A Survey of Current Gonioscopy Practise in the United Kingdom.

PRCIS: This survey highlights a deficiency in gonioscopy practices across the UK, particularly in the utilization of indentation gonioscopy and training of junior ophthalmologists. Recommendations include standardizing practice and enhancing training opportunities to improve patient care. BACKGROUND: Gonioscopy is an important general skill learnt and practised by all grades of ophthalmologists. The aim of this study is to discover the general attitude, perception and practice of gonioscopy among ophthalmologists in the UK. METHODS: A National gonioscopy survey was carried out by utilising an anonymous electronic questionnaire of 18 questions. The questionnaire was electronically distributed online, using the survey tool, Microsoft 2016 'MS Forms' to all grades of ophthalmologists in the UK. RESULTS: A total of 146 responses were analysed. Overall, 89% of the participants felt 'comfortable in performing slit lamp gonioscopy' but only 38% of junior trainees (ophthalmic specialist trainees years 1-3) felt comfortable in gonioscopy. Only 13% of the junior trainees felt they had adequate training in performing gonioscopy compared with 68% of the total respondents. Surprisingly, the majority of consultants (58%) did not 'strongly agree' to being confident in assessing the angle and its configuration on gonioscopy. The most commonly used gonioscopic lens in this survey was the Zeiss four-mirror gonio lens, but only 38% of participants performed indentation gonioscopy routinely. The majority of the participants utilised the modified Shaffer's classification for gonioscopy. Fewer than expected numbers performed gonioscopy routinely for new glaucoma patients. CONCLUSION: This survey suggests that gonioscopy is not being performed according to the UK national recommendations and few ophthalmologists perform indentation gonioscopy. Additional gonioscopy training in the curriculum may be helpful.

Do ophthalmology residents know how to check the calibration of a Goldmann applanation tonometer?

PURPOSE: The purpose of this observational study was to determine whether ophthalmology residents know how to check Goldmann applanation tonometer (GAT) calibration. METHODS: The step-by-step technique for checking the calibration of a GAT was taken from the manufacturer's manual and developed into a mark sheet. Ophthalmology residents in years 2-8 of training from 11 hospitals were individually observed and assessed checking calibration of a GAT. Participation was voluntary. Contact between participants was minimised to prevent communication about the study. RESULTS: Sixty-eight per cent (n = 30) of eligible ophthalmology residents (years 2-8) from 11 hospitals (three teaching hospitals and eight local general hospitals) were observed checking GAT calibration. Only 33% (n = 10; 95% CI: 16-50%) of ophthalmology residents were able to correctly check GAT calibration. Those participants who were previously taught (p = 0.046) or assessed (p = 0.015) were more likely to be successful in GAT calibration. CONCLUSIONS: Most ophthalmology residents were unable to correctly check GAT calibration. Although better than previously published results, this observational study shows that further training and assessment is required for ophthalmology residents to learn the technique of checking GAT calibration.

Topical prostaglandin analogue use and cystoid macular oedema following uneventful cataract surgery: a randomised control trial.

BACKGROUND/AIMS: The association between the development of cystoid macular oedema (CMO) following uneventful cataract surgery and prostaglandin analogue (PGA) therapy has not been fully determined. The study aim was to investigate whether discontinuation of PGA therapy following uneventful cataract surgery affected the incidence of postoperative CMO. METHODS: A prospective randomised controlled trial of 62 eyes of 62 participants with ocular hypertension (OH) or primary open angle glaucoma (POAG) treated with PGAs prior to cataract surgery. Participants were randomised to continue with PGA therapy after cataract surgery (CPGA) (n=31) or to discontinue PGA therapy (n=31). The primary outcome measure was the development of CMO at 1-month postoperatively, determined by a masked observer assessment of optical coherence tomography scans. The secondary outcome measure was change from baseline intraocular pressure (IOP). RESULTS: The incidence of CMO was identical in both groups at 12.9% (4 of 31 eyes) at the 1-month postoperative visit (OR 1.000; 95% CI 0.227 to 4.415). At 1-month postoperatively, the IOP was significantly lower in the CPGA group compared with baseline IOP. CONCLUSION: Continuation of PGA therapy following uneventful cataract surgery in eyes with normal macular morphology did not increase the incidence of CMO. Continuation of PGA therapy significantly reduced IOP at 1-month postoperatively suggesting that, when indicated, it might be beneficial to continue PGA therapy in patients with POAG or OH after uneventful cataract surgery in the absence of other risk factors for developing CMO.

