Abstract-The authors describe a straightforward experimental technique for measuring the facet temperature of a semiconductor laser under high-power operation by analyzing the laser emission itself. By applying this technique to 1-mm-long 980-nm lasers with 6-and 9-m-wide tapers, they measure a large increase in facet temperature under both continuous wave (CW) and pulsed operation. Under CW operation, the facet temperature increases from 25 C at low currents to over 140 C at 500 mA. From pulsed measurements they observe a sharper rise in facet temperature as a function of current ( 400 C at 500 mA) when compared with the CW measurements. This difference is caused by self-heating which limits the output power and hence facet temperature under CW operation. Under pulsed operation the maximum measured facet temperature was in excess of 1000 C for a current of 1000 mA. Above this current, both lasers underwent catastrophic optical damage (COD). These results show a striking increase in facet temperature under high-power operation consistent with the facet melting at COD. This is made possible by measuring the laser under pulsed operation.
PurposeSilicone oil a burgeoning adjuvant in the treatment of uveal melanoma where it is used for tissue protection during I-125 brachytherapy. While risk factors in the development of radiation retinopathy (RR) have been identified, treatment modulation for high-risk patients has largely been overlooked. We seek to expand the literature on this subject by reporting outcomes of I-125 brachytherapy with silicone oil in a high-risk population in the community setting.MethodsFive patients with uveal melanoma and at least one risk factor for RR development underwent iodine-125 (I-125) plaque brachytherapy with concurrent pars plana vitrectomy (PPV), silicone oil administration, and fine needle aspiration biopsy (FNAB). Plaque and silicone oil removal were performed after seven days. Minimum follow-up was 12 months.ResultsFollow-up ranged from 12 to 56 months. Macular radiation doses ranged from 12.55 to 141.5 Gy; the two eyes with the largest doses developed RR at 34 and 15 months as well as neovascular glaucoma (NVG). Surgical complications included one rhegmatogenous retinal detachment (RD) and an intra-operative vitreous hemorrhage with post-operative hyphema requiring additional intervention.ConclusionRR may be attenuated by silicone oil administration in patients with some risk factors. In tumors farther from the macula, this benefit is more readily apparent. Tumors located more posteriorly may not benefit from silicone oil administration considering postoperative complications and operating time. Patient demographics, tumor characteristics, and anticipated macular radiation dosage may help determine which patients can benefit from silicone oil and identify patient risks for adverse outcomes.
The Rho kinase inhibitor netarsudil is a recently approved therapeutic option for the management of increased intraocular pressure in the United States. Although phase 3 clinical trials noted corneal changes related to the medication-namely, nonvisually-significant corneal verticillata-descriptions of a unique form of cystic epithelial edema began to surface as netarsudil (and its sister drug ripasudil, approved in Japan) gained widespread use. This series adds 3 new cases and reviews the current literature on this unique side effect.
A paramedian pontine stroke may herald the unique symptom of "salt and pepper" eye pain, in which patients describe the sensation of pepper rubbed into the eye. While localization of the lesion is a common thread among published cases, the mechanism for the sensation of eye pain is still a matter of conjecture. It is important for clinicians to be aware of this unique symptom because strokes rarely present with eye pain and failure to establish this diagnosis might lead to a poor clinical outcome.
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