"Culture-positive exogenous endophthalmitis related to XEN45 gel stent implantation"

PURPOSE

The XEN45 gel stent implant (Allergen, CA, USA) is one of many micro-invasive surgical options available to glaucomatologists. Our case series describes the presentation, treatment, and possible risk factors of XEN45 gel stent related endophthalmitis.

OBSERVATIONS

A 71 year old Chinese man and a 88 year old Caucasian woman underwent XEN45 gel stent implantation for primary open angle glaucoma. They presented with endophthalmitis at 7 and 4 months post-surgery respectively. The first patient had stent exposure with blebitis while the second patient did not show any signs of conjunctival defect, stent exposure, bleb leak nor blebitis. Both patients were treated immediately with intravitreal, topical and systemic antibiotics, followed by early vitrectomy. The implant was removed in the first, but not in the second patient. Vitreous cultures grew Streptococcus Viridans in the first patient and Haemophilus influenzae in the other. Unfortunately, the first patient eventually sustained a total retinal detachment requiring surgery and did not recover his vision. The second patient however, recovered with a good Snellen's visual acuity of 6/9 and maintenance of good intraocular pressure and bleb formation.

CONCLUSIONS

Exogenous endophthalmitis related to XEN45 gel stent implantation is a rare but devastating complication. The risks factors identified were multiple post-operative procedures, bleb exposure, conjunctival defect, use of antifibrotics, blepharitis and prolonged post-operative antibiotics. XEN45 gel stent implant provides a different challenge to ophthalmologists compared to trabeculectomy as more post-operative procedures are required to prevent subconjunctival scarring. Great care should be taken to individualize the use of antifibrotics in each patient to balance the risk of subconjunctival fibrosis with the risk of infection. In patients with stent exposure we propose early closure of the conjunctiva to close off the portal of entry for pathogens and reduce the need for prophylactic topical antibiotics.

Comparison of Ethnic-specific Databases in Heidelberg Retina Tomography-3 to Discriminate Between Early Glaucoma and Normal Chinese Eyes

Purpose:

To compare the diagnostic accuracy of the 3 race-specific normative databases in Heidelberg Retina Tomography (HRT)-3, in differentiating between early glaucomatous and healthy normal Chinese eyes.

Method:

52 healthy volunteers and 25 glaucoma patients were recruited for this prospective cross-sectional study. All underwent standardized interviews, ophthalmic examination, perimetry and HRT optic disc imaging. Area under the curve (AUC) receiver operating characteristics, sensitivity and specificity were derived to assess the discriminating abilities of the 3 normative databases, for both Moorfields Regression Analysis (MRA) and Glaucoma Probability Score (GPS).

Results:

A significantly higher percentage (65%) of patients were classified as “within normal limits” using the MRA-Indian database, as compared to the MRA-Caucasian and MRA-African-American databases. However, for GPS, this was observed using the African-American database. For MRA, the highest sensitivity was obtained with both Caucasian and African-American databases (68%), while the highest specificity was from the Indian database (94%). The AUC for discrimination between glaucomatous and normal eyes by MRA-Caucasian, MRA-African-American and MRA-Indian databases were 0.77 (95% CI, 0.67-0.88), 0.79 (0.69-0.89) and 0.73 (0.63-0.84) respectively. For GPS, the highest sensitivity was obtained using either Caucasian or Indian databases (68%). The highest specificity was seen with the African-American database (98%). The AUC for GPS-Caucasian, GPS-African-American and GPS-Indian databases were 0.76 (95% CI, 0.66-0.87), 0.77 (0.67-0.87) and 0.76 (0.66-0.87) respectively.

Conclusion:

Comparison of the 3 ethnic databases did not reveal significant differences to differentiate early glaucomatous from normal Chinese eyes.

Comparative Efficacy and Tolerability of Topical Prostaglandin Analogues for Primary Open-Angle Glaucoma and Ocular Hypertension

