Morphometric Analysis of the Ophthalmic and Central Retinal Arteries via the Endoscopic Endonasal Trans-ethmoidal Approach: Surgical Relevance of Vascular Components Within the Medial Intraconal Zones.

BACKGROUND: The endoscopic endonasal approach (EEA) offers a minimally invasive route to treat medial intraconal space (MIS) lesions. Understanding the configuration of the ophthalmic artery (OphA) and the central retinal artery (CRA) is crucial. METHODS: An EEA to the MIS was performed on 30 orbits. The description of the intraorbital part of the OphA was divided into 3 segments and classified as type 1 and type 2 and the MIS was divided into three surgical zones (A, B, C). The CRA's origin, course, and point of penetration (PP) were analyzed. The relationship between the position of the CRA in the MIS and the OphA type was analyzed. RESULTS: The OphA type 2 was present in 20% of specimens. The site of origin of the CRA from the OphA was found on the medial surface in type 1 and on the lateral surface of type 2. The point of penetrationof the central retinal arterywas found in 87% of the specimens on the inferomedial surface, just anterior to the inferior muscular trunk, at an average distance of 9.5 mm ± 1 from the globe and 17 mm ± 1.5 from the AZ. The presence of the CRA in Zone C was associated only with OphA type 1. CONCLUSIONS: OphA type 2 is a common finding and can compromise the feasibility of an EEA to the MIS. A detailed preoperative analysis of the OphA and CRA should be conducted prior to approaching the MIS due to the implications of the anatomical variations that can compromise safe intraconal maneuverability during an EEA.

[Retinal Arterial Macroaneurysms (RAM)--pathology, differenzial diagnoses, and therapy]. / Retinale arterielle Makroaneurysmen (RAM)--Pathologie, Differenzialdiagnose und Therapie.

Retinal arterial macroaneurysms (RAM) are unilateral, solitary, acquired saccular or fusiform dilatations of the large arterioles of the retina, usually within the first three orders of bifurcation. They are associated with systemic vascular conditions such as hypertension and arteriosclerotic disease and occur most commonly in elderly women. Cases of simple RAM are predominated by the vascular ectasia. These macroaneurysms regress without treatment and without causing decreased visual acuity and will usually remain undetected. Complex RAM often go along with vision loss due to haemorrhage or oedema affecting the macula. Poor visual outcome may occur secondary to foveal exudates and subfoveal haemorrhage, the latter appear as pre-retinal, intra-, and subretinal haemorrhage. This overview discusses conservative and surgical therapeutic options for complex cases.

Assessment of retinal and choroidal blood flow changes using laser Doppler flowmetry in rats.

PURPOSE: A new noninvasive laser Doppler flowmetry (LDF) probe (one emitting fiber surrounded by a ring of eight collecting fibers, 1-mm interaxis distance) was tested for its sensitivity to assess the retinal/choroidal blood flow variations in response to hypercapnia, hyperoxia, diverse vasoactive agents and following retinal arteries photocoagulation in the rat. MATERIALS AND METHODS: After pupil dilation, a LDF probe was placed in contact to the cornea of anesthetized rats in the optic axis. Hypercapnia and hyperoxia were induced by inhalation of CO(2) (8% in medical air) and O(2) (100%) while pharmacological agents were injected intravitreously. The relative contribution of the choroidal circulation to the LDF signal was estimated after retinal artery occlusion by photocoagulation. RESULTS: Blood flow was significantly increased by hypercapnia (18%), adenosine (14%) and sodium nitroprusside (16%) as compared to baseline values while it was decreased by hyperoxia (-8%) and endothelin-1 (-11%). Photocoagulation of retinal arteries significantly decreased blood flow level (-45%). CONCLUSIONS: Although choroidal circulation most likely contributes to the LDF signal in this setting, the results demonstrate that LDF represents a suitable in vivo noninvasive technique to monitor online relative reactivity of retinal perfusion to metabolic or pharmacological challenge. This technique could be used for repeatedly assessing blood flow reactivity in rodent models of ocular diseases.

