EU postmarket surveillance plans for medical devices.

PURPOSE: Recent public health safety issues involving medical devices have led to a growing demand to improve the current passive-reactive postmarket surveillance (PMS) system. Various European Union (EU) national competent authorities have started to focus on strengthening the postmarket risk evaluation. As a consequence, the new EU medical device regulation was published; it includes the concept of a PMS Plan. METHODS: This publication reviewed Annex III Technical Documentation on PMS and Annex XIV Part B: Postmarket clinical follow-up from the new Regulation (EU) 2017/745 of the European Parliament and of the Council on medical devices. RESULTS: The results of the PMS activities will be described in the PMS plan and will be used to update other related documents. A modular approach to structure the contents of the PMS plan will help to consistently update other PMS information. It is our suggestion that the PMS plan should consist of a PMS plan Core and a PMS plan Supplement. The PMS plan Core document will describe the PMS system, and the PMS plan Supplement will outline the specific activities performed by the manufacturer for a particular medical device. CONCLUSIONS: The PMS plan may serve as a thorough tool for the benefit-risk evaluation of medical devices. If properly developed and implemented, it will function as a key player in the establishment of a new framework for proactive safety evaluation of medical devices.

Evaluation of an integrated orbital tissue expander in congenital anophthalmos: report of preliminary clinical experience.

PURPOSE: To evaluate the effectiveness of an orbital tissue expander designed to stimulate orbital bone growth in an anophthalmic socket. DESIGN: Retrospective, noncomparative, interventional case series. SETTINGS: Institutional. STUDY POPULATION: Nine consecutive patients with unilateral congenital anophthalmos. INTERVENTION: The orbital tissue expander is made of an inflatable silicone globe sliding on a titanium T-plate secured to the lateral orbital rim with screws. The globe is inflated by a transconjunctival injection of normal saline through a 30-gauge needle to a final volume of approximately 5 cm(3). Computed tomography scans were used to determine the orbital volume. The data studied were: demographics, prior orbital expansion procedures, secondary interventions, orbital symmetry, and implant-related complications. MAIN OUTCOME MEASURES: The primary outcome measure was the orbital volume change, and the secondary outcome measures were changes in forehead, brow, and zygomatic eminence contour and adverse events. RESULTS: The average patient age at implantation was 41.89 ± 39.42 months (range, 9 to 108 months). The initial average volume of inflation was 3.00 ± 0.87 cm(3) (range, 2.0 to 4.0 cm(3)), and the average final volume of 4.33 ± 0.50 cm(3) (range, 4.0 to 5.0 cm(3)) was achieved. The duration of expansion was 18.89 ± 8.80 months (range, 4 to 26 months). All patients demonstrated an average increase in the orbital tissue expander implanted orbital volume of 5.112 ± 2.173 cm(3) (range, 2.81 to 10.38 cm(3)). The average difference between the volume of the implanted and the initial contralateral orbit was 5.68 ± 2.34 cm(3), which decreased to 2.53 ± 1.80 cm(3) at the final measurement (P < .001, paired t test). All implants remained inflated except for 2 iatrogenic punctures at the second inflation and 1 that was the result of implant failure. All were replaced. CONCLUSIONS: The integrated orbital tissue expander is safe and effective in stimulating anophthalmic socket bone growth.

Estimation of intraocular pressure in rabbits with commonly used tonometers.

BACKGROUND AND OBJECTIVES: To validate accuracy and reproducibility of the Perkins tonometer, pneumatonometer, and Tono-Pen XL (Medtronic Solan, Jacksonville, FL) in estimating intraocular pressure (IOP) in rabbits. MATERIALS AND METHODS: IOP was increased from 5 to 50 mm Hg in 5-mm increments. Measurements were compared to readings of two digital manometers simultaneously measuring real IOP in the anterior chamber and vitreous cavity. Interobserver accuracy was evaluated using 4 eyes with the Perkins tonometer. RESULTS: The Perkins tonometer and Tono-Pen XL underestimated IOP and were more accurate at pressures less than 30 mm Hg. No statistically significant difference was found between real IOP and Tono-Pen XL readings. The pneumatonometer overestimated pressures in the low ranges but was accurate at pressures greater than 40 mm Hg. The Tono-Pen XL had more variability than the Perkins tonometer and pneumatonometer at high IOP. CONCLUSIONS: None of the tonometers are accurate or reproducible in estimating IOP in rabbits over the tested range. Pneumatonometry, although not very accurate, has the advantage of having acceptable variability.

A newly designed glaucoma drainage implant made of poly(styrene-b-isobutylene-b-styrene): biocompatibility and function in normal rabbit eyes.

