Unequal pupils: Understanding the eye's aperture.

BACKGROUND: Unequal pupils (anisocoria) may be physiological, pathological or pharmacological. Importantly, anisocoria can indicate underlying disease of the eye, orbit, brain, neck or chest. Examination of the pupils is therefore a crucial part of any eye examination. OBJECTIVE: As a clinician, it is important to determine whether a patient with anisocoria can be reassured or requires referral for further investigation. This review examines the anatomy of the pupillary pathway, and provides a structured approach to examination of the pupils. The aim is to provide clinicians with confidence when encountering patients with anisocoria. DISCUSSION: Anisocoria can imply serious underlying pathology, so accurate pupil testing and astute observation are paramount. This review discusses the differential diagnosis of a large pupil (anisocoria more obvious in the light) and a small pupil (anisocoria more obvious in the dark), and discusses the relevant afferent pupillary defect, in which there is no anisocoria but both pupils react differently depending on which eye is illuminated.

The Multifocal On- and Off-Responses in the Human Diabetic Retina.

The characteristics of the on- and off-responses in the human diabetic retina by a "long-duration" multifocal electroretinogram (mfERG) paradigm were investigated. Changes in the retinal antagonistic interaction were also evaluated in the early stage of diabetes mellitus (DM). Twenty type II diabetic patients with no or mild non-proliferative diabetic retinopathy (NPDR) and twenty-one age-matched healthy controls were recruited for "long-duration" mfERG measurements. A 61-hexagon mfERG stimulus was displayed under two chromatic conditions (white/black and blue/black) at matched luminance. The amplitudes and implicit times of the on-response components (N1, P1 and N2) and off-response (P2) components were analysed. The blue stimulation generally triggered greater mfERG amplitudes in P1, N2 and P2 (p<0.05) than those from white stimulation in both control and diabetic groups. The diabetic group showed significantly greater N2 amplitude than the controls under white stimulation in mid-retinal regions (Rings 2 and 4) (p<0.05). When the stimulus was changed from white to blue, the diabetic group showed a smaller percentage change in N2 amplitude than the controls in peripheral retinal region (Ring 5) (p<0.02). When a stimulus is changed from white (broad-band spectral stimulation) to blue (narrow-band spectral stimulation), a decrease in the involvement of lateral antagonism would be expected. The larger amplitude of the on-response component (N2) in the diabetic patients suggested an imbalance of lateral antagonism, and the lesser percentage change of N2 amplitude in the diabetic group may indicate an impairment of the cross-talk at the middle retinal level in early stages of DM.

Hyperferritinemia-cataract syndrome: Long-term ophthalmic observations in an Italian family.

BACKGROUND: Hyperferritinemia-cataract syndrome (HCS) is a rare Mendelian condition characterized by bilateral cataract and high levels of serum ferritin in the absence of iron overload. METHODS: HCS was diagnosed in three adult siblings. In two of them it was possible to assess lens changes initially in 1995 and again in 2013. Serum ferritin, iron, transferrin concentrations and transferrin saturation percentage were also measured, and the Iron Responsive Element (IRE) region of the L-ferritin gene (FTL) was studied. RESULTS: Serum ferritin concentrations were considerably elevated while serum iron, transferrin and transferrin saturation levels were within the normal range in each sibling. Cataract changes in our patients were consistent with those previously reported in the literature. Progression of the cataract, an aspect of few studies in this syndrome, appeared to be quite limited in extent. The heterozygous +32G to T (-168G>T) substitution in the IRE of the FTL gene was detected in this family. CONCLUSIONS: Ophthalmic and biochemical studies together with genetic testing confirmed HCS in three family members. Although the disorder has been extensively described in recent years, little is known regarding cataract evolution over time. In our cases, lens evaluations encompassed many years, identified bilateral cataract of typical morphology and supported the hypothesis that this unique clinical feature of the disease tends to be slowly progressive in nature, at least in adults.

Prevalence of papillary changes and folliculosis of the palpebral conjunctiva in asymptomatic Chinese children.