Infraorbital Nerve Decompression for Infraorbital Neuralgia/Causalgia following Blowout Orbital Fractures: A Case Series.

The purpose of this study was to present the management of a series of patients referred with infraorbital nerve paraesthesia that developed after insignificant orbital floor fracture without diplopia or exophthalmos, and that did not require initial surgical repair. This is a retrospective interventional case series. The main outcome and measures were assessment of preoperative symptoms including neuralgia and sensory symptoms; review of periorbital computed tomography (CT) scans; and assessment of postoperative effects of surgery for infraorbital nerve decompression. Nine patients were identified who developed neuralgia affecting the infraorbital nerve distribution from a cohort of 79 patients who presented with orbital floor fracture. Six were female and three were male. Age range was 22 to 73 years with a mean of 48 years. Six patients were clinically depressed due to the chronic pain. In addition, two patients had dizziness on upgaze; one patient had blurring of central vision on eye movements; and one patient had mood swings. Reviews of CT scans revealed subtle disruption of the infraorbital canal in all cases. All nine patients underwent infraorbital nerve decompression. Abnormal adhesions between the nerve and its bony canal were found in five of nine cases. Follow-up ranged from 3 to 37 months (mean: 18 months). Following surgery, after a variable period of time ranging from 1 day to 3 months, all patients had resolution of their symptoms. Mean follow-up was 18 months. Reconstructive surgeons should be aware that infraorbital nerve neuralgia, secondary to disruption of the nerve in the distorted bony canal, may be another indication for surgical intervention following orbital floor trauma in selected cases, in addition to more traditionally accepted indications. Neuralgia and causalgia are probably more common than previously thought and symptoms should be actively sought in the patient's history or else risk being overlooked and inappropriately managed. Long-term follow-up of such patients is unlikely to be practical. Patient and/or family practitioner education of possible sequelae may be one possible solution to detect this type of problem early. Nerve decompression, where indicated, may improve the patient's neuralgia and associated behavioral changes and quality of life. An optimal diagnostic and management algorithm is yet to be established.

Effect of phacoemulsification on trabeculectomy function.

BACKGROUND: To evaluate the effect of phacoemulsification on trabeculectomy function. DESIGN: Retrospective case-control study. PARTICIPANTS: Forty-eight patients who underwent trabeculectomy surgery and had at least 2 years of follow up. METHODS: Patients were classified into two groups: patients who had phacoemulsification subsequent to trabeculectomy (Trab_phaco, n = 18) and patients who were pseudophakic for greater than 6 months preceding their trabeculectomy (Phaco_trab, n = 30). Groups were matched for length of follow up of 2 years from time of trabeculectomy. MAIN OUTCOME MEASURES: The primary outcome measures were target intraocular pressure of criteria A, ≤12 mmHg; B, ≤15 mmHg; C, ≤18 mmHg with or without additional topical treatment. A separate measure for bleb function failure was also used; with failure defined as the need for additional topical antiglaucoma therapy or surgical intervention to achieve control of intraocular pressure. RESULTS: There was no significant difference in achieving each intraocular pressure criterion between groups (12 months, P = 1.0; 24 months, P = 0.330). In the first 12 months, significantly more trabeculectomies in the Trab_phaco group failed, requiring additional intervention to control the IOP (39%) compared with the Phaco_trab (10%) group (P = 0.028). Although this trend continued at 24 months, there were no significant differences in failure rates (P = 0.522). CONCLUSIONS: Phacoemulsification performed after trabeculectomy significantly increased rates of bleb failure in the following 12 months but not at 24 months.

Rise of intraocular pressure in a caffeine test versus the water drinking test in patients with glaucoma.

BACKGROUND: There is increasing emphasis on the importance of intraocular pressure peaks and fluctuations as risk factors for glaucoma progression. It is well recognized that the water drinking test raises intraocular pressure and there is reasonable evidence that caffeine can also raise intraocular pressure. The aim of this study is to directly compare the effect of a caffeine test to that of the water drinking test on intraocular pressure, in patients with glaucoma. DESIGN: Prospective, observer-masked, cross-over study. PARTICIPANTS: Fourteen eyes of 14 patients with primary open-angle glaucoma. METHODS: Patients were initially randomized to either caffeine test or water drinking test. Intraocular pressure was measured in both eyes with a Goldmann applanation tonometer at baseline and every 15 min for 1 h, by a masked examiner. This was repeated the following week at the same time of day for the other test (the cross-over). Peak intraocular pressure and maximum fluctuation from baseline were compared between groups using paired t-tests. MAIN OUTCOME MEASURES: Peak and fluctuation of intraocular pressure, time of maximum frequency of peak intraocular pressure. RESULTS: The maximum intraocular pressure from the water drinking test (19.7 ± 4.1) was greater than the caffeine test (16.7 ± 4.1) and showed greater fluctuation in intraocular pressure (4.3 ± 2.7 mmHg [27.7%]; P < 0.0001) compared with the caffeine test (1.8 ± 1.9 mmHg [11.7%]); P = 0.004). CONCLUSION: The rise in intraocular pressure was greater with water drinking test than the caffeine test. Caffeine does not appear to provide an alternative for patients unable to tolerate the water drinking test.

