Ординатура / Офтальмология / Английские материалы / Clinical Ophthalmic Echography_Harrie_2008

DJ is a 34-year-old man who noted flashes of light in the right eye for 2 days and then a “lacy cobweb with lots of little black specks” on the day of presentation at his ophthalmologist’s office. Examination revealed visual acuity of 20/200 with some variability as he moved his eye around. Ophthalmoscopy found a 2+ vitreous hemorrhage that obscured visualization of the peripheral inferior temporal fundus. Some vitreous membrane formation was noted but retinal detail was hazy.

Echography was performed and demonstrated a total posterior vitreous detachment with moderate intravitreal hemorrhage. An area of vitreoretinal traction was noted at the 5:00 position anterior to the equator. There was the appearance of a flap tear but the adjacent retina was not elevated and no subretinal fluid could be detected (Fig. 181). He was carefully followed by daily echography to verify that the retina was not detaching. When the vitreous hemorrhage had cleared to allow a reasonable view of the fundus, photocoagulation around the tear was performed.

Echography can detect subretinal fluid in the presence of a retinal tear and this provides the retinal surgeon with information to assist in optimizing treatment options from laser to a scleral sponge.

FIG. 181. B-scan of posterior vitreous detachment with vitreous traction on flap tear (arrows)

KP is a 32-year-old moderately myopic man who presented with the history of several days of flashing lights and “cobwebs with lots of tiny little dots” in his right eye. His vision was somewhat impaired by the floaters. Examination showed best corrected vision in his right eye of 20/50 by moving his eye back and forth to see through the floaters. The visual acuity in the left eye was 20/20. Fundus examination found a mild vitreous hemorrhage in the right eye with a Weiss ring in the anterior vitreous. There was some clumping of blood inferiorly with obscuration of the view of the retina in the inferotemporal quadrant.

Echography revealed a partial posterior vitreous detachment with moderate intravitreal opacities consistent with hemorrhage. A focal area of vitreoretinal traction was noted at the 7:00 equator consistent with an elevated flap tear with focal subretinal fluid (Fig. 182). This was discussed with the patient and he was advised to reduce physical activity, stop nonsteroidal anti-inflammatory drugs, and return every few days for repeat echography until the vitreous hemorrhage cleared enough to allow treatment of the retinal tear with careful monitoring of the degree of subretinal fluid.

Other causes of vitreous opacification include asteroid hyalosis. This condition is usually idi-

opathic and often unilateral. It can be dense enough to preclude visualization of the fundus, but yet the patient generally has surprisingly good vision. The reason for this optical paradox is not understood. A patient presenting for the first time to the examiner is best served by an ultrasound evaluation of the eye to rule out fundus pathology.

FIG. 182. B-scan of posterior vitreous detachement with vitreous traction and subretinal fluid (arrow)

MB is a 26-year-old woman who had a history of a “spot” in her left eye since childhood. Her vision had always been good and she was seen by an optical chain store optometrist every few years to update her contact lens prescription. Dilated fundus examination had not been performed during the last several years. She noted the onset of a “film” over her left eye for several days. This progressed to the point where she could only make out vague shapes and forms. She had no complaints of pain or tenderness. Examination by an ophthalmologist found best-corrected vision OD of 20/20 and of hand motions at 1 meter in the left eye. There was a mild anterior chamber reaction with trace flare and cells and dense vitreous cells. Indirect ophthalmoscopy suggested the presence of a lesion just above the macula (“headlight in the fog”). Other fundus details were obscured by the vitreous opacities.

Echography demonstrated 2+ vitreous dotlike opacities and a small solid lesion just above the macula. A- and B-scan of the lesion showed high internal reflectivity and no vascularity (Fig. 184). Calcification wasn’t detected. The differential diagnosis included toxoplasmosis and the patient was begun on therapy with triple sulfa and trimethoprim. The vitreous inflammation cleared steadily over several weeks and allowed a view of the fundus with the ophthalmoscope. A yellowish elevated lesion adjacent to an area of chorioretinal scarring was seen which was typical for toxoplasmosis.

