Surgical Intervention of Steroid-Induced Ocular Hypertension from Ozurdex

Use of Intravitreal Dexamethasone Implant in Patients with Cataract and Macular Edema Undergoing Phacoemulsification

Purpose

To study the safety and efficacy of intravitreal dexamethasone implant in patients with cataract and macular edema undergoing phacoemulsification and intraocular lens (IOL) implantation.

Methods

Twenty-four eyes with macular edema secondary to diabetic retinopathy (diabetic macular edema [DME]) and retinal vein occlusion (RVO) were retrospectively reviewed. These eyes underwent phacoemulsification with IOL implantation and intravitreal dexamethasone implant 0.7 mg at the same setting between September 2012 and September 2013. Demographic data, best-corrected visual acuity (BCVA), central macular thickness (CMT), intraocular pressure (IOP), surgical time, and complications were recorded.

Results

Twelve eyes had DME and 12 eyes had RVO (10 central RVO and 2 branch RVO). Median baseline logMAR BCVA was 1.0 (Snellen 20/200) and mean baseline CMT was 530.2 ± 218.9 µm. Median follow-up duration was 13 months. At last follow-up, median visual acuity improved significantly to 0.523 (Snellen 20/66) (p = 0.003) and CMT decreased to 300.7 ± 78.1 µm (p = 0.000). Median surgical time was 23 minutes. There were no intraoperative complications. In 12 eyes, macular edema recurred, requiring further treatment, and median time to recurrences was 21 weeks. One eye had raised IOP after second dexamethasone implant for recurrent macular edema. No major complication such as vitreous hemorrhage, retinal detachment, or endophthalmitis occurred.

Conclusions

Combined cataract surgery with intravitreal dexamethasone implant seems to be safe and effective in treating patients with cataract and macular edema in this small case series. A larger prospective study with longer follow-up is necessary to demonstrate the long-term benefit of this combined procedure.

Statistical design for formulation optimization of hydrocortisone butyrate-loaded PLGA nanoparticles

The aim of this investigation was to develop hydrocortisone butyrate (HB)-loaded poly(D,L-lactic-co-glycolic acid) (PLGA) nanoparticles (NP) with ideal encapsulation efficiency (EE), particle size, and drug loading (DL) under emulsion solvent evaporation technique utilizing various experimental statistical design modules. Experimental designs were used to investigate specific effects of independent variables during preparation of HB-loaded PLGA NP and corresponding responses in optimizing the formulation. Plackett-Burman design for independent variables was first conducted to prescreen various formulation and process variables during the development of NP. Selected primary variables were further optimized by central composite design. This process leads to an optimum formulation with desired EE, particle size, and DL. Contour plots and response surface curves display visual diagrammatic relationships between the experimental responses and input variables. The concentration of PLGA, drug, and polyvinyl alcohol and sonication time were the critical factors influencing the responses analyzed. Optimized formulation showed EE of 90.6%, particle size of 164.3 nm, and DL of 64.35%. This study demonstrates that statistical experimental design methodology can optimize the formulation and process variables to achieve favorable responses for HB-loaded NP.