Surveillance of late-onset bleb leak, blebitis and bleb-related endophthalmitis--a UK incidence study.

AIMS: To determine the incidence of late-onset bleb leak (BL), blebitis (B) and bleb-related endophthalmitis (BRE) after trabeculectomy surgery, and report the management approaches employed by UK ophthalmologists. METHODS: Prospective case ascertainment study reporting of incident cases fulfilling the study definitions of BL, B and BRE through the reporting mechanism provided by the British Ophthalmic Surveillance Unit (BOSU; United Kingdom) for the period July 2007 to August 2008 (13 months). Two questionnaires completed at initial reporting and 6 months later were used to collect clinical details related to presentation, early and late management and outcome. RESULTS: Ninety-eight cases were reported to the British Ophthalmic Surveillance Unit during the study period. Seventy-one first questionnaires were returned (response rate 72.4%). Of these, 11 were erroneous/duplicated. Sixty second questionnaires were sent out, and of these 37 fully completed questionnaires were returned. Analysis was, therefore, based upon 60 initial and 37 follow-up questionnaires. Overall incidences were estimated for isolated bleb leak (0.22%), blebitis without bleb leak (0.1%), blebitis with bleb leak (0.11%), and BRE with or without bleb leak (0.17%). Visual outcome in the BL group was good; however, in the BRE group half the patients ended with visions of perception of light or worse. There was a great variance in the initial and late management of these conditions. Surgical intervention for bleb leak seemed to result in the best chance of leak closure. CONCLUSIONS: These complications of trabeculectomy surgery are relatively low but potentially visually devastating. This study updates the knowledge of the incidence of these complications, and suggests that no consistent management approach to any of the reported conditions was practised. In view of the potentially catastrophic consequences of these complications, formal guidance as to best practice would be beneficial, and further research to establish this is required.

Early bleb leak after trabeculectomy and prognosis for bleb failure.

AIM: To determine whether early bleb leak after MMC trabeculectomy affects intermediate intraocular pressure (IOP) outcome. METHODS: Retrospective case note review. All cases of MMC trabeculectomy with at least 1-year follow-up were included. Cases where a bleb leak occurred within the first month were identified. All cases without an early bleb leak formed the control group. Patient demographics and clinical factors were analysed to determine any factors predisposing to bleb leakage. IOPs were compared for 1 year postoperatively and final follow-up. RESULTS: A total of 119 trabeculectomies were included. Of these 27 (22.7%) had an early bleb leak. The remaining 92 cases formed the control group. Mean age of cases was 70.7 years. Mean follow-up time was 19.5 months. Mean time of detection of the bleb leak was 9 days (range 1-21 days). Four cases (14.8%) were managed by primary resuturing. Thirteen cases (48.1%) were managed conservatively with a bandage contact lens. Ten cases (37.0%) resolved with expectant management. There was no statistically significant difference between the two groups with regards to IOP measurement at any time point. Intervention rates were similar with regards to bleb massage, 5-fluorouracil injection, and needling revision. No factors were identified between the two groups that predisposed to bleb leaks occurring. CONCLUSION: Our data suggest that early bleb leak is not a poor prognostic indicator for intermediate bleb survival and IOP control in patients undergoing MMC trabeculectomy. No additional bleb manipulations compared with the control group were required to achieve a satisfactory IOP outcome.

Anticoagulation therapy in glaucoma surgery.

PURPOSE: To identify the practices of ophthalmologists when undertaking glaucoma surgery on patients concurrently using warfarin or acetylsalicylic acid (aspirin). METHODS: A questionnaire was designed to examine perioperative management of patients being treated with warfarin and aspirin prior to and during glaucoma surgery. The questionnaire was posted with stamped self-addressed envelopes to all glaucoma specialists registered on a glaucoma shared care scheme database. RESULTS: Of the 93 eligible participants, 64 returned a completed questionnaire, representing a response rate of 68.8%. Twenty-one surgeons (32.8%) routinely stopped warfarin before surgery. Mean time prior to surgery of drug cessation was 4 days (range 2-7). Three surgeons (14.3%) routinely commenced heparin if they stopped warfarin. Ten (47.6%) never used heparin, while the remaining eight (38.1%) would use heparin depending upon the indication for anticoagulation. Forty-two surgeons (81.25%)were happy to operate only at an INR < or =3 at the time of surgery. The remainder (18.75%) were happy to operate at higher INRs, including two surgeons (3.1%) who would operate at any level. Twenty surgeons (31.2%) routinely stopped aspirin before surgery, while the rest did not. Of those who stopped aspirin, the mean time prior to surgery was 7.1 days (range 4-14 days). CONCLUSIONS: The majority of surgeons do not stop warfarin or aspirin prior to glaucoma surgery. There is a great diversity in current practice with regard to the management of anticoagulant therapy prior to glaucoma surgery amongst glaucoma surgeons in England. Currently there is little information available to offer definitive guidance.

