Richard S B Newsom

Local anaesthesia for 1221 vitreoretinal procedures

BACKGROUND Vitreoretinal (VR) surgery has been increasingly performed under local anaesthesia (LA) in this unit. The results of an audit monitoring this change are presented. METHODS Data were collected on 1497 patients including type, volume, and position of the anaesthetic block, type of surgery, complications, and patient reactions. RESULTS 1221/1479 (82%) patients had LA. They were older than those having general anaesthesia (GA) 63.5 years v 45.9 years; 146 (10.6%) blocks were intracone, 130 (10.6%) peribulbar, and 927 (75.9%) combined. Operations included 436 vitrectomies, 545 retinopexy with or without vitrectomy, and 238 buckling procedures. Some pain was felt by 9.4%, 8.8%, and 19.7% of patients during vitrectomy, retinopexy with or without vitrectomy, and buckling surgery respectively. CONCLUSION Local anaesthesia for VR surgery is well tolerated by patients, being effective throughout longer and more stimulating ocular surgery.

Ocular morbidity associated with intravitreal triamcinolone acetonide

AimTo report on the complications associated with the use of intravitreal triamcinolone acetonide (IVTA) in a tertiary referral hospital setting.Materials and methodsA retrospective case series review of all IVTA injections carried out over a period of 30 months.ResultsOne hundred and thirty IVTA injections were performed; nine with limited local follow-up were excluded. Thus, 121 injections (108 patients, 114 eyes) were included in the study. Triamcinolone (4 mg) was used in all cases. Indications were diabetic macular oedema (n=41 eyes), retinal vein occlusions (n=27), postoperative cystoid macular oedema (n=24), exudative age-related macular degeneration (n=16), and others (n=6). No intraoperative complications were recorded. Postoperative intraocular pressure (IOP) readings of 22, 28, 35, and 40 mmHg or higher were recorded in 46.5, 29.8, 12.3, and 7.9% of eyes, respectively. IOP elevation was treated with antiglaucoma medication in all but one eye (0.9%) that required trabeculectomy and one (0.9%) that required vitrectomy with cataract extraction for suspected phacoanaphylactic glaucoma. Two eyes (1.8%) developed retinal detachment; both had previously been treated for retinal breaks. One eye (0.9%) developed culture-positive endophthalmitis.ConclusionsSignificant morbidity is associated with IVTA injection; clinicians should be aware when considering treatment options.

Intravitreal bevacizumab (Avastin) for the treatment of choroidal neovascularization in age-related macular degeneration: results from 118 cases

Several vascular endothelial growth factor inhibitors have recently been studied as treatments for neovascular AMD.1 2 Pegaptanib sodium improved visual acuity in 6% of patients at one year;1 Ranibizumab 0.5 mg improved vision by three lines in 33% of patients at one year.2 Michels et al. 3 initially reported the use of intravenous bevacizumab for the treatment of choroidal neovascularization (CNV), and others have found visual improvement and reduction in macular thickness with intravitreal bevacizumab.4–8 We present the results from 118 cases treated with intravitreal bevacizumab based at a single centre. A retrospective review of 115 consecutive patients (118 eyes) based at Southampton Eye Unit, treated with intravitreal bevacizumab for CNV was performed. Lesions of all types irrespective of size or location that were either ineligible for photodynamic therapy (PDT) under the National Health Service (including minimally classic and occult CNV) or those not responding to PDT (classic or predominantly classic CNV with recurrent or persistent CNV activity) were included in the study (table 1). All patients underwent visual acuity testing (best corrected Snellen), slitlamp examination and fundus fluorescein angiography. Central macular thickness (CMT) was assessed using Stratus optical coherence tomography (Carl Zeiss Meditec, USA). View this table: Table 1 Baseline characteristics After discussion about the off-label nature of treatment and the potential risks, informed …

Expanding role of local anaesthesia in vitreoretinal surgery.

