Alexandros N. Stangos

Primary Vitrectomy without Scleral Buckling for Pseudophakic Rhegmatogenous Retinal Detachment

PURPOSE To report the anatomic and functional results of primary vitrectomy without scleral buckling for the treatment of pseudophakic rhegmatogenous retinal detachment (PsRD). DESIGN Prospective, nonrandomized surgical technique study. METHODS One hundred eyes of 98 patients with PsRD were operated by vitrectomy alone. Internal subretinal fluid drainage, cryocoagulation and/or endolaser and fluid-air exchange with sulfur hexafluoride 20% was applied in all cases. The preoperative and postoperative characteristics were analyzed. Main outcome measures were anatomic success rates after initial surgical intervention and after reoperation for primary failures, visual outcome at the last follow-up visit, and complications. RESULTS Mean follow-up +/- standard deviation (SD) was 12 +/- 6.3 months (range, seven to 36 months). Mean final visual acuity +/- SD was 0.42 +/- 0.45 logarithm of the minimum angle of resolution (logMAR) compared with 0.95 +/- 0.73 logMAR before surgery (P < .01). Mean number +/- SD of retinal breaks found before surgery was 1.36 +/- 1.12 (range, zero to five), and an additional 1.58 +/- 2.26 (range, zero to 15) retinal breaks were found during surgery. The retina was reattached successfully after a single surgery in 92 eyes (92%). Recurrence of retinal detachment occurred in eight eyes (8%), caused by proliferative vitreoretinopathy in six eyes (75%) and by new breaks in two eyes (25%). Final anatomic reattachment was obtained in these cases after a mean of 1.75 subsequent operations. Three eyes required permanent silicone oil tamponade so that final anatomic success was achieved in 97 eyes (97%). The most common postoperative complication was ocular hypertonia of more than 21 mm Hg, observed in 36 (36%) eyes, which was managed successfully. CONCLUSIONS Primary vitrectomy without scleral buckling provides a high anatomic success rate in eyes with PsRD and is associated with few complications.

Lamellar macular holes: tomographic features and surgical outcome.

PURPOSE To categorize tomographically the distinct entity of lamellar macular holes (MH) and present the surgical outcomes in our patient cohort. DESIGN Prospective observational and interventional study. METHODS All cases were clinically diagnosed initially with slit-lamp biomicroscopy and confirmed with the use of optical coherence tomography (OCT)-3. Cases either were observed or underwent surgical intervention with a 25-gauge pars-plana vitrectomy (PPV) technique. Follow-up was at least 12 months for all cases and ranged from 12 to 46 months. Main outcome measures included closure of the lamellar MH following surgical intervention; best-corrected visual acuity (BCVA) preoperatively and postoperatively for the cases that underwent surgery. RESULTS We identified 32 eyes of 30 patients with lamellar MH diagnosed by OCT-3. Lamellar MHs were classified into 3 different categories: 1) associated with macular epiretinal membrane (ERM) (20 eyes), 2) secondary to cystoid macular edema (8 eyes), and 3) attributable to partial-thickness macular avulsion after acute posterior vitreous detachment (PVD) (4 eyes). Visual acuity was less affected in cases with an associated ERM. Surgery included PPV and ERM removal (when present), followed by internal limiting membrane (ILM) removal and 16% C(3)F(8) injection. Postoperatively, BCVA improved in 17 out of the 20 cases (85%) operated from the first group of patients; 3 cases retained the same BCVA preoperatively and postoperatively. Mean BCVA improvement in the first group was 2.6 Snellen lines, which was statistically significant (P = .002, paired t test). CONCLUSIONS Surgical treatment of lamellar MH associated with an ERM may result in preservation or improvement of visual acuity, by relieving the tangential traction caused by the ERM.

Multiple Evanescent White Dot Syndrome Following Simultaneous Hepatitis-A and Yellow Fever Vaccination

Purpose: To report a case of multiple evanescent white dot syndrome (MEWDS) following simultaneous hepatitis-A virus (HAV) and yellow fever (YF) vaccination. Methods: Review of the clinical, laboratory, photographic, and angiographic records of a patient suffering from MEWDS. Results: A healthy 50-year-old woman presented with rapidly progressive left-eye visual loss, associated with photopsias and a para-central scotoma, one week after receiving simultaneous HAV and YF vaccination. Both anterior segments and right-eye fundus were unremarkable. Fundus examination of the left-eye disclosed papillitis with multiple, small, white, outer-retinal lesions. Angiographic tests were pathognomonic for MEWDS. Perimetry revealed left-eye blind spot enlargement. Initial inflammatory/infectious work-up was negative. Signs and symptoms resolved spontaneously within 6 weeks, with concomitant normalization of ancillary exams. Conclusions: The clinical presentation and the benign course were consistent with the diagnosis of MEWDS. No other aetiopathogenic factor than simultaneous HAV and YF immunization was identified, suggesting an autoimmune basis for MEWDS in predisposed patients.

