Surgical Approaches and Steps
Pradeep Venkatesh in Handbook of Vitreoretinal Surgery, 2023
Tenotomy is the surgical step of incising the tenons capsule [and intermuscular septa] to gain access to the muscle insertion and scleral surface [Figure 9.2]. This is followed by bridling the recti muscles [see section on surgical anatomy], taking precautions to not split the muscle, the muscular arteries, and fibres of the superior and inferior oblique [Figure 9.3]. Thick cotton thread or silk suture could be used to for this purpose. Bridle suture must be about 10 cm in length [after doubling] and is knotted proximally at about 10 mm from the muscle insertion and distally close to the ends of the suture. Knots at about 10 mm from the muscle insertion allow the surgeon to have better control on the muscles, thereby allowing precise globe rotation and preventing sudden slippage [while passing scleral sutures].
Scleritis and episcleritis
Gwyn Samuel Williams, Mark Westcott, Carlos Pavesio, Bushra Thajudeen in Practical Uveitis, 2017
The most useful clinical examination that can be performed in clinic is a B-scan ultrasound. This will demonstrate a thickening of the posterior coats of the eye, with a thickness greater than 2 mm considered abnormal. In unilateral disease a comparison can be made with the unaffected eye. An additional textbook giveaway sign is fluid collecting between the sclera and Tenon capsule which results in the famous ‘T sign’ with the optic nerve and fluid forming the stem and arms of the letter ‘T’, respectively (Figure 7.5). The investigations for this are identical again to the above but on top of these, due to the different presentation other causes for choroidal folds and a swollen disc also need to be considered and ruled out, the most important of which is raised intracranial pressure. Other conditions that can mimic posterior scleritis include orbital inflammatory disease, choroidal haemangioma, uveal effusion syndrome, atypical central serous chorioretinopathy and Vogt–Koyanagi–Harada (VKH) syndrome. All of these will have distinctive features on fluorescein angiography, B-scan ultrasound (for instance the lack of a T sign), orbital and even brain MRI imaging that can help us distinguish between them.
Sclera
Mostafa Khalil, Omar Kouli in The Duke Elder Exam of Ophthalmology, 2019
There are three parts to the sclera: Episclera (outermost): Thin vascularized connective tissue anterior to the sclera and posterior to the Tenon capsule.Substantia propria: Made of irregularly arranged type I collagen fibrils.Lamina fusca (innermost): Made of loosely arranged connective tissue and separated from the choroid by the suprachoroidal space.
Posterior auricular muscle patch graft for exposed orbital implant
Published in Orbit, 2019
Catherine Y. Liu, Michael G. Sun, Scott Jones, Pete Setabutr
Attention was then turned to the exposed ocular implant. The thinned conjunctiva was dissected until tenons capsule was identified. The conjunctiva was freed by undermining so that it could be approximated without tension. Careful inspection was taken to rule out infection and the orbit was thoroughly irrigated with antibiotic solution. The fascia/muscle graft was then placed fascia side up over the implant and sutured into place using interrupted 6-0 vicryl sutures ensuring good attachment to the tenons and deeper tissue (Figure 2). The edges of exposed tenons and conjunctiva were freshened prior to closure. The conjunctiva was closed without tension over the graft using interrupted 6-0 vicryl sutures. A conformer and erythromycin ointment was applied to the operated socket. A suture tarsorrhaphy was placed for two weeks before removal. The eye was patched with two eyepads and paper tape.
Sub-Tenon Sustained Controllable Delivery of Dexamethasone for Treating Severe Acute Experimental Uveitis
Published in Ocular Immunology and Inflammation, 2020
Libei Zhao, Xuetao Huang, Manqiang Peng, Qian Tan, Wenxiang Lin, Muhammad Ahmad Khan, Qiongyan Tang, Ding Lin
The described SSCDDS was prepared according to our previous experiment with modification.21 Briefly, after topical application of 0.5% proparacaine hydrochloride for three times, a small closed catheter (0.7 mm×19 mm) with a 24G needle (BD Intima) Closed IV Catheter System, Becton Dickinson Co.) was inserted into tenon capsule in the same manner as sub-tenon injection. Following catheter insertion, the needle was withdrawn, and the catheter was fixed between tenon capsule and sclera. Then, 0.3 ml of 5 mg/ml DXM was trickled into the sub-tenon as initial dosage. Another end of the catheter was combined with an auto-infusion pump (BYZ-810T, BIYANG Corp., Changsha, China) and sustained release of DXM at the rate of 0.1 ml/h for 10 h to the sub-tenon (Figure 1).
Controversies in Pediatric Angle Surgery and Secondary Surgical Treatment
Published in Seminars in Ophthalmology, 2023
Alexander K. Young, Deborah K. Vanderveen
Long-term surgical failure of glaucoma valves is common in the pediatric population. While it is not always readily apparent due to encapsulation, this is a well-described challenge for maintaining continuous flow through the tube and a pressure differential between the anterior chamber and the subconjunctival space.24 The most common approach to address encapsulation formation is to revise the bleb and excise fibrotic tissue, although the success of these procedures is limited.37 Adjunctive mitomycin C (MMC) has been described as a technique to reduce the development of encapsulation and reservoir fibrosis, but its efficacy remains controversial in pediatric cases.26 Larger studies in adults have also not demonstrated sufficient efficacy of MMC, and encapsulation remains a significant challenge for long-term postoperative outcomes.38 Another effort to reduce encapsulation is the placement of the tube reservoir in between conjunctiva and tenon’s capsule, or the ‘supra-Tenon capsule’ space, with reported success. However, a comparison study between this technique and the traditional episcleral placement has not been done.39
Related Knowledge Centers
- Conjunctiva
- Corneal Limbus
- Inferior Oblique Muscle
- Meninges
- Optic Nerve
- Subdural Space
- Superior Oblique Muscle
- Sclera
- Periscleral Lymph Space
- Extraocular Muscles