Aim: To compare 25-gauge vs 20-gauge system for pars plana vitrectomy in a prospective, randomised, controlled clinical trial. Methods: Three-port pars plana vitrectomy was performed in 60 patients belonging to 2 groups. Evaluations were performed preoperatively, intraoperatively, during the first three postoperative days, at 1 week, and at 1 and 3 months. The main outcome measure was time for surgery, divided into duration of wound opening, vitrectomy, retinal manipulation and wound closure. Results: The total duration of surgery showed no significant difference between the groups (p = 0.67). The 25-gauge group showed significantly shorter duration of wound opening (p,0.001) and wound closure (p,0.001). In contrast, the vitrectomy duration was significantly longer in the 25-gauge group (p,0.001). Conjunctival injection and subjective postoperative pain showed significantly lower irritation in the 25-gauge group (p,0.001 for both). Conclusion:The 25-gauge vitrectomy system offered significantly improved patient comfort during the first postoperative week. The smaller surgical openings facilitated wound healing and minimised pain. Duration of surgery was comparable between the two systems-the shorter time needed for wound opening and closure in the 25-gauge group being equalised by the longer vitrectomy duration. Intraoperative as well as retinal manipulation and illumination caused more surgical difficulties using the 25-gauge system.T hree-port 20-gauge vitrectomy systems have been the gold standard for vitreous surgery since 1974. 1 During the past 30 years, its instrumentation has successfully been developed further. The standard system, demanding conjunctival incisions and sclerotomies of 0.89 mm diameter (20 gauge), was subsequently made smaller and less traumatic. For example, a 23-gauge system was developed in the 1980s by Peyman 2 , and 23-gauge-sized instruments have been mainly used for paediatric ophthalmic surgery.In 2002, a 25-gauge system was developed and made commercially available by Fujii et al. 3 First reports have emphasised several advantages in the use of the new sutureless transconjunctival system. [4][5][6] One advantage was a gain in time for surgery by avoiding extra efforts to open and close sclera and conjunctiva separately. This subsequently minimises surgically induced trauma and foreign body perception otherwise caused by manipulation and sutures, as well as the possible reactions related to the suture material itself. This was supposed to reduce the duration of the convalescence period and of the postoperative inflammatory response. The microcannulas of the system permit interchangeability of instruments between entry sites and might protect the vitreous base from mechanical traction.On the other hand, suction and flow rates in the 25-gauge system are significantly lower than the comparable parameters in the established 20-gauge technique, as a result of the smaller diameter of the 25-gauge system. 7 This could eventually cause difficulties in removing tight vitreous strands, epir...
The present study indicates that lower choroidal perfusion is a risk factor for the development of CNV in the fellow eye of patients with unilateral CNV.
The 23-gauge system for pars plana vitrectomy offers significantly higher patient comfort during the early postoperative period. Time of surgery is almost equal--a shorter time for wound closure is neutralised by a longer vitrectomy time in the 23-gauge group.
ABSTRACT.Purpose: To evaluate the influence of the needle size used for intravitreal (IVT) injections on patients' pain experience in a randomized, double-armed, singleblinded, clinical trial. Methods: Patients included were randomized to have an IVT injection performed with a 27-gauge needle (group 1) or with a 30-gauge needle (group 2). The topical anaesthesia before the injection was standardized. Immediately after the injection, patients were asked to grade their pain using the visual analogue scale (VAS) and the Wong-Baker FACES scale. The main outcome measure was the pain score assessment. Cofactors analysed were patients' demographics (age and gender) and clinical characteristics (such as the number of previous IVT injections). In addition, scaled surgeon's questionnaires to assess the IVT injection procedure were evaluated. For statistical analysis, a regression model was used. Results: The data of 208 patients (group 1: 104 patients; group 2: 104 patients) were analysed. There was no significant difference in the VAS pain scores (p > 0.18) and in the Wong-Baker pain scores (p > 0.59) between both treatment groups. Gender (p = 0.0288) and the number of previous IVT injections (p = 0.0028) significantly influenced the VAS pain scores (p < 0.05). Female patients and patients with a history of previous IVT injections had higher pain scores. The surgeon's questionnaire showed an overall preference towards the use of a 30-gauge needle for IVT injections. Conclusion: The use of a 30-gauge needle for IVT injections showed no significant effect in pain relief compared to the use of a 27-gauge needle. However, a 30-gauge needle was preferred by all surgeons.
These data indicate abnormal CBF regulation in chronic smokers compared with age-matched nonsmoking subjects during isometric exercise. The pathways responsible for this abnormal blood flow response remain to be elucidated.
. Purpose: Today, pars plana vitrectomy represents a standard surgical procedure for a number of retinal diseases that were previously considered inoperable. The aim of the present study is to investigate the entry site of pars plana vitrectomy as a possible source of retinal detachment. Methods: We reviewed retrospectively all cases of uncomplicated pars plana vitectomies because of macular hole, macular pucker and diabetic macular oedema performed in our department between 1 January 2001 and 7 July 2004. Results: Over 3.5 years, 244 pars plana vitrectomies because of macular disease were performed. Sclerotomy‐related retinal detachment was observed in 11 (4.5%) cases. These retinal detachments occurred at a mean of 37 (2–100) days after surgery. They appeared within the first 4 weeks in 55% of the cases. Conclusion: Iatrogenic retinal breaks and detachment continue to be a severe complication of pars plana vitrectomy, despite improvements in instrumentation and surgical techniques. A 4.5% incidence of sclerotomy‐related retinal detachment after simple vitrectomy calls for action. Current approaches to reduce this complication – such as circular peripheral cryoretinopexy, scleral buckling or 360° laser treatment – are invasive. We recommend extended vitreous base cleaning with scleral indentation and examination of the entry sites, performed with a three‐mirror lens or via careful indirect ophthalmoscopy into the periphery, 4 weeks after surgery.
The data indicate that sildenafil increases retinal venous diameters and retinal blood flow in healthy subjects. By contrast, it does not affect intraocular pressure and flicker-induced retinal vasodilation. Further studies are needed to elucidate whether this drug may be therapeutically used in retinal ischemic disease.
Aim: To investigate a potential difference in ocular vascular reactivity during carbogen breathing in optic nerve head, choroid, and retina between healthy smokers and nonsmokers. Methods: 25 (13 smokers and 12 non-smokers) healthy male volunteers participated in this observer masked, two cohort study. During inhalation of carbogen (5% CO 2 and 95% O 2 ) over 10 minutes measurements were taken using laser Doppler flowmetry to assess submacular choroidal and optic nerve head blood flow, laser interferometry to assess fundus pulsation amplitudes, and retinal vessel analyser (RVA) to assess retinal vessel diameters. Results: At baseline choroidal blood flow was higher (p = 0.018, ANOVA) in smokers than in non-smokers. During administration of carbogen the response in choroidal blood flow was significantly different between the two groups: there was an increase in non-smokers after carbogen breathing (p = 0.048) compared with relatively stable blood flow in smokers (p = 0.049 between groups, ANOVA). A similar response pattern was seen for fundus pulsation amplitude, which increased notably after carbogen breathing in non-smokers but not in smokers (p,0.001 between groups, ANOVA). Optic nerve head blood flow and retinal vessel diameters were reduced in both groups to a comparable degree during carbogen breathing. Conclusion: The study indicated abnormal choroidal vascular reactivity in chronic smokers. These early haemodynamic changes may be related to the increased risk to smokers of developing ocular vascular diseases. The specific mechanisms underlying abnormal choroidal vascular reactivity in chronic smokers remain to be characterised.
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