Objective: To systematically review the efficacy and tolerability of 4 prostaglandin analogues (PGAs) as first-line monotherapies for intraocular pressure (IOP) lowering in adult patients with primary open-angle glaucoma or ocular hypertension. Data Sources: A literature search was performed in PubMed (1965-June 2013) and the Cochrane Library (1980-June 2013) using the search terms ocular hypertension, open-angle glaucoma, prostaglandin analogues, bimatoprost, latanoprost, tafluprost, and travoprost. Additional studies were searched from the reference lists of identified publications. Study Selection and Data Extraction: In all, 32 randomized controlled trials comparing between PGAs (bimatoprost 0.03%, latanoprost 0.005%, tafluprost 0.0015%, and travoprost 0.004%) or PGA with timolol were selected. Data Synthesis: A network meta-analysis was conducted. Using timolol as reference, the relative risks (RRs) of achieving treatment success, defined as the proportion of patients achieving at least 30% IOP reduction, with 95% CIs, were as follows: bimatoprost, 1.59 (1.28-1.98); latanoprost, 1.32 (1.00-1.74); travoprost, 1.33 (1.03-1.72); and tafluprost, 1.10 (0.85-1.42). The mean IOP reductions after 1 month were 1.98 (1.50-2.47), 1.01 (0.55-1.46), 1.08 (0.59-1.57), and 0.46 (−0.41 to 1.33) mm Hg, respectively, and the results were sustained at 3 months. Bimatoprost was associated with the highest risk of developing hyperemia, whereas latanoprost had the lowest risk, with RRs (95% CI) of 4.66 (3.49-6.23) and 2.30 (1.76-3.00), respectively. Conclusions: Bimatoprost achieved the highest efficacy in terms of IOP reduction, whereas latanoprost had the most favorable tolerability profile. This review serves to guide selection of the optimal PGA agent for individual patient care in clinical practice.

High-Dose Intravenous Immunoglobulins in the Treatment of Toxic Epidermal Necrolysis: An Asian Series

Toxic epidermal necrolysis (TEN) is a severe, immune-mediated, mucocutaneous reaction resulting in extensive keratinocyte apoptosis. High-dose human intravenous immunoglobulins (IVIG) have been proposed as an effective treatment for TEN. Retrospective data from 8 patients with TEN and 4 patients with Stevens-Johnson syndrome-toxic epidermal necrolysis (SJS-TEN) overlap treated with high-dose IVIG were analysed. The total dose of IVIG administered was 2 g/kg body weight, with the exception of 2 patients who received a total dose of 1.5 g/kg body weight. Their mean age was 49.9+/-18.8 years (range, 19 to 70 years). The mean time from the first sign of skin lesion or mucosal or epidermal detachment to commencement of IVIG was 8.7+/-5.5 days (range, 3 to 22 days). Of the 11 patients who survived, the mean time to objective response was 3.6+/-1.9 days (range, 2 to 8 days). The length of stay (LOS) in hospital was 20.4+/-8.0 days (range, 10 to 37 days). The survival rate was 91.6%. One patient developed permanent mucocutaneous sequelae following TEN. There were no adverse reactions to IVIG. We conclude that high-dose IVIG may be a safe and effective therapy for Asian patients with TEN.

Rarebit perimetry: normative values and test-retest variability

BACKGROUND

We aim to establish normative values and evaluate test-retest variability for the central and foveal field tests of version 4 of rarebit perimetry.

DESIGN

This was a prospective study undertaken in collaboration between Tan Tock Seng Hospital, Singapore, and Singapore Polytechnic.

PARTICIPANTS

Fifty-four normal subjects were recruited and included in the study.

METHODS

Subjects underwent rarebit perimetry testing, studying the central and foveal fields. All subjects repeated the test within 1 month of the initial visit. The 'mean hit rates' of one eye of every subject were analysed.

MAIN OUTCOME MEASURES

Mean hit rates of subjects were analysed to establish normative values for the central and foveal fields. Test-retest variability was also analysed.

RESULTS

Overall normative mean hit rates were 86.3 ± 13.95% for the central field and 91.6 ± 6.35% for the foveal field. For every increasing year of age, we found a 0.47% decrease in the central mean hit rates (P < 0.001). Normative mean hit rate for central and foveal fields were 90.6 ± 12.3% and 98.2 ± 3.7% respectively, in 'young' subjects, and 81.9 ± 15.6% and 85.0 ± 9.0% respectively, in 'mature' subjects. We found no significant test-retest variability in the foveal field (P = 0.554). There was significant test-retest variability in the central field (P < 0.001), but the difference was a 3.5 unit mean hit rate increase, which may be clinically significant.

CONCLUSIONS

Rarebit perimetry is repeatable and reliable. We have established normative values for two age groups.

Ocular manifestations and complications of Stevens-Johnson syndrome and toxic epidermal necrolysis: an Asian series

BACKGROUND

To describe the acute and late ocular manifestations and complications in toxic epidermal necrosis (TEN) and Stevens-Johnson syndrome (SJS), and identify predictors for development of late complications.

