Ординатура / Офтальмология / Учебные материалы / Retinal Vascular Disease Joussen Springer

thick blood clot. Furthermore, the risk of surgically induced trauma was thought to be significantly lower.

Pneumatic displacement using an expansive gas was introduced in the late 1990s. The majority of eyes treated suffered from subretinal hemorrhage due to ARMD or were cases with hemorrhage of unknown origin. The rationale for gas-induced displacement

22 III was to prevent toxic photoreceptor cell damage and to allow early diagnosis, if additional therapy of the underlying disease was possible. Most reports stated that gas displacement was effective, but results varied considerably [40, 70]. We found that blood dislocation after gas injection alone was incomplete, most likely due to the fact that hemorrhages are already coagulated or partially organized and adhere firmly to the aneurysm. Attempts to dislocate blood with a gas bubble alone were therefore disappointing.

Improvement in the management of submacular hemorrhages occurred through the combination of pneumatic displacement and fibrinolytic agents, e.g., intravitreal rt-PA in conjunction with gas [6, 18, 20, 70]. Although most of the reports documented hemorrhagic ARMD, a few cases with RAMs were treated as well. Final visual outcomes were poor in ARMD eyes, but improved or remained stable in non-ARMD cases [18, 24, 39].

Another more invasive variant is to perform vitrectomy with subretinal rt-PA application and subtotal gas tamponade. A few clinical case series in ARMD patients have been reported. The studies showed successful displacements of macular hemorrhages, with vision limited by the underlying pathology [19, 33, 58]. We observed that subretinal rt-PA application using 40 gauge cannules was an atraumatic and effective approach that led to reliable clot lysis in fresh subretinal hemorrhages (Fig. 22.3.15b).

It has not yet been established whether subretinal rt-PA application with intraoperative blood removal or just pneumatic displacement is the safer and more efficient method.

To summarize: Surgical therapy for complex RAMs is still under debate. There are no clear recommendations on “when and how” to treat symptomatic RAMs. It is left to the surgeon to decide individual cases, taking into account the risk versus benefit for each patient.

22.3.8.3Pearls and Pitfalls of Surgery for Hemorrhagic RAMs

Treatment concepts for RAMs have changed over the years. We investigated the impact on clinical practice at our clinic by retrospectively analyzing the medical records. A total of 205 patients with the diagnosis of RAMs were identified between 1995 and 2006, and 27 of them were operated on for hemorrhagic complications.

22.3.8.3.1 Patient Selection

As subretinal blood, with or without associated exudative maculopathy, is the most relevant symptom for prognosis in RAMs, these particular cases are potential candidates for surgical intervention. However, we have found that patient selection was difficult for the following reasons:

In patients referred for vitreous hemorrhage of unknown origin approximately 5 – 10 % had complex RAMs as the source of bleeding [68]. Usually, clinicians rule out retinal detachment by ultrasound examination and wait for spontaneous blood resorption. Treatment is postponed until diagnosis becomes evident; complications arise or visual rehabilitation does not occur within a few months. With regards to subretinal bleeding, irreversible macular damage may already be present, when the right diagnosis is ultimately made (Fig. 22.3.8).

In cases in which RAM is identified as the source of vitreous or preretinal hemorrhage, this may obscure a significant subretinal blood component. If the clinician decides to wait for spontaneous resolution, the same consequences may occur as mentioned above (Fig. 22.3.13a). Patients presenting with submacular hemorrhage may be diagnosed for exudative ARMD. Differential diagnosis is difficult, when other signs of ARMD are lacking and the characteristic aneurysmic nodule is covered by blood. In contrast to ARMD, hemorrhages due to RAM surround the RAM, and are located eccentrically. However, these characteristics are not always present

(Fig. 22.3.1d, e).

22.3.8.3.2 Surgical Technique

The basic procedures are listed above. Surgical maneuvers varied according to the individual situation: In the case of preretinal and vitreous hemorrhage, vitrectomy was done, a PVD created and the ILM peeled off. In the case of submacular hemorrhage, careful subretinal balanced salt solution (BSS) injection via a small retinotomy was carried out and followed by drainage or extraction of the blood clot (early series) (Fig. 22.3.10). When rt-PA became available, additional clot lysis by injecting 12.5 μg/cc (0.1 – 0.2 cc) subretinally prior to drainage or extraction was performed (11 eyes) (cases depicted in Fig. 22.3.12 – 22.3.15). Initially, the aneurysm itself was not treated in view of the expected spontaneous prognosis, but later on, active appearing RAM received additional laser treatment (Figs. 22.3.9c, 22.3.14c).