Lactate-Induced Retinal Arteriolar Vasodilation Implicates Neuronal Nitric Oxide Synthesis in Minipigs

PURPOSE To investigate the role of neuronal nitric oxide (NO) synthesis in the retinal vasodilatory response to lactate in minipigs. METHODS Thirteen eyes of 13 minipigs were evaluated. Ten eyes received an intravenous infusion of N(omega)-nitro-L-arginine methyl ester (L-NAME). After 1 hour, the same eyes received an intravitreous juxta-arteriolar microinjection of 30 microL of L-lactate 0.5 M (pH 7.4) through a micropipette. Ten minutes later, 9 of 10 eyes received an intravitreous juxta-arteriolar microinjection of 30 microL of L-NAME 0.01 M (pH 7.4), and 1 received physiologic saline solution (PSS). The remaining three eyes received a microinjection of 30 microL of L-lactate 0.5 M (pH 7.4), without intravenous or intravitreous L-NAME. RESULTS The three eyes that received juxta-arteriolar injection of L-lactate only showed a reproducible increase in retinal arteriolar diameter that persisted during the entire study period (maximum effect at 20 minutes, 40.9% +/- 3.2%). Retinal arteriolar diameter decreased by 4.1% 1 hour after intravenous L-NAME when compared with baseline but the difference did not reach significance. The juxta-arteriolar injection of L-lactate induced a significant increase in retinal arteriolar diameter (22.7% and 28.7% at 5 and 10 minutes, respectively; P < 0.01), followed by a significant decrease (8.6%; P < 0.01) 10 minutes after juxta-arteriolar injection of L-NAME. Injection of PSS had no effect on retinal arteriolar diameter. CONCLUSIONS Juxta-arteriolar administration of L-lactate induced vasodilation, which was also observed with continuous intravenous infusion of L-NAME. Moreover, juxta-arteriolar L-NAME microinjection significantly suppressed the vasodilatory effect of L-lactate. These data suggest that neuronal-derived NO is an important mediator of lactate-induced vasodilation in minipigs.

The Vasodilatory Effect of Juxta-arteriolar Microinjection of EndothelinA Receptor Inhibitor in Healthy and Acute Branch Retinal Vein Occlusion Minipig Retinas

Purpose. To investigate the effect of the endothelin(A) receptor inhibitor BQ-123 on the retinal arteriolar vasculature in minipig retinas in normal eyes and eyes with acute branch retinal vein occlusion (BRVO). Methods. Seven healthy eyes of seven minipigs and six eyes of six minipigs with experimental BRVO were evaluated under systemic anesthesia. An intravitreal juxta-arteriolar microinjection of 30 microL BQ-123 0.61 microg/mL (pH 7.4) was performed in all but one eye from each group, into which the physiologic saline vehicle alone was injected. Vessel-diameter changes were measured with a retinal vessel analyzer. Results. In healthy minipig retinas (n = 6), arteriolar diameter (+/-SD) increased 6.19% +/- 3.55% (P < 0.05), 25.98% +/- 2.37% (P < 0.001), 23.65% +/- 1.2% (P < 0.001), and 16.84% +/- 1.95% (P < 0.001), at 1, 5, 10, and 15 minutes, respectively, after BQ-123 microinjection. Two hours after experimental BRVO (n = 5), the retinal arteriolar diameter had decreased (13.07% +/- 5.7%; P < 0.01). One, 5, 10, and 15 minutes after BQ-123 microinjection, retinal arteriolar diameter had increased by 7.14% +/- 3.3% (P < 0.01), 26.74% +/- 7.63% (P < 0.001), 23.67% +/- 6.4% (P < 0.001), and 16.09% +/- 3.41% (P < 0.001), respectively. Vehicle only injection had no vasoactive effect on physiologic or BRVO retinas. Conclusions. A significant increase in retinal arteriolar diameter was demonstrated after juxta-arteriolar BQ-123 microinjection in healthy and in acute BRVO minipig retinas. The results suggest a role for endothelin-1 in maintaining retinal basal arteriolar tone. Reversing the BRVO-related vasoconstriction by juxta-arteriolar BQ-123 microinjection could bring a new perspective to the management of BRVO.

