British Journal of Ophthalmology

Barton, Keith; Chodosh, James; Jonas, Jost B

doi: 10.1136/bjophthalmol-2018-313481pmid: N/A

Ausayakhun, Somsanguan; Yen, Michael; Jirawison, Choeng; Ausayakhun, Sakarin; Khunsongkiet, Preeyanuch; Leenasirimakul, Prattana; Kamphaengkham, Siripim; Snyder, Blake M; Heiden, David; Holland, Gary N; Margolis, Todd P; Keenan, Jeremy D

doi: 10.1136/bjophthalmol-2018-312191pmid: 30206157

AimsTo determine if early dilated fundus examination for cytomegalovirus (CMV) retinitis leads to better visual outcomes in areas with limited HIV care, where patients may have long-standing retinitis before they are diagnosed with HIV.MethodsTwenty-four eyes of 17 patients with CMV retinitis who were seen at an urban HIV clinic in Chiang Mai, Thailand, were included in this retrospective cohort study. Participants were divided into two groups based on the amount of time from the first documented CD4 count below 100 cells/mm3 to the first eye examination for CMV retinitis. Average visual acuity in each group was calculated at the time CMV retinitis was first detected, and then at 3, 6 and 12 months after diagnosis.ResultsThe group of patients who received an eye examination within approximately 4 months of the initial low CD4 count measurement had better baseline visual acuity (median 20/30,IQR 20/20 to 20/60) compared with patients who presented later (median 20/80, 20/60 to hand motion); p=0.03). Visual acuity did not change significantly during the 12-month study period in either the early group (p=0.69) or late group (p=0.17).ConclusionIn this study, patients who were examined sooner after a low CD4 count had better vision than patients who were examined later. Routine early screening of patients with CD4 counts under below 100 cells/mm3 may detect earlier disease and prevent vision loss.

Kraus, Courtney L; Culican, Susan M

doi: 10.1136/bjophthalmol-2018-312173pmid: 29871968

The treatment of anisometropic or ametropic amblyopia has traditionally enjoyed a high treatment success rate. Early initiation and consistent use of spectacle correction can completely resolve amblyopia in a majority of patients. For those with anisometropic amblyopia that fail to improve with glasses wear alone, patching or atropine penalisation can lead to equalisation of visual acuity. However, successful treatment requires full-time compliance with refractive correction and this can be a challenge for a patient population that often has one eye with good acuity without correction. Other barriers for a select population with high anisometropic  or ametropic amblyopia include rejection of glasses for various reasons including discomfort, behavioural or sensory problems, postural issues and visually significant aniseikonia. When consistent wear of optical correction proves difficult and patching/atropine remains a major obstacle, surgical correction of refractive error has proven success in achieving vision improvement. Acting as a means to achieve spectacle independence or reducing the overall needed refractive correction, refractive surgery can offer a unique treatment option for this patient population. Laser surgery, phakic intraocular lenses and clear lens exchange are three approaches to altering the refractive state of the eye. Each has documented success in improving vision, particularly in populations where glasses wear has not been possible. Surgical correction of refractive error has a risk profile greater than that of more traditional therapies. However, its use in a specific population offers the opportunity for improving visual acuity in children who otherwise have poor outcomes with glasses and patching/atropine alone.

Koh, Shizuka; Tung, Cynthia I; Inoue, Yasushi; Jhanji, Vishal

doi: 10.1136/bjophthalmol-2018-312333pmid: 29907632

The precorneal tear film is maintained by blinking and exhibits different phases in the tear cycle. The tear film serves as the most anterior surface of the eye and plays an important role as a first refractive component of the eye. Alterations in tear film dynamics may cause both vision-related and ocular surface-related symptoms. Although the optical quality associated with the tear film dynamics previously received little attention, objective measurements of optical quality using wavefront sensors have enabled us to quantify optical aberrations induced by the tear film. This has provided an objective method for assessing reduced optical quality in dry eye; thus, visual disturbances were included in the definition of dry eye disease in the 2007 Dry Eye Workshop report. In addition, sequential measurements of wavefront aberrations have provided us with valuable insights into the dynamic optical changes associated with tear film dynamics. This review will focus on the current knowledge of the mechanisms of wavefront variations that are caused by different aspects of tear film dynamics: specifically, quality, quantity and properties of the tear film, demonstrating the respective effects of dry eye, epiphora and instillation of eye drops on the quality of vision.

