V. P. Saw

Acanthamoeba keratitis: diagnosis and treatment update 2009.

PURPOSE To describe the current management of Acanthamoeba keratitis (AK). DESIGN A perspective based on the literature and author experience. RESULTS Early diagnosis and appropriate therapy are key to a good prognosis. A provisional diagnosis of AK can be made using the clinical features and confocal microscopy, although a definitive diagnosis requires culture, histology, or identification of Acanthamoeba deoxyribonucleic acid by polymerase chain reaction. Routine use of tissue diagnosis is recommended, particularly for patients unresponsive to treatment for AK. Topical biguanides are the only effective therapy for the resistant encysted form of the organism in vitro, if not always in vivo. None of the other drugs that have been used meet the requirements of consistent cysticidal activity and may have no therapeutic role. The use of topical steroids is controversial, but probably beneficial, for the management of severe corneal inflammatory complications that have not responded to topical biguanides alone. The scleritis associated with AK is rarely associated with extracorneal invasion and usually responds to systemic anti-inflammatory treatment combined with topical biguanides. Therapeutic keratoplasty retains a role for therapy of some severe complications of AK but not for initial treatment. With modern management, 90% of patients can expect to retain visual acuity of 6/12 or better and fewer than 2% become blind, although treatment may take 6 months or more. CONCLUSIONS Better understanding of the pathogenesis of the extracorneal complications, the availability of polymerase chain reaction for tissue diagnosis, and effective licensed topical anti-amoebics would substantially benefit patients with AK.

Incidence, presenting features, and diagnosis of cicatrising conjunctivitis in the United Kingdom.

PurposeCicatrising conjunctival disorders are uncommon, and are difficult to diagnose and manage. This study was designed to assess the annual incidence and underlying diagnosis of patients with cicatrising conjunctivitis (CC) within the United Kingdom.MethodsClinical data of newly diagnosed cases of CC were reported via the British Ophthalmological Surveillance Unit at diagnosis and at 12 months follow-up.ResultsA total of 50 (61%) ocular mucous membrane pemphigoid (OcMMP), 16 (20%) Stevens–Johnson syndrome/toxic epidermal necrolysis (SJS-TEN) and 16 (20%) other causes of CC, equating to an incidence of 0.8, 0.2, and 0.2 per million, respectively, were reported. Although diagnosis of SJS-TEN was usually within a median of 7 days of symptom-onset, that for OcMMP and other CC was a median 225 days for both. At diagnosis, 64/163 (39%) eyes had moderate/severe conjunctival inflammation, and 102/164 (62%) had symblepharon formation. Although 43/82 (52%) patients were commenced on immunosuppression or had this therapy modified, at follow-up there was an increase in the number of symblepharon, despite control of inflammation (P<0.001). Mortality only occurred in the SJS-TEN group (4/16 (25%)).ConclusionCC has a substantial morbidity and for non-SJS-TEN causes, diagnosis is frequently delayed. The proportion of patients given immunosuppressive therapy to prevent disease progression may be less than optimal. These data highlight the need for developing patient access to specialist-designated centres with expertise in CC.

Validation of a fornix depth measurer: a putative tool for the assessment of progressive cicatrising conjunctivitis

Background/aims Documentation of conjunctival forniceal foreshortening in cases of progressive cicatrising conjunctivitis (PCC) is important in ascertaining disease stage and progression. Lower fornix shortening is often documented subjectively or semi-objectively, whereas upper forniceal obliteration is seldom quantified. Although tools such as fornix depth measurers (FDMs) have been described, their designs limit upper fornix measurement. The purpose of this study was to custom-design a FDM to evaluate the upper fornix and to assess variability in gauging fornix depth. Methods A polymethylmethacrylate FDM was constructed using industry-standard jewellery computer software and machinery. Two observers undertook a prospective independent evaluation of central lower fornix depth in a heterogeneous cohort of patients with clinically normal and abnormal conjunctival fornices both subjectively and by using the FDM (in mm). Upper central fornix depth was also measured. Agreement was assessed using Bland–Altman plots. Results Fifty-one eyes were evaluated. There was 100% intraobserver agreement to within 1 mm for each observer for lower fornix measurement. The mean difference in fornix depth loss using the FDM between observer 1 and 2 was 1.19%, with 95% confidence of agreement (±2SD) of −15% to +20%. In total, 86% (44/51) of measurements taken by the two observers agreed to within 10% of total lower fornix depth (ie, ±1 mm) versus only 63% (32/51) of the subjective measurements. Mean upper fornix difference was 0.57 mm, with 95% confidence of agreement of between −2 and +3 mm. Conclusions This custom-designed FDM is well tolerated by patients and shows low intraobserver and interobserver variability. This enables repeatable and reproducible measurement of upper and lower fornix depths, facilitating improved rates of detection and better monitoring of progression of conjunctival scarring.

