A Comparison of the Laser Flare Cell Meter and Fluorophotometry in Assessment of the Blood-Aqueous Barrier

Purpose. To evaluate and compare the use of the Kowa laser flare cell meter and intravenous anterior chamber fluorophotometry in assessment of the blood-aqueous barrier after cataract surgery. Method. Laser flare and cell measurements and fluorophotometry were performed at 1 and 3 months after surgery in 48 eyes of 44 patients admitted for routine cataract surgery. The fellow pseudophakic eyes of these patients were used as controls. Results. The two techniques measure different parameters, but both methods are able to document the integrity or breakdown of the blood-aqueous barrier. However, the laser flare cell meter is more sensitive in quantifying subtle changes in barrier function to large molecules (proteins). Various methods of assessing anterior chamber fluorophotometry data were also compared. Measurement of a diffusion coefficient (requiring the measurement of plasma fluorescence) was not found to be more sensitive than other methods and did not alter the clinical significance of data obtained from the measurement of anterior chamber fluorescence alone. Conclusions. Both the laser flare cell meter and fluorophotometry provide a method for the assessment of the postoperative blood-aqueous barrier. However, the laser flare cell meter is rapid, noninvasive, and relatively easier to use. Therefore, for clinical use, it has great practical advantages over fluorophotometry. Invest Ophthalmol Vis Sci. 1993;34:3124-3130

An In Vitro Evaluation of the Anew Zephyr Open-Bag IOL in the Prevention of Posterior Capsule Opacification Using a Human Capsular Bag Model

PURPOSE. During cataract surgery an IOL is placed within the capsular bag. Clinical studies show that IOLs with a square edge profile and complete contact between the IOL and the anterior capsule (AC) are currently the best way to prevent posterior capsule opacification (PCO). This has been challenged by recent clinical and experimental observations, which suggest that if the capsular bag is kept open with separation of contact between the AC and posterior capsule (PC) by an "open-bag device" PCO is dramatically reduced. Therefore, the current study set out to evaluate the putative merits of an open-bag IOL (Anew Zephyr) in a human capsular bag model. METHODS. An in vitro organ culture model using the bag-zonular-ciliary body complex isolated from fellow human donor eyes was prepared. A capsulorhexis and lens extraction were performed, and an Alcon Acrysof IOL or Anew Zephyr IOL implanted. Preparations were secured by pinning the ciliary body to a silicone ring and maintained in 6 mL Eagle's minimum essential medium (EMEM) or EMEM supplemented with 2% vol/vol human serum (HS) and 10 ng/mL TGF-beta 2 for 28 days. Cell growth and capsular modifications were monitored with phase-contrast and modified dark-field microscopy. RESULTS. In serum-free EMEM culture conditions, cells were observed growing onto the PC of preparations implanted with an Anew Zephyr IOL, but this was retarded relative to observations in match-paired capsular bags implanted with an Alcon Acrysof IOL. In the case of cultures maintained in 2% HS-EMEM plus TGF-b2, the movement on to the PC was again delayed with the presence of an Anew Zephyr IOL. Differences in the degree of growth on the PC and matrix modifications were apparent with the different donors, but in each case the match-paired Alcon Acrysof implanted bag exhibited significantly greater coverage and modification of the capsule. CONCLUSIONS. The Anew Zephyr open-bag IOL performs consistently better than the Alcon Acrysof IOL in the human capsular bag model. We propose that the benefits observed with the Anew Zephyr result from a reduction in growth factor levels available within the capsular bag and a barrier function imposed by the ring haptic