Choroidal Biopsy

■A decision to perform choroidal biopsy should balance the risk of surgical complications against the

value of the information potentially gained.

■ Choroidal biopsy can be performed if primary intraocular lymphoma (PIOL) is suspected despite prior negative diagnostic vitrectomy.

■Infectious chorioretinitis may require choroidal biopsy if microbiologic, immunologic, and molecular testing of vitreous or aqueous humor is negative.

Contents

25.2Indications  . . . . . . . . . . . . .   249

This chapter contains the following video clips on DVD: Video 42 shows Diagnostic Vitrectomy with air, Video 43 shows Choroidal biopsy (Surgeon: Karl-Ulrich BartzSchmidt), Video 44 shows Subretinal aspiration and choroidal biopsy in ocular lymphoma (Surgeon: Matthias Becker ) and Video 45 shows Choroidal biopsy (Surgeon: Marc de Smet).

25.1 Introduction

Surgical procedures to perform chorioretinal biopsy while preserving the integrity and function of the eye were described for the first time by Peyman and coworkers in the 1980s [5, 6]. Remarkable progress in vitreoretinal surgery has been made since then, including therapeutic subretinal surgery for resection of choroidal neovascularization membranes and endoresection of choroidal melanomas. Advanced vitreoretinal surgical techniques are rarely used in the diagnosis of posterior uveitis; however, the informative value of diagnostic vitrectomy may be limited in cases where the pathology is primarily located at the level of the choroid and the retina [4]. Thus the decision to perform choroidal biopsy may be warranted in cases in which the risks of surgical

complications are outweighed by the potential gain of information that may help in the treatment of either the biopsied eye or the fellow eye [1].

25.2 Indications

In the literature, several cases have been reported in which chorioretinal biopsy was used to diagnose severe posterior uveitis of unknown etiology. Multifocal choroiditis, ocular sarcoidosis and acute retinal necrosis have been investigated in this manner [1, 4]. However, in our opinion, the most important indication to perform choroidal biopsy is the suspicion of primary intraocular lymphoma (PIOL). This sightand life-threatening diffuse large cell B-cell lymphoma, which belongs to the so-called masquerade syndromes that mimic uveitis, has been described in more detail in the previous chapter on diagnostic vitrectomy. Diagnosing PIOL is often challenging. Lymphoma cells are fragile and may be damaged during diagnostic vitrectomy or during processing. Although diagnostic vitrectomy is the most common technique used in the diagnosis of PIOL, it often fails to confirm or definitively exclude the diagnosis even if repeated [2]. In such cases, and especially if a subretinal

Fig. 25.1  Subretinal masses in PIOL

or choroidal infiltrate is present (Fig. 25.1), choroidal biopsy should be considered to confirm the diagnosis in order to initiate adequate treatment rapidly.

25.3 Surgical Procedure

Prior to choroidal en bloc biopsy, the area for excision is selected based on location of the infiltrated choroid, respecting the visual impact of the biopsy. If possible, the macular area is always avoided, but it is also import­ ant to avoid nasal or superior block biopsy if possible because of the importance of the temporal and inferior visual fields. However, the goal of biopsy is to obtain an adequate specimen, and this may require invasion of visually important areas. As is the case for vitreous biopsy, systemic steroids should be discontinued at least 2 weeks before the procedure in eyes with suspected intraocular lymphoma.

A traditional 20-G, three-port approach is preferred because of more secure extraction of the choroidal tissue block through an enlarged sclerotomy and the likelihood of silicone oil exchange.

