Spontaneous subconjunctival orbital fat prolapse: presentation of four cases

BACKGROUND: Subconjunctival orbital fat prolapse is a benign entity characterized by orbital fat herniation through a dehiscence in Tenon's capsule, usually between the superior and lateral recti muscles. It is often associated with ocular trauma or surgery, although spontaneous cases have also been reported with a predilection for obese individuals. PATIENTS AND METHODS: A retrospective study of four subconjunctival orbital-fat prolapse cases with no history of ocular surgery or trauma was performed. A trans-conjunctival surgical approach with Tenon's capsule repair was offered to all subjects. Differential diagnosis is discussed. RESULTS: The diagnosis of subconjunctival orbital fat prolapse was confirmed in all cases by histopathological examination. Functional and aesthetic postoperative results were excellent, with no recurrences during follow-up, for all cases. CONCLUSIONS: Although rare, subconjunctival orbital fat prolapse should be recognized. Surgical management offers excellent results

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

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

Intravitreal injection of expansile perfluoropropane (c(3)f(8)) for the treatment of vitreomacular traction

To study the efficacy of a single intravitreal injection of expansile gas in releasing vitreomacular traction

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-μm-diameter sharp edge was used for micropuncture of the occluded vein and endovascular microinjection of tissue plasminogen activator (50 μg/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

Standardization of choroidal thickness measurements using enhanced depth imaging optical coherence tomography

AIM: To describe and evaluate a standardized protocol for measuring the choroidal thickness (ChT) using enhanced depth imaging optical coherence tomography (EDI OCT). METHODS: Single 9 mm EDI OCT line scans across the fovea were used for this study. The protocol used in this study classified the EDI OCT images into four groups based on the appearance of the choroidal-scleral interface and suprachoroidal space. Two evaluation iterations of experiments were performed:first, the protocol was validated in a pilot study of 12 healthy eyes. Afterwards, the applicability of the protocol was tested in 82 eyes of patients with diabetes. Inter-observer and intra-observer agreements on image classifications were performed using Cohen’s kappa coefficient (k). Intraclass correlation coefficient (ICC) and Bland-Altman’s methodology were used for the measurement of the ChT. RESULTS: There was a moderate (k=0.42) and perfect (k=1) inter- and intra-observer agreements on image classifications from healthy eyes images and substantial (k=0.66) and almost perfect (k=0.86) agreements from diabetic eyes images. The proposed protocol showed excellent inter- and intra-observer agreements for the ChT measurements on both, healthy eyes and diabetic eyes (ICC>0.90 in all image categories). The Bland-Altman plot showed a relatively large ChT measurement agreement in the scans that contained less visible choroidal outer boundary. CONCLUSIONS: A protocol to standardize ChT measurements in EDI OCT images has been developed; the results obtained using this protocol show that the technique is accurate and reliable for routine clinical practice and research