Cicatrising conjunctivitis with anti-basement membrane autoantibodies in ectodermal dysplasia

Aims: To report circulating and mucosa-deposited anti-basement membrane zone autoantibodies in a series of six ectodermal dysplasia patients with severe bilateral cicatrising conjunctivitis and blindness due to both corneal disease and intractable surface inflammation. We also report clinical improvement with steroid-sparing systemic immunosuppression combined with clearance of bacterial colonisation. Methods: Conjunctival and buccal immunohistopathology, and serological analysis using a panel of epithelial basement membrane zone proteins including the bullous pemphigoid antigen 180 (BP180) were carried out as part of an ocular pemphigoid work-up in each patient. The degree of photophobia, conjunctival inflammation and visual acuity were monitored to evaluate the response to immunosuppression. The mean duration of follow-up was 31 (SD 6) months. Results: Four of the six patients showed positive immunopathology: direct immunofluorescence testing of the conjunctiva in one patient demonstrated linear IgA deposition along the basement membrane zone, and IgG and IgM in the buccal mucosa of another patient. Circulating autoantibodies to BP180 were detected in two other patients. Treatment with systemic immunosuppression, combined with clearance of bacterial colonisation, reduced the severity of photophobia and degree of conjunctival inflammation in 5/6 (83%) patients. Conclusions: Systemic immunosuppression, used as steroid-sparing therapy, combined with clearance of bacterial colonisation can control inflammation and disabling photophobia, and allow improvement in vision, in a subgroup of ectodermal dysplasia patients who have severe cicatrising conjunctivitis which shares clinical and immunopathological features with ocular mucous membrane pemphigoid.

Upper and lower conjunctival fornix depth in healthy white caucasian eyes: a method of objective assessment.

PurposeEvaluating anti-scarring therapies require objective assessment of scarring, and knowledge of normal fornix anatomy. Measurement of conjunctival scarring has focused on inferior fornix shortening, although the superior fornix is often overlooked. There are data on normal fornix depth (FD) in South Asians, but there are no studies investigating normal conjunctival FD in white Caucasians. We designed a fornix depth measurer (FDM) for objective measurement of upper and lower conjunctival FD. The purpose of this study was to evaluate intra- and inter-observer variability, and to establish a reference for normal conjunctival FD in an ethnically white Caucasian population.Patients and methodsProspective cross-sectional study evaluating conjunctival FD in 252 clinically normal white Caucasian participants aged 20–80. Paired observers evaluated inter- and intra-observer variability. Data was analyzed using Bland–Altman plots and analysis of variance.ResultsFor white Caucasian subjects, mean upper and lower conjunctival fornix depths were 15.6 mm (95% confidence interval (CI), 12.5–18.8) and 10.9 mm (95% CI, 8.0–13.7), respectively. Females have smaller FDs (upper FD 15.3 mm±1.6 females, 16.2 mm±1.4 males, P<0.001; lower FD 10.6 mm±1.3 females, 11.3 mm±1.4 males, P<0.001). There was a progressive decline in FD with age (upper fornix depth 16.3 mm±1.2 at age 20–29, and 15.0 mm±1.8 at age 80+ (P=0.04)). There was 94–100% intra-observer and inter-observer agreement for upper and lower fornix measurements.ConclusionsUsing a slightly different custom-designed FDM, central conjunctival fornix depth in white Caucasian eyes appears to be similar to data previously reported in South Asian eyes. Fornix depth measurements were repeatable and reproducible.

Management of Ocular Mucous Membrane Pemphigoid

■ Early diagnosis and appropriate treatment of ocular mucous membrane pemphigoid (MMP) will prevent its severe sight-threatening complications. After excluding other causes of conjunctival scarring, a clinical diagnosis of ocular MMP, based on a history of progressive scarring and typical clinical signs, is sufficient. A negative immunofluorescence biopsy does not exclude the diagnosis of ocular MMP ■ Once the diagnosis has been made, it is important to first eliminate and treat local ocular surface disease causing inflammation such as blepharitis, dry eye or exposure, microbial infection, and toxicity