PURPOSE: To determine the prevalence of papillary changes of the upper palpebral conjunctiva and folliculosis of the lower palpebral conjunctiva in Chinese children with no history of contact lens wear. METHOD: Ninety-nine subjects (aged 6-15 years old) who were interested in a myopia control study were screened for papillary changes and folliculosis of the palpebral conjunctiva. Photodocumentation was performed under white and blue light (after the application of fluorescein) with a yellow filter and the photographs were graded by a group of practitioners according to a pre-set grading scale. Analysis was performed with the subjects divided into groups according to gender and age. RESULTS: More than 48% of the subjects had clinically significant (≥Grade 3) papillary changes in the upper palpebral conjunctiva. The prevalence of significant folliculosis in the lower lid was about 33%. The prevalence of significant papillary changes and folliculosis were similar between genders. No differences were observed between younger (age≤10 years old) and older (age>10 years old) in papillary changes but younger subjects showed a higher prevalence of folliculosis. CONCLUSIONS: The prevalences of clinically significant papillary changes and folliculosis of unknown aetiology are high in Chinese children.

Early local functional changes in the human diabetic retina: a global flash multifocal electroretinogram study.

PURPOSE: To investigate early functional changes of local retinal defects in type II diabetic patients using the global flash multifocal electroretinogram (MOFO mfERG). METHODS: Thirty-eight diabetic patients and 14 age-matched controls were recruited. Nine of the diabetics were free from diabetic retinopathy (DR), while the remainder had mild to moderate non-proliferative diabetic retinopathy. The MOFO mfERG was performed at high (98 %) and low (46 %) contrast levels. MfERG responses were grouped into 35 regions for comparison with DR classification at those locations. Z-scores of the regional mfERG responses were compared across different types of DR defects. RESULTS: The mfERG waveform consisted of the direct component (DC) and the induced component (IC). Local reduction in DC and IC amplitudes were found in diabetic patients with and without DR. With increasing severity of retinopathy, there was a further deterioration in amplitude of both components. Under MOFO mfERG paradigm, amplitude was a useful screening parameter. CONCLUSION: The MOFO mfERG can help in detecting early functional anomalies before the appearance of visible signs, and may assist in monitoring further functional deterioration in diabetic patients.

The effect of hydrogel and silicone hydrogel contact lenses on the measurement of intraocular pressure with rebound tonometry.

PURPOSE: To assess the accuracy of intraocular pressure (IOP) measurements using rebound tonometry over disposable hydrogel (etafilcon A) and silicone hydrogel (senofilcon A) contact lenses (CLs) of different powers. METHODS: The experimental group comprised 36 subjects (19 male, 17 female). IOP measurements were undertaken on the subject's right eyes in random order using a rebound tonometer (ICare). The CLs had powers of +2.00D, -2.00D and -6.00D. Six measurements were taken over each contact lens and also before and after the CLs had been worn. RESULTS: A good correlation was found between IOP measurements with and without CLs (all r≥0.80; p<0.05). Bland Altman plots did not show any significant trend in the difference in IOP readings with and without CLs as a function of IOP value. A two-way ANOVA revealed a significant effect of material and power (p<0.01) but no interaction. All the comparisons between the measurements without CLs and with hydrogel CLs were significant (p<0.01). The comparisons with silicone hydrogel CLs were not significant. CONCLUSIONS: Rebound tonometry can be reliably performed over silicone hydrogel CLs. With hydrogel CLs, the measurements were lower than those without CLs. However, despite the fact that these differences were statistically significant, their clinical significance was minimal.

Use of the Optomap with lid retraction and its sensitivity and specificity.

BACKGROUND: Optomap uses the ultra-wide field scanning laser ophthalmoscopy to provide retinal examination. It permits fundus examination without the use of a mydriatic, which is more comfortable for the patients. This paper determines the sensitivity and specificity of the Optomap for detecting retinal signs under non-mydriatic conditions. METHODS: Fifty-four eyes identified with retinal/choroidal signs and eight normal eyes were recruited from 31 Hong Kong Chinese subjects. Photo-documentation of fundal changes was obtained with the Optomap under non-mydriatic conditions before a dilated fundus examination by a clinician using standard procedures. The eyelid was retracted using a cotton bud when necessary. Dilated fundus examinations were performed by another clinician using binocular indirect ophthalmoscopy and slitlamp biomicroscopy with a fundus lens. The Optomap images were evaluated by four other investigators under masked condition. The International Classification of Disease, Ninth Revision (ICD-9-CM) was adopted for recording retinal features. Screening results were compared with those obtained using the dilated fundus examination as the gold standard. RESULTS: The cotton bud method for eyelid retraction showed an improvement in the area of retina that could be visualised. The sensitivity and specificity of the Optomap averaged 76.4 and 71.9 per cent, respectively. Some fundal signs were missed by all observers in the Optomap but not with the biomicroscope. These included white-without-pressure, lattice degeneration, paramacular drusen and pigmentary changes at central fundus. CONCLUSION: Optomap serves as a reliable screening tool for fundus examination especially because it covers a much wider area of the peripheral retina than other digital instruments for fundus photography.

