Efficacy and Safety of a Novel Blunt Cannula Trans-Sub-Tenon's Retrobulbar Block for Vitreoretinal Surgery.

PURPOSE: To evaluate a novel trans-sub-Tenon's retrobulbar block (TSTRB) compared to sub-Tenon's block (STB) and peribulbar block (PBB) anesthesia for vitreoretinal surgery. METHODS: This study was a prospective evaluation of cases undergoing TSTRB, STB, or PBB. The Kallio scale and Brahma scales were used to score hemorrhage and extraocular motility, respectively. Pain was documented on a visual analog score graded (1-10) at induction, intraoperatively, and postoperatively, any confounding variables were noted. RESULTS: Seventy eyes have been used in this analysis, of which TSTRB was used in 37% (n = 26), PBB in 34% (n = 24), and STB in 29% (n = 20). Postoperative analgesia was required by 10% (n = 2) of STB and 8% (n = 2) of PBB; none of the TSTRB cases required analgesia (P = 0.003). The mean volume required with each technique was as follows: TSTRB, 4.8 ml; STB, 5.3 ml; and PBB, 10.4 ml (P = 0.030). The volume of anesthesia was correlated with the level of proptosis and even more important affected the ease of surgery most (P = 0.005). Akinesia was greatest with TSTRB > PBB > STB (P = 0.040). There were no complications such as brainstem anesthesia, globe perforation, or retrobulbar hemorrhage. CONCLUSION: Intentionally extending a STB into the retrobulbar space, via a TSTRB fenestration utilizes a familiar skill set. TSTRB produced the best levels of reduced kinesia during surgery and increased duration of postoperative analgesia. The technique uses a small-volume anesthesia.

Observations on a set of Greco-Roman eye, ear, nose, and throat surgical instruments.

The tools described in this article are verified to be Greco-Roman medical and surgical instruments for the eye, ear, nose, and throat. They include three myrtle leaf-shaped scalpels, three ear spoons, a "Q-tip," a forceps, a needle, and two arrow-pointed scalpels. One of the arrow-pointed scalpels is nearly identical to a Juerger keratome, suggesting that in Roman times, cataracts were extracted, not just "couched" into the posterior chamber. The description presented here goes beyond traditional archeological claims, because as a head and neck surgeon, I evaluated these instruments from a surgeon's point of view. For example, nonsurgeon medical historians have claimed the myrtle leaf-shaped items were used as handles or for blunt dissection, which I feel is mistaken. Review of the literature reveals the Greco-Roman surgeons were doing tonsillectomies, tracheotomies, and cataract extractions, and recognized that swimming in dirty water could cause ear infection. However, it is clear that with poor or no anesthesia, the pain from blunt dissection would have been intolerable, and unnecessary tissue planes would have been opened increasing wound infection risks. Therefore, there would have been no need for the myrtle leaf-shaped blade if it were just a handle. Laryngoscope, 2016 127:354-358, 2017.

Detachable microsphere scalpel tips for potential use in ophthalmic surgery with the erbium:YAG laser.

Vitreoretinal surgery is performed using mechanical dissection that sometimes results in iatrogenic complications, including vitreous hemorrhage, retinal breaks, incomplete membrane delamination, retinal distortion, microscopic damage, etc. An ultraprecise laser probe would be an ideal tool for cutting away pathologic membranes; however, the depth of surgery should be precisely controlled to protect the sensitive underlying retina. The ultraprecise surgical microprobe formed by chains of dielectric spheres for use with the erbium:YAG laser source (λ=2940 nm), with extremely short optical penetration depth in tissue, was optimized. Numerical modeling demonstrated a potential advantage of five-sphere focusing chains of sapphire spheres with index n=1.71 for ablating the tissue with self-limited depth around 10 to 20 µm. Novel detachable microsphere scalpel tips formed by chains of 300 µm sapphire (or ruby) spheres were tested on ophthalmic tissues, ex vivo. Detachable scalpel tips could allow for reusability of expensive mid-infrared trunk fibers between procedures, and offer more surgical customization by interchanging various scalpel tip configurations. An innovative method for aiming beam integration into the microsphere scalpel to improve the illumination of the surgical site was also shown. Single Er:YAG pulses of 0.2 mJ and 75-µs duration produced ablation craters in cornea epithelium for one, three, and five sphere structures with the latter generating the smallest crater depth (10 µm) with the least amount of thermal damage depth (30 µm). Detachable microsphere laser scalpel tips may allow surgeons better precision and safety compared to mechanical scalpels when operating on delicate or sensitive areas like the retina.

Evaluation of intraocular reactivity to metallic and ethylene oxide contaminants of medical devices in a rabbit model.

