High-Resolution Optical Coherence Tomography Retinal Imaging: A Case Series Illustrating Potential and Limitations

Purpose. To present a series of retinal disease cases that were imaged by spectral domain optical coherence tomography (SD-OCT) in order to illustrate the potential and limitations of this new imaging modality. Methods. The series comprised four selected cases (one case each) of age-related macular degeneration (ARMD), diabetic retinopathy (DR), central retinal artery occlusion (CRAO), and branch retinal vein occlusion (BRVO). Patients were imaged using the Heidelberg Spectralis (Heidelberg Engineering, Germany) in SD-OCT mode. Patients also underwent digital fundus photography and clinical assessment. Results. SD-OCT imaging of a case of age-related macular degeneration revealed a subfoveal choroidal neovascular membrane with detachment of the retinal pigment epithelium (RPE) and neurosensory retina. Using SD-OCT, the cases of DR and BRVO both exhibited macular edema with cystoid spaces visible in the outer retina. Conclusions. The ability of SD-OCT to clearly and objectively elucidate subtle morphological changes within the retinal layers provides information that can be used to formulate diagnoses with greater confidence

Worldwide Argus II implantation: recommendations to optimize patient outcomes

Abstract Background A position paper based on the collective experiences of Argus II Retinal Prosthesis System investigators to review strategies to optimize outcomes in patients with retinitis pigmentosa undergoing retinal prosthesis implantation. Methods Retinal surgeons, device programmers, and rehabilitation specialists from Europe, Canada, Middle East, and the United States were convened to the first international Argus II Investigator Meeting held in Ann Arbor, MI in March 2015. The recommendations from the collective experiences were collected. Factors associated with successful outcomes were determined. Results Factors leading to successful outcomes begin with appropriate patient selection, expectation counseling, and preoperative retinal assessment. Challenges to surgical implantation include presence of staphyloma and inadequate Tenon’s capsule or conjunctiva. Modified surgical technique may reduce risks of complications such as hypotony and conjunctival erosion. Rehabilitation efforts and correlation with validated outcome measures following implantation are critical. Conclusions Bringing together Argus II investigators allowed the identification of strategies to optimize patient outcomes. Establishing an on-line collaborative network will foster coordinated research efforts to advance outcome assessment and rehabilitation strategies.http://deepblue.lib.umich.edu/bitstream/2027.42/134581/1/12886_2016_Article_225.pd

Photobiomodulation reduces drusen volume and improves visual acuity and contrast sensitivity in dry age-related macular degeneration.

PURPOSE To evaluate the efficacy of photobiomodulation (PBM) treatment for patients with dry age-related macular degeneration (AMD). METHODS Assessments on 42 eyes with dry AMD (age related eye disease study (AREDS) 2-4) were conducted. Multiwavelength light emitting diode (LED) light comprising of yellow (590 nm), red (670 nm) and near-infrared (790 nm) bandwidths was applied to subjects' eyes for a treatment course of 3 weeks. Outcome measures were changes in best-corrected visual acuity (BCVA), contrast sensitivity (CS), drusen volume and central drusen thickness. RESULTS Significant improvement in mean BCVA of 5.90 letters (p < 0.001) was seen on completion of the 3-week treatment and 5.14 letters (p < 0.001) after 3 months. Contrast sensitivity improved significantly (log unit improvement of 0.11 (p = 0.02) at 3 weeks and 3 months (log unit improvement of 0.16 (p = 0.02) at three cycles per degree. Drusen volume decreased by 0.024 mm(3) (p < 0.001) and central drusen thickness was significantly reduced by a mean of 3.78 μm (p < 0.001), while overall central retinal thickness and retinal volume remained stable. CONCLUSION This is the first study demonstrating improvements in functional and anatomical outcomes in dry AMD subjects with PBM therapy. These findings corroborate an earlier pilot study that looked at functional outcome measures. The addition of anatomical evidence contributes to the basis for further development of a non-invasive PBM treatment for dry AMD

Evaluating the safety of air travel for patients with scleral buckles and small volumes of intraocular gas