Phakic patients may benefit from small incision lens surgery with foldable hydrophobic acrylic lens in combination with an implantation of a PMMA capsular tension ring prior to biopsy. The phako tunnel should be placed at the 12 o’clock position, because suturing of the

25 inferotemporal sclerotomy after vitrectomy might lead to opening of a temporal corneal incision. Usually the eyes have already had the vitreous completely removed during a prior diagnostic vitrectomy, with separation of the posterior vitreous. If not, the posterior hyaloid should be removed before biopsy. The procedure is

started with a small retinotomy at the peripheral edge of the planned biopsy area. A localized retinal detachment is created by injection of balanced salt solution using a double lumen cannula. Alternatively, a 40-G Teflon cannula can be used for both retinotomy and injection. At least a 180° detachment 1–2 mm posterior to the abnormal area is necessary. After anterior retin­ otomy using the automated handpiece or scissors, the retina is folded back, exposing the retinal pigment epithelium and choroid. If the BIOM visualization system is used, the retinotomy must be performed with scleral indentation. Indentation is not needed when using a wide-angle contact lens system. To hold the detached retinal flap in place, perfluorocarbon liquid (PFCL) is injected. Endodiathermy is used to coagulate choroidal vessels surrounding the biopsy area before excision with Heimann scissors. Alternatively, continuous frequency doubled green endolaser (continuous mode 500 mW) can be used to cut and coagulate the choroid. The tissue bloc is then detached from the underlying sclera by a spatula and extracted using forceps through an enlarged sclerotomy.

To reattach the retina, PFCL is removed completely and reinjected after unfolding of the retina. Following complete reattachment of the retina, standard laser photocoagulation and PFCL silicone oil exchange is performed. The use of a capsular tension ring will inhibit silicone oil spillover into the anterior chamber. The tissue block is rapidly transferred to the pathology laboratory for processing.

Typically, a first attempt to remove silicone oil can be made at 3 months. The IOL power should be calculated as refraction after silicone oil removal, especially when the macular region is preserved during the biopsy procedure.

25.4 Processing of Specimens

Choroidal biopsies are fixed in 4%-buffered formalin and sent to an experienced pathology laboratory as rapidly as possible. For the diagnosis of PIOL, these tissue specimens allow a larger range of immunohistochemical investigations than vitreous aspirates. Conventional histology of PIOL in the choroidal specimens reveals infiltration of atypical lymphocytes. The neoplastic cells are medium to large-sized with a basophilic cytoplasm, oval-shaped nuclei and conspicuous nucleoli. Mitotic figures sometimes can be seen [3].

Vitreous specimens that were also harvested during the procedure of choroidal biopsy should be processed as described in the previous chapter on diagnostic vitrectomy.

Choroidal Biopsy

Take Home Pearls

■In the hands of an experienced vitreoretinal surgeon, choroidal biopsy represents an important diagnostic tool for severe inflammatory disorders of unclear origin affecting the retina or choroid.

■Suspected intraocular lymphoma may be an indication for choroidal biopsy if previous diagnostic vitrectomy has failed to confirm or exclude the diagnosis.

References

1.Chan CC, Palestine AG, Davis JL, De Smet MD, McLean IW, Burnier M, Drouilhet JD, Nussenblatt RB (1991) Role of chorioretinal biopsy in inflammatory eye disease. Ophthalmology 98: 1281–1286

2.Coupland SE, Bechrakis NE, Anastassiou G, Foerster AMH, Heiligenhaus A, Pleyer U, Hummel M, Stein H (2003) Evaluation of vitrectomy specimens and chorioretinal biopsies in the diagnosis of primary intraocular lymphoma in patients with masquerade syndrome. Graefes Arch Clin Exp Ophthalmol 241: 860–870

3.Coupland SE, Heimann H, Bechrakis NE (2004) Primary intraocular lymphoma: a review of the clinical, histopatho­ logical and molecular biological features. Graefes Arch Clin Exp Ophthalmol 240: 901–913

4.Martin DF, Chan CC, de Smet MD, Palestine AG, Davis JL, Whitcup SM, Burnier MN Jr, Nussenblatt RB (1993) The role of chorioretinal biopsy in the management of posterior uveitis. Ophthalmology 100: 705–714

5.Peyman GA, Juarez CP, Raichand M (1981) Full-thick- ness eye-wall biopsy: long-term results in 9 patients. Br J Ophthalmol 65: 723–726

6.Peyman GA, Raichand M, Schulman J (1986) Diagnosis and therapeutic surgery of the uvea—part I: surgical technique. Ophthalmic Surg 17: 822–829

■The simplest biopsy technique that will provide an answer should be selected.