[Diagnosis of systemic disease after bilateral retinal arterial macroaneurysm]. / Diagnóstico de patología sistémica tras macroaneurisma arterial retiniano bilateral.

CASE REPORT: An 85 year old male suffered vision loss in both eyes due to ruptured bilateral retinal arterial macroaneurysms. DISCUSSION: We report this unusual case and show the importance of studying these types of patients in order to detect associated systemic diseases.

Accurate course and relationships of the intraorbital part of the ophthalmic artery in the sagittal plane.

INTRODUCTION: Knowledge of variations in the course and distribution of the intraorbital part of ophthalmic artery (OA) is necessary for the diagnosis and treatment of anterior cranial and orbital disorders. MATERIAL: 38 human cadaver dissections to demonstrate the microsurgical anatomy of the intraorbital part of the OA were studied in three stages, considering its neighbourhood with the optic nerve in the sagittal plane. RESULTS: The first part of the OA was located on the inferolateral aspect of the optic nerve in 89.47%. The diameter and the length of the first part of the OA were 1.69+/-0.34 mm and 7.58+/-0.89 mm. 73.68% of the cases crossed the optic nerve superiorly, and 26.31% inferiorly. The diameter and length of the second part of the OA were as 1.52+/-0.29 mm and 4.12+/-0.85 mm. The diameter and length of the third part of the OA were 1.07+/-0.18 mm and 4.12+/-0.85 mm. The first branch of the intraorbital part of the OA was the central retinal artery in 26.31% of the specimens. CONCLUSION: A better understanding of the vascular anatomy of the orbit should allow for the modification of surgical techniques to reduce bleeding during biopsy or excision of orbital structures.

Microsurgical anatomy of the central retinal artery.

OBJECTIVE: To define the microsurgical anatomy of the central retinal artery (CRA) and to provide a guide to avoiding damage to it during surgery. METHODS: The anatomic characteristics of the CRA and small arteries distributed to the optic sheath were examined in 109 orbits. The origin, course, and site of entry of the artery into the optic sheath and the distance between the orbital apex and the site of entry into the sheath were examined. RESULTS: The CRAs originated directly from the intraorbital ophthalmic artery or in a common trunk with a posterior ciliary or a muscular branch. The CRAs most commonly originated on the inferomedial side of the ophthalmic artery an average of 8.4 mm distal to the orbital end of the optic canal. They penetrated the optic sheath near the junction of the middle and anterior thirds of the length of the intraorbital optic nerve an average of 18.6 mm distal to the optic canal. More than 70% of CRAs penetrated near the midline of the lower surface of the optic sheath, 21% entered the inferomedial surface, and 7% the inferolateral or lateral surface of the optic sheath. Only one CRA gave off a branch before penetrating the nerve. CONCLUSION: The CRA is at risk of being damaged or occluded during procedures involving a large part of the orbit. Procedures directed along the lower half of the proximal two-thirds of the optic sheath have the greatest risk of interrupting the artery.

Arterio-venous dissection after isovolaemic haemodilution in branch retinal vein occlusion: a non-randomised prospective study.

PURPOSE: The rationale for this pilot study was to add arterio-venous dissection (AVD) after unsuccessful medical treatment in a well-defined group of patients with branch retinal vein occlusion (BRVO). METHODS: In this prospective, interventional case series 35 consecutive patients with a visual acuity (VA) of 0.4 (logMar) or worse were scheduled for surgery within the first 3 months of the onset of BRVO. The study endpoint was VA 1 year after AVD. Secondary study endpoints were: correlation of VA and successful vessel dissection; complication rate; and number of additional surgical procedures within the first year of AVD. RESULTS: Preoperative VA (logMar) was 0.82+/-0.05 (range 0.2-1.6). VA 6 weeks postoperatively was 0.54+/-0.06 (range 0-1.6), 3 months postoperatively 0.61+/-0.07 (0-1.56), 6 months postoperatively 0.74+/-0.08 (range 0-2) and 12 months postoperatively 0.55+/-0.07 (range 0.1-1.5). VA improved 1 year after AVD (p=0.0004). An improvement in VA did not depend on successful separation of the artery and the vein. Four patients had a retinal detachment, 19 patients needed cataract surgery within the first year of AVD. A total of 24 additional surgical procedures were needed. CONCLUSIONS: Patients with BRVO may profit from AVD compared with a historical control group. Visual improvement was found irrespective of the successful dissection of vessels. The cataract formation rate and additional surgery was a shortcoming of the AVD procedure.