PurposeLocal anaesthesia (LA) is increasingly common in vitreoretinal surgery. However, younger patients often have such surgery under general anaesthesia (GA). We reanalysed the anaesthetic practice for vitreoretinal surgery in our unit over a 19-month period.MethodsA total of 1003 patients undergoing vitreoretinal surgery between August 2000 and February 2002 were studied. Type of surgery, patient pain score to anaesthesia and surgery, need for sedation and incidence of complications related to the local anaesthetic were recorded. Comparisons were made between this case series and previous data from our unit.ResultsIn total, 920/1003 (91.7%) patients had LA. Total operations comprised 418 vitrectomies, 518 retinopexies with or without vitrectomy and 67 buckling procedures. More patients under the age of 35 years had LA than previously (60.2 vs35.7%, P<0.001). In 920/920 (100%) of cases, LA was administered via intraconal injection, compared to 164/1221 (13.4%) of procedures previously. Significantly more patients under the age of 35 years required sedation (35.9%) than did older patients (19.2%). Overall, use of sedation was significantly increased since our previous study (20.2 vs7.8%). Anaesthesia and surgery were well tolerated by patients. There were no cases of orbital haemorrhage or ocular perforation. Complications included bradycardia requiring atropine 1/920 (0.1%) and chemosis 88/920 (9.6%).ConclusionsLA is well tolerated and effective even in younger patients. Sedation may well be required in younger patients and for procedures involving scleral buckling. The main indication for GA was patient preference. Despite this, such patients accounted for only 5.2% of the total.

Use of optomap for retinal screening within an eye casualty setting

Aim: To compare nurse-guided Optomap retinal imaging with examination by an eye casualty officer, in detecting clinically significant peripheral retinal lesions in patients with retinal symptoms. Methods: 219 patients presenting to eye casualty with retinal symptoms (flashing lights and floaters) were recruited. Retinal images were taken with the Optomap imaging system, and graded by an independent masked ophthalmologist. The findings from the Optomap and casualty officer were compared with a gold-standard examination with scleral indentation performed by a retinal specialist. We calculated the sensitivity and specificity of the Optomap and casualty officer. Results: The final analysis included 205 eyes of 187 patients. The sensitivity of the Optomap for detecting retinal detachment (n = 7) was 100% (95% CI 59–100%), the same as the casualty officer. For retinal holes/tears (n = 18) the Optomap sensitivity was 33% (13–59%), compared with 67% (41–87%) for the casualty officer. Combining all retinal lesions (n = 52), the sensitivity was 62% (47–75%) and 73% (59–84%), with specificity 96% (92–99%) and 98% (94–100%) for the Optomap and casualty officer respectively. Conclusion: The Optomap detects retinal detachments successfully but, due to limitations in the optics, is not able to accurately detect retinal holes and tears.

Effect of digital image compression on screening for diabetic retinopathy

BACKGROUND/AIMS Digital imaging is widely used for diabetic retinopathy screening. The storage and transmission of digital images can be facilitated by image compression. The authors aimed to assess the effect of image compression on the accuracy of grading diabetic retinopathy. METHODS Forty nine 35 mm transparencies (17 with no retinopathy, eight with background, five with preproliferative, and 19 with proliferative retinopathy) were digitised and subjected to JPEG compression by 90%, 80%, 70%, and 0%. The 196 images were randomised and graded on a portable computer. Two masked graders assessed the images for grade of retinopathy and image quality (0–10). The sensitivity and specificity of retinopathy grading were calculated with a weighted kappa for grading agreement between levels of compression. RESULTS The sensitivity of retinopathy grading was reduced by JPEG compression. At 90%, 80%, 70%, and 0% compression the sensitivities were 0.38, 0.50, 0.65, and 0.72, respectively; the specificity results were 1.00, 1.00, 0.83, and 0.84, respectively; and the weighted kappa scores were 0.60, 0.75, 0.77, and 0.84, respectively. The quality scores for 90%, 80%, 70%, 0% compression were 2.9 (SD 1.1, 95% CI; 2.7–3.2), 4.6 (SD 1.1, 95% CI; 3.0–5.6), 5.8 (SD1.5, 95% CI 5.0–6.6), 6.3 (SD1.4, 95% CI; 5.4–7.2) (p<0.01 for each intergroup comparison). CONCLUSION The results demonstrate significant loss of sensitivity to the features of diabetic retinopathy with JPEG compression; this was compounded by the thin film transistor (TFT) screen. The authors found the quality of uncompressed images on TFT screens too poor to give grading sensitivities which reach current guidelines for diabetic retinopathy screening.