■More aggressive biopsies can be performed if simpler techniques are inadequate.

■Tissue biopsies are limited in most cases to sightor life-threatening disorders such as intraocular infections or intraocular lymphoma.

■Various techniques for biopsy have been described, but only a small number of cases are reported in the literature.

■Selection of technique and site should be individualized for each patient.

26.2.1Subretinal Aspiration  . . . . . . . .   254

26.1Introduction

Gholam Peyman is credited with the technique of ab interno retinal biopsy, initially in experimental animals [1] and then in a small series of 14 patients with disparate diagnoses [2]. Various series and case reports have appeared that correlate histopathologic results of biopsy with clinical diagnoses [3–10]. Rao proposed the strategy of biopsy of the most accessible tissue first [3]. For most cases of viral retinitis, the most accessible tissue is aqueous humor, and excellent results from specimens obtained by paracentesis [11] make diagnostic vitrectomy unnecessary in most cases. Aqueous humor analysis to detect elevated levels of interleukin-10 may provide a minimally invasive way to screen for intraocular lymphoma [12].

When a diagnosis of intraocular lymphoma is suspected, diagnostic vitrectomy is usually performed. In a series of 84 biopsy specimens from 80 patients, 12 cases of intraocular lymphoma were identified based on the vitreous specimen, and an additional 3 were diagnosed after chorioretinal biopsy with an automated cutter and 2 after enucleation [10]. Lymphoma has also been diagnosed by direct biopsy of the retina [13], in which a sample of the retina is removed (endoretinal biopsy),

26.2.2Endoretinal Biopsy  . . . . . . . . .   255

and by chorioretinal biopsy ab externo. Peyman was the first to describe successful diagnosis of lymphoma by this technique [14]. Chapter 25 of this volume describes a method of biopsying subretinal tissues that involves disinsertion of 180° of peripheral retina, followed by retinal detachment repair.

Retinal biopsy and chorioretinal biopsy find applications in diseases other than lymphoma. The preponderance of cases in the literature are from viral retinitis at the time of retinal detachment repair [7] which often is more easily diagnosed by PCR of intraocular fluid. Multifocal choroiditis and subretinal fibrosis, sarcoidosis, tuberculosis, candidal endophthalmitis, HTLV-1- associated leukemia, and viral retinitis have been diagnosed by these techniques [5–8]. They may be applicable to other infections that preferentially affect the subretinal tissues, such as Nocardia, and are difficult to culture from the vitreous (Fig. 26.1a,b). Use of these techniques assumes that simpler diagnostic methods such as diagnostic paracentesis or diagnostic vitrectomy have not yielded a diagnosis. Occasionally, they may be combined with diagnostic vitrectomy to reduce the risk of a second procedure if the vitreous specimen is inadequate. Vitrectomy with elevation of the hyaloid is required before any tissue biopsy.

Fig. 26.1  a Ultrasound of the left eye at presentation of a 58- year-old woman with systemic lupus erythematosus on oral corticosteroids with complaints of reduced vision. Vision was hand motions, and there was a large white subretinal deposit involving the nasal half of the retina. Vitreous cultures were negative. Subretinal aspiration of the mass grew Nocardia asteroides. A systemic focus was eventually identified in a foot ulcer. b Fundus, left eye. The eye was imaged after subretinal aspiration and repair of retinal detachment with silicone oil. The majority of the abscess has cleared with high doses of intravenous trimethoprim-sulfamethoxazole and intravit-

When tissue is acquired, the biopsy specimen is generally divided in the operating room into portions for histology, culture and/or PCR, and immunopathology. Consultation with laboratory personnel is advised prior to biopsy.

26.2 Surgical Techniques

26.2.1 Subretinal Aspiration

Removal of material from the subretinal space by aspiration is the easiest and least traumatic of biopsy methods. Intraocular lymphoma is particularly favorable for subretinal aspiration because it forms yellow retinal pigment epithelial detachments filled with highly concentrated and freely mobile cells (Fig. 26.2a, b).