OBJECTIVE: To evaluate the intraocular reactivity to metallic and ethylene oxide (EO) contaminants of ophthalmic devices in rabbits. DESIGN: Two experimental animal studies. PARTICIPANTS: Thirty-five New Zealand white rabbits. METHODS: A metallic exposure study and an EO exposure study were performed. In the first study, both eyes of 25 rabbits were equally allocated to intracameral injections of alumina 0.2 µg, alumina 20 µg, copper sulfate 0.4 µg, copper sulfate 20 µg, or an aqueous control. In the second study, 10 rabbits were allocated (5 per group) to receive intracamerally an ophthalmic viscosurgical device (OVD) exposed to EO or not exposed to EO (control). All eyes were examined by slit lamp at baseline and 3, 6, 9, 24, 48, and 72 hours after exposure, with dilated indirect ophthalmoscopy being performed at 24 and 72 hours. Tonometry was performed only in the first study. MAIN OUTCOME MEASURES: Grade of corneal clouding, anterior chamber (AC) flare, AC cells, AC fibrin, iridal hyperemia, cell and fibrin on the lens surface, vitreous haze and cells, lens opacities, intraocular pressure, and onset time. RESULTS: For metallic compounds at the study's low doses, mean inflammatory grades were 0.2 or less above the control for all responses at all time points. For the high-dose alumina, mean inflammatory grades peaked at 6 to 9 hours at 0.5 to 0.7 above the control responses for conjunctival congestion, iris hyperemia, AC cells, flare, and fibrin and declined over the remaining time points. For the high-dose copper sulfate, mean inflammatory grades peaked between 3 and 24 hours at 1.2 to 1.8 above the control responses for conjunctival congestion, iris hyperemia, AC cells, flare, fibrin, and corneal clouding, then subsequently declined. The intraocular pressure changes appeared significant for only high-dose copper sulfate, with mean declines of 4.3 to 7.5 mmHg at 6 to 72 hours. No clinically meaningful differences in ocular inflammation were observed between the OVD exposed to EO and the OVD not exposed to EO. CONCLUSIONS: Alumina and copper sulfate did not cause clinically meaningful ocular inflammation at the low study levels (levels expected with ophthalmic devices). Ethylene oxide exposure of an OVD was not associated with inflammation.

Optics of conductive keratoplasty: implications for presbyopia management.

PURPOSE: To define the corneal optics of conductive keratoplasty (CK) and assess the clinical implications for hyperopia and presbyopia management. METHODS: Four analyses were done. (1) Multifocal effects: In a prospective study of CK, uncorrected visual acuity (UCVA) for a given refractive error in 72 postoperative eyes was compared to control eyes. (2) Surgically induced astigmatism (SIA): 203 eyes were analyzed for magnitude and axis of SIA. (3) Higher-order optical aberrations: Corneal higher-order optical aberrations were assessed for 36 eyes after CK and a similar patient population after hyperopic laser in situ keratomileusis (LASIK). (4) Presbyopia clinical trial: Visual acuity, refractive result, and patient questionnaires were analyzed for 150 subjects in a prospective, multicenter clinical trial of presbyopia management with CK. RESULTS: (1) 63% and 82% of eyes after CK had better UCVA at distance and near, respectively, than controls. (2) The mean SIA was 0.23 diopter (D) steepening at 175 degrees (P < .001); mean magnitude was 0.66 D (SD, 0.43 D). (3) After CK, composite fourth- and sixth-order spherical aberration increased; change in (Z12) spherical aberration alone was not statistically significant. When compared to hyperopic LASIK, there was a statistically significant increase in composite fourth- and sixth-order spherical aberration (P < .01) and spherical aberration (Z12) alone (P < .02); spherical aberration change was more prolate after CK. (4) After the CK monovision procedure, 80% of patients had J3 or better binocular UCVA at near; 84% of patients were satisfied. Satisfaction was associated with near UCVA of J3 or better in the monovision eye (P = .001) and subjectively good postoperative depth perception (P = .038). CONCLUSIONS: CK seems to produce functional corneal multifocality with definable introduction of SIA and higher-order optical aberrations, and development of a more prolate corneal contour. These optical factors may militate toward improved near vision function.

New support for ophthalmic drapes.

A new flexible support for ophthalmic drapes with the possibility of continuous oxygen supplementation was designed for use in patients undergoing eye surgery under local anesthesia. This new equipment is easy to handle and prevents contact between the patient's face and the ophthalmic drape. To prevent hypoxia of spontaneously breathing patients, the ambient air under the drapes can be supplemented with oxygen using this new equipment and no other devices. The equipment described here is advantageous for practical use in patients undergoing eye surgery under retrobulbar anesthesia.

Evaluación de una nueva técnica periocular (Bloqueo Retro-Ecuatorial Medial)

Se elabora una descripción transversal en estudio prospectivo de 102 pacientes en una Institución Oftalmológica privada, con el fin de evaluar la bondad de una nueva técnica anestésica periocular (bloqueo retro-ecuatorial nasal, REN). Se describen y analizan entre las siguientes variables: edad, sexo, ASA, antecedentes médicos personales, tiempo de aquinesia, presión intraocular y complicaciones. La edad promediode los pacientes (45 por ciento hombres y 57 por ciento mujeres) fue de 63ñ16 años, el 85 por ciento tenían antecedentes; de HTA 9,4 por ciento, EPOC 27,1 por ciento, D. M. 4,7 por ciento, Enfermedad coronaria 1,2 por ciento, HTA y D. M. 31,8 por ciento, HTA y otros 16,5 por ciento, Resto 9,3 por ciento (IRA, IRC y LES), ASA I 18, ASA II 75, ASA III 9. De acuerdo a los objetivos el bloqueo fue clasificado como bueno en todos los casos Van Lint mas, en 1 de cada 4; el tiempo de aquinesia fue de 7.1ñ2,5, volumen utilizado 4,1ñ7. Las presiones intraoculares inicial y final fueron 14.1ñ1.2 y 14.0ñ1 (disminuyó en 1 por ciento) todos fueron sedados con Midazolam y no se presentaron complicaciones de ningún tipo. Se concluye que dada la excelente sedación, la ausencia de complicaciones a pesar de la edad y los antecedentes médicos personales, los bajos tiempos de aquinesia y el hecho de no aumentarse la presión intraocular, se puede recomendar la técnica y la dosis utilizada en el estudio para ser empleada en poblaciones similares