FIG. 184. Top: A-scan of toxoplasmosis lesion (small arrows) with vitreous cells (large arrows). Bottom: B-scan of toxoplasmosis lesion (small arrow) with vitreous cells (large arrow)

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Neoplastic intraocular lesions can incite vitreous reaction. This is especially true for rapidly growing tumors, such as retinoblastoma. The exophytic type can seed the vitreous with tumor cells and the patient’s immune system responds with an out-

Case Study 93. Ocular Toxoplasmosis

pouring of lymphocytes, polymorphonuclear leukocytes, and other inflammatory mediators. Such vitreous debris can mask the inciting malignancy. Echography is essential in detecting and differentiating such an entity.

DJ is a 2-year-old child who was noted by his parents to have a “wandering eye.” He was taken to his ophthalmologist who noted a 30-prism diopter left exotropia. He was unable to see a red reflex in the left eye. The fundus of the right eye was normal. He referred the child for echography.

Dense dotlike vitreous opacities and a solid subretinal mass were imaged but no calcium was detected on B-scan. A-scan demonstrated medium internal reflectivity and mild spontaneous vascularity (Fig. 185). The optic nerve was of normal thickness and no mass lesions were detected in the orbit. The differential diagnosis included a noncalcified retinoblastoma with vitreous seeding. Vitreous aspiration was performed and cytology confirmed the diagnosis of retinoblastoma. The eye was enucleated and chemotherapy was instituted.

Another example of a malignant process with vitreous involvement is central nervous system (CNS) large cell lymphoma. There is a strong correlation between intraocular non-Hodgkin’s lymphoma and involvement of the CNS. The vitreous opacities are distinctively larger than other cellular infiltrates that can invade this cavity. This condition is not uncommonly misdiagnosed as chronic uveitis, but a high level of suspicion should exist for lymphoma when a patient over 40 presents with what appears to be intermediate uveitis.

FIG. 185. Top: A-scan of noncalcified retinoblastoma (vertical arrows). Bottom: B-scan of the tumor (arrow)

MT is a 52-year-old man who presented with complaints of “spots” in his vision and generalized blurring. His past medical history was unremarkable. Examination of the eye documented visual acuity of 20/20 in the right eye and 20/70 in his left eye. No keratoprecipitates were noted on the corneal endothelial surface and the anterior chamber was clear. The vitreous was hazy with larger yellowish cells floating within it. The diagnosis of pars planitis with intermediate uveitis was made and he was treated with topical and oral steroids. The process was not changed after 2 weeks of treatment so an injection of subtenon’s triamcinolone was given. He was seen in another 2 weeks with no improvement.

Echography was performed and 3+ vitreous opacities were noted with focal thickening of the retinochoroid layer (Fig. 186). This finding was felt to be unusual for uveitis so a vitreous biopsy

FIG. 186. B-scan of choroidal large cell lymphoma (arrow)

was recommended. Cytology demonstrated large cell lymphoma. A spinal tap was performed and showed lymphoma cells in the cerebrospinal fluid. An MRI scan showed enhancement of the brain’s meningeal coverings.

A potentially devastating cause of vitreous opacification is endophthalmitis. This can occur via endogenous sources, such as an infection at a distant site in the body. It more commonly is associated with an exogenous seeding of microorganisms, such as penetrating trauma or surgery. The combination of reduced vision, eye pain, and a red angry eye is highly suggestive of infectious endophthalmitis, but the presence of one or more of these findings should raise suspicions for the entity. It is critically important to diagnose endophthalmitis at the earliest stage. This potentially blinding condition can progress over hours, necessitating the institution of appropriate treatment promptly. Mild vitreous opacities may be difficult to detect if the anterior segment is not clear. A patient who has recently undergone intraocular surgery is at risk for endopthalmitis and rapid diagnosis is critical. The classic signs of pain and decreased vision may be subtle especially in the immediate postoperative period when the vision is not expected to be perfectly clear because of mild corneal edema and anterior chamber reaction.