Subretinal aspiration with fine needles can provide 26 a specimen for cytologic examination [9, 15]. Conventional sharp-pointed needles may be less suitable for aspiration of these shallow collections of cells because the tip impales the choroid before the bevel is well within

real amikacin, but persistent deposits are visible below the optic nerve, confined to the subretinal space at the level of the retinal pigment epithelium without retinal invasion. All deposits eventually cleared after further antibiotic treatment. Detachment probably occurred because the aspiration site could not be adequately lasered due to persistent deposits in the subretinal space. Primary infusion of silicone oil may have avoided this complication, but would have created a different set of problems, such as inability to effectively use intravitreal amikacin and compartmentalization of the inflammation

the cellular deposit. A 20-gauge silicone-tipped extrusion needle, conventionally used in repair of retinal detachment by vitrectomy, has several advantages in subretinal aspiration. The flexible tip can be cut to the desired length, shallowly beveled if desired, and inserted easily through a knife slit in the retina. The tube bends so that it can remain parallel to the retina in the subretinal space and travel a short distance. Even directed vertically, it is atraumatic to the choroid. The other advantage is that the cells can be seen entering the tubing. Aspiration into a 3-cc syringe with no more than 0.5–1 ml infusate from the central vitreous cavity provides a good cytologic specimen. Endolaser photocoagulation can be applied around the biopsy site, but the retinal hole is likely self-healing; short-acting gas tamponade should provide ample time for this to occur if it is desirable to avoid photocoagulation, for example in macular lesions.

In the technique described by Bechrakis et al. [16] and used in the review series of Coupland et al. [10], biopsy of subretinal tissue was performed by penetrating the retina with a knife blade as for subretinal aspiration above and inserting the vitreous cutter in the subretinal space. Using high aspiration pressure and low cutting

Fig. 26.2  a Fundus of the right eye of an 83-year-old man with complaints of floaters. There are solid detachments of the retin­ al pigment epithelium characteristic of intraocular lymphoma. Diagnostic vitrectomy was performed. Examination of the vitreous specimen did not confirm the diagnosis of intraocular lymphoma, but material from aspiration from these lesions

rate, the surgeon takes a few bites of the underlying mass. No laser photocoagulation was used, and tamponade with a short-acting gas was sufficient to maintain retinal attachment. In Bechrakis’s original series, biopsy of solid tumors was described. Tumors such as intraocular lymphoma that are easily aspirable probably do not require cutting. The vitrectomy probe could be used to aspirate subretinal contents, especially 25-gauge instrumentation in which the port is closer to the tip of the instrument. All aspirations through the vitrector should be done into a syringe connected directly inline without a stopcock, as close to the vitrector handle as possible.

Subretinal aspiration of exudative fluid may be helpful in the diagnosis of metastasis and uveal melanocytic proliferation [7, 17].

26.2.2 Endoretinal Biopsy

Direct biopsy of the retina is conceptually simple. A pathologic area is identified, cut free, and removed from the eye. Selection of the site of biopsy is more critical than with subretinal aspiration as tissue will be removed.

did. During surgery, the flexible silicone cannula permitted drainage of the three largest lesions from a single retinotomy. b Fundus of the right eye after vitrectomy and external beam radiation. There are laser photocoagulation scars surrounding the involved area, and the media are now clear

Although most authors discuss removal of pieces of 1–2 mm [13, 18], such small biopsies may be inadequate, or lost, or prevent division. In addition, it is considered desirable to include a portion of normal retina at the border zone if possible to assist in orientation of the specimen. Size up to 3–5 mm is not unreasonable. Consideration should be taken of the surgeon’s hand posit­ ion to facilitate cutting and the position of large retinal vessels, which, if they cannot be avoided, can be closed with diathermy. Diathermy use should be minimized to avoid tissue injury.