Fig. 22.3.12. Bilateral presentation of hemorrhagic RAMs. The patient experienced vitreous bleeding in her right eye (a). Vitrectomy revealed a “mixed type” of bleeding. A flat subretinal hemorrhage extended just into the macula, but appeared to be in resorption and was not removed. The RAM had already undergone involution (b). Postoperative vision remained 0.3 due to exuda- tion-related macular changes. One year later, the patient returned because of vitreous and macular hemorrhage in her left eye. After clearance of some vitreous bleeding (VA=0.1), a dense subretinal hemorrhage extending into the macula became visible (c). rt-PA-assisted blood removal was performed. Despite a pucker formation at the retinotomy site, vision improved to 0.3 (d)

a

c

b

d

Fig. 22.3.16. Visual outcomes after surgery for hemorrhagic RAM. Intraoperatively, a classification according to the predominant location of blood was made. Furthermore, the median interval between the onset of symptoms and surgery is indicated. Reasons for poor or limited functional results in individual cases are indicated in the graph

mentioned, and subretinal blood was already found to be organized. Furthermore, we mechanically removed clots using forceps, which led to significant trauma, subretinal RPE changes and pucker formation at the retinotomy site. Two eyes developed postoperative PVR. We learned that the use of subretinal rt-PA with earlier intervention was key to more favorable outcomes, e.g., better vision and fewer complications.

Other peculiarities were found in this particular patient group. Multiple RAMs in the same eye were identified in five cases (Figs. 22.3.11, 22.3.13). Four were located on the same vessel: Three showed focal vessel sclerosis and surrounding pigment changes after rupture and localized bleeding at an earlier time, but were asymptomatic. One eye developed another symptomatic RAM after subretinal surgery. Marked exudation with macular involvement required laser therapy, and vision was restored. Another eye had Nd:YAG hyaloidotomy years before and showed vitreous bleeding out of RAM elsewhere in the fundus.

Follow-up examinations revealed other unexpected findings: In four eyes of our early series RAM remained open after surgery and did not undergo spontaneous involution. Exudative retinopathy persisted and FAG disclosed prolonged abnormal leakage. Subsequent laser therapy was performed (Fig. 22.3.14c). Closure of the RAM was achieved and resulted in resolution of retinal edema.

The frequency of multiple, recurrent and persisting RAM is remarkable and indicates that in terms of RAM involution, the prognosis is not as good as expected from previous studies. One may speculate that the clinical course in the subgroup of hemorrhagic RAMs is more aggressive. Our conclusions from these observations were: Firstly, in case the RAM appears open during surgery, we perform additional soft laser treatment (Fig. 22.3.9c). This was done in 10/26 eyes, and all showed rapid regression of the vessel malformation. Secondly, patients should be monitored after surgery for hemorrhagic RAMs, as they may show persisting active or new RAM formation, and early treatment should be considered (Fig. 22.3.13b).

22.3.8.3.5 Discussion

In the face of the poor prognosis of subretinal hemorrhage in eyes with RAMs [38, 54, 65], functional results of the present case series are encouraging. Poor outcomes were associated with:

Too late diagnosis

Underestimated subretinal blood component Iatrogenic damage

By contrast, good function was achieved with:

Early diagnosis

Immediate therapeutic intervention

Atraumatic surgical techniques

The awareness that vitreous and macular hemorrhages may result from a ruptured RAM and the fact that a total of 66 % of eyes had significant subretinal hemorrhage (half of them had complex bleedings with preand submacular components, the latter of which was often masked) motivated us to be less conservative in terms of early surgical intervention. Thus, to keep a balance between patient selection for surgery (those with vision-threatening alterations) and patient selection for observation (to avoid unnecessary surgery and complications) is a sensitive issue. Furthermore, multiple RAMs were not infrequent in our series, and they may threaten the macula again. Thus, we suggest continued monitoring of these eyes.

22.3.9Conclusions and Practical Recommendations

The overall natural history of acquired RAMs is one of gradual spontaneous involution with good visual

prognosis, with the majority of cases remaining asymptomatic. The usual benign course becomes vision-threatening when prolonged leakage with macular involvement or rupture with bleeding occurs, e.g., exudative maculopathy due to edema and lipid deposits or submacular hemorrhage. Visual prognosis largely depends on the degree and loca-

tion of exudates or bleeding [41, 65]. III 22 The role of laser is not yet established, but clinical

practice shows quick resolution of exudative complications due to chronic leakage from the aneurysm. In other words, laser shortens the active phase of the disease and reduces the risk of structural damage to the central retina. Retinal tissue recovers astonishingly well; at times, however, some visual loss is encountered in a significant number of cases.

