Internal Eye

·         Diluted pilocarpine drops (0.1%) can be used to diagnose a Holmes–Adie pupil. These drops will not constrict a normal pupil, but will constrict a Holmes–Adie pupil due to denervation sensitivity.

·         Holmes–Adie pupil is an idiopathic condition, typically affecting young women, presenting with an enlarged pupil that is poorly reactive to light and accommodation. Absent ankle jerks are a frequent association. A Holmes–Adie pupil causes no harm, except blurring vision when reading in some patients. Adie’s pupil is due to a postviral degeneration in the ciliary ganglion. The pupil is initially dilated, with a tonic reaction to light and sectorial vermiform movements. The pupil is hypersensitive to 0.125% pilocarpine. The near vision is impaired by accommodative spasm but this recovers in a few months. The pupil sphincter later becomes fibrosed and the pupil miosed. Holmes–Adie syndrome is the combination of Adie’s pupil with hyporeflexi.

·          Red desaturation – ie when red looks paler to one eye than the other – is a sensitive sign of optic nerve dysfunction

·         If the entire anterior chamber is full of blood and no iris can be seen (a 100% hyphaema), the term ‘8-ball hyphaema’ has been used.

·         CHRPE (congenital hypertrophy of the retinal pigment epithelium) can be ‘typical’ or ‘atypical’. Typical CHRPE are grey or black, with depigmented lacunas, and are found in one quadrant of one eye. They do not affect vision. Atypical CHRPE have a white fishtail, and are bilateral. They do not affect vision, but if there are more than four atypical CHRPE in each eye then familial adenosis polyposis or Gardner’s syndrome may be suspected as an association. Colonoscopy and examination of all family members would therefore be appropriate. Fluorescein angiography will add nothing in terms of a diagnosis.

The lesion appears as a cluster of gray to black, well-defined RPE lesions that have been likened to bear tracks on the retina.

Retinitis pigmentosa causes ‘bone spicule’ pigmentation in the retinal mid-periphery, along with a waxy disc pallor and retinal arteriolar attenuation. Patients with retinitis pigmentosa often suffer from night blindness and restricted peripheral vision (‘tunnel vision’ when the disease is advanced).

Metastases to the choroid can appear as large dark lesions under the retina, often with overlying exudative (as opposed to rhegmatogeneous) retinal detachment. Potential sources of primary lesions include the gastrointestinal tract, breasts, kidneys, testes and prostate. However, the appearance does not sound typical of a metastasis to the choroid. Discrete pigmented spots in the retina, often with pale rims of atrophy, could be due to either previous laser treatment (in a diabetic patient with signs of retinopathy and a history of new blood vessel formation, for example) or scars from previous toxoplasmosis infections.

Congenital or old toxoplasmosis lesions can reactivate in adulthood, appearing as pigmented retinal lesions with a white fluffy edge, often obscured on examination by vitreous inflammatory debris (vitritis); hence the descriptive term for the appearance of active toxoplasmosis, ‘a headlight in the fog’. Old inactive lesions require no treatment.

·         Giant-cell arteritis affects the large- and medium-sized arteries. Ocular involvement is due to inflammation and occlusion of the ophthalmic artery and its branches to the optic nerve head, the posterior ciliary arteries. Occlusive vasculitis causes pallor and swelling of the optic nerve head (nicknamed ‘pale papilloedema’). This condition is known as ‘anterior ischaemic optic neuropathy’ (AION). Central retinal artery occlusion (CRAO) is very unusual in giant-cell arteritis.

·         The earliest sign of diabetic retinopathy is the presence of microaneurysms on fluorescein angiography. The ERG and VEP would be affected very late in the disease as the patient became blind, as would the response of the pupil. Autonomic neuropathy in patients with diabetes is another cause of abnormal pupillometry. Ocular ultrasound will not be abnormal until there is anatomical derangement of the eye, as would occur in retinitis proliferans with tractional retinal detachment. (Incidentally, this test is useful when there is also a cataract and the retina cannot be seen.)

·         Optic nerve sheath meningioma: ‘railroad-track”  sign of a central lucent optic nerve surrounded by tumor.

·         Hypoplasia of the optic nerve: typical double ring sign is seen. The nerve fiber layer is practically nonexistent.

·         Another optic nerve atrophy distinguishable from LHON ( nasal, 20-30 yrs, Retinal peripapillary telangiectasis, a typical finding in LHON, is evident.) is dominant optic atrophy. Visual acuity depression is mild in dominant optic atrophy ( more temporal pallor, 4-8 yrs of age).