Aim: To evaluate the effect of scleral buckling on intraocular pressure (IOP) change during atmospheric decompression for eyes with small volumes of intravitreal gas. Methods: 12 eyes of 12 patients, including 6 with and 6 without scleral buckles, were evaluated in a hypobaric chamber simulating air travel approximately 1 month post pars plana vitrectomy with 15% C 3F8 gas fluid exchange. The chamber was decompressed with an ascent rate of 300 feet/min to a peak altitude of 8000 feet. After 15 min of cruising, descent was undertaken at 300 feet/min. IOP was measured at baseline and then every 5 min using slit-lamp mounted Goldmann applanation tonometry. The data were entered onto a spreadsheet and comparative statistics were done. Results: During ascent, IOP steadily rose from an average of 13±3 mm Hg to a peak of 26±9 mm Hg at 8000 feet. Patients with scleral buckles had significantly lower peak IOPs compared with those without buckles (20±5 mm Hg vs 32±8 mm Hg, p=0.013, t test) representing lower absolute increases in IOP (7±1 mm Hg vs 19±7 mm Hg, p=0.001, t test) and lower percentage increases in IOP from baseline (62±25% vs 140±40%, respectively). Conclusions: Eyes with small volumes of intravitreal gas demonstrate significant IOP changes during atmospheric decompression in simulated flight. The presence of a scleral buckle significantly limits the magnitude of IOP change, suggesting that such patients can likely tolerate typical air travel without undue risk of dangerous IOP elevation.Link_to_subscribed_fulltex

Retinal blood flow in response to an intravitreal injection of ranibizumab for neovascular age-related macular degeneration

Purpose: To assess the hemodynamic response of retinal arterioles and venules following a single intravitreal injection of ranibizumab in neovascular age-related macular degeneration (NV-AMD) patients and to assess the influence of the number of prior injections on this response. Methods: Fifteen NV-AMD patients were prospectively recruited and grouped according to the dosage of ranibizumab previously received. Group 1 NV-AMD patients (n = 7) had previously received 1.50 mg or less, and group 2 patients (n = 8) had received more than 1.50 mg in the study eye. A group of 12 non-NV AMD patients were also recruited for control comparison. Vessel diameter, centreline blood velocity and blood flow were assessed with the Canon Laser Blood Flowmeter immediately prior to an injection and at a mean follow-up of 37.7 and 36.7 days for group 1 and group 2 patients, respectively. Results: The NV-AMD patients as a whole and the group 1 cohort had a significantly greater arteriolar diameter at baseline than the non-NV AMD patients. There was a significant reduction in arteriolar diameter, velocity and blood flow in group 1 but not in group 2 NV-AMD patients at follow-up. There was only an insignificant decrease in measured parameters of the retinal venules. At follow-up, there was no difference in the diameter, velocity or flow between AMD patients. Conclusion: Intravitreal ranibizumab treatment for NV-AMD induces a reduction in arteriolar diameter, velocity, and blood flow in patients who have received <1.50 mg of ranibizumab. © 2011 Acta Ophthalmologica Scandinavica Foundation.Link_to_subscribed_fulltex

Pneumatic displacement of submacular hemorrhage [6] (multiple letters)

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An assessment of intraocular pressure rise in patients with gas-filled eyes during simulated air flight

Purpose: To investigate the safety of aircraft flight for patients with small volumes of residual postoperative intraocular gas. Design: Nonrandomized comparative trial. Participants: Seventeen eyes (nine gas filled and eight control eyes) of nine patients and one eye of one control subject were tested. Methods: Patients with postoperative intraocular gas and the control subject were tested in the controlled environment of a hypobaric chamber to simulate the cabin depressurization associated with a typical commercial aircraft flight. Before, during, and after a simulated flight, the intraocular pressure (IOP) in the gas-containing and contralateral eyes was tested using the Perkins (Edinburgh, UK) and Tono-Pen XL (Jacksonville, FL) tonometers. Main Outcome Measures: The absolute and percentage change in IOP with varied cabin pressurization. Results: Of the nine patients with intraocular gas, seven had 10% to 15% gas volume and two had 20% gas volume. In the 10% to 15% gas volume group, the IOP rose by an average of 109% from baseline during ascent to an average cabin altitude of 7429 feet above sea level. The IOP dropped to an average of 30% above baseline IOP during the cruise phase and further decreased to an average of 38% below baseline IOP on return to baseline altitude. In the 20% gas volume group, the IOP rose by an average of 84% from baseline during ascent to an average cabin altitude of 3400 feet above sea level. The IOP dropped to an average of 42% below baseline IOP on return to baseline altitude. The IOP in the contralateral control eyes did not vary with altitude changes. No patient experienced pain or visual loss during the experiments. Conclusions: Our results demonstrate that IOP may rise significantly in gas-filled eyes during simulated air flight, supporting the current conservative recommendation against air travel for most patients with intraocular gas bubbles. Further testing is warranted to develop a more objective measure of intraocular gas volume estimation and to define better the tolerability of aircraft flight for patients with intraocular gas. © 2001 by the American Academy of Ophthalmology.Link_to_subscribed_fulltex