Carnt, Nicole; Hoffman, Jeremy J; Verma, Seema; Hau, Scott; Radford, Cherry F; Minassian, Darwin C; Dart, John K G

doi: 10.1136/bjophthalmol-2018-312544pmid: 30232172

Background/aims Acanthamoeba keratitis (AK) is a chronic debilitating corneal infection principally affecting contact lens (CL) users. Studies were designed to test claims that the UK incidence may have increased in 2012–2014 and to evaluate potential causes.MethodsAnnualised incidence data were collected from January 1984 to December 2016. Case-control study subjects were recruited between 14 April 2011 and 05 June 2017. Reusable CL users with AK were recruited retrospectively and prospectively. Controls were reusable CL users, recruited prospectively, with any disorder other than AK. Multivariable analysis of questionnaire data measured independent risk factors for AK.ResultsThe current outbreak of AK started in 2010–2011 with an incidence threefold higher than in 2004–2009. Risk factors for AK were: Oxipol disinfection, CLs made of group IV CL materials, poor CL hygiene, deficient hand hygiene, use of CLs while swimming or bathing, being white British, and for those in social classes 4–9.ConclusionAK is a largely preventable disease. The current outbreak is unlikely to be due to any one of the identified risk factors in isolation. Improving CL and hand hygiene, avoiding CLs contamination with water and use of effective CL disinfection solutions, or daily disposable CLs, will reduce the incidence of AK. In the longer-term, water avoidance publicity for CL users can be expected to reduce the incidence further. Ongoing surveillance of AK numbers will identify changes in incidence earlier. Evaluation of Acanthamoeba contamination in end-user drinking water would contribute to our understanding of regional variations in the risk of exposure.

Bagga, Bhupesh; Sharma, Savitri; Madhuri Guda, Sai Jeevan; Nagpal, Ritu; Joseph, Joveeta; Manjulatha, Kodiganti; Mohamed, Ashik; Garg, Prashant

doi: 10.1136/bjophthalmol-2017-311360pmid: 29545414

Background Pythium insidiosum is a parafungus that causes keratitis resembling fungal keratitis. This study compares outcome in a large cohort of patients with P insidiosum keratitis treated with antifungal drugs, to a pilot group treated with antibacterial antibiotics.MethodsBetween January 2014 and December 2016, 114 patients with culture positive P insidiosum keratitis were included in the study. A subset of culture isolates was tested in vitro for response to nine antibacterial antibiotics by disc diffusion and E test. Patients were treated with topical natamycin in 2014, 2015 and up until mid 2016. Thereafter, the patients received a combination of topical linezolid and topical and oral azithromycin. Therapeutic penetrating keratoplasty (TPK) was done for patients not responding to medical therapy.ResultsIn vitro disc diffusion assay showed linezolid to be most effective. The rate of TPK was significantly higher in 2015 compared with 2016 (43/45, 95.6% vs 22/32, 68.8%; p=0.002). Eighteen patients were treated with antibacterial and 14 were treated with antifungal antibiotic in 2016. One patient was lost to follow-up in each group. The rate of TPK was higher and proportion of healed ulcers was lower (p=0.21, Fisher’s exact test) in the group on antifungal therapy (TPK—11/13, 84.6%; Healed—2/13, 15.3%) compared with the group on antibacterial therapy (TPK—11/17, 64.7%; Healed—6/17, 35.2%).ConclusionsWe report favourable but not statistically significant response of P insidiosum keratitis to antibacterial agents in a pilot series of patients. Further evaluation of this strategy in larger number of patients is recommended.

Lee, Weng Hon; Tey, Adrian; Gales, Kevin; Mudhar, Hardeep Singh; Figueiredo, Francisco C

doi: 10.1136/bjophthalmol-2017-311333pmid: 29483081

AimTo describe a cohort of patients with irreversible unilateral bullous keratopathy (BK) of undetermined aetiology.MethodRetrospective, single-centre case series in a tertiary corneal referral centre.ResultsEleven consecutive patients (nine females; mean age 71.7 years) presented from 1999 to 2009 with acute onset unilateral visual loss. At presentation, the best-corrected visual acuity of the affected eyes was 6/9 or worse with mean central corneal thickness (CCT) of 684 (SD 66) μm. Specular microscopy was not possible in the affected eyes. There was no other ocular pathology in the affected eye. The fellow eye remained normal throughout the study (mean endothelial cell density (ECD) of 1980 (SD 736) cells/mm2 and CCT of 536 (SD 34) μm). Topical steroid, antiviral treatments (both topical and systemic) or a combination of both did not yield any improvement. After a mean follow-up of 82.2 months, eight eyes had penetrating keratoplasty (PK). One required two regrafts. Histology showed typical BK features, with endothelial cell (EC) loss and thickened Descemet’s membrane (DM). Transmission electron microscopy revealed DM abnormalities in a non-consistent pattern, featuring variable collagen deposition posterior to the non-banded zone. The ECs were degenerated, reduced or absent. Neither viruses nor pseudoexfoliation material was identified.ConclusionWhile medical treatment is not beneficial, PK appears to offer good results. Non-guttate Fuchs’ corneal endothelial dystrophy merits consideration but it would be unusual to see an exclusively unilateral presentation. DM thickening is reflective of a chronic EC loss but the cause of this loss remains elusive.

