Factors associated with the development of blepharoptosis after pars plana vitrectomy surgery.

PURPOSE: To determine the incidence and risk factors for developing blepharoptosis after vitrectomy surgery. METHODS: This prospective observational study conducted in patients who had vitrectomy surgery at the University of California, San Francisco. The patients' eyelids were photographed before, surgery and follow-up visits at 1 day, 1 week, 1 month, 3 months, and 6 months after surgery. Levator excursion (LE), palpebral fissure (PF) height and marginal reflex distance 1 (MRD1) changes from baseline were evaluated. Operative parameters associated with lid parameter changes were analyzed. RESULTS: Thirty-eight eyes were enrolled in the study. Multivariate analysis performed for PF changes from pre-operative were -0.47 mm, 0.33 mm, and 0.09 mm at 1 week, 1 month and 6 months after surgery, respectively (p-value 0.1, 0.2, and 0.8). The mean change of LE from preoperative was -0.44 mm, -0.15 mm, and 0.35 mm at 1 week, 1 month and 6 months after surgery, respectively (p-value 0.3, 0.7 and 0.4). The reduction of MRD1 at 1 week, 1 month and 6 months after surgery were -0.08 mm, -0.13 mm and -0.01 mm, respectively (p = .003, p = .6 and 0.9). Triamcinolone usage was associated with reduction of MRD1 and LE. CONCLUSION: Blepharoptosis presents most during the first week after surgery. The possibility of developing transient changes in eyelid position after vitrectomy surgery should be discussed with patients.

VITREOMACULAR TRACTION AFTER DEXAMETHASONE INTRAVITREAL IMPLANT (OZURDEX) INJECTION: THE EFFECT OF ANOMALOUS POSTERIOR VITREOUS DETACHMENT.

PURPOSE: To describe an unusual macular complication after dexamethasone intravitreal implant (Ozurdex) injection. METHODS: Case history and macular optical coherence tomography findings are described. The report describes a patient with proliferative diabetic retinopathy and vitreoschisis who received Ozurdex treatment for diabetic macular edema. RESULTS: After Ozurdex injection, visual acuity worsened because of newly formed vitreomacular traction that was demonstrated on optical coherence tomography imaging. A mechanism is proposed by which the medication might have contributed to this outcome. CONCLUSION: In this patient with vitreoschisis, a thickened posterior hyaloid membrane and traction developed after Ozurdex injection. The authors recommend careful evaluation of the macula before injection, particularly in diabetic patients with vitreoschisis.

Kinematic study of ozurdex injection in balanced salt solution: modeling the behavior of an injectable drug delivery device in vitrectomized eyes.

PURPOSE: To analyze the kinematics of a dexamethasone intravitreal implant, Ozurdex, after its injection in a balanced salt solution (BSS) at different release angles to simulate its movement in BSS/aqueous-filled eyes. METHODS: Eighteen Ozurdex implants were injected into a BSS-filled box at different release angles (15°, 30°, 45°), using 6 implants/group. The movement of injected implants was recorded by a high-speed video camera. Each implant's trajectory was graphically demonstrated by plotting over time. By using a distance-time function graph, the implant's velocity and normalized energy were calculated. RESULTS: The high-speed video revealed that implants injected at 15° followed a more horizontal trajectory compared to those injected from 30° and 45°, respectively. The implant injected at 15° also achieved the highest mean initial velocity and mean initial normalized energy. The implant velocity from each injection angle decreased exponentially over time and reached nearly zero at 0.1 s. An injection of the implant at a flatter angle was also associated with higher mean retinal impact normalized energy. CONCLUSIONS: An implant injected at a flatter angle tends to travel farther in the horizontal plane and has more initial velocity, which theoretically generates higher initial normalized energy and retinal impact normalized energy. The accidental injection at a flatter angle, which results in shortening of the effective travel distance, may carry the potential risk of direct retinal injury from the injected implant. The amount of energy necessary to cause direct retinal injury, and whether this would be clinically significant, requires further study.

2.5% and 10% phenylephrine for mydriasis in diabetic patients with darkly pigmented irides.

OBJECTIVE: To compare the clinical efficacy and systemic side effects of2.5% and 10%phenylephrinefor mydriasis in diabetic patient with darkly pigmented irides. MATERIAL AND METHOD: A prospective randomized double-blind controlled trial was conducted. One hundred diabetic patients were randomly allocated into 2.5% and 10% phenylephrine groups by block randomization. Pupil diameter, blood pressure and heart rate were measured before and after eye drop instillations. RESULTS: The mean pupil diameters after instillation in the right eye were 7.05 +/- 0.71 mm (2.5% phenylephrine group) and 7.40 +/- 0.72 mm (10% phenylephrine group, p = 0.02) and in the left eye were 7.05 +/- 0.72 mm (2.5% phenylephrine group) and 7.39 +/- 0.72 mm (10% phenylephrine group, p = 0.02). There was no clinically significant difference in mean heart rate, mean systolic and diastolic blood pressure. CONCLUSION: In diabetic patients with darkly pigmented irides, 10% phenylephrine is more effective than 2.5% phenylephrine with statistical significance. The authors recommend a single dose of 10% phenyleprine for mydriasis in these patients. However the lower concentration is recommended for use in those who exhibit a higher prevalence ofsignificant vascular disease and autonomic dysfunction and seem to be susceptible to severe adverse reaction of phenylephrine.