Ординатура / Офтальмология / Учебные материалы / Uveitis Text and Imaging Text and Imaging Text and Imaging 2009

Ciliary injection is seen in its classical form as dusky red circumlimbal vasodilatation in the area where the ciliary and scleroconjunctival circulation anastomose and reflects inflammation of the anterior uveal tract.

CORNEA

The cornea may show epithelial dendrites and disciform oedema in herpetic infection. Decreased corneal sensation may be present in these cases. The corneal dendrites can be stained with fluorescein and rose bengal dye.

Fluorescein dye stains the diseased areas as well as the areas of epithelial defects, but to some extent diffuses rapidly into the intercellular spaces or stroma when disruption of cell-cell junction occurs (Figures 13A and B). Hence the cornea is examined immediately

Figures 13A and B: Anterior segment photograph showing sodium fluorescein staining of the corneal dendrite seen with cobalt blue filter, taking a geographic aspect in disease favoured by inadvertently given corticosteroid drops (A). Typical dendritic pattern shown in (B) (Courtesy Dr Carl P Herbort)

Figure 14: Anterior segment photograph showing rose bengal staining of the corneal dendrite. (Courtesy Dr Carl P Herbort)

after fluorescein is applied. Fluorescence is detected with a cobalt blue filter. It is useful in evaluating various forms of epithelial defects, status of precorneal tear film, contact lens fitting, and detection of aqueous humour leakage.

Rose Bengal dye is routinely used for evaluation of tear deficiency states and detection of various epithelial lesions. Rose Bengal stains cells that are devitalised or have lost their normal mucin surface (e.g. punctate epithelial keratitis). The red-free light filter accentuates its visibility.

Herpetic disciform keratitis presents as corneal stromal and epithelial oedema in a round or oval distribution associated with keratic precipitates underlying the zone of oedema (Figures 15A and B).

Interstitial keratitis is non-necrotising stromal keratitis presenting as unifocal or multifocal whitening of the stroma in the absence of epithelial ulceration. Mild stromal oedema may accompany this. Long standing syphilis is the most common cause of interstitial keratitis, but rare causes include leprosy and tuberculosis (Figures 16A and B).

Keratic precipitates (KPs) are the most commonly reported corneal finding in uveitis. These may be small, very difficult to photograph as they appear merely as dust in case of non-granulomatous uveitis. Once KPs can be individualised and have an architecture (Figure 17) they are considered to be granulomatous even if they are small (microgranulomatous KPs) such as in Fuchs’ uveitis (Figures 18A and B). Only one such granulomatous KP is sufficient to classify a uveitis case into the group of granulomatous uveitis (Figure 17). Medium or large KPs usually have

Figure 15A: Anterior segment photograph showing localised corneal oedema in a case of herpetic keratouveitis called disciform keratitis in diffuse illumination technique. (Courtesy Dr Carl P Herbort)

Figure 15B: The same case of herpetic keratouveitis taken with the direct fine slit beam technique showing the thickened cornea and granulomatous KPs on the endothelium (Courtesy Dr Carl P Herbort)

greasy, mutton fat appearance (most commonly seen in granulomatous disorders such as sarcoidosis, tuberculosis, VKH disease and sympathetic ophthalmia) (Figure 19). These are inflammatory deposits of epithelioid and inflammatory cells on the endothelium of the cornea and are distributed in a base down triangular distribution (Arlt’s triangle) on the inferior cornea because of the convection currents of the aqueous.3 In herpetic keratouveitis, granulomatous KPs accumulate in a round localised way producing overlying disciform oedema (Figure 21) in the cornea.

Diffuse distribution of the keratic precipitates can be seen in herpetic kerato-uveitis4 although it mostly accumulates in a circular fashion (Figure 21), whereas in Fuch’s uveitis this is the rule5 (Figures 18A and B).

Band shaped keratopathy (Figure 22) is commonly seen with chronic intraocular inflammation, such as juvenile rheumatoid arthritis associated with iridocylitis.6 This represents an accumulation of calcium at the level of Bowman’s membrane, usually confined to intrapalpebral zone (due to pH of the exposed area of cornea facilitates calcium deposition in that area).

Figure 17: Small granulomatous KP. Only one such KP is sufficient to classify the case as a granulomatous uveitis. This anterior segment slit beam photograph was taken in birdshot patient, known now to be a granulomatous disease. (Courtesy Dr Carl P Herbort)

Figure 18A: Microgranulomatous KPs as seen in Fuchs’ uveitis, typically distributed over the whole cornea, also present above the median horizontal line (Courtesy Dr Carl P Herbort)

Figure 18B: Microgranulomatous KPs as seen in Fuchs’ uveitis at a higher magnification with the diffuse illumination technique

Figure 19: Direct slit beam with slight retro illumination showing large mutton fat KPs in a case of ocular sarcoidosis (Courtesy Dr Carl P Herbort)

ANTERIOR CHAMBER

The anterior chamber is easily examined with the slit lamp for signs of ocular inflammation. The hallmark of anterior uveitis is the presence of cells and flare in the anterior chamber. In a quiet eye, aqueous is devoid of cells and has a very low concentration of protein. The presence of cells and flare (increased protein) in the anterior chamber is the spillover from the inflamed iris or ciliary body. Anterior chamber cells are best seen

Figure 20: Large granulomatous keratic precipitates seen in diffuse illumination giving a general overview of the distribution of the KPs

Figure 21: Round distribution typical for herpetic keratouveitis (Courtesy Dr Carl P Herbort)

Figure 22: Bilateral band keratopathy (mostly prominent in the interpalpebral fissure) associated with juvenile idiopathic arthritis seen in diffuse illumination

by directing the slit lamp beam obliquely across the eye and focusing on to the cornea (Figure 23).

