Critical analysis of techniques and materials used in devices, syringes, and needles used for intravitreal injections.

Intravitreal injections have become the most commonly performed intraocular treatments worldwide. Because intravitreal injections may induce severe adverse events, such as infectious and noninfectious endophthalmitis, cataract, ocular hypertension, vitreous hemorrhage, or retinal detachment, appropriate awareness of the materials and techniques used are essential to reduce these sight-threatening complications. This review provides insights into the needles, syringes, silicone oil coating, sterilization methods, devices to assist intravitreal injections, scleral piercing techniques using needles, syringe handling, anesthesia, and safety issues related to materials and techniques. It is paramount that physicians be aware of every step involved in intravitreal injections and consider the roles and implications of all materials and techniques used. The ability to understand the theoretical and practical circumstances may definitely lead to state-of-the-art treatments delivered to patients. The most important practical recommendations are: choosing syringes with as little silicone oil as possible, or, preferably, none; avoiding agitation of syringes; awareness that most biologics (e.g., antiangiogenic proteins) are susceptible to changes in molecular properties under some conditions, such as agitation and temperature variation; understanding that improper materials and techniques may lead to complications after intravitreal injections, e.g., inflammation; and recognizing that some devices may contribute to an enhanced, safer, and faster intravitreal injection technique.

Pilot Study Comparing Topical Anesthetic Agents in Pterygium Surgery: Subconjunctival Injection Versus 2% Lidocaine Gel Versus 5% Lidocaine Gel.

PURPOSE: To compare the efficacy of different concentrations of topical lidocaine gel with standard subconjunctival anesthesia. METHODS: This was a prospective randomized controlled pilot study with 3 different groups. Group SC received subconjunctival lidocaine and proparacaine drops as needed during surgery. Group L2 received 2% lidocaine gel and group L5 received 5% lidocaine gel. Both lidocaine gel groups could receive another gel dose as needed during the procedure. The primary outcome was pain, which was experienced during and after surgery. The assessment was done using a 10-point linear analog scale at predetermined stages of surgery (1-first incision, 2-pterygium body excision, 3-conjunctival suturing, 4-immediate postoperative period after patching, and 5-assessment by a trained nurse in the absence of a surgeon after operation). RESULTS: We enrolled 45 consecutive patients who underwent primary pterygium surgery. Statistical significance between groups was found in mean pain at administration (2.2 vs. 0.4 vs. 0.0 in SC, L2, and L5 groups, respectively, with P < 0.05). The number of reapplications of anesthetic drops did not differ between the groups. We found a correlation between reapplication of the anesthetic and pain at administration and duration of the procedure. CONCLUSIONS: We demonstrated that the use of lidocaine gel at concentrations of 2% and 5% in pterygium surgery was as effective as subconjunctival injection of lidocaine in reducing intraoperative and postoperative pain, producing significantly less pain during initial administration of the anesthetic.

Patient pain during intravitreal injections under topical anesthesia: a systematic review.

BACKGROUND: Intravitreal injection (IVI) is a very common vitreoretinal procedure, and multiple injections are often required per patient. This systematic review was conducted to evaluate the effectiveness of various local anesthetic techniques in reducing pain during injection. METHODS: A systematic review was conducted based on searches of Cochrane, LILACS, PubMed, Scopus, Web of Science, and the gray literature (Google Scholar). The end search date was February 19, 2016, across all databases. We classified pain by converting visual analog scale (VAS) scores (0-100 mm) into Jensen's classification levels: 0-4, no pain; 5-44, mild pain; 45-74, moderate pain; and 75-100, severe pain. An intervention was considered clinically significant when pain score change was >12 mm on a 100-mm scale. RESULTS: Eight studies out of 23 met the eligibility criteria. The total number of patients was 847. Most studies (5/8 [62.5%]) were at unclear risk of bias because of unclear randomization, thus providing only moderate evidence to this review. The anesthetic techniques included eye drops with proparacaine, tetracaine or cocaine, a lidocaine pledget or gel, and subconjunctival injection of 2% lidocaine or 0.75% levobupivacaine. No study comprised all of the techniques. Pain was mild (VAS scores, 5-44 mm) regardless of anesthetic technique. A clinically significant intervention (pain score change >12 mm) was found for only one study comparing proparacaine drops, lidocaine gel, and subconjunctival lidocaine; in that study, a subconjunctival injection of 2% lidocaine provided the greatest pain reduction. A meta-analysis was not possible due to study heterogeneity. CONCLUSIONS: Patient pain during IVI under topical anesthesia is mild regardless of anesthetic technique. A subconjunctival injection of 2% lidocaine could be an option for highly sensitive patients. However, with moderate level of evidence, no single anesthetic technique could be defined as the best option for IVI.

Comparative Study Between Lidocaine Gel 2% and 5% for Ophthalmic Procedures.

