Ординатура / Офтальмология / Английские материалы / Applied Pathology for Ophthalmic Microsurgeons_Naumann, Holbach, Kruse_2008

b

d

Fig. 5.4.13. Primary malignant rhabdomyosarcoma of the “iris root” in 5-year-old girl treated by sector iridectomy followed by four repeated recurrences within 4 years in spite of various types of radiotherapy requiring enucleation (see also Fig. 5.3.16).

a Preoperatively. b Highly cellular neoplasm reaching beyond the iris root. c Recurrence in iris root and ciliary body. d Massive infiltration of the ciliary body. Processes of the iris root cannot be removed completely with a sector iridectomy, they require block excision including the adjacent pars plicata of the ciliary body. After 36-year- old follow-up patient is in good health. (Reported by Naumann et al. 1972)

5.4.2.7

Epithelial Ingrowth Involving the Anterior Chamber Angle

Any epithelial ingrowth both of the diffuse and cystic type involving the anterior chamber angle covers not only the surface of the iris root and the back of the cornea but – by necessity – also the “face of the ciliary body,” or in other words: the insertion of the ciliary muscle to the scleral spur. As direct manipulation and separation of the delicate corneal, conjunctival or epidermal epithelial layers – often only one to two cell layers – is impossible, the adjacent tissues must be “used as a shell,” resulting in block excision together with cornea, sclera, and pars plicata of the ciliary body and iris (Fig. 5.4.8). Partial excision attempted by sector iridectomy or laser application will convert the cystic into a diffuse type of epithelial ingrowth – both approaches are contraindicated (Tables 5.4.6, 5.4.8).

5.4.2.8

Zonular Apparatus in Pseudoexfoliation Syndrome and Homocystinuria

Both in pseudoexfoliation syndrome and homocystinuria basement membrane material and microfibrillar intercellular matrix is interposed between the origin of the zonular fibers and the non-pigmented ciliary epithelium. This causes weakening of the anchoring of the zonules at their origin in the ciliary body leading to phacodonesis or spontaneous dislocation or even luxation of the lens (see Chapter 5.5).

5.4.2.9

Non-invasive In Vivo Diagnostic Procedures

Echography, ultrasound biomicroscopy, optical coherence tomography (OCT), diaphanoscopy in addition to gonioscopy and funduscopy with indentation of the ora serrata are used. Laser tyndallometry measures the involvement of the blood-aqueous barrier.

5.4.3

Indications for Procedures Involving the Ciliary Body

The ciliary body itself until recently was considered a “taboo zone” for direct intraocular microsurgery because of concerns about hemorrhage, vitreous loss, lens subluxation and their complications. We shall show that these concerns can be controlled.

5.4.3.1

Posterior Sclerotomy

Penetrating incisions of the sclera 4 mm behind the limbus open the supraciliary space and allow drainage of fluid from the choroidal detachment particularly with postoperative or post-traumatic defects in the anterior segment causing acute or persisting ocular hypotony. The anterior ciliary arteries are avoided by entering in the sectors between the rectus muscles. Choroidal detachments develop after all perforating injuries that do not seal spontaneously. If wound closure is delayed, reforming the anterior chamber may be possible only after the fluid of the choroidal detachment is released by posterior sclerotomy.

5.4.3.2

Pars Plana Vitrectomy

This approach, pioneered by Machemer (1972), has revolutionized not only vitreal surgery but has also set an example for minimally invasive microsurgery in other organs of the body. It starts with posterior sclerotomies and traverses both the sclera and the pars plana of the ciliary body.* It is indicated: (1) in acute ciliary block angle closure glaucomas with abnormal accumulation of aqueous in the vitreous behind the lens and (2) to treat a multitude of vitreoretinal pathologies via multiple ports combining infusion, cutting, suction and illumination – and implantation of gas and silicone (see Chapter 5.6).

5.4.3.3

Direct Cyclopexy for Treating Persisting Ocular Hypotony Resulting from Traumatic or Iatrogenic Cyclodialysis

Cyclodialysis for up to 2 h (60°) may close and heal spontaneously or after thermal argon laser coagulation. Closure of larger clefts by direct thermic lasers usually is not successful – nor is intravitreal gas injection, with or without capsular tension rings placed in the sulcus ciliaris. Direct cyclopexy describes the reattachment of the anterior attachment line of the ciliary muscle to the scleral spur by suturing under direct microsurgical control (Fig. 5.4.7, 5.4.8 and Table 5.4.2). This procedure is only indicated: (1) if there is functional impairment, (2) morphologic consequences of ocular hypotony like macular star with cystoid maculopathy, choroidal edema and papilloedema ex vacuo persist, (3) the cyclodialysis

Block excision is defined as in toto removal of the process involving the anterior uvea and angle structures together with the adjacent iris, pars plicata of the ciliary body, full thickness sclera and cornea up to 150° of the circumference.

The defect in the eye wall then is closed by a corresponding corneoscleral tectonic graft (Tables 5.4.4 – 5.4.8; Naumann and Rummelt 1996; Rummelt et al. 1994) (Fig. 5.4.15 – 22).