B-scan is useful in demonstrating the formation of membranes and dotlike vitreous opacities, but this is usually a later finding as the process advances to the level of a vitreous abscess. A-scan is helpful in the early stages. The probe is placed against the eye and the gain is increased by 6 decibels above the tissue sensitivity setting (T + 6), increases system sensitivity. The vitreous cavity is examined for

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tiny vertical deflections above the baseline, which can be the first sign of vitreous reaction. As the process advances, the echographic findings become more pronounced. The cellular reaction coalesces into membranes with more prominent opacities on

Case Study 95. Ocular Large Cell Lymphoma

B-scan and higher spikes on A-scan. The retinochoroid layer is thicker as it becomes edematous from the generalized inflammation and in some cases from direct invasion of the tissue by the infectious organisms.

AB is a 72-year-old man who underwent cataract surgery in the right eye and was seen in the office the next day for a postoperative check-up. The cataract was a stage 4 sclerotic nucleus and phacoemulsification had been performed for a prolonged period of time because of the density of the nucleus. He complained of a mild aching pain during the night and blurry vision. Examination found visual acuity of 20/400 in the right eye with a moderate amount of corneal edema and 2 to 3+ cells and flare in the anterior chamber. The vitreous and fundus could not be well seen because of the anterior segment changes of corneal swelling and anterior chamber reaction. He was sent home and instructed to use topical antibiotic and steroid drops. He called later that day and stated that his symptoms were worse and he was concerned. He was brought back to the office and the clinical findings were about the same with possibly a slight increase in the anterior chamber reaction.

The B-scan showed a partial posterior vitreous detachment. However, the A-scan gain was set at T + 6 and demonstrated multiple tiny blips in the vitreous cavity (Fig. 187). This was interpreted as early vitreous reaction with a differential diagnosis including hemorrhage or inflammatory cells. In the clinical setting of recent cataract surgery, the diagnosis of endophthalmitis was made and he was referred to a retinal specialist for a vitreous tap and the injection of intraocular antibiotics. As recommended by the collaborative endophthalmitis study, vitrectomy was not performed because the

FIG. 187. A-scan of vitreous opacities in aggressive endophthalmitis (arrows)

patient had vision at the 20/400 level. If it had been hand motions or worse, then vitrectomy would have been indicated.32

He was followed daily over a week with serial A-scans to monitor the vitreous reaction. His clinical symptoms improved concurrently and an adequate view of the fundus could be obtained at this time. He ultimately improved to a visual acuity of 20/40 as the vitreous reaction cleared and the corneal edema resolved. The final culture report was read as “significant Staphylococcus epidermidis.”

Endophthalmitis can follow an indolent course as a low-grade iritis that does not respond to treatment with anti-inflammatory medications.

FT is an 80-year-old woman who underwent uncomplicated cataract surgery with intraocular lens implantation and had an unremarkable examination on her first postoperative visit. Her uncorrected visual acuity was measured to be 20/200 in the operative eye. She was noted to have 1+ corneal edema and 1 to 2+ cells and flare. She was seen for follow-up in a week with improvement in her vision to 20/60, but there was a persistent lowgrade anterior chamber reaction. The topical steroids were continued and she returned in 2 weeks with vision of 20/70 with 1+ cell and flare in the anterior chamber. A whitish plaque was noted in the periphery of the capsular bag.

Echography was performed and the B-scan was unremarkable. A-scan was done with the gain increased to tissue sensitivity plus 6 decibels. Multiple tiny blips were detected within the vitreous cavity compatible with inflammatory cells (Fig. 188). In the clinical setting of recent intraocular surgery, this finding was most consistent with endophthalmitis. The delayed time course and low degree of inflammatory response suggested an indolent process, such as that caused by propionibacter acnes. An aqueous tap was performed and the diagnosis was confirmed by culture. She failed

FIG. 188. A-scan of vitreous opacities in indolent endophthalmitis (arrows)

to respond to antibiotic treatment and the organism was only eradicated after removal of the intraocular lens and the capsular bag.

The most posterior cause of media opacity is a retrohyaloid or preretinal hemorrhage that obscures the fundus. This can occur spontaneously but is most often due to an underlying vasculopathy, such as diabetes. Echography can be useful in evaluating the retinochoroid layer for abnormalities, such as edema or hemorrhage.