OBJECTIVE: To report clinical evaluation, flow patency, and histopathological findings of a novel glaucoma drainage implant (GDI) made of poly(styrene-b-isobutylene-b-styrene) (SIBS) in rabbits. METHODS: In 16 normal eyes, the proximal end of the SIBS GDI was inserted into the anterior chamber while the distal end was placed in the subconjunctival space. A control group underwent implantation of a similarly designed silicone GDI. Slitlamp follow-up and intraocular pressure measurements were recorded. Flow patency was evaluated by injecting 0.01% fluorescein into the anterior chamber. Immunostaining against collagen IV, macrophages, and alpha smooth muscle actin was performed. RESULTS: Slitlamp examination suggested adequate biocompatibility. A low and diffuse bleb was observed in the SIBS group. All SIBS tubes were patent 6 months after insertion. Immunostaining demonstrated noncontinuous collagen deposition. No macrophages or myofibroblasts were visible around the SIBS tubes. In contrast, silicone induced collagen deposition and myofibroblast differentiation. CONCLUSION: This new GDI is clinically biocompatible in the rabbit and maintained 100% patency at 6 months. A remarkable difference was the absence of myofibroblasts in the surrounding tissue in the SIBS group. CLINICAL RELEVANCE: This novel GDI made of SIBS would prevent the feared complication of hypotony and will decrease the amount of subconjunctival fibrosis.

Validation of the Barraquer tonometer for high intraocular pressure estimation.

PURPOSE: To compare the pneumatonometer and the Tono-Pen XL in a closed ex-vivo system in human eye bank eyes at high intraocular pressures (IOP) and evaluate the validity of high IOP measurements with the Barraquer tonometer. METHODS: Intraocular pressure was monitored by cannulation of the anterior chamber and vitreous cavity in eight human cadaver eyes (mean donor age: 77.3 +/- 4.9 years, range: 72 to 84 years). Intraocular pressure measurements were taken at 50, 65, and 90 mmHg with the Tono-Pen XL and pneumatonometer. Intraocular pressure was raised to 110 mmHg and then the eyes were deflated slowly until they reached 50 mmHg. Pressure readings with the Barraquer tonometer were recorded when the corneal tonometer interface reached the inner and outer rings. RESULTS: The Tono-Pen XL underestimated IOP, a tendency that was more evident at higher IOP In contrast, the pneumatonometer was more accurate and reliable at IOP of 50 and 65 mmHg but its readings underestimated IOP at 90 mmHg. The Barraquer tonometer used in this experiment accurately estimated high IOP A variability of 5.9 mmHg and 5.8 mmHg were recorded for the inner and outer ring, respectively. CONCLUSIONS: The Tono-pen XL is an inadequate instrument to assess pressures normally encountered during LASIK flap creation in an ex vivo model using human cadaver eyes. The pneumatonometer and the Barraquer tonometer are accurate instruments at high IOP; however, the pneumatonometer underestimated pressures around 90 mmHg.

Efficacy of various drugs in the prevention of posterior capsule opacification: experimental study of rabbit eyes.

PURPOSE: To assess the efficacy of various drugs in the prevention of posterior capsule opacification (PCO) in a closed capsular bag technique. SETTING: Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami School of Medicine, Miami, Florida, USA. METHODS: Lens material was removed using phacoaspiration or phacoemulsification through a microcapsulorhexis according to the hardness of the crystalline lens correlated with the weight and age of the rabbits. A mixture of an ophthalmic viscosurgical device (sodium hyaluronate 1.4% [SHA]) and a drug was injected into the empty capsular bag, allowed to remain inside for 3 minutes, and removed. The capsular bag was rinsed with balanced salt solution (BSS) and refilled with SHA. In a group of rabbits, the capsulorhexis was sealed with a minicapsulorhexis valve (MCV). Rabbits were treated with 1 of the following: SHA (control), BSS, mitomycin-C (MMC, 0.2 mg/mL), ethylenediaminetetraacetic acid (EDTA) (10 mM and 15 mM), 5-fluorouracil (5-FU, 33 mg/mL), acetic acid (3%, 0.3%, and 0.003%), and distilled water. RESULTS: Upon completion of the study, the control and treated eyes had PCO and new lens material (not residual). Anterior capsule proliferation was observed in eyes treated with 5-FU. The order of PCO appearance (earliest to latest) was as follows: 15 mM EDTA, SHA, MMC, acetic acid 0.3%, acetic acid 3%, BSS, distilled water (small animals; no MCV), acetic acid 0.003%, 5-FU, 10 mM EDTA, and distilled water (large animals; MCV). The earliest appearance was day 1 postoperatively and the latest, day 47. CONCLUSIONS: Distilled water and 10 mM EDTA treatments were the most efficient in retarding the appearance of PCO.