Anterior chamber flare is due to leakage of proteins into the anterior chamber due to breakdown of bloodaqueous barrier (Figure 24).

Hypopyon is a collection of leukocytes that settles in the lower angle of the anterior chamber (Figure 25). The cause of hypopyon is unclear. It is related to

Figure 23: Anterior chamber cells seen in direct focal oblique beam focused in anterior chamber

Figure 24: Anterior chamber flare demonstrated with direct focal oblique slit beam focused in anterior chamber (Courtesy Dr Carl P Herbort)

Figure 25: Anterior chamber hypopyon seen in diffuse illumination

number of cells in the anterior chamber that sediment when present in excess. The type of cells may also play a role, the polymorphonuclear cells, mainly present in the Behçet’s disease seem to be more prone to sedimentation. (The presence of fibrin may also cause cells to clump and settle down).

Fibrinous exudates and pigmentary deposits on the anterior lens surface can be seen with diffuse and direct illumination (Figures 26-28).

IRIS

Synechiae are adhesions between the iris and the lens capsule (posterior synechiae) (Figures 29 and 30) or the iris and the cornea in the periphery (peripheral anterior

Figure 26: Anterior chamber exudates seen on anterior lenticular surface

Figure 27: Clotted fibrin in a case of acute anterior uveitis associated with HLA-B27 antigen (Courtesy Dr Carl P Herbort)

Figure 29: Posterior synechiae in eyes with chronic anterior uveitis in diffuse illumination

Figure 30: Posterior synechiae in eyes with chronic anterior uveitis

Figure 28: Retracting fibrin with pigmentary deposits with posterior synechiae seen in diffuse illumination

synechiae (Figure 31). The presence of synechiae represents chronic or recurrent disease. Posterior synechiae formation are seen more commonly in granulomatous disorders like sarcoidosis.7

Posterior synechiae formation may lead to the development of pupillary block glaucoma due to seclusio pupillae (Figure 32) and the formation of iris bombe (Figure 33).

The iris may show sectorial atrophy (Figure 34) or diffuse atrophy (Figure 35) in uveitis due to herpes group of viruses. Unilateral anterior uveitis with sectorial atrophy of the iris without associated keratitis is a distinct entity among herpetic eye diseases. The most likely cause of recurrent unilateral anterior

Figure 31: Anterior segment photograph showing peripheral anterior synechiae temporally

Figure 32: Posterior synechiae (seclusio) with fibrin membrane and complete occlusion of the pupil (not responsive to mydriatic)

Figure 33: Completely secluded pupil leading to the formation of iris bombe seen with narrow slit beam focused in the anterior chamber under diffuse illumination

Figure 34: Sectorial iris atrophy seen in transillumination in a case of unilateral anterior granulomatous hypertensive uveitis due to herpes. Note also inferiorly the round zone of keratic precipitates with area of disciform oedema (Courtesy Carl P. Herbort)

Figure 35: Anterior herpetic uveitis (VZV) complicated with secondary glaucoma (note the diffuse iris atrophy secondary to the uveitis)

uveitis with iris atrophy and/or elevated intraocular pressure is HSV.8

Iris nodules are accumulation of inflammatory cells, i.e. leukocytes which lie on the iris surface and pupillary margins. Iris nodules are an uncommon clinical sign in uveitis and tend to be found in granulomatous diseases. The diseases most commonly associated with iris nodules and uveitis include sarcoidosis, Vogt-Koyanagi-Harada syndrome, multiple sclerosis, Fuchs’ heterochromic iridocyclitis, and metastatic infection.9 The Koeppe nodule develops on the pupillary border (Figures 36 and 37), whereas

Figure 36: Koeppe nodules seen at the pupillary margin

Figure 37: Koeppe nodules observed at margin of the pupil

Figure 39: Neovascular glaucoma post-uveitis neovascular glaucoma (radial twig-like iris vessels)

the Busacca’s nodules occur on the surface of iris (Figure 38).