Frequency of bleb manipulations after trabeculectomy surgery.

AIM: To quantify the type and frequency of postoperative bleb manipulations undertaken after modern glaucoma surgery. METHODS: Bleb manipulations were recorded after trabeculectomy surgery on 119 consecutive patients with at least 1 year of follow-up. The type of intervention and time after surgery were recorded. Statistical analysis identified success rates at various intraocular pressure (IOP) cut-off definitions and identified factors that increased the risk for bleb manipulation. RESULTS: In all, 78.2% of trabeculectomies were followed by some form of bleb manipulation. Almost 49% of blebs underwent massage and a similar number required at least one suture removal, 31.1% required at least one 5-fluorouracil (5-FU) injection and 25.2% required at least one needling and 5-FU injection. The median time to the first intervention for massage, suture removal, 5-FU injection, and needling and 5-FU injection were 1, 14, 14 and 43 days, respectively. IOP measurements were higher at all follow-up time points in the intervention group. Failure to achieve specific IOP target pressures was also generally poorer in the 5-FU, and needling and 5-FU intervention groups. CONCLUSIONS: Postoperative intervention is a frequent occurrence after modern glaucoma surgery. This requires intensive postoperative follow-up and is a labour-intensive undertaking. Despite interventions in our group of patients, IOP in the intervention group was always higher than in the group that required no intervention.

Long-term follow-up of porous polyethylene spherical implants after enucleation and evisceration.

PURPOSE: To present long-term follow-up data on enucleations and eviscerations carried out with placement of spherical porous polyethylene implants. METHODS: A retrospective, interventional, noncomparative case series of all patients undergoing primary evisceration or enucleation surgery from one teaching hospital ophthalmology department. RESULTS: In total, 106 cases were identified. Eighty patients (75.5%) underwent enucleation (group A) and 26 (24.5%) underwent evisceration (group B). Patient demographics were similar in both groups. Mean implant size in group A was 20.5 mm and 17.2 mm in group B. Mean follow-up in group A was 40 months (range, 12 to 80 months). Mean follow-up in group B was 63 months (range, 12 to 72 months). Six cases (7.5%) in group A had complications (excluding implant exposure), whereas one case (3.8%) in group B had a complication (excluding implant exposure). Five patients (6.3%) in group A had implant exposure; 14 cases (53.8%) of implant exposure occurred in group B. CONCLUSIONS: Our case series revealed a significantly higher incidence of implant exposure after evisceration than after enucleation. Our data suggest that enucleation should be the procedure of choice when removing an eye to minimize the risk of subsequent complications, particularly orbital implant exposure.

Orbital implant exposure treatment with porcine dermal collagen patching.

PURPOSE: To present a small case series of orbital implant exposures treated with porcine dermal collagen (Permacol, Tissue Science Laboratories PLC, Aldershot, Hants, UK) patching. METHODS: A retrospective chart review of three cases of orbital implant exposure treated with Permacol patching. RESULTS: Three cases were identified. There were 4 operative episodes of Permacol patching (one socket had two attempts at permacol patching). In all 4 cases the patch rapidly failed and melted away leaving behind the orbital implant exposure. All 3 patients required implant removal. CONCLUSIONS: Orbital implant exposure remains a major long-term complication of evisceration and enucleation procedures. On the basis of our experience, we would not recommend using Permacol as a non-autologous material for covering exposed Medpor (Medpor, Porex Surgical, Atlanta, Georgia, USA) orbital implants. Further study is required to fully assess the safety and efficacy profile of Permacol in socket surgery.

First day review after uncomplicated phacoemulsification: is it necessary?

PURPOSE: To determine whether first day follow-up is necessary after routine uncomplicated phacoemulsification cataract surgery. METHODS: Data collected prospectively at day 1 postoperative review. RESULTS: In 510 consecutive cases, serious complications occurred in 8 (1.6%) (wound leak [4], corneal abrasion [2], iris prolapse [1], hyphema [1]). Intraocular pressure (IOP) >30 mmHg was found in 26 (5.1%) and was strongly associated with a diagnosis of pre-existing glaucoma or ocular hypertension (odds ratio [OR] 7.7). Symptoms of headache or ocular discomfort occurred in 40 (7.8%), mostly in association with raised IOP, and were also associated with pre-existing glaucoma or ocular hypertension (OR 4.7). Central corneal edema was found in 61 (12.0%). In the absence of corneal edema, IOP was >30 mmHg in only two cases (0.39%). CONCLUSIONS: Few sight-threatening complications were detected on the morning after an uncomplicated procedure. First day follow-up may be safely omitted if adequate patient counseling is undertaken and there is provision of adequate access to eye services. Review prior to discharge on the day of surgery would provide an opportunity to detect these few surgical complications and for counseling. A diagnosis of glaucoma or ocular hypertension is a risk factor for significantly raised next day IOP and these patients are more likely to experience postoperative discomfort. They may benefit from prophylactic treatment.