Combined surgical ablation and intravitreal triamcinolone acetonide for retinal angiomatous proliferation.

PURPOSE: Neovascular age-related macular degeneration (ARMD) with retinal angiomatous proliferation (RAP) has a poor natural history and the efficacy of any treatment has not yet been established. The authors describe a combined surgical treatment. METHODS: A 76-year-old woman presented with a best-corrected visual acuity (BCVA) of 20/600 in the right eye and macula with stage 3 RAP as identified by fluorescein angiography (FA), indocyanine green angiography (ICGA), and optical coherence tomography (OCT). After a standard three-port pars plana core vitrectomy (PPV), endodiathermy of the arteriolar and venous feeder vessels of each lesion was performed, intraretinal RAP feeder vessels were cut with manual vertical intraocular scissors, and 0.1 mL of triamcinolone acetonide (TAAC) was injected intravitreally. At 1 and 4 weeks and at the sixth month, the patient underwent a complete eye examination, FA, ICGA, and OCT to assess outcomes and complications. RESULTS: Six months later, BCVA was stable at 20/300, intraocular pressure was 15 mmHg, anterior segment and vitreous cavity were clear without evidence of TAAC granules, and retina was attached. FA and ICGA showed a complete occlusion of the RAP and absence of leakage or ischemia and OCT demonstrated decreased macular thickness with resolution of both intraretinal edema and pigment epithelium detachment, and the restoration of the normal macular profile. At the end of follow-up, the authors did not observe any ocular or systemic complication. CONCLUSIONS: Surgical approach to RAP stage 3 with intravitreal injection of 4 mg of TAAC was safe and anatomically effective.

[Surgical approach to retinal vein occlusion]. / Chirurgische Therapie retinaler Venenverschlüsse.

Retinal vein occlusions are the second most common vision threatening retinal vascular disorders. Our therapeutic armamentarium for functional improvement was very limited in the past for all types of retinal vein occlusions (branch, central and hemi-central retinal vein occlusion). Also pathomechanism and risk factors are not completely understood yet. Argon-laser-photocoagulation can prevent the development and treat neovascularizations successfully, but is unable to improve visual function in most cases. Thrombolytic therapy applied systemically is limited due to serious side effects but may be helpful when injected intraocularly. Isovolemic hemodilution may be efficacious in central retinal vein occlusion (CRVO). The creation of a laser-induced chorioretinal venous anastomosis showed serious complications. Since 1999 numerous reports on successful surgical techniques were published. It could be shown that the dissection of the adventitial sheath with separation of the artery from the vein at the arteriovenous crossing where branch retinal vein occlusion occurs can re-establish the retinal blood flow with reduction of macular edema. But it is still unclear which step of the surgery (vitrectomy, ILM-peeling, sheathotomy) is causative for the results. A new surgical approach in CRVO is the radial optic neurotomy (RON). This technique was primarily performed under the hypothesis of decompression of the central vein by cutting the scleral ring. Meanwhile there is some evidence that the formation of chorioretinal shunts may be the decisive factor in cases of successfully performed RON. Due to inconsistent and rare data this surgical procedure needs further evaluation. Another surgical option is the cannulation of the occluded vein. This technique seems to be feasible but the clinical results still have to be proved. Despite several uncertainties and open questions, surgical techniques are likely to overcome the desolate therapeutic situation for retinal vein occlusion of the past.

