An Experimental Design to Compare the Compatibility of Absorbable and Nonabsorbable Suture Materials in the Lateral Canthus Area.

Polyglactin 910 (Vicryl) and polypropylene (Prolene) are common suture materials used in ophthalmic surgical procedures. However, there are limited studies assessing tissue reactions to different sutures in eyelid areas. In this study, these suture materials were used subcutaneously in 10 lateral canthi of 5 pigs. Clinical reactive score (CRS) was assessed 14 days and 60 days after surgery. On histology, subcutaneous tissue reactions were assessed by the presence of different inflammatory cells, and the aggregate tissue irritation score was calculated. CRS and the histology score did not differ between these sutures. None of the suture materials used were superior for use in the lateral canthi of pig eyes. Therefore, we recommend both of these sutures for use in the subcutaneous tissue of the eyelid area in animal experiments or clinical practice.

The Efficacy of Orbital Septal Flap in the Treatment of Moderate and Severe Upper Eyelid Retraction.

PURPOSE: To assess the long-term effectiveness of the orbital septal flap to lengthen the levator muscle in management of moderate and severe upper eyelid retraction. METHODS: This study reports 46 eyes of 43 consecutive patients with moderate or severe upper eyelid retraction who were recommended for surgery. The period of the study was between October 2016 and October 2019. All cases were evaluated for eyelid position before and at 3, 6, and 12 months after the operation. Successful outcome was defined as "perfect," "acceptable," and "failure". RESULTS: The average age was 33.3 years (range, 16-59 years). The average orbital septal flap height was 5.28 ± 0.77 mm. Before surgery, 78.3% had 1 of 3 central upper eyelid retraction (group 1), and 21.7% had 1 of 3 lateral upper eyelid retraction (group 2). During follow-up postoperatively, all eyelid parameters of upper marginal reflex distance, upper scleral show, and palpebral fissure height significantly decreased compared with preoperative values in both groups. The result was considered "perfect" or "acceptable" in 42 eyes (91.3%). However, at 12 months after surgery, of the 36 middle eyelid retraction cases (group 1), 35 (97.2%) showed a successful outcome (perfect or acceptable results), while the success rate in group 2 was 70% (7 of 10 cases), a significant difference (p = 0.008). No severe complications were seen during follow up. CONCLUSIONS: Orbital septal flap is a safe and reliable procedure for management of upper eyelid retraction of moderate and severe degree.

Changes in Eyelid Position Following Silicone Tube Insertion and Removal in Dacryocystorhinostomy.

AIMS: The authors sought to assess the changes in eyelid position after silicone tube insertion and removal in endoscopic dacryocys-torhinostomy. METHODS: The authors retrospectively reviewed 60 eyes of 48 consecutive patients who underwent endoscopic dacryocystorhinostomy operation at Korea University Guro Hospital, Seoul, Republic of Korea, between April 2019 and November 2019. All cases were evaluated to discern eyelid positioning, focusing on the marginal reflex distance 1, medial palpebral fissure, central palpebral fissure (PF-2), lateral palpebral fissure (PF-3), and medial canthal angle (MCA) before surgery and at 1 week and 1, 2, 3, and 4 months postoperatively. RESULTS: Twelve patients (25%) were operated on bilaterally and 36 patients (75%) were operated on unilaterally. The average patient age was 56.5years and 9 men (18.8%) and 39 women (81.3%) were included in this study. At 2 months postoperatively, all values of interest (marginal reflex distance 1, medial palpebral fissure, PF-2, PF-3, and MCA) had decreased significantly (p < 0.05, Friedman test), but the changes in PF-3 immediately after surgery were not significant (P = 0.062, Wilcoxon rank-sum test). From 2 to 3 months after surgery, all 5 indicators of interest increased significantly. After silicone tube removal, whereas there was no statistically significant difference in medial palpebral fissure, PF-3, and marginal reflex distance 1 values; the changes in PF-2 and MCA values as compared with before surgery was 0.47 mm (p = 0.02, Wilcoxon test) and 3.25° (p = 0.000, Wilcoxon test), respectively, which was significantly different. However, with these small gaps, it will be difficult to notice the changes in PF-2 and MCA values during clinical examination. CONCLUSION: Insertion of a silicone tube during endoscopic dacryo-cystorhinostomy leads to temporary deformation of the lid position. However, after silicone tube removal, all eyelids recovered to their original shape.

Structural changes in the retina after implantation of subretinal three-dimensional implants in mini pigs.

The retinal structural changes after subretinal implantation of three-dimensional (3D) microelectrodes were investigated in a mini pig. Three types of electrode were implanted into the subretinal spaces of nine mini pigs: 75-µm-high 3D electrodes on a 200-µm-thick right-angled polydimethylsiloxane (PDMS) substrate (group 1); a 140-µm-thick sloped PDMS substrate without electrodes (group 2); and a 140-µm-thick sloped PDMS substrate with 20-µm-high 3D electrodes (group 3). One mini pig was used as a control. Spectral domain-optical coherence tomography (SD-OCT) images were obtained at baseline and 2, 6, and 12 weeks post-surgery. Retinal specimens were immunostained using a tissue-clearing method 3 months post-implantation. The 75-µm-high 3D electrodes progressively penetrated the inner nuclear layer (INL) and touched the inner plexiform layer (IPL) 2 weeks post-surgery. At 6 weeks post-operatively, the electrodes were in contact with the nerve-fiber layer, accompanied by a severe fibrous reaction. In the other groups, the implants remained in place without subretinal migration. Immunostaining showed that retinal ganglion and bipolar cells were preserved without fibrosis over the retinal implants in groups 2 and 3 during the 12-week implantation period. In summary, SD-OCT and immunohistology results showed differences in the extent of reactions, such as fibrosis over the implants and penetration of the electrodes into the inner retinal layer depending on different types of electrodes. A sloped substrate performed better than a right-angled substrate in terms of retinal preservation over the implanted electrodes. The 20-µm-high electrodes showed better structural compatibility than the 75-µm-high 3D electrodes. There was no significant difference between the results of sloped implants without electrodes and 20-µm-high 3D electrodes, indicating that the latter had no adverse effects on retinal tissue.