METHODS

Cases of TEN and SJS during a 9-year period were included. Patients with ocular involvement were reviewed for acute ocular complications. Patients with a minimum 6 months follow-up were reviewed for late complications. Records were reviewed for their demographics, etiology, and severity of ocular involvement.

RESULTS

There were 117 patients with a mean age of 52.2 +/- 18.6 years. Eighty-one of these (69%) had acute ocular involvement. This was mild in 40%, moderate in 25% and severe in 4%. Adverse drug reactions were the predominant cause. Patients with thrombocytopenia had more severe acute ocular involvement. Forty-four patients had a minimum 6 months of follow-up and half developed late complications. Severe dry eyes and trichiatic lashes were the commonest late complications. Patients treated with topical antibiotic were more likely to have late complications, particularly dry eyes. There was no difference in the severity of acute eye involvement or late complications when SJS and TEN patients were compared. The severity of the acute ocular disease and abnormal laboratory tests were not found to be the significant risk factors of late complications.

CONCLUSIONS

Ocular involvement is common in SJS and TEN and can be severe and blinding. The severity of acute ocular complications does not predict late complications. The diagnosis of TEN does not imply a more severe ocular involvement or increased frequency of late ocular complications compared with SJS. Care should be taken even in mild cases. Appropriate intervention during acute ocular disease may prevent late complications.

Measurement of anterior lens growth after acute primary angle-closure glaucoma

CASE REPORT

A 51-year-old woman present with bilateral acute primary angle-closure glaucoma. Glaukomflecken were prominent. Anterior lens growth in front of the glaukomflecken was measured 12 years later.

COMMENTS

Lens thickness is important in the pathogenesis of acute primary angle closure, and lens growth can become significant with time in eyes already at risk.

Case series: Monocular visual loss associated with subarachnoid hemorrhage secondary to ruptured intracranial aneurysms

PURPOSE

To describe variations in the presentation of monocular visual loss associated with intracranial aneurysm rupture. The clinical course, possible etiologies and management of visual loss in three patients are described.

CLINICAL FEATURES

The first patient developed Terson's syndrome (vitreal hemorrhage associated with raised intracranial pressure secondary to subarachnoid hemorrhage). Following aneursymal clipping, her postoperative management was conservative and there was no improvement in visual acuity. The second patient underwent surgical clipping of internal carotid aneursysms and sustained visual loss subsequent to surgical dissection and temporary clipping around the optic nerve and anterior choroidal artery. The vessel subsequently thrombosed. Potential contributing factors to visual loss in this case included intraoperative hypotension and anemia. This patient received anti-platelet medications, and experienced subsequent improvement in visual acuity to 6/9. A third patient underwent a right orbito-frontal keyhole craniotomy with the cranial flap retracted across the orbit. Elevated intraocular pressure secondary to external orbital compression may have compromised retinal and choroidal perfusion. This patient also developed vasospasm of both anterior cerebral arteries which resolved partially with papaverine therapy. Hypertension-hypervolemia therapy was instituted, with subsequent partial recovery of visual acuity in her right eye.

CONCLUSION

Perioperative monocular visual loss associated with intracranial aneurysm repair is an infrequent occurrence, and clinical presentations may be quite variable. The primary pathophysiological mechanisms are intraocular hemorrhage and ischemia of ocular structures, including the optic nerve. Early detection, via regular fundoscopic examination and treatment aimed at decreasing intraocular pressure and augmenting ocular perfusion may improve outcomes.

High-dose intravenous immunoglobulin in the treatment of toxic epidermal necrolysis: a study of ocular benefits

PURPOSE

To compare acute ocular complications of toxic epidermal necrolysis (TEN) following treatment with high-dose human intravenous immunoglobulin (IVIG) with a historical cohort not treated with IVIG.

METHODS

Retrospective, historically controlled study. In all, 10 consecutive patients with TEN (treatment cohort) presenting between 1 July 2001 and 30 June 2002. Totally, 18 consecutive patients with TEN (historical cohort). SettingTan Tock Seng Hospital, Singapore. The treatment cohort received high-dose IVIG (2 g/kg body weight over 2 days). Patients' records were retrospectively reviewed for their demographic characteristics, causative drug, treatment, ocular involvement (if any, as assessed by an ophthamologist), and its severity. The historical cohort comprised patients coded with a diagnosis of TEN (ICD Code 695.1) between 1 July 1995 and 30 June 2001.

