Initial report of quantification of retinal blood flow velocity in normal human subjects using the Retinal Functional Imager (RFI).

The Retinal Functional Imager (RFI) is a novel method for assessing retinal blood flow (RBF) velocity. The purpose of this study was to evaluate RBF velocities in normal human retinas using the RFI. RBF velocity measurements were performed in normal subjects using the RFI (Optical Imaging Ltd., Rehovot, Israel) at the Retina Center of The New York Eye and Ear Infirmary, New York, USA. Using proprietary software processing, the characteristics of the RBF were visualized and measured. The study population comprised fifty-four eyes of 27 normal subjects (20 male and 34 female). The average arterial blood flow velocity was 4.6 ± 0.6 mm/s in males and 4.8 ± 0.7 mm/s in females (the difference was not statistically significant, p value = 0.27). The average venous blood flow velocity was 3.8 ± 0.5 mm/s in males and 3.6 ± 0.4 mm/s in females (the difference again was not statistically significant, p value = 0.11). The average arterial blood flow velocity was 4.8 ± 0.5 mm/s in the right eye and 4.6 ± 0.7 mm/s in the left eye. The average venous blood flow velocity was 3.7 ± 0.4 mm/s in the right eye and 3.6 ± 0.3 mm/s in the left eye. Venous and arterial blood flow velocities were found to be faster in the right eye than in the left eye in our sample, but the differences were not statistically significant (p value = 0.53 and 0.33, respectively). This is the first report of quantification of the RBF using the RFI. The RFI appears to be an effective tool in quantitative evaluations of RBF velocities. The values from the study constitute a normative database which can be used to evaluate and compare eyes with known or suspected pathology.

Descemet stripping automated endothelial keratoplasty after failed penetrating keratoplasty.

PURPOSE: To report the rate of graft dislocation, surgical anatomic success, and postsurgical complications associated with Descemet stripping automated endothelial keratoplasty (DSAEK) after previous primary failed penetrating keratoplasty (PK). METHODS: Institutional review board-approved, single-center, retrospective chart review study of 30 eyes of 30 patients with prior failed PK who underwent DSAEK with a minimum of 3 months follow-up. Primary outcomes measured included rates of anatomic success and failure, postoperative complications, lenticle size, visual acuity, intraocular pressure change, and a report of external factors that may affect success. RESULTS: Thirty eyes of 30 patients were identified. The primary dislocation rate was 16.7%. Five primary DSAEKs detached; 1 was successfully rebubbled in the office, 2 had repeat successful DSAEKs, and 2 failed on a second attempt and had a subsequent PK. Despite successful anatomic attachment, 1 eye had primary graft failure, 3 that cleared initially failed within 6 months, and 1 that successfully cleared had subsequent graft rejection resulting in failure at 6 months. The 2 eyes requiring PK were excluded from the visual outcomes analysis, leaving 28 eyes with successfully attached lenticles. At 3 months postoperatively, of the 28 eyes, 19 showed an improvement in visual acuity, 6 had no change in vision from preoperative data, and 1 had worsening of vision (anatomic attachment but endothelial failure). Two of the 28 eyes had no data at that time point. CONCLUSIONS: DSAEK eyes after failed PK demonstrated improved vision with a low complication rate in a majority of patients. The graft dislocation rate and postoperative complications rates are comparable with the primary DSAEK dislocation rates in our own published series and in the literature.