Argon laser photocoagulation for the treatment of idiopathic, bilateral, recurrent, diffuse retinal arterial aneurysms.

Spontaneous resolution of retinal arterial aneurysms may occur, but recurrences are uncommon. A case of idiopathic, bilateral, recurrent, diffuse retinal arterial aneurysms treated with direct laser photocoagulation is described. A 30-year-old woman with a history of physiologic menopause was found to have bilateral, diffuse, multiple retinal arterial aneurysms with massive subretinal exudates and intraretinal hemorrhages. Fluorescein angiography demonstrated multiple retinal arterial aneurysms with leakage. Direct argon laser photocoagulation successfully closed the aneurysms. During 6 years of follow-up, the aneurysms reoccurred twice, coinciding with a postpartum period. Recurrences were successfully treated with repeated laser photocoagulation with the aneurysms closed off. Hormonal imbalance may play a role in this condition. Recurrent retinal arterial aneurysms can be managed by direct laser photocoagulation.

Preliminary clinical observation of arteriovenous sheathotomy for treatment of branch retinal vein occlusion.

PURPOSE: To document the anatomic and functional improvement of six patients with branch retinal vein occlusion (BRVO) following successful arteriovenous adventitial sheathotomy (AAS). METHODS: Retrospective study of 6 patients (6 eyes) with BRVO treated with AAS. All patients were not eligible for laser photocoagulation and had both macular edema and intraretinal hemorrhage. The visual acuity was in the range of 0.4 to 0.02. All patients underwent pars plana vitrectomy and AAS. The clinical improvement was determined by fundus photograph, fluorescein angiography (FAG), optical coherence tomography (OCT) and multifocal electroretinography (ERG). All patients were followed postoperatively for an average of 20 months ranging from 12 to 24 months. RESULTS: Sheathotomy and decompression of the arteriole/venule (A/V) crossing were achieved in all 6 patients. 5 patients have improved their best-corrected visual acuity 4 lines or more. The best one could reach to 1.0. One month after the operation, fundus photograph and FAG demonstrated the resolution of intraretinal hemorrhage, reduction of non-perfusion area and apparent resolution of retinal venous dilation and tortuosity. OCT confirmed remarkable reduction of retinal thickness. The microcysts at the fovea diminished. Multifocal ERG showed the recovery of the central peak at the macular and the peripheral response density. However, capillary nonperfusion area and microaneurysm were found out by FAG in four patients at the points distal to the sheathotomy three months after the operation. CONCLUSIONS: Anatomic and functional improvement of retina can be achieved in patients with BRVO through AAS. However, the capillary nonperfusion and microaneurysm may follow this surgical procedure in some cases that need further treatment with laser photocoagulation. The better visual improvement may be expected in the patients with earlier surgical intervention.

Vitrectomy with arteriovenous decompression and internal limiting membrane dissection in branch retinal vein occlusion.

PURPOSE: The therapeutic armamentarium for functional improvement after branch retinal vein occlusion (BRVO) is limited with uncertain efficacy. Some surgeons have proposed surgical decompression of the vein at the arteriovenous (AV) crossing. METHODS: Forty-three patients with BRVO were treated in the authors' department from August 1999 to April 2001 with AV decompression. Twenty-five patients with comparable BRVO who refused this surgical intervention served as a control group. All 68 patients received an isovolemic hemodilution therapy for 10 days. The surgical procedure consisted of a standard pars plana vitrectomy and separation of the overlying artery from the vein using microscissors. In 16 cases dissection of the internal limiting membrane (ILM) in the macular area and around the AV crossing was also performed. Assessment of visual acuity, fluorescein angiography, and multifocal electroretinography were performed preoperatively and 6 weeks after surgery in seven patients. RESULTS: Surgical procedure and postoperative course were uneventful. In most of the treated eyes visual acuity improved and fluorescein angiography revealed capillary reperfusion. Functional results in patients with AV decompression were highly significantly better than in the control group. Furthermore, removal of the ILM seems to have an additional beneficial effect on the functional outcome. CONCLUSION: These results demonstrate the therapeutic effect of surgical AV decompression in BRVO. Additional removal of the ILM seems to improve the functional results. Further experience may answer some open questions.