RESULTS

Nine (90%) of 10 patients treated with IVIG had ocular involvement. Phenytoin was the implicated drug in three (37.5%) patients. Of the nine patients, 1 died of septic shock. Of the eight survivors, IVIG was initiated immediately upon onset of TEN as all the patients were hospitalized by the time of onset of an exanthema. Acute ocular complications were mild in two (25%) (lid oedema or mild conjunctival injection), moderate in four (50%) (pseudomembranes) and severe in two (25%) (nonhealing epithelial defect with visual loss and symblepharon). In total, 10 (55.6%) of 18 patients in the historical cohort with TEN had acute ocular involvement. Two patients died. Ocular involvement in survivors was mild in five (62.5%) cases and moderate in three (37.5%), with no severe cases.

CONCLUSIONS

IVIG did not appear to reduce the severity of visually significant ocular complications. Larger studies are needed to confirm this finding.

An unusual presentation of a giant frontal sinus mucocele manifesting with a subcutaneous forehead mass

INTRODUCTION

To describe the unusual manifestation of a giant frontal sinus mucocele.

CLINICAL PICTURE

A 33-year-old female presented with blurring of vision in the left eye, periorbital swelling and a painless forehead mass. There was proptosis, partial ptosis, and an elongated, soft, subcutaneous mass over the left side of the forehead. CT scan showed a mass arising from the frontal sinus with both intraorbital and intracranial extension.

TREATMENT

Surgical excision of the mass confirmed the diagnosis of a mucocele.

OUTCOME

Postoperatively, the patient was asymptomatic.

CONCLUSIONS

A subcutaneous soft-tissue mass may be the presenting complaint of a frontal mucocele. Careful examination of the surrounding skin may suggest the diagnosis of sinus-related disease and thus direct appropriate investigations.

Visual field loss from primary angle-closure glaucoma: a comparative study of symptomatic and asymptomatic disease

PURPOSE

To assess the degree of visual field (VF) loss in subjects diagnosed with primary angle-closure glaucoma (PACG), and to compare the severity of such loss between those with symptomatic and asymptomatic disease.

DESIGN

Observational case series.

PARTICIPANTS

Seventy-six consecutive subjects with PACG who presented at a Singapore hospital.

METHODS

Primary angle-closure glaucoma was defined as the presence of glaucomatous optic neuropathy and compatible VF loss associated with closed angles. There were 2 groups of subjects studied: group A consisted of those who presented with acute symptomatic angle closure, and group B consisted of those who were asymptomatic. Subjects underwent static automated threshold perimetry, and the first reliable VF was analyzed using the Advanced Glaucoma Intervention Study (AGIS) scoring system. The field tests were graded according to severity as mild, moderate, severe, and end-stage VF defects, based on AGIS scores of 0 to 5, 6 to 11, 12 to 17, and 18 to 20 respectively.

MAIN OUTCOME MEASURES

Advanced Glaucoma Intervention Study scores of the first reliable threshold VF test.

RESULTS

The mean age of study subjects was 61.4+/-9.6 years (range: 33-84), and the majority of subjects were female (59%) and Chinese (91%). In group A (n = 40), most eyes had mild or moderate VF defects (23 eyes [57.5%]), whereas 7 eyes (17.5%) had end-stage defects. This was in contrast to group B (n = 36), in which the majority of eyes had end-stage VF loss (19 eyes [52.8%]), with only 5 eyes (13.7%) having mild VF defects. Mean AGIS scores were 9.1+/-7.6 for group A and 14.2+/-6.9 for group B (P = 0.004). Cup-to-disc ratio was a significant predictor for VF loss, but age, gender, and level of presenting intraocular pressure were not correlated with VF outcome.

CONCLUSIONS

Eyes with asymptomatic PACG often present with severe to end-stage VF loss at the time of first presentation to hospital. In contrast, most PACG eyes with previous symptomatic angle closure present with mild or moderate VF defects. The visual morbidity of PACG may be related to the finding that the asymptomatic form of the disease is visually destructive.

"I've got a UFO stuck in my throat!"--an interesting case of foreign body impaction in the oesophagus

This is a case report of an elderly lady with odynophagia because she accidentally swallowed a tablet which was still wrapped in its blister pack. A discussion of foreign body ingestion, particularly in the elderly, is included. To the authors' knowledge, this is the first paper that includes a lateral cervical radiograph of an ingested blister pack.

Complete chaos in a simple epidemiological model

A first-order difference equation which constitutes a simple model for a lethal parasite-host interaction is studied. Completing a study initiated by May and Anderson, the dynamics are shown to be completely chaotic.