Square biopsies are easier to cut than round ones. It is not necessary to detach the retina, as has been described [13]. Either the retina can be incised with a sharp knife, or one blade of a vertical or horizontal cutting vitreoretinal scissor is inserted through the retina. Cuts are made on four sides, freeing three corners. The remaining corner remains attached to the retina to prevent loss of the biopsy. The specimen is then aspirated into a 10-cc syringe attached to an 18–19-gauge extrusion needle, using the force of aspiration to break the remaining connection to the retina. Additional fluid 2–3 cc is aspirated from the central vitreous cavity, and the translucent specimen is visualized in the syringe [19].

Transfer to a sterile Petri dish is then made by removing the plunger and pouring the specimen into the dish. The retinal biopsy can be “beached” by tilting the plate and the excess fluid carefully dried. Fixation at this point with formalin or paraformaldehyde may help transfer the specimen atraumatically. Forceps removal or allowing the specimen to float freely out of one of the sclerotomies is unnecessarily damaging and risks loss of the specimen [18].

Endoretinal biopsy probably requires endolaser photocoagulation and gas–fluid exchange. Silicone oil tamponade could be considered if good adhesion could not be obtained in diseased tissue or the patient could not position adequately.

Choroidal biopsy can be easily performed through the retinal biopsy site. The biopsy is more difficult to cut, and more difficult to elevate from the sclera than the endoretinal biopsy. Diathermy is needed to reduce bleeding.

26.2.3 Ab Externo Chorioretinal Biopsy

Localization of the biopsy site is a critical preoperative procedure. Ideally, the site should be anterior to the equator, rendering this impractical in many cases. Superior locations are preferred. If retina is to be removed, preoperative demarcation of the biopsy site with laser may help reduce the risk of postoperative retinal detachment.

Published descriptions of biopsy technique can be consulted [6, 14, 18, 20]. Vitrectomy with placement of an infusion line helps stabilize the globe. Care must be taken to position the line so that a full rotation of the eye can be obtained. Muscle sling sutures, as for scleral buckling, are helpful. A Flieringa ring sutured to sclera surrounding the biopsy site will also help stabilize the globe.

Circular flaps are easier to close with sutures than square ones. Partial-thickness trephination can be helpful, leaving a one-clock-hour hinge. Deep dissection leaving only the inner laminae of sclera produces a sturdy hinged flap. Diathermy at the edge of the biopsy site can reduce the risk of hemorrhage. The inner sclera, uvea, and retina are incised with a sharp blade, grasped with forceps, and cut free with scissors or a blade. As for endoretinal biopsy, square or rectangular biopsies are easier to cut. The flap is then sutured in place with multiple interrupted 9-0 nylon sutures, leaving the knots

26 exposed. Fibrin or cyanoacrylate glue can be helpful if the flap is not watertight. Additional vitrectomy, laser, air, or gas–fluid exchange can be performed at this point.

Take Home Pearls

■Subretinal aspiration is a simple, atraumatic, and useful technique suited to cellular deposits such as intraocular lymphoma.

–Laser demarcation is optional.

–Short-acting gas tamponade is advised.

■Endoretinal biopsies should be of sufficient size to permit comprehensive testing.

–Laser demarcation is advised.

–Gas tamponade is usually adequate.

–Silicone oil tamponade can be considered.

■Choroidal biopsies can be removed though an endoretinal site.

–More bleeding is expected.

–Choroidal biopsies are harder to remove.

■Chorioretinal biopsy ab externo is probably best suited to cases in which an entire lesion is being excised, i.e., tumors, as ab interno biopsy appears safer and should suffice for most indications.

