leakage (D).
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Slit-lamp examination of the right eye revealed no posterior corneal deposits or aqueous flare; however, mydriatic examination revealed posterior synechiae (iris adhesions to the lens) occurring at the 6 to 8 o'clock positions, and lens opacity was observed (Figures 1A, B). Fundus fluorescein angiography (FFA) showed extensive subretinal and epiretinal membranous hyperfluorescence in the late stage (Figure 1C). The patient's left eye showed normal examination findings (Figures 1D, 2A-D).
DEX implants were used to control uveitis. The images of B-scan ultrasound, laser-scanning wide-field ophthalmoscopy, macular OCT B-scan images and OCTA full-thickness macular retinal thickness images were obtained at initial diagnosis and follow-up. At the time of initial diagnosis, B-scan ultrasonography of the left eye showed clear vitreous cavity (A), laser scanning wide-field ophthalmoscopy image showed clear optic disk boundaries, flat retina, and visible macular reflection in the left eye (B), OCT B-scan image of the macular showed normal macular thickness (C), and OCTA image showed a full-thickness macular foveal retinal thickness of 240 mum (D). Examination of the right eye showed a reduction in vitreoretinal inflammation with DEX implant treatment. At initial diagnosis, a few light spots and strips were seen in the vitreous (white arrowhead), and a thick band of cord-like light adhering to the optic disc (white circle) was also observed (E). Vitreous opacity was scored as 1+, the nasal and inferior borders of the optic disc were unclear in the right eye (white arrowhead), and a proliferative membrane anterior to the optic disc extends into the nasal and inferior retina (white arrows). The inferior peripheral retina is obscured by vitreous opacity (black arrows) (F). Examination of the right eye showed increased full thickness of the macular area (full thickness of the macular fovea was 253 mum), coarse internal limiting and macular epiretinal membranes (white arrowhead), cystoid retina (white arrow), and thickened and elevated peripapillary retina (the asterisk) (G, H). At re-examination 2 months after the first injection of DEX implant, the number of light spots in the vitreous (white arrowheads) decreased, indicating slightly reduced opacity (I). Vitreous opacity was reduced and scored as Trace, and the proliferative membrane was unchanged (white arrows) (J). The right eye showed decreased full thickness of the macular area (235 mum at the fovea), and the cystoid retina was still visible (white arrow) (K, L). At re-examination 3 months after the first injection of DEX implant (the day before the second injection), more light spots were observed in the vitreous compared with the previous month (white arrowheads), indicating increased opacity (M). The vitreous opacity score increased to 1+, and the proliferative membrane was unchanged (white arrows) (N). The right eye showed a thicker full thickness of the retina compared with the previous month (242 mum at the fovea) and increased retinal cystoid change (white arrow) (O, P). At re-examination 3 months after the second injection of DEX implant, the light spot in the vitreous (white arrowheads) decreased, indicating reduced opacity (Q). Vitreous opacity was reduced and scored as Trace, and the proliferative membrane was unchanged (white arrows) (R). The right eye showed thinning of the full thickness of the retina (229 mum at the fovea) and reduced retinal cystoid changes (white arrow) (S, T).
