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Glaucoma
Published in Charles Theisler, Adjuvant Medical Care, 2023
Glaucoma is a group of eye conditions that damage the optic nerve, leading to loss of vision or blindness. Glaucoma develops often as a result of abnormally high pressure in the anterior chamber of the eye. However, not every person with increased eye pressure will develop optic nerve damage.1 There are two major types of glaucoma: open angle and closed angle. Open angle is the most common form, accounting for 90% of all cases. At first, open-angle glaucoma has no symptoms. It causes no pain and vision stays normal. Nonetheless, over time and without treatment, increased intraocular pressure damages the optic nerve. In closed-angle glaucoma, drainage canals are blocked so pressure in the eye increases. Individuals with glaucoma gradually lose their peripheral (side) vision. If glaucoma remains untreated, objects to the side and out of the corner of the eye can be missed. In more advanced cases, patients often report that their vision is like looking through a tunnel. Over time, central vision may also decrease until no vision remains.1
Medicine
Published in Seema Khan, Get Through, 2020
For each patient below, choose the SINGLE most likely diagnosis from the list of options. Each option may be used once, more than once or not at all. A 55-year-old woman presents with an entirely red right eye. The iris is injected, and the pupil is fixed and dilated. The intraocular pressure is high.A 20-year-old man presents with a non-tender red eye. On examination the sclera is bright red with a white rim around the limbus. The iris, pupil, cornea and intraocular pressure are normal.A 33-year-old woman presents with a painful red eye. The conjunctival vessels are injected and blanch on pressure. The iris, pupil, cornea and intraocular pressure are normal.A 40-year-old man presents with redness most marked around the cornea. The colour does not blanch on pressure. The iris is injected, and the pupil is small and fixed. The cornea and intraocular pressure are normal.A 20-year-old man with non-specific urethritis and seronegative arthritis is also noted to have red eye associated with Reiter’s syndrome.
Trauma to the Eyelids and Periorbital Region
Published in Amy-lee Shirodkar, Gwyn Samuel Williams, Bushra Thajudeen, Practical Emergency Ophthalmology Handbook, 2019
Slit lamp biomicroscopy will allow for accurate assessment of the ocular surface, lacrimal system, and integrity of the anterior globe. A Siedel test should be performed if a leak is suspected (see Figure 4.2). Dilated fundal examination should be completed on all patients with possible posterior segment involvement. Gonioscopy is useful in the detection of lesions such as angle recession in blunt trauma or to look for an IOFB located within the angle. However, this should not be performed in open globe injuries as the pressure may result in intraocular contents being squeezed through the wound. It is vital that the intraocular pressure is recorded; the form of tonometry will vary depending on availability and mobility of the patient. Lids should always be flipped to look for subtarsal foreign bodies.
Classification of Seasonal Hyperacute Panuveitis (SHAPU)
Published in Ocular Immunology and Inflammation, 2022
Ranju Kharel Sitaula, Anadi Khatri, Pratap Karki, Sagun Narayan Joshi, Haramaya Gurung, Eliya Shrestha, Indraman Maharjan, Ananda K Sharma, Madan Prasad Upadhyay
Moderate SHAPU cases have more severe anterior chamber reaction with ≥1+ cell and ≥1+ flare (based on SUN’s Classification11). The fibrinous exudates may be seen in front of the pupil and iris crypts with or without the presence of hypopyon. The hypopyon is mobile, predominantly yellow in color, plano or convex in shape (Figure 2a). The lens is clear but the pupillary light reflex may be altered due to the exudates present in the vitreous leading to subtotal leucokoria in a red eye. But the fundal glow is still appreciable and the visible portion of retina appears apparently normal. The B scan ocular ultrasonography shows hyperechoic shadows in anterior and mid vitreous with attached retina but increased thickness of retinochoriodal complex (Figure 2b). Intraocular pressure can be (i) normal, (ii) lower due ciliary shutdown, or (iii) raised due to the outflow obstruction in the trabecular meshwork by the cells/exudates or pupillary block secondary angle closure glaucoma. Hence, moderate SHAPU cases have features predominantly of anterior and intermediate uveitis, which may start involving the retina if appropriate interventions are not taken at this stage.
Mechanistic links between systemic hypertension and open angle glaucoma
Published in Clinical and Experimental Optometry, 2022
Ying-kun Cui, Li Pan, Tim Lam, Chun-yi Wen, Chi-wai Do
In the eye, the intraocular pressure exerts pressure on the retina. Since there are no venous valves to control the direction of blood flow in ocular veins, the compression caused by intraocular pressure would hinder rather than enhance ocular circulation. It is suggested that venous pressure in the eye is roughly equivalent to the intraocular pressure. As shown in Figure 1B, the arterial pressure pushes the blood to flow downstream against the venous pressure, and the pressure in the veins before leaving the eye slightly exceeds the intraocular pressure under normal conditions.41 In the eye, the ocular perfusion pressure is the difference between arterial pressure and intraocular pressure. In principle, the higher the ocular perfusion pressure, the higher the ocular blood flow to the tissue.42
Inter-Eye Comparison in Highly Myopic Patients with Unilateral Myopic Traction Maculopathy
Published in Current Eye Research, 2022
Jiaxin Tian, Yue Qi, Yinghan Zhang, Caixia Lin, Ningli Wang
From January 2021 to May 2021, 54 eyes of 27 patients (ID: PM01-PM27) with unilateral MTM, including 22 females and 5 males, were enrolled in the study. Three patients lost the OCT images of 3D Widefield MCT, so the protrusion of the sclera was assessed by radial line scans in OCT. The mean age was 48.89 ± 12.78 years with a range of 18 to 65 years. The average intraocular pressure was 15.85 ± 3.22 mmHg. The AXL positively correlated with the mean PSH, horizontal height and vertical height (r = 0.610, P < .001; r = 0.559, P < .001; r = 0.588, P < .001). Among the eyes with MTM, 10 eyes were classified as T1, 10 eyes were classified as T2, 6 eyes were classified as T3, and 1 eye with macular hole retinal detachment was classified as T5. All the eyes had outer retinoschisis, 6 eyes had S1, 4 eyes had S2, 4 eyes had S3, and 13 eyes had S4. The inter-eye comparison showed the affected eyes had worse BCVA and longer AXL than the fellow eyes (P < .001; P < .001). Moreover, the eyes with MTM had greater PSH no matter in the horizontal plane, the vertical plane, or the total mean. The inter-eye PSH difference in nasal was most obvious in four quadrants (P = .004). Besides, higher rates of posterior staphylomas, vitreovascular traction and ERMs were observed in the affected eyes (P = .010; P = .002; P < .001). While there was no significant inter-eye difference in the location of the protrusion of the sclera in the horizontal and vertical plane (P = .525; P = .650; Table 1).