The rationale of retinal endovascular fibrinolysis in the treatment of retinal vein occlusion: from experimental data to clinical application.

Purpose: We describe a retinal endovascular fibrinolysis technique to directly reperfuse experimentally occluded retinal veins using a simple micropipette. Methods: Retinal vein occlusion was photochemically induced in 12 eyes of 12 minipigs: after intravenous injection of 10% fluorescein (1-mL bolus), the targeted retinal vein segment was exposed to thrombin (50 units) and to Argon laser (100–200 mW) through a pars plana approach. A beveled micropipette with a 30-&mgr;m-diameter sharp edge was used for micropuncture of the occluded vein and endovascular microinjection of tissue plasminogen activator (50 &mgr;g/mL) in 11 eyes. In one control eye, balanced salt solution was injected. The lesion site was examined histologically. Results: Retinal vein occlusion was achieved in all cases. Endovascular microinjection of tissue plasminogen activator or balanced salt solution led to reperfusion of the occluded retinal vein in all cases. Indicative of successful reperfusion were the following: continuous endovascular flow, unaffected collateral circulation, no optic disk ischemia, and no venous wall bleeding. However, balanced salt solution injection was accompanied by thrombus formation at the punctured site, whereas no thrombus was observed with tissue plasminogen activator injection. Conclusion: Retinal endovascular fibrinolysis constitutes an efficient method of micropuncture and reperfusion of an experimentally occluded retinal vein. Thrombus formation at the punctured site can be prevented by injection of tissue plasminogen activator.

The Effect of Learning Curve on the Surgical Outcome of Viscocanalostomy

PurposeTo evaluate the influence of learning curve on the surgical outcome of viscocanalostomy. MethodsRetrospective, interventional study. Chart review of the first consecutive open-angle glaucoma cases that received viscocanalostomy in 1 institution between July 1996 and June 2000. Overall success was defined as no visual field deterioration; postoperative intraocular pressure (IOP) ⩽20 mm Hg; and IOP reduction ≥30% compared with baseline values with or without medication. When medications were not required, success was defined as complete. Demographic, procedural, and postoperative data were tabulated and analyzed. Primary outcome measures: overall and complete success rates. Secondary outcome measures: number of glaucoma medications and surgical complications. ResultsA total of 180 cases were analyzed. Mean follow-up (±SD) was 28.9±5.9 months (range, 12-36 mo). Overall success has significantly improved from 64% to 91% when comparing the first 45 to the last 45 cases of the series (Mantel-Cox, P=0.005). Similarly, complete success has significantly improved from 38% to 73% (Mantel-Cox, P=0.004). The mean number of glaucoma medication (±SD) significantly decreased from 2.58±0.94 before surgery to 0.53±0.79 after surgery (Wilcoxon, P<0.001). Surgical complications decreased from 16 in the first 45 cases to 10 in the last 45 cases without reaching statistical significance (Pearson &khgr;2, P=0.315). ConclusionsViscocanalostomy appears to safely reduce IOP in cases with medically uncontrolled open-angle glaucoma. Mastering viscocanalostomy procedure is achievable after the first 40 cases.

Cavernous sinus thrombosis elicited by a central retinal vein venous stasis retinopathy

BackgroundCentral retinal vein occlusion is a relatively common retinal disorder in the elderly, and those with cardiovascular or thrombophilic risk factors are at increased risk. Although still unsatisfying, some treatments for the acute and chronic phases have been established based on randomized studies. However, for rare conditions mimicking central retinal vein occlusion, treatment of the acute phase should be targeted at etiology. A rare condition mimicking central retinal vein occlusion in a 70-year-old man is presented and discussed.MethodsA 70-year-old man was admitted to the hospital for isovolemic hemodilution related to a central retinal vein occlusion of the elderly, after a sudden decrease in visual acuity to 0.1.ResultsClinical and laboratory work-up demonstrated a venous stasis retinopathy, related to an atypical cavernous sinus thrombosis of undetermined origin. The patient had experienced in the past 6 months intermittent diplopia and an irreducible conjunctival hyperemia. Hemodilution was dismissed. Soon after initiation of anticoagulation therapy, the patient’s clinical signs and symptoms improved. Final visual acuity was 0.8.ConclusionVenous stasis retinopathy secondary to cavernous sinus thrombosis is rare. However, careful clinical examination and extensive laboratory work-up is needed to exclude central retinal vein occlusion not associated with common vascular pathologies of the elderly.