References

1.Peyman GA, Barrada A. Retinochoroidectomy ab interno. Ophthalmic Surg 1984; 15(9):749–751

2.Peyman GA. Internal retinal biopsy: surgical technique and results. Int Ophthalmol 1990; 14(2):101–104

3.Cote MA, Rao NA. The role of histopathology in the diagnosis and management of uveitis. Int Ophthalmol 1990; 14(5–6):309–316

4.Chan CC, Palestine AG, Davis JL, de Smet MD, McLean IW, Burnier M et al. Role of chorioretinal biopsy in inflammatory eye disease. Ophthalmology 1991; 98(8):1281–1286

5.Barondes MJ, Sponsel WE, Stevens TS, Plotnik RD. Tuberculous choroiditis diagnosed by chorioretinal endobiopsy. Am J Ophthalmol 1991; 112(4):460–461

6.Martin DF, Chan CC, de Smet MD, Palestine AG, Davis JL, Whitcup SM et al. The role of chorioretinal biopsy in the management of posterior uveitis. Ophthalmology 1993; 100(5):705–714

7.Rutzen AR, Ortega-Larrocea G, Dugel PU, Chong LP, Lopez PF, Smith RE et al. Clinicopathologic study of retinal and choroidal biopsies in intraocular inflammation. Am J Ophthalmol 1995; 119(5):597–611

8.Levy-Clarke GA, Buggage RR, Shen D, Vaughn LO, Chan CC, Davis JL. Human T-cell lymphotropic virus type-1 associated T-cell leukemia/lymphoma masquerading as necrotizing retinal vasculitis. Ophthalmology 2002; 109(9):1717–1722

9.Rao M. Primary intraocular lymphoma diagnosed by fine needle aspiration biopsy of a subretinal lesion. Retina 2002; 22(4):512–513

10.Coupland SE, Bechrakis NE, Anastassiou G, Foerster AM, Heiligenhaus A, Pleyer U et al. Evaluation of vitrectomy specimens and chorioretinal biopsies in the diagnosis of primary intraocular lymphoma in patients with masquerade syndrome. Graefes Arch Clin Exp Ophthalmol 2003; 241(10):860–870

11.Tran TH, Rozenberg F, Cassoux N, Rao NA, Lehoang P, Bodaghi B. Polymerase chain reaction analysis of aqueous humour samples in necrotising retinitis. Br J Ophthalmol 2003; 87(1):79–83

12.Cassoux N, Giron A, Bodaghi B, Tran TH, Baudet S, Davy F et al. IL-10 measurement in aqueous humor for screening patients with suspicion of primary intraocular lymphoma. Invest Ophthalmol Vis Sci 2007; 48(7):3253–3259

13.Cassoux N, Charlotte F, Rao NA, Bodaghi B, Merle-Beral H, Lehoang P. Endoretinal biopsy in establishing the diagnosis of uveitis: a clinicopathologic report of three cases. Ocul Immunol Inflamm 2005; 13(1):79–83

14.Peyman GA, Juarez CP, Raichand M. Full-thickness eyewall biopsy: long-term results in 9 patients. Br J Ophthalmol 1981; 65(10):723–726

15.Levy-Clarke GA, Byrnes GA, Buggage RR, Shen DF, Filie AC, Caruso RC et al. Primary intraocular lymphoma diagnosed by fine needle aspiration biopsy of a subretinal lesion. Retina 2001; 21(3):281–284

16.Bechrakis NE, Foerster MH, Bornfeld N. Biopsy in indeterminate intraocular tumors. Ophthalmology 2002; 109(2):235–242

17.Sternberg P Jr, Tiedeman J, Hickingbotham D, McCuen BW, Proia AD. Controlled aspiration of subretinal fluid in the diagnosis of carcinoma metastatic to the choroid. Arch Ophthalmol 1984; 102(11):1622–1625

18.Gonzales JA, Chan CC. Biopsy techniques and yields in diagnosing primary intraocular lymphoma. Int Ophthalmol 2007; 27(4):241–250

19.Moshfeghi DM, Dodds EM, Couto CA, Santos CI, Nicholson DH, Lowder CY et al. Diagnostic approaches to severe, atypical toxoplasmosis mimicking acute retinal necrosis. Ophthalmology 2004; 111(4):716–725

20.Nussenblatt RB, Davis JL, Palestine AG. Chorioretinal biopsy for diagnostic purposes in cases of intraocular inflammatory disease. Dev Ophthalmol 1992; 23:133–138