Foveal detachment after successful retinal reattachment for macula on rhegmatogeneous retinal detachment: an ocular coherence tomography evaluation.

PURPOSE: Foveal detachment after apparently successful retinal reattachment surgery for macula-on retinal detachments (RDs) has been previously documented. This pilot study aimed to utilize ocular coherence tomography (OCT) imaging to investigate foveal architecture after routine retinal detachment surgery and correlate this to visual acuity. METHODS: Prospective recruitment of patients attending one unit with macula-on RDs. Patients underwent full clinical examination including OCT preoperatively and RD surgery undertaken by scleral buckling, external drainage and air injection. Postoperatively patients had clinical examinations and OCT at 1 week, 1, 3, 6, and 12 months. RESULTS: A total of 12 consecutive patients were recruited into the study. All had macula-on RDs and normal OCTs at onset. There were no operative or postoperative complications. Retinal reattachment was achieved in all cases within 24 h postoperatively. At 1 month six of 12 patients (50%) showed foveal detachment on OCT, which was invisible on clinical examination. At 3 months, the foveal detachment persisted in four (33%) of these patients. In these cases the foveal detachment persisted at 6 months follow-up, however, a reduction in subfoveal fluid was noted. All cases had foveal reattachment by 12 months postoperatively. Visual acuity was closely correlated to the presence of foveal attachment. DISCUSSION: A high proportion of patients with successful retinal reattachment surgery had foveal detachments postoperatively. This phenomenon was associated with reduced visual acuity. The aetiology of this occurrence is unknown and warrants further investigation as there is the potential of a long-term effect on vision.

Fornix vs limbal-based trabeculectomy with mitomycin C.

PURPOSE: To compare the effectiveness of limbus- and fornix-based conjunctival flaps in patients undergoing trabeculectomy with mitomycin-C augmentation. METHODS: A retrospective review of the records of 71 consecutive eyes of 59 patients who underwent trabeculectomy with mitomycin C. All the patients had at least 6 months of follow-up. The first 35 eyes underwent surgery with a limbal-based flap, whereas all subsequent surgeries were by fornix-based procedures. RESULTS: No significant difference was detected between the groups with regard to patient demographics, preoperative visual field and intraocular pressure parameters, postoperative intraocular pressures at day 1, months 1, 3, and 6 postoperatively, need for intervention, need for supplementary glaucoma medication, and final visual acuity. There were four cases of overdrainage and hypotony in the limbal-based group, whereas none occurred in the fornix-based group. In all 83% percent of eyes in the limbal-based group achieved intraocular pressures off medication of less than 18 mmHg, whereas 94% of the fornix based group obtained such IOP control. One patient in the limbal-based group developed late postoperative endophthalmitis. CONCLUSION: Trabeculectomy with MMC augmentation is a safe and effective procedure for reduction of IOP and visual rehabilitation whether a fornix- or a limbal-based conjunctival flap is utilised. In this series, there was a greater risk of excessive drainage with subsequent hypotonous complications when surgery was undertaken by a limbal-based procedure.

Visual acuity and legal visual requirement to drive a passenger vehicle.

OBJECTIVES: (1). To test the consistency and ease with which number-plates of different component figures can be read under DVLA driving test conditions; (2). to test the relative difficulty of reading corresponding figures on registration plates of white and yellow backgrounds.Design Prospective study of consecutive eligible clinic patients. SETTING: Ophthalmology outpatients. SUBJECTS: 210 individuals with a corrected visual acuity with both eyes open of between 6/9 and 6/12. MAIN OUTCOME MEASURES: The ability to read three different number-plates under standard DVLA driving-test conditions (ie at 20.5 m in good daylight with glasses if worn) and the ability to read identical number-plates against a white and a yellow background. RESULTS: There is a significant difference between the ease with which three different number-plates can be read depending on their letter and numeral composition, although this did not seem to be significantly affected by whether they were printed on a yellow or white background. Only 92.3% of subjects could read all the number-plates at the legal distance, 96.7% could read at least one number-plate at the legal distance and 3.3% of the test subjects could not read any of the number-plates at 20.5 m. CONCLUSIONS: The current test protocol used to obtain a driving licence and, moreover, the test the police will employ to assess visual competence to drive, is highly variable and is unlikely to give consistent repeatable results. The performance of those with equally good visual acuity is unpredictable and is highly dependent on the number-plate they are asked to read. This variability could exclude some who would otherwise pass the test or pass an individual with a visual acuity below accepted standards. The forthcoming changes in the regulations for design of number-plates is an ideal opportunity to standardise the whole testing procedure for driving visual acuity.