Age-related changes in optical and biometric characteristics of emmetropic eyes.

We measured optical and biometric parameters of emmetropic eyes as a function of age. There were approximately 20 subjects each in age groups 18-29, 30-39, 40-49, 50-59, and 60-69 years with similar male and female numbers. One eye was tested for each subject, having spherical equivalent in the range -0.88 D to +0.75 D and

Large interface particles from LASIK surgery.

The presence of interface debris is commonly reported in patients having undergone LASIK refractive surgery. The patient described here had numerous large particles believed to be plastic and metal artefacts from the surgery at the level of the stroma/flap interface, along with a corneal scar consistent with a foreign body injury. The aetiology and possible sequelae of the particles and scar are discussed.

Is it blepharitis?

Blepharitis is a ubiquitous disease and arguably, among the most common conditions that eye care practitioners encounter. Usually, its diagnosis is straight forward. However, any deviation from its predicted clinical appearance should cause the practitioner to consider other possibilities. The patient described in this report was diagnosed with blepharitis and treated as such. However, the true cause of her difficulties was basal cell carcinoma. This condition is briefly reviewed.

The fundus in oculodermal melanocytosis. Is this a new observation?

An unusual case of bilateral oculodermal melanocytosis or the naevus of Ota is reviewed. In this condition, there is hyperpigmentation of ocular structures and the skin of the face. In this case, a pigmentary mottling of the fundus was observed using long wavelength light.

The detection of diabetic retinopathy by Australian optometrists.

BACKGROUND: Diabetes mellitus is a systemic disease affecting approximately 750,000 Australians of whom more than 70,000 are Queenslanders. It can have serious ocular consequences and patients with diabetes require regular eye examinations to determine the degree of ocular involvement and the stage of retinopathy, if present. It is important that optometrists detect diabetic retinal changes and refer appropriately. We sought to determine the proficiency of optometrists at detecting retinal changes caused by diabetes. METHODS: The study comprised four parts: 1. Nineteen randomly recruited Australian optometrists practising in Queensland completed a questionnaire on their experiences seeing patients with diabetes. 2. They examined the ocular fundi of 10 patients. 3. They viewed retinal slides of 12 additional cases. 4. They attended a follow-up seminar on diabetes and the cases. They were informed that the patients did not necessarily have diabetes and instructed not to discuss the condition with the patient or their colleagues. The optometrists were allowed seven minutes per station to examine the patient or the slides and write down their responses before moving to the next station. RESULTS: When the slides and patients were considered together, cases where diabetic retinopathy was present were correctly identified by 94.0 per cent of the optometrists and cases where retinopathy was not present were correctly identified by 93.6 per cent of the optometrists. When all assessments were considered together, the correct detection/differential diagnosis rate was 88.3 per cent. Sub-classification of diabetic retinopathy severity agreed with that of the reference examiners in 58.3 per cent of assessments and there was agreement on management in 79.4 per cent of cases. Of the 22 assessments undertaken by each optometrist, there were, on average, 2.5 errors. CONCLUSION: Randomly selected Australian optometrists are able to detect and grade diabetic retinal changes solely by retinal examination and refer the patients requiring specialist care.

Iris mammillations in ocular melanocytosis.

Hyperpigmentation of the ocular tissues and of the skin around the eye is uncommon. In ocular melanosis, the episclera, uveal tract and the angle of the anterior chamber may be involved. Heterochromia iridis may be present, if the iris is affected. In oculodermal melanocytosis or the naevus of Ota, hyperpigmentation of the skin follows the distribution of the first and second divisions of the fifth cranial nerve. This report documents a patient with episcleral pigment, heterochromia iridis and numerous tiny pigmented nodules on the iris (mammillations). The possible significance of these findings is discussed.

Giant papillary conjunctivitis associated with an ocular prosthesis.

A case of giant papillary conjunctivitis associated with the wearing of an ocular prosthesis is described. Potential causes and treatment regimens are briefly reviewed.