·         Acute, recurrent toxoplasmosis: headlight in fog

·         CMV retinitis: brushfire border

·         Acute retinal necrosis demonstrating the hallmark finding of grayish-white patches in the retinal periphery.

·         Bird-shot choroiditis. The classic finding is a creamy yellow, multifocal choroiditis. The central vision is excellent; the patient's main complaints were floaters and peripheral spots.

·         Presumed ocular histoplasmosis syndrome. The classic findings of juxtapapillary chorioretinal scars and macular scarring, with a greenish yellow area and blood along the edge, fulfill the clinical picture of choroidal neovascularization. Peripheral scars are often seen.

·         ocular sarcoidosis: candle-wax drippings

·         The PORN syndrome is associated with acute peripheral retinal necrosis, indicated here by the whitish areas located peripherally in the superior retina

·         masquerade syndrome to describe eyes with uveitis (or simulated uveitis) in which the cause of inflammation is either neoplastic or nonuveitic in origin.

·         Fluorescein angiogram demonstrating the “leopard spots” pattern resulting from patchy subretinal infiltrates in a patient with reticulum cell sarcoma.

·         Hollenhorst plaque within a retinal arteriole in the fundus in an eye without a clinically evident retinal arterial obstruction

·         Acute hypertensive choroidopathy. Yellow, “Elschnig's spots” can be seen at the level of the retinal pigment epithelium.

·         Photodynamic therapy (PDT) is the treatment of choice for subfoveal and juxtafoveal classic CNVM. In PDT, vertiporfin, a photosensitizer or light activated dye is injected intravenously. The area of CNVM is then exposed to light from a diode laser source at a wavelength (689 nm) that corresponds to absorption peak of the dye. The light-activated dye then causes disruption of cellular structures and occlusion of CNVM with minimum damage to adjacent RPE, photoreceptors and capillaries.

·         Endophthalmitis:

Postoperative cases: Staphylococcus epidermidis

Penetrating trauma: Bacillus cereus and Streptococcus species

Patient with a central venous catheter or prolonged antibiotic therapy: Candida albicans

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·         Pigment dispersion syndrome (PDS) is an autosomal dominant disorder characterized by disruption of the iris pigment epithelium (IPE) and deposition of pigment granules on the structures of the anterior segment. Pigment granule accumulation in the trabecular meshwork then leads to progressive trabecular dysfunction and ocular hypertension with or without associated glaucomatous optic neuropathy. Because the age of onset often is in the third or fourth decade of life, this disorder is an important and often underdiagnosed glaucoma affecting younger people

The classic triad of clinical signs of PDS consists of a Krukenberg spindle, slitlike, radial, midperipheral iris transillumination defects, and pigment deposition on the trabecular meshwork.

·         Best disease, also termed vitelliform macular dystrophy, is an autosomal dominant disorder involving the long arm of chromosome 11 (11q12-q13), which classically presents in childhood with the striking appearance of a yellow or orange yolklike lesion in the macula.

Lesions in this disease are restricted to the eye. No systemic associations exist. Abnormalities in the eye result from a disorder in the retinal pigment epithelium (RPE). Lipofuscin (periodic acid-Schiff [PAS] positive) accumulates within the RPE cells and in the sub-RPE space, particularly in the foveal area. The RPE appears to have degenerative changes in some cases, and secondary loss of photoreceptor cells has been noted

1.       Stage 1 (previtelliform) - Normal macula or subtle RPE pigment changes, EOG abnormal

2.       Stage 2 (vitelliform) - Well-circumscribed, 0.5-5 mm round, elevated, yellow or orange lesion; described as an egg-yolk appearance; usually centered on the fovea; can be multifocal; the rest of the fundus has a normal appearance.

3.       Stage 3 (pseudohypopyon) - Yellow material can break through the RPE and accumulate in the subretinal space in a cyst with a fluid level formed. The yellow material will shift with extended changes in position (60-90 min). This stage most often is found in the teenage years, but it has been described in individuals aged 8-38 years.

4.       Stage 4 (vitelliruptive) - Scrambled egg appearance is due to the breakup of the uniform vitelliform lesion. Pigment clumping and early atrophic changes may be noted. Visual acuity may deteriorate moderately.

5.       Stage 5 (atrophic) - As the yellow material disappears over time, an area of RPE atrophy remains. This appearance is difficult to distinguish from other causes of macular degeneration. Visual acuity can deteriorate more markedly at this stage.

6.       Stage 6 (choroidal neovascular/cicatricial) - Following the atrophic stage, choroidal neovascularization can develop, leading to a whitish subretinal fibrous scar