PURPOSE: To compare same-day pain control and safety of 2 different anesthetic gels utilizing 5% and 2% lidocaine gel. Main outcome is to determine whether 5% lidocaine gel is more effective in decreasing pain during conjunctival clamping compared to 2% lidocaine gel 5 and 10 min after gel application. METHODS: This is a prospective, randomized double-blind clinical trial. Patients were randomized to receive 2% or 5% lidocaine gel in each eye. Discomfort during the gel instillation and pain during conjunctival clamping 5 and 10 min after gel application were compared. Extent of corneal conjunctival staining was graded according to the Oxford scale. RESULTS: Eighty eyes of 40 patients were enrolled. The groups were similar in gender, with a mean age of 48 ± 16.26 years. The 5% lidocaine gel resulted in higher discomfort during initial instillation (P = 0.092), however, the pain during conjunctival clamping was lower in the 5% lidocaine gel eyes (P = 0.564) in both 5 and 10 min later (P < 0.001). The majority of patients (80%) had no corneal conjunctival dye staining. The tear break-up time was not statistically different after lidocaine gel 2% (20.35 ± 7.37 s) and lidocaine 5% (19.75 ± 7.00 s). CONCLUSION: Five percent and 2% lidocaine gel have similar efficacy controlling pain 5 min after instillation, however, 5% lidocaine gel appears to be more effective with a longer duration of action, without corneal toxicity. There was no corneal toxicity noted with either concentration.

Safety and efficacy of various concentrations of topical lidocaine gel for intravitreal injection.

INTRODUCTION: Intravitreal injection (IVT) is one of the most common vitreoretinal procedures, a large majority are performed with local anesthesia. The purpose of this study was to investigate the safety to the cornea and anesthetic efficacy of five concentrations of lidocaine gel. METHODS: A prospective clinical trial was conducted testing lidocaine gel in five preparations: 2, 3.5, 5, 8 and 12%. Patients with macular degeneration, diabetic edema or retina vein occlusion were scheduled for intravitreal treatment received topical anesthesia with lidocaine gel 5 and 10 min before the procedure. Patients answered the visual analog scale for pain during the procedure. Corneal and conjunctival was evaluated using the Oxford scale. RESULTS: In total, 260 patients were randomized into five groups. The mean pain scores (± standard deviation) were 2.63 (± 1.68) in the 2% group, 2.08 (± 1.35) in the 3.5%; 2.00 (± 1.65) in the 5%, 1.93 (± 1.40) in the 8% and 1.83 (± 1.35) in the 12% group. Mean pain score among all groups was similar (p = 0.077). There was no significant difference between groups in regard to keratitis mean score (p = 0.897). CONCLUSIONS: Lidocaine gel at concentrations from 2 to 12% induced similar anesthetic effect for IVTs, without adverse effects on cornea and conjunctiva.

Comparação de eficácia da ropivacaína 1 por cento quando associada ou não à hialuronidase na anestesia peribulbar para cirurgia de catarata / Comparison of 1 percent ropivacaine efficacy when associated or not with hyaluronidase in peribulbar anaesthesia for cataract surgery

Objetivo: Avaliar o tempo de instalação e a qualidade da anestesia peribulbar com ropivacaína 1 por cento, quando associada ou não à hialuronidase para realização de cirurgia de catarata. Métodos: Por meio de um ensaio clínico controlado, foram estudados 57 pacientes, submetidos à extração extracapsular da catarata sob anestesia peribulbar, distribuídos aleatoriamente em dois grupos. Grupo C: ropivacaína 1 por cento com hialuronidase 100 UTR/ml, e Grupo S: apenas com ropivacaína 1 por cento. Foram avaliados o tempo de instalação do bloqueio de 2 em 2 minutos, utilizando-se a acinesia pela escala da motilidade ocular de Nicoll, intensidade da dor durante o procedimento e a necessidade de complementação anestésica. O bloqueio foi considerado satisfatório quando apresentava valor

Anestesia venosa total para laparoscopia pélvica / Total intravenous anesthesia for pelvic laparoscopy

Justificativa e objetivos - O propofol apresenta características desejáveis para a realização de procedimentos laparoscópicos, como rápido início de ação estabidade hemodinâmica e ausência de efeitos colaterais e residuais ao final do procedimento. Em virtude destas propriedades vem sendo cada vez mais empregado na indução e manutenção da anestesia para laparoscopia. O objetivo deste estudo foi avaliar alterações hemodinâmicas, efeitos colaterias, condições de recuperação pós-anestésica e necessidade de complementação per-operatória com propofol e/ou opióides, durante anestesia com propofol em infusão contínua. Método - Foram estudadas 30 pacientes submetidas a laparoscopia pélvica diagnosticada. A indução da anestesia foi feita com propofol (2,5 mg.kgúû) precedido de alfentanil (50mg.kgúû). Succinilcolina foi empregada para a intubação traqueal. A anestesia foi mantida com infusão venosa contínua de propofol (0,1 mg.kgúû.minúû). Injeções complementares de propofol e/ou opióides foram utilidos em presença de sinais de anestesia superficial como lacrimejamento, movimentos das extremidades, aumento da pressão arterial média e frequência cardíaca acima de 25 por cento dos valores iniciais. A infusão de propofol foi interronpida imediatamente após a reversão do pneumoperitônio. Resultados - Observou-se redução estatisticamente significativa nos valores médios de pressão arterial média e frequência cardíaca após a indução anestésica, com retorno para valores próximos aos iniciais após as manobras de laringoscopia e intubação traqueal. Em três pacientes (10 por cento) houve necessidade de doses complemtares de alfentanil. Em cinco pacientes (16,6 por cento) foi necessário a injeção complementar de uma única dose de propofol (0,5 mg.kgúû). Não foram observados efeitos colaterais. Os tempos médios de despertar e de alta da recuperação pós-anestésica foram 8,50 ñ 4,01 e 49,63 ñ 10,24 minutos, respectivamente. Conclusões - A técnica empregada monstrou-se eficaz para a realizaão de laparoscopia pélvica, apresentando estabilidade hemodinâmica, ausência de efeitos colaterias e rápida recuperação das funções psicomotoras.