The use of surgical facemasks during cataract surgery: is it necessary?

AIM: To assess whether facemask utilisation by the surgeon during cataract surgery has any effect on the bacterial load falling onto the operative site. METHOD: Prospective randomised masked study. Consent was obtained from 221 patients. Cases were randomised to wearing a new mask or not wearing any mask throughout the procedure. Blood agar settle plates were placed adjacent to the patient's head in the operative field. Duration of procedure was noted. Plates were incubated and read at 48 hours. Colony forming bacteria were counted and identified. RESULTS: There were significantly fewer organisms cultured when the surgeon used a facemask (p=0.0006). The majority of organisms were Staphylococcus epidermidis, Bacillus spp, and Diphtheroid spp; however Staphylococcus aureus and Pseudomonas aeruginosa were cultured on several occasions. There were no cases of infective complication. CONCLUSIONS: The main purpose of an operating mask is to prevent bacteria falling on to the operative site from the surgeon's oropharynx or nasopharynx with the concomitant theoretical risk of infective complication. Operating masks were shown to have a significant effect on the volume of bacterial organisms falling to the operative site; however, whether this is clinically significant is unknown.

Optometrists' examination and referral practices for patients presenting with flashes and floaters.

INTRODUCTION: Patients experiencing flashes and floaters commonly present to their optometrist. Some of these patients may have significant pathology, yet there is a great deal of variability with regard to examination technique and referral practice. METHODS: A questionnaire survey was undertaken to determine the current management of patients presenting to their optometrist with flashes and floaters. All practising community optometrists within Southern Derbyshire received a questionnaire and 74 (56.9%) completed replies were received. RESULTS: Optometrists estimated that an average of 14 patients per month per optometrist presented with symptoms of flashes and/or floaters. Mydriasis was utilised routinely for examination in approximately half of the patients. Mean relative confidence was 2.0 at identifying a vitreous haemorrhage and 6.5 for vitreous pigment (complete confidence = 0, complete lack of confidence = 10). Eight percent of responders were unfamiliar with the clinical sign of vitreous pigment, and 17% identifying this sign did not refer all such patients to the hospital services. CONCLUSIONS: Patients presenting to their optometrists with flashes and/or floaters make up a sizeable part of the community optometrist's workload and the management of these patients is highly variable. A large proportion of these patients are examined without mydriasis, even in the presence of various risk factors for retinal detachment. There is a relative lack of confidence amongst optometrists with regards the detection of vitreous pigment and the prognostic implications of this finding. Educational measures such as study days may help the level of understanding and heighten the appreciation of the implications of flashes and floaters and the various clinical signs encountered.

Vascular amyloidosis causing spontaneous mediastinal haemorrhage with haemothorax.

Bleeding diathesis is a recognised complication of amyloid disease. Localised and generalised bleeding manifestations are usually associated with intravascular coagulopathy related to isolated or multiple coagulation factor deficiencies. Recently, there have been reports of haemorrhage due to amyloid deposition in blood vessel walls and in the perivascular region leading to increased fragility and poor haemostasis. We report a case of spontaneous mediastinal haemorrhage due to amyloid involvement of vascular tissue in the absence of coagulopathy.

The effect of sub-Tenon's anaesthesia on intraocular pressure.

PURPOSE: To assess the effect of sub-Tenon's anaesthesia on intraocular pressure (IOP) prior to cataract surgery. METHODS: Fifty consecutive patients undergoing phacoemulsification of cataract were recruited. Routine sub-Tenon's anaesthesia was administered with 5 ml unpreserved 2% lignocaine. IOPs were measured immediately prior to and at 1, 3, 5 and 10 min after injection. Efficacy was assessed subjectively by the operating surgeon. No ocular compression was used. Pre- and post-injection IOPs were compared using the Wilcoxon signed rank test, whereas all other results were compared with baseline using Student's two-tailed paired t-tests. RESULTS: All patients achieved good analgesia and akinesis. There was no significant difference between the IOP prior to and 1 min after injection. At all time intervals after 3 min there was a significant reduction in IOP compared with the pre-injection measurement. At 5 min, the mean IOP reduction was 2.72 mmHg and at 10 min IOP was lowered by 2.92 mmHg. Both reductions were statistically significant compared with baseline. CONCLUSIONS: Sub-Tenon's anaesthesia does not cause any significant rise in IOP, thereby possibly making it the anaesthetic technique of choice when an increase in IOP is undesirable. There is no indication for the use of an ocular pressure-reducing device when sub-Tenon's anaesthesia is employed.