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B-mode ultrasound examination showed hyperechoic spots and streaks in the vitreous, as well as hyperechoic cord-like thick light bands adhering to the optic nerve head (Figure 2E). Laser-scanning wide-field ophthalmoscopy showed unclear nasal and inferior boundaries of the optic disk, extension of the anterior proliferative membrane to the nasal 3 and 5 o'clock positions and inferotemporal region, and vitreous opacity obscuring the peripheral retina below the 3 to 9 o'clock positions (Figure 2F). Moreover, B-scan images of optical coherence tomography (OCT) revealed retinal thickening with cystoid changes, peripapillary retinal thickening and swelling, preretinal vitreous opacity granules, and epiretinal membrane, described as a rough internal limiting membrane (Figure 2G). Optical coherence tomography angiography (OCTA) revealed increased macular retinal thickness (full-thickness central macular retinal thickness, 253 mum) (Figure 2H). The patient's left eye showed normal examination findings (Figures 1D, 2A-D). Moreover, laser-scanning wide-field ophthalmoscopy indicated the presence of epiretinal proliferative membrane in the posterior pole and peripheral retina from the 3 to 9 o'clock positions (Figure 2F). B-ultrasound showed reduced vitreous opacity compared with that before the intervention (Figure 2I). Additionally, laser-scanning wide-field ophthalmoscopy also revealed reduced vitreous opacity scored as Trace (Nussenblatt scale) (Figure 2J). OCT B-scan showed retinal thickness thinning in the right eye after treatment, suggesting reduced edema (OCTA showed a full-thickness retinal thickness of the macular fovea at 235 mum) (Figures 2K, L). B-ultrasonography and laser-scanning wide-field ophthalmoscopy revealed worsening vitreous opacity, which was scored as 1+ (Nussenblatt scale) (Figures 2M, N). OCT B-scan revealed increased edema (OCTA revealed the full-thickness retinal thickness of 242 mum in the central fovea) (Figures 2O, P). B-ultrasonography and laser-scanning wide-field ophthalmoscopy showed reduced vitreous opacity, which was scored as Trace (Nussenblatt scale) (Figures 2Q, R). OCT B-scan revealed decreased retinal thickness and reduced retinal cystoid changes, suggesting reduced edema (OCTA showed the full-thickness foveal retinal thickness of 229 mum) (Figures 2S, T). Furthermore, laser-scanning wide-field ophthalmoscopy revealed stable proliferative membranes during the whole process (Figures 2E, J, N, R).
Preoperative UBM aids in diagnosing OT and guiding the selection of DEX implant injection sites. UBM examination images (A-H) and surgical video screenshots (I, J) of the right eye. Anterior segment at 3 o'clock and 9 o'clock positions (A). Anterior segment at 12 o'clock and 6 o'clock positions (B). Central anterior chamber depth ~2.84 mm. The iridocorneal angle is open in all directions. The distance from the ciliary process to the equator of the lens varies in different directions (A, B). Examination after pupil dilation: moderate echo detected in the ciliary body and peripheral vitreous at ~3, 4, 5, 6, 7, and 8 o'clock positions (C-H). Granulomas can be seen on the surface of the ciliary body (the asterisks) (E-H), adhering to the ciliary body but with clear boundaries. The surrounding vitreous opacity strand attaches anteriorly to the lens and posterior iris (feint arrowhead) (F-H), and posteriorly to the ciliary body at one attachment point (white arrowhead) (C-F), causing mild tractional ciliary body detachment (white arrow) (C, E). The vitreous opacity strand also extends toward the lens-vitreous direction (feint arrow) (C-E). Based on preoperative UBM examination results, the anterior segment at the 10 o'clock and 12 o'clock positions appears normal (I, J). Surgical video screenshots of the right eye intravitreal injection of DEX implants (white arrows) (two injections spaced 3 months apart) (I, J). The first injection is performed at the 12 o'clock position (I), and the second injection is performed at the 10 o'clock position (black arrow) (J).
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The distance from the ciliary process to the equator of the lens varied in different directions, with moderate to strong echoes in the ciliary body and surrounding vitreous at the 3 to 8 o'clock positions (Figures 3A-H). The vitreous strand was also observed extending in the direction of the lens and vitreous (Figures 3C-H). Preoperative UBM examination indicated the presence of peripheral granulomas in the ciliary body and surrounding vitreous body from the 3 to 8 o'clock positions (Figures 3C-H). Therefore, the surgeon selected the 12 and 10 o'clock positions where there were no granulomas and peripheral vitreous strand for the subsequent two DEX implant injections, respectively, to avoid the granulomas and proliferative membranes, preventing injection-related complications (Figures 3I, J). On July 15, 2021, he underwent an intravitreal DEX implant injection in the right eye under general anesthesia (Figure 3I). Thus, a second intravitreal DEX implant injection was performed under general anesthesia on the next day (Figure 3J).
Timeline summarizing the progression of OT in the right eye. The key events or multimodal imaging examination results in the progression of OT are indicated by short lines along the timeline.
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No other adverse events related to the local application of DEX implants, such as corneal edema, rapid cataract progression, retinal breaks, retinal detachment, or intraocular infection, were observed (Figure 4).