P2X7 receptor activation mediates retinal ganglion cell death in a human retina model of ischemic neurodegeneration.

PURPOSE: There is evidence implicating ischemia and excitotoxicity in the pathogenesis of glaucoma. ATP-mediated excitotoxicity via activation of the P2X7 receptor (P2X7R) has been proposed to play a role in retinal ganglion cell (RGC) degeneration in this disease. The aim of this research was to determine whether stimulation of the P2X7R mediated ischemia-induced RGC death in the human retina. METHODS: Human organotypic retinal cultures were exposed to the P2X7R agonist 2',3'-O-(4-benzoylbenzoyl)-ATP (BzATP) and simulated ischemia (oxygen/glucose deprivation) in the presence or absence of the P2X7R antagonist, Brilliant Blue G (BBG). Neuronal death in the RGC layer was quantified by neuronal nuclei (NeuN)-positive cell counts and quantitative real-time PCR for THY-1 mRNA. The P2X7R was localized by immunohistochemistry and P2X7R mRNA profiling using a cryosectioning technique. RESULTS: P2X7R stimulation by BzATP (100 µM) induced loss of RGC markers in human organotypic retinal cultures (HORCs), which was inhibited by BBG (1 µM). Simulated ischemia led to loss of RGCs that was also inhibited by BBG, indicating that ischemia-induced RGC degeneration was mediated by the P2X7R. The P2X7R was immunolocalized to the outer and inner plexiform layers of the human retina, and P2X7R mRNA expression was confirmed in the inner retina and ganglion cell layer. CONCLUSIONS: These studies demonstrated that stimulation of the P2X7R can mediate RGC death and that this mechanism plays a role in ischemia-induced neurodegeneration in the human retina.

Intraocular pressure lowering is associated with an increase in the photopic negative response (PhNR) amplitude in glaucoma and ocular hypertensive eyes.

PURPOSE: The aim of our study was to determine whether IOP lowering in glaucomatous and ocular hypertensive (OHT) eyes leads to an improvement in the full-field photopic negative response (PhNR) of the electroretinogram. METHODS: A prospective nonrandomized interventional cohort study was conducted. Patients with OHT or glaucomatous optic neuropathy were recruited, and photopic full-field electroretinograms (ERG) were performed at baseline and then repeated 1 to 2 months later. The change in PhNR amplitude was compared between those eyes that had a significant lowering in IOP (defined as >25% decrease from baseline or to a predetermined target IOP) during follow-up and those that did not. RESULTS: From a cohort of 30 eyes, 18 eyes had a significant reduction in IOP during follow-up (n = 18) and 12 eyes had no significant change in IOP (<25% reduction in IOP, n = 12). A significant increase in PhNR amplitude and the PhNR/b-wave amplitude ratios was observed in the reduced IOP group, but not in the IOP stable group for the two flash intensities used (2.25 and 3.00 cd.s/m(2)). CONCLUSIONS: The full-field PhNR amplitude provides a potentially reversible measure of inner retinal function that improves after IOP lowering. Further study now is required to assess its use as a measure of optic nerve health in glaucoma patients.

Bleb vascularity following post-trabeculectomy subconjunctival bevacizumab: a pilot study.