Neovascularisation is an infrequent but serious complication of uveitis. The retina and optic disk appear to be affected most often, although new blood vessels may arise from the iris, ciliary body, and choroid as well (Figure 39). Clinically uveitic neovascularisation appears to be determined most directly by the severity of the inflammation and the presence of retinal nonperfusion.10

ANTERIOR CHAMBER ANGLE

In uveitis, anterior chamber angle is examined to assess for associated glaucoma, neovascularisation (Figure 10), occult foreign body, ciliary body malignancy and peripheral granuloma. (Figure 40) In sarcoidosis, anterior chamber angle shows small, grayish white nodular exudates on the trabecular meshwork. Tentlike, small peripheral anterior synechiae or goniosynechiae also are frequently seen. These findings in the chamber angle are termed trabecular sarcoidosis.7

Figure 38: Busacca nodules and Koeppe nodules seen on the surface of iris with diffuse illumination

Figure 40: Anterior chamber granuloma seen with gonioscopy lens with broad direct focal beam

Figure 41: Posterior subcapsular cataract in a patient with chronic recurrent anterior uveitis

Figure 42: Complicated cataract with posterior synechiae seen with diffuse illumination

LENS

In uveitis, patients develop cataract because of the underlying inflammation and the use of corticosteroids to treat the disease. Posterior subcapsular cataract is most commonly seen (Figure 41) but advanced cataracts with nuclear, cortical and capsular opacities are also seen (Figure 42).

ANTERIOR VITREOUS

Increased cells and protein characterise inflammation in the vitreous cavity. Vitreous inflammation in the anterior vitreous can be photographed using direct focal slit beam examination (Figure 43). Large vitreous opacities such as “snow ball” opacities seen in sarcoidosis or intermediate uveitis can be seen in the anterior

Figure 43: Vitreous cells demonstrated with direct focal slit beam focused in anterior vitreous

Figure 44: Large vitreous cells seen in anterior vitreous in intraocular cysticercosis

vitreous using direct focal examination (Figure 44) as well as in mid and posterior vitreous with the help of three-mirror contact lens or 90-diopter lens (Figure 11).

KEY POINTS

1.Slit lamp photography is useful for documenting structural abnormalities and disease processes.

2.Illumination techniques may be used alone or in combination.

3.Diffuse illumination under low magnification gives overall view of the subject and can be taken as first photograph.

4.Light source of the illumination system is placed on the temporal side while the eye is being photographed.

5.With the newer digital systems, it is possible to store, retrieve and compare the data.

REFERENCES

1.Cunningham D. Basic photography. Clinical ocular photography. Thorofare, New Jersey: Slack Incorporated 1998;13-31.

2.Cunningham D. Slit lamp photography. Clinical ocular photography. Thorofare, New Jersey: Slack Incorporated, 1998;101-18.

3.Rao NA, Forster DJ. Text book of Ophthalmology Vol 2. The Uvea: Uveitis and intraocular neoplasms. In: Podor SM, Yanoff M (Section Editors), Rao NA, Forster DJ, Augsburger JJ (Eds). Several approach to the uveitis patient. New York: Gower Medical Publishing 1995;2.1- 2.18.

4.O’Connor GR. Recurrent herpes simplex uveitis in humans. Surv Ophthalmol 1976;21:165-70.

5.Liesegang TJ. Clinical features and prognosis in Fuchs’ uveitis syndrome. Arch Ophthalmol 1982;100:1622-6.

6.Smiley WK. The eye in juvenile rheumatoid arthritis. Trans Ophthalmol Soc UK 1974;94:817-29.

7.Uyama M. Uveitis in Sarcoidosis. Int Ophthalmol Clin 2002;42:143-50.

8.Van der Lelij A, Ooijman FM, Kijlstra A, Rothova A. Anterior uveitis with sectoral iris atrophy in the absence of keratitis: A distinct clinical entity among herpetic eye diseases. Ophthalmology 2000;107:1164-70.

9.Myers TD, Smith JR, Lauer AK, Rosenbaum JT. Iris nodules associated with infectious uveitis. Br J Ophthalmol 2002;86:969-74.

10.Kuo IC, Cunningham ET Jr. Ocular neovascularization in patients with uveitis. Int Ophthalmol Clin 2000;40:111-26.

INTRODUCTION

Intraocular inflammation is characterised by the disruption of the blood-ocular barriers allowing the influx into the eye of serum proteins and inflammatory cells. In the anterior chamber these abnormal elements can be easily detected using the slit lamp. The slit lamp was the first device that made it possible to evaluate anterior chamber inflammation with some precision representing a major development in the appraisal of intraocular inflammation. For those inflammatory conditions producing a level of inflammation sufficient to be detectable in the anterior chamber, the slit lamp not only allowed to determine the type of inflammation (granulomatous versus non-granulomatous) but also made it possible to grade inflammation.

The two parameters used to grade inflammation in the anterior chamber were the detection of aqueous cells and the “Tyndall effect” or flare, an optical phenomenon caused by the back-scattering of light by “cloudy matters” described for the first time by Lord John Tyndall in 18691 (Figures 1A and B). The phenomenon described by Lord Tyndall occurs in any situation where a narrow beam of light goes across a space with dust or particles and this is particularly well demonstrated in the darkness of a church or a mosque or any dark room into which shines a beam of light coming through small openings (Figure 2A). Exactly the same phenomenon occurs in the anterior chamber when a small beam is shone into it in the presence of (inflammatory) proteins; it is called flare or Tyndall effect (Figure 2B).

Figure 1A: Original article by Sir John Tyndall. Cover page of the journal where Sir Tyndall published in 1869 his article on the interaction of light with cloudy matters