Importance Visual acuity is the most frequently performed measure of visual function in clinical practice and the majority of people worldwide living with visual impairment are living in low and middle-income countries Objective To design and validate a smartphone-based visual acuity test that is not dependent on familiarity with symbols or letters commonly used in the English language. Design Validation study comparing results from smartphone Peek Acuity to Snellen Acuity (clinical normal) and the Early Treatment Diabetic Retinopathy Study (ETDRS) LogMAR chart (reference standard). Setting This study was nested within the six-year follow-up of the Nakuru Eye Disease Cohort in central Kenya. Participants Three hundred adults aged 55 years and above, recruited consecutively from the Nakuru Eye Disease Cohort Study.. Main Outcome(s) and Measure(s) Outcome measures were monocular logarithm of the minimum angle of resolution (LogMAR) visual acuity scores for each test: ETDRS LogMAR, Snellen and Peek. Peek was compared, in terms of test-retest variability (TRV) and measurement time, with that of the Snellen and ETDRS LogMAR chart in participants’ homes and temporary clinic settings in rural Kenya in 2013/2014. Results The 95% confidence limits for TRV of smartphone acuity data were +/-0.033 LogMAR. The mean difference between smartphone and ETDRS and smartphone and Snellen acuity data was 0.07 (95%CI: 0.05-0.09) and 0.08 (95%CI: 0.06-0.10) LogMAR respectively indicating that smartphone acuities agreed well with those of the ETDRS chart and Snellen. The agreement of Peek and ETDRS was greater than Snellen with ETDRS, p=0.08 (95%CI 0.05 to 0.10). The local Kenyan community health care workers readily accepted the Peek Acuity smartphone test; it required minimal training and took no longer than Snellen; 77s vs. 82s (95%CI: 71 – 84s vs. 73 – 91s, p=0.13). Conclusions The study demonstrated that the Peek Acuity smartphone test is capable of accurate and repeatable acuity measurements consistent with published data on the TRV of acuities measured using five-letter-per-line retro-illuminated LogMAR charts.

Importance Visualization and interpretation of the optic nerve and retina is an essential part of most physical examinations. Objectives To design and validate a smartphone-based retinal adapter enabling image capture and remote grading of the retina Design, setting and participants Validation study comparing the grading of optic nerves from smartphones images with those of a Digital Fundus Camera. Both image sets were independently graded at Moorfields Eye Hospital Reading Centre. Nested within the six-year follow-up of the Nakuru Eye Disease Cohort in Kenya: 1,460adults (2,920eyes) aged 55years and above were recruited consecutively from the Study. A sub-set of 100 optic disc images from both methods were further used to validate a grading app for the optic nerves. Main outcome(s) and measure(s) Vertical cup-to-disc-ratio (VCDR) for each test was compared, in terms of agreement (Bland-Altman & weighted Kappa) and test-retest variability (TRV). Results 2,152 optic nerve images were available from both methods (additionally 371 from reference but not Peek, 170 from Peek but not the reference and 227 from neither the reference camera or Peek). Bland-Altman analysis demonstrated a difference of the average of 0.02 with 95% limits of agreement between -0.21 and 0.17 and a weighted Kappa coefficient of 0.69 (excellent agreement). An experienced retinal photographer was compared to a lay photographer (no health care experience prior to the study) with no observable difference in image acquisition quality between them. Conclusions and relevance Non-clinical photographers using the low-cost Peek Retina adapter and smartphone were able to acquire optic nerve images at a standard that enabled comparable independent remote grading of the images to those acquired using a desktop retinal camera operated by an ophthalmic assistant. The potential for task-shifting and the detection of avoidable causes of blindness in the most at risk communities makes this an attractive public health intervention.

Cystinosis is a rare autosomal recessive disorder characterized by the accumulation of cystine within the cells of different organs. Infantile nephropathic cystinosis is the most common and severe phenotype. With the success of renal transplantation, these patients are now living longer and thus more long-term complications within different organs are becoming apparent. Ophthalmic manifestations range from corneal deposits of cystine crystals to pigmentary retinopathy. With increasing age, more severe ocular complications have been reported. Photophobia is a prominent symptom for patients. With prolonged survival and increasing age, this symptom, along with corneal erosions and blepharospasm, can become debilitating. This review revisits the basic pathogenesis of cystinosis, the ocular manifestations of the disease, and the treatment of corneal crystals.

The incidence of orbital cellulitis is higher in children than in adults. In children, it commonly follows upper respiratory infection and sinus disease; however, in adults, preceding illness and trauma are more common. Respiratory pathogens are common in affected children. Intravenous antibiotics and surgical treatment of abscesses remain the preferred management.