The role of surgery is even more debatable. Attention has been paid mostly to subfoveal hemorrhagic complications. In view of the uncertain or poor prognosis and difficult treatment, most clinicians prefer a conservative approach [2, 38], whereas others recommend prompt surgical intervention for the reasons mentioned [6, 23, 70]. Doubtlessly, subretinal application of rt-PA is a big step toward an atraumatic technique for subretinal blood displacement or

removal [24]. Hamayun et al. [23] reported no complications in a series of nine patients. We observed one eye with a macular hole (successfully repaired), one eye with late PVR development (final VA was 0.2 after subsequent silicone oil surgery) and one case with subretinal re-bleeding (the patient refused further treatment). Out of the 11 eyes treated with vit-

22 III rectomy, subretinal rt-PA and gas, all but two (82 %) improved and no eye lost vision.

Preretinal hemorrhages generally do not require treatment. Exceptions to this are cases of delayed visual rehabilitation. More importantly, however, preretinal blood can mask a significant subretinal blood component. Vitrectomy is a safe procedure in these cases. Surgery is hence preferable, in case of doubt.

22.3.10Personal Approach to Symptomatic RAMs

There are still no clear recommendations “when and how” to treat RAMs. Having gone through all the therapeutic approaches mentioned, my current point of view can be summarized as follows. In general, treatment is restricted to active, symptomatic lesions only (Table 22.3.2).

In the particular situations listed, visual prognosis is either uncertain or poor and intervention justified. Risks of laser treatment, if carefully applied, appear irrelevant. Taking into account risks and complications due to surgery, the methods mentioned carry a reasonable risk/benefit ratio in the hands of an experienced surgeon.

Controlled randomized clinical trials to study the efficacy of various treatment options would be desirable. However, the relative benignancy and infrequent occurrence of complications due to RA will make it difficult to conduct such a trial. In the case of a patient with complex RAMs, we must keep in mind the patient’s natural history, and the individual treatment will rely on logic-based considerations.

Acknowledgements. Surgery for RAMs was carried out by S. Bopp and K. Lucke (Augenklinik Universitätsallee).

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Core Messages

Coats’ disease presents with teleangiectasia and aneurysm-like abnormalities of the retinal vessels

Massive subretinal lipid exudates develop in later stages of the disease

Mostly unilateral, in healthy young boys Differential diagnosis is to be made toward retinoblastoma

Treatment aims at control of exudation by the pathological retinal vessels

22.4.1 Introduction

Coats’ disease is a rare disorder of the retinal vessels. Other terms are Coats’ retinitis, Coats’ syndrome, exudative retinitis, Leber’s miliary aneurysms and retinal telangiectasis. It is a developmental retinal vascular disorder presenting with telangiectasia and aneurysm-like abnormalities of retinal vessels that may show significant leakage in fluorescein angiography. In more advanced stages of the disease, ophthalmoscopy reveals massive subretinal lipid exudates around the typical retinal vessel anomalies. Based on these primary pathologies, initially two different entities were described: a more severe form by Coats and a milder form by Leber [4, 11]. Today these two clinical presentations are thought to present variable expressions of the same disease and they are now subsumed under the term Coats’ disease. Nevertheless, the cause of the disease is still unknown. Males are more often affected, but no genetic, racial or ethnic predispositions have been found. Furthermore some sporadic case reports of Coats’ disease in patients with chromosomal deletions or in combination with other clinical syndromes have been reported [2, 3, 5, 16]. Retinal vessel anomalies, similar to those observed in Coats’ disease, have been described in 3.6 % of patients with retinitis pigmentosa [7].

Characteristically, Coats’ disease is unilateral in about 90 % of the cases and occurs in otherwise healthy, young boys [18]. The average age at the onset of symptoms is about 8 years, but it ranges between 4 months and the 7th decade of life. The majority of cases are diagnosed before the age of 20 years [6]. More than two-thirds of patients are males [18].

Presenting symptoms at the time of diagnosis are leukocoria, strabismus and reduced visual acuity. In more advanced stages of the disease, heterochromia and secondary glaucoma may be present.

In early stages, Coats’ disease is normally detected during a routine examination. Localized areas with retinal telangiectasis, typically located in the periphery of the retina, are found (Fig. 22.4.1). Without treatment, the disease usually shows progression. Chronic leakage from the atypical vessels leads to pronounced retinal edema and lipid exudates, which dominates the clinical picture and may obscure the underlying pathology. Further progression of the disease shows the development of aneurysm-like abnormalities of retinal vessels and sometimes large areas of capillary non-perfusion and retinal hemorrhage. Ultimately a partial or total exudative retinal detachment occurs (Figs. 22.4.1, 22.4.3). Further late symptoms are rubeosis iridis and neovascular glaucoma, which leads to painful phthisis of the eye. Other complications during the course of the disease are vitreous hemorrhage, cataract, uveitis, neovascularization of the disk and elsewhere. Some rare cases develop a proliferative vitreoretinopathy or a rip of the retinal pigment epithelium [10, 19]. Visual deterioration is the result of macular edema, subretinal lipid exudates and the exudative retinal detachment. Subfoveal neovascularization may occur as a complication of the fibrous organization of long-standing subfoveal exudates.

An increased permeability of vascular endothelial cells in the area of vessel malformation is thought to be the principal pathomechanism in Coats’ disease [12]. The clinical symptoms can be explained by an endothelial cell dysfunction. Telangiectasis and