BACKGROUND: To determine whether postoperative subconjunctival bevacizumab significantly alters bleb vascularity. DESIGN: A randomized, prospective interventional study. PARTICIPANTS: Forty-three eyes from 39 patients were recruited, with 21 eyes randomized to subconjunctival injections of 5-fluorouracil, and 22 eyes to combined 5-fluorouracil/bevacizumab. METHODS: All patients who underwent uncomplicated primary antimetabolite augmented trabeculectomy who subsequently required postoperative subconjunctival 5-fluorouracil injection within 4 weeks of surgery were eligible. Patients were randomized to receive subconjunctival 5-fluorouracil only (7.5 mg/0.15 mL) or 5-fluorouracil plus bevacizumab (1.25 mg/0.05 mL). MAIN OUTCOME MEASURES: Primary outcome was bleb vascularity with secondary endpoints including visual acuity, intraocular pressure, bleb morphology, complications and total numbers of 5-fluorouracil injections were recorded at baseline, week 12 and 18 months. RESULTS: At week 12, there was no significant difference between groups for visual acuity, intraocular pressure, bleb vascularity and morphology, or total number of 5-fluorouracil injections. By 18 months, 47.4% of the 5-fluorouracil/bevacizumab group exhibited central bleb avascularity compared with 21.1% of the 5-fluorouracil group (Fisher's exact test, P = 0.17). Two bleb complications (one blebitis; one suture abscess) recorded in the 5-fluorouracil/bevacizumab group. CONCLUSIONS: After a single combined injection, a trend for increased central bleb avascularity was observed, although this effect was not sufficient to reach statistical significance. This, in addition to the occurrence of two bleb-related complications in the bevacizumab group, suggests the need for a larger clinical trial to further evaluate the safety and efficacy of bevacizumab as a modulating agent in glaucoma filtration surgery.

The development of human organotypic retinal cultures (HORCs) to study retinal neurodegeneration.

AIMS: To develop human organotypic retinal cultures (HORCs) to study retinal ganglion cell (RGC) death in response to ischaemic and excitotoxic insults, both known to cause loss of RGCs and proposed as mechanisms involved in glaucomatous retinal neurodegeneration. METHODS: Human donor eyes were obtained within 24 h post mortem. The retina was isolated and explants cultured using two techniques. THY-1 mRNA (assessed by real-time quantitative PCR) and neuronal nuclei (NeuN) (assessed by immunohistochemistry) were used as markers of RGCs. Apoptosis was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL). RESULTS: The distribution of THY-1 mRNA and NeuN-labelling within the human retina was consistent with the expected distribution of RGCs. Gross morphology and retinal architecture remained stable over a 96 h culture period. THY-1 mRNA and NeuN-labelled RGC layer cells decreased over the culture period, and there was an increase in TUNEL-labelling with time, but HORCs cultured in serum-free DMEM/HamF12 medium were useful for up to 48 h in culture. N-methyl-d-aspartate (10 µM) caused a reduction in THY-1 mRNA by 24 h and decreased the numbers of NeuN-labelled RGC layer neurons by 48 h, suggesting that the loss of THY-1 mRNA was a marker of RGC stress prior to death. Simulated ischaemia (60 min oxygen/glucose deprivation) caused a reduction at 24 h in both THY-1 mRNA and the numbers of NeuN-labelled neurons of HORCs. CONCLUSION: HORCs provide a useful model to investigate RGC insult by neurodegenerative mechanisms that may lead to glaucoma in human eyes.

Pigment dispersion syndrome and pigmentary glaucoma--a major review.

Pigment dispersion syndrome (PDS) is an interesting condition that can lead to secondary open angle glaucoma. Pigmentary glaucoma is primarily a disease of young people, myopes and men. PDS is characterized by the presence of Krukenberg spindles, iris trans-illumination defects, trabecular meshwork pigmentation and backward bowing of the iris. Posterior bowing of the iris causes rubbing of the pigmented iris epithelium against lens structures, liberation of pigment and trabecular meshwork changes that result in reduced aqueous outflow with the risk of glaucoma. Peripheral laser iridotomy can reverse backward bowing of the iris and may prevent progression of pigmentary glaucoma.

Acanthamoeba keratitis associated with misuse of daily disposable contact lenses.

PURPOSE: To report a case of Acanthamoeba keratitis that occurred in a daily disposable contact lens wearer. METHOD: Case report. RESULTS: A 70-year-old gentleman presented to eye casualty with a red left eye with reduced vision and corneal epithelial changes. Acanthamoeba keratitis was not suspected initially as he was a daily disposable contact lens wearer. This led to a delay of 17 days in initiating treatment. He responded well to topical polyhexamethylene biguanide and propamidine and made a full recovery. CONCLUSION: Acanthamoeba keratitis can occur in patients who reuse daily disposable contact lenses. A diagnosis of Acanthamoeba keratitis can be difficult to make and should be considered in all patients who wear contact lenses, including daily disposable lenses. All patients who wear daily disposable contact lenses should be reminded that the benefits of this modality of contact lens are only possible if the lenses are worn once and thrown away.