Basu, Sayan; Mohan, Sashwanthi; Bhalekar, Swapnil; Singh, Vivek; Sangwan, Virender

doi: 10.1136/bjophthalmol-2017-311506pmid: 29453224

AimsCultivated limbal epithelial transplantation (CLET) fails in around 20%–30% of cases. This study aimed to report the clinical outcomes of autologous simple limbal epithelial transplantation (SLET) in eyes with recurrent unilateral limbal stem cell deficiency (LSCD) due to failure of CLET.MethodsThis was a prospective case series which included 30 eyes of 30 patients who underwent SLET between 2010 and 2016 after failure of one (n=24) or two (n=6) previous CLET procedures for chronic unilateral ocular burns. The primary outcome measure was success of SLET defined on the basis of relative improvement in five objective criteria: best corrected visual acuity (BCVA), and grades of symblepharon, corneal conjunctivalisation, vascularisation and opacification.ResultsAt a mean follow-up of 2.3 years, 24 (80%) of the 30 eyes maintained a successful outcome. Kaplan-Meier analysis showed a 5-year survival probability of 77%±8%. At 1 year postoperatively statistically significant improvement was noted in BCVA (logarithm of the minimum angle of resolution of 3 to 1) and in the median grades of corneal conjunctivalisation (2 to 0), vascularisation (2 to 0) and opacification (2 to 1) (P≤0.0026). In 62.5% of successful cases, BCVA improved to 20/200 or better. The success rate of SLET in failed CLET was better than that of repeat CLET (53.5%, P=0.011). None of the donor eyes developed any complications.ConclusionSLET is an effective alternative to CLET in eyes with recurrence of LSCD after previously failed CLET procedures. Since SLET is single-staged and less expensive, it is probably preferable to repeating CLET.

Ross, Andrew R; Said, Dalia G; El-Amin, Abdalla; Altaan, Saif; Cabrerizo, Javier; Nubile, Mario; Hogan, Emily; Mastropasqua, Leonardo; Dua, Harminder Singh

doi: 10.1136/bjophthalmol-2017-311349pmid: 29615397

Zhang, Guisen; Tham, Yih-Chung; Gong, Hui; Ren, Fengmei; Morige, Jilitu; Dai, Wei; Cheng, Ching-Yu; Zhang, Han; Liu, Lei

doi: 10.1136/bjophthalmol-2017-311633pmid: 29439090

BackgroundTo determine the prevalence and causes of visual impairment (VI), and to describe the characteristics of cataract surgery coverage and related barriers among adults aged ≥50 years residing in Hohhot, Inner Mongolia.MethodsA population-based cross-sectional study was performed. Presenting visual acuity (PVA) was measured using the Rapid Assessment of Avoidable Blindness (RAAB) methodology. All VI cases were defined using the WHO definition, based on the PVA of the better-seeing eye. Details on history of cataract surgery and barriers to cataract surgery were also obtained using a standardised questionnaire.ResultsOf 4500 eligible individuals, 3985 (88.6% response rate) were examined. The age-standardised prevalence of moderate VI (PVA <6/18 to ≥6/60) was 5.4% (95% CI 4.6% to 6.3%), and severe VI (PVA <6/60 to ≥3/60) was 0.9% (95% CI 0.6% to 1.3%). The age-standardised prevalence of blindness (PVA <3/60) was 1.2% (95% CI 0.8% to 1.6%). Uncorrected refractive error (40.1%) and cataract (37.9%) were the leading causes of overall VI. Cataract (34.9%) was the leading cause of blindness. Among individuals with blindness, cataract surgical coverage was 80.7%. Among individuals with blindness due to cataract, the main barriers to cataract surgery were lack of awareness (38.1%).ConclusionsThe age-standardised prevalence rate of blindness in Hohhot was lower compared with other RAAB studies in China. Cataract was the leading cause of blindness. These findings provide useful information for the planning of public healthcare services in Inner Mongolia.