1. EYE DISORDERS

2. A 15-year-old boy who emigrated to the United States from Sudan presents with bilateral eye irritation and itching. Physical examination reveals photophobia, conjunctivitis, and fi brovascular opacity in the superior cornea (shown in the image). Giemsa staining of a conjunctival scrape demonstrates cytoplasmic inclusion bodies. What term describes the corneal lesion?

3. Trachoma Trachoma is a chronic, contagious conjunctivitis caused by Chlamydia trachomatis. As the disease progresses, lymphoid aggregates enlarge, and the conjunctiva becomes focally hypertrophic and scarred. The cornea is invaded by blood vessels, and fibroblasts form a trachomatous pannus. In children, the disease usually heals spontaneously. In adults, it may cause blindness, especially if combined with bacterial superinfection.

4. Conjunctivitis -may be caused by: Infection: ophthalmia neonatorum due to Chiamydia trachomatis or Neisseria gonorrhoeae Chemical: erythromycin eye drops in newborns used to prevent bacterial infection Allergy: seasonal itching of eyes.

5. conjunctivitis External hordeolum

6. A 67-year-old woman complains that she has had poor vision for 4 years. Ophthalmic examination shows a selective loss of central vision. Which of the following is the most likely diagnosis? (A) Cataract (B) Corneal dystrophy (C) Gaucher disease (D) Macular degeneration

7. Macular degeneration. The most common cause of amblyopia (impaired visual acuity) in the United States is age-related macular degeneration. The center of the macula (foveola) is the point of greatest visual acuity. In this area, a high concentration of cones rests on the retinal pigment epithelium. Surrounding the macula, the retina has a multi layered concentration of ganglion cells. With aging, the macula may degenerate, in which case central vision is impaired.

8. There are two types. Dry type-thinning of the retina and formation of yellowishwhite deposits called drusen. Wet type-vessels under retina rupte and cause retinal cell death and creat blind spot. Antioxidants reduce the risk. Macular degeneration

9. Optic neuritis: inflammation of the optic nerve producing blurry vision or loss of vision; causes include Multiple sclerosis and methyl alcohol poisoning.

10. Amaurosis fugax: sudden unilateral loss of vision due to a retinal embolus of atheromatous plaque material; described as a "curtain" going down and then coming up.

11. Glaucoma: increased intraocular pressure. chronic open angle -due to decreased rate of aqueous outflow into the canal of Schlemm Eg-Near sightedness. Acute angle closure type-It is an medical emergency, Usually severe pain and redness. or narrowing of the anterior chamber angle.

12. Angle-closure glaucoma It is an acute rise in pressure due to physical blockage of the anterior chamber angle structures, leading to symptoms of redness, ocular pain, photophobia, cloudy vision, and seeing haloes around lights.

13. Primary open angle glaucoma is the most common type, occurring in about 4 % of the U.S. population over 40 years of age. It may escape detection until advanced injury has occurred, since it is insidious and often asymptomatic. The chronically increased intraocular pressure leads to loss of ganglion cells, the axons of which make up the nerve fiber layer and optic nerve. The optic disc becomes increasingly cupped, as shown in this fundus photograph (rim of cupping outlined by arrows).

15. Background diabetic retinopathy is characterized by numerous microaneurysms, dot hemorrhages and hard exudates, and occasional cotton-wool spots (blue arrow) in the posterior fundus. Most of the red dots seen in this picture represent hemorrhages; microaneurysms are more easily seen on fluorescein angiography.

16. Fundus appearance in central retinal artery occlusion shows a cherry red spot in the fovea (arrow) due to edema (without hemorrhage) of the surrounding retina. The fovea, being the thinnest area of the retina, allows the red reflex of the choroid to show through. Central retinal artery occlusion causes immediate, complete blindness and is irreversible if untreated within hours

17. Malignant tumor: retinoblastoma in children, malignant melanoma in adults. retinoblastoma

18. Uveitis: inflammation of the uveal tract (iris, ciliary body, choroid), producing blurry vision; causes include sarcoidosis, ulcerative colitis, and ankylosing spondylitis.

19. Cataract Cataract is lenticular opacities Acquired Congenital Due to Diabetes mellitus, Wilson disease, Galactcosemia Age related cataract due to lens nucleus opacification.

20. Retinal detachment-It is the separation of neurosensory retina from retinal pigment epithelium.

21. pterygium Clinically it is a triangular (“wing- shaped”) fibrovascular growth onto the corneal surface, which requires excision if it encroaches into the pupillary axis. It also is due to sun damage and typically occurs at the medial limbus of the eye

22. A 17-year-old man presents with nocturnal pain in the bone of his left leg. He relates that the pain is quickly relieved by taking aspirin. X-rays reveal a round, radiolucent area with central mineralization that is surrounded by thickened bone. The lesion measures approximately 1.2 cm in diameter. Which of the following is the most likely diagnosis? a. Chondroma b. Chondrosarcoma c. Osteoblastoma d. Osteoma e. Osteoid osteoma

23. An 11-year-old boy presents with an enlarging, painful lesion that involves the medullary cavity of his left femur. X-rays reveal an irregular, destructive lesion that produces an “onion-skin” periosteal reaction. The lesion is resected surgically, and histologic sections reveal sheets of uniform small, round, “blue” cells. Most cases of this type of tumor are associated with which one of the listed translocations? a. t(11;22) b. t(14;18) c. t(15;17)

24. A 65-year-old woman presents with pain, stiffness, and swelling of her knees. Physical examination of her knees reveals marked crepitus. Reconstructive surgery is performed on her knees. The resected bone reveals destruction of the articular cartilage and eburnation of the underlying exposed bone. Which one of the following best describes the etiology of this woman’s disease? a. “Wear and tear” destruction of articular cartilage b. Anti-IgG autoantibodies c. Deficient enzyme in the metabolic pathway involving tyrosine d. Deposition of needle-shaped negatively birefringent crystals e. Deposition of short, stubby, rhomboid-shaped positively birefringent crystals

25. A 54-year-old man presents with chronic knee pain. Resection of the patella reveals chalky white deposits on the surface of intraarticular structures. Histologic sections reveal long, needle-shaped, negatively birefringent crystals. a. Osteoarthritis b. Rheumatoid arthritis c. Ochronosis d. Gout e. Pseudogout