Transretinal feeder vessel ligature in von Hippel-Lindau disease.

PURPOSE: To present a new technique called transretinal feeder vessel ligature for the treatment of retinal angiomas. METHODS: Case report of a patient with peripheral retinal angiomas previously treated unsuccessfully with photocoagulation who responded to this new, alternative surgical treatment. RESULTS: The retinal angiomas decreased in size although two new feeder vessels appeared and the lesions showed a regression pattern after additional laser therapy over the vascular tumors. CONCLUSIONS: A transretinal feeder vessel ligature in association with vitrectomy and photocoagulation may be useful for some advanced or non-responsive cases of retinal angiomas.

Arterial crimping in branch retinal vein occlusion with macular edema.

PURPOSE: To evaluate the effects of arterial crimping plus grid pattern laser photocoagulation on the macular edema due to branch retinal vein occlusion. PATIENTS AND METHODS: Seventy two eyes (70 patients) with macular edema due to BRVO were divided into two similar groups according to age, gender, location and extent of the occluded area. Grid pattern laser photocoagulation alone was applied in 34 eyes (group A), whereas arterial crimping plus grid pattern laser was used in 38 eyes (group B). Visual acuity, central 30 degree perimetry, and fundus fluorescein angiography were carried out in all patients at each examination. Patients were followed up for an average of 23 mo (ranging from 11 to 34 mo). FINDINGS: A rate of 62% and 79% improvement in macular edema was recorded in groups A and B, respectively (p=0.057). The perimetric performance value improved more in group B than in group A (p=0.028). In addition, visual acuity improved more in group B than group A (p=0.041). CONCLUSION: In patients with BRVO, grid pattern retinal photocoagulation treatment plus arterial crimping resulted in better visual performance two years after treatment than did grid pattern photocoagulation alone.

Expression of c-fos and c-jun mRNA following transient retinal ischemia: an approach using ligation of the retinal central artery in the rat.

The expression of the proto-oncogenes c-fos and c-jun was examined by in situ hybridization at various timepoints following transient retinal ischemia by means of ligation of the retinal central artery in the rat. Ischemia of 90-minute duration resulted in the degeneration of neurons in both the ganglion cell layer and the inner nuclear layer at 48 hours after reperfusion. The expression of c-fos and c-jun messenger RNA throughout the entire inner nuclear layer was transiently coinduced following 90-minute retinal ischemia with a peak at 1 hour after reperfusion. This expression was also found in the ganglion cell layer at 3 hours after reperfusion. Weak signals for c-fos and c-jun mRNA were observed at 24 hours after reperfusion and returned to near control levels by 48 hours. c-jun protein expression was detected in the ganglion cell layer, the middle of the inner nuclear layer, and optic nerve head at 3 hours, but not 1 hour, after lethal ischemia/reperfusion; however, c-fos protein expression was not detected after reperfusion. Whereas no neuronal degenerative changes were found at 7 days after 30-minute ischemic retina, c-fos and c-jun messenger RNA were also induced at 1 hour postreperfusion. To our knowledge, this study is the first report to show expression patterns of immediate-early genes after retinal ischemia/reperfusion. These results suggest that changes in expression of c-fos and c-jun after transient retinal ischemia are similar to those after transient brain ischemia, and the selective occlusion of the central retinal artery will provide a useful model for studying ischemic neuronal degeneration in vivo in the rat retina.

Capillary macroaneurysms in central retinal vein occlusion.

The occurrence of macroaneurysms as a consequence of central retinal vein occlusion was previously reported in one study only with the appearance of a single capillary macroaneurysm. We report a case of central retinal vein occlusion presenting several capillary macroaneurysms. It may be supposed that retinal ischemia plays an important role in the pathogenesis of capillary macroaneurysms, in association with the pressure increase in the capillary network due to venous obstruction.