Clinical evaluation of 'local contrast enhancement' for oral fluorescein angiograms

Purpose: To describe and assess the clinical impact of ‘local contrast enhancement’ on oral fluorescein angiograms.Methods: Oral fluorescein angiograms (OFA) were performed on 12 patients with a range of diabetic retinopathy. The digital images were processed using two enhancement techniques: histogram equalisation, a widely available method; and ‘local contrast enhancement’. Twelve control images and 24 enhanced images were randomised and subjectively graded for clarity between 1 and 100 on a visual analogue scale by two masked observers. A score of 50% was chosen as the cut-off for clinically useful images.Results: The mean score for the unenhanced images was 38.8% (SD 19.4); the histogram equalisation performed better at 54.7% (SD 10.0) (p = 0.016) and ‘local contrast enhancement at 69.4% (SD 13.6) (p < 0.001). These results equate to a 14.7% improvement in comparison with histogram equalisation and a 30.3% improvement with the ‘local contrast enhancement’ technique. All the ‘local contrast enhancement’ images were clinically useful, compared with 58.3% of the histogram equalisation images (χ2 2.08, p = 0.2), and 33.3% of the control images (χ2 = 6.75, p = 0.01).Conclusion: This pilot study has demonstrated the power of ‘local contrast enhancement’ techniques for low-contrast fluorescein angiograms. Using ‘local contrast enhancement’ oral fluorescein angiograms can give high-quality images and may allow safer patient investigation.

Can optical coherence tomography predict the outcome of laser photocoagulation for diabetic macular edema

BACKGROUND AND OBJECTIVE To compare the effectiveness of augmented superior oblique Z-tenotomy (SOZT) with fixed standard SOZT in canceling preoperative superior oblique overaction associated with A pattern anisotropia or V pattern in Browns syndrome. PATIENTS AND METHODS Sixteen consecutive patients with superior oblique overaction or Browns syndrome were treated by removal of a triangular piece of the superior oblique tendon near its insertion (augmented SOZT). Outcome was compared with 20 consecutive historical controls after standard SOZT. RESULTS The decrease in superior oblique overaction in the right and left eyes and fundus intorsion and the collapse of A pattern anisotropia were more significant for patients with superior oblique overaction (P = .003, P = .007, P = .05, P = .0015, respectively) and patients with Browns syndrome (P = .025, P = .03, and P = .05, respectively). No study patient with superior oblique overaction and A pattern anisotropia required reoperation compared with 5 of 14 controls (37.5%); rates for patients with Browns syndrome were 0 for the study group and 3 of 6 (50%) for the control group. CONCLUSIONS Augmented SOZT is superior to standard SOZT for correcting superior oblique overaction, intorsion, A or V pattern, and stereopsis. It is not associated with complications or reoperation. The size of the Z-tenotomy can be modified according to the intraoperative assessment to achieve symmetric results.

UK survey of attitudes to local anaesthesia for vitreoretinal surgery.

Background The use of local anaesthesia (LA) for vitreoretinal (VR) surgery is growing although surgeons in the UK traditionally use general anaesthesia.Purpose To assess the use and attitudes towards local anaesthesia for VR surgery among the members of the British and Eire Association of Vitreo-retinal Surgeons (BEAVRS).Methods A questionnaire was sent to members of BEAVRS. Use of LA was assessed for the following procedures: macular hole; diabetic vitrectomy; vitrectomy; cryopexy and gas; buckling and re-buckling procedures. Attitudes of surgeons generally using LA for primary retinal detachment surgery (< 50% of cases) were compared with those generally using general anaesthesia (GA) (< 50% of cases).Results 33.6% of surgeons preferred LA for macular hole; 26.2% for diabetic vitrectomy; 23.3% for vitrectomy, cryopexy and gas; 21.4% for buckling procedures; and 9.35% for re-buckling procedures. When surgeons routinely using LA were compared with those regularly using GA they considered LA less stressful for patients and surgeon, patients tolerant to longer operations, and buckling or redo surgery no more difficult under LA. However, both groups considered surgery on young patients and teaching relatively more difficult under LA.Conclusion The use of LA may convey benefits for VR surgery and faster rehabilitation for patients. However, we identified wide variations in the use of and attitudes to LA for VR surgery in British surgeons.

Endophthalmitis following globe perforation with a hypodermic needle

Editor,—Exogenous endophthalmitis is a common complication of intraocular foreign bodies (IOFBs).1 It commonly occurs in association with a non-metallic foreign body and often results in profound visual loss.2 Early diagnosis and treatment with intravitreal antibiotics are essential in its treatment.3 We describe an unusual case of exogenous endophthalmitis caused by a heroin filled needle, the patient rapidly losing vision despite active intervention. ### CASE REPORT A 24 year old remand prisoner presented to the casualty department with a vague 2 day history of visual loss in his right eye. He had been stabbed in the eye 2 days previously with a …