گلوکوم

2. گلوکوم • دکتر علی صالحی • فلو شیپ بیماریهای شبکیه

4. علل چشم قرمز • گلوکوم حاد • یوییت • اند افتالمیت • اجسام خارجی • انواع گلوکوم • گلوکوم زاویه باز • گلوکوم زاویه بسته • گلوکوم مادر زادی • گلوکوم متعاقب مصرف کورتون • گلوکوم همراه با دیابت و میوپی

6. Intraocular Pressure (IOP) Pressure of the aqueous humorthat fills the anterior and posteriorchambers of the eye Anterior Chamber = area between iris and cornea Posterior Chamber = area between back or iris andfront of lens

7. Route of Aqueous Humor Aqueous is produced by ciliary body, located in posterior chamber Has to pass over lens, through pupil, and into anterior chamber Drained out through the trabecular meshworkin the “angle” Into venous system

8. Trabecular Meshwork Sieve-like structure Drains 90% of aqueous humor Network of both loosely-organized and tightly-linked cells offers varying levels of resistance to outflow Varies in amount of pigmentation

9. Level of IOP Determined by balance between: Rate of aqueous production by ciliary body and Rate of aqueous drainage by the trabecular meshwork - Measured in mmHg

10. Fluctuation in IOP Normal IOP varies with time of day, heart beat, blood pressure level, respiration Diurnal curve Range of fluctuation Mean range is 5 mmHg for normal eyes Greater variability can be indicative of glaucoma Single IOP measurement may be misleading

11. “What’s normal?” Statistically, Normal pressure is 10 to 22 mmHg Mean is 16 mmHg Bell curve & Standard deviation 97.5 % of population between 10 & 22 2.5 % will have pressures below 10 and above 21 just by statistics, not pathology

12. IOP is Risk Factor **The higher the pressure, the more likely glaucomatous damage is to occur There are patients with IOP higher than “normal” but never develop glaucoma = Ocular Hypertension There are also patients with IOP in the normal range who do develop glaucoma = Normal Tension Glaucoma (NTG or LTG)

13. Measuring IOP Non-Contact Tonometry (NCT) “air puff” test easy to use, no anesthetic required, minimal training only accurate in low to mid ranges of IOP Tono-pen hand-held, portable good for irregular cornea, narrow lid aperatures overestimates low IOP, underestimates high IOP Perkins hand-held applanation tonometer does not require slit lamp can be difficult to get reliable readings Goldmann Applanation Tonometry gold standard, most accurate requires anesthetic and trained staff

14. Goldmann Applanation Tonometry Correct endpoint is when inner edges just touch (c) Potential errors: Inappropriate Fluorescein Pattern Not being in the center of the cornea External pressure to the Globe (holding patient’s lids open) Patient not breathing, squeezing eyes shut, forcing themselves into slit lamp Corneal Pathology

15. ıs an ımbalance between the ınflow and outflow of aqueous humor. The cause of the high ıop RAISING THE IOP!!

17. Morphologic effect of elevated IOP Increased ıop damages retınal ganglıon cells and theır axons The result of glaucomatous process ıs excavatıon of optıc dısc and eventually optıc atrophy

18. گلوکوم 1-فشار داخل چشم 2-میدان بینایی 3-وضعیت سر عصب بینایی

19. Cup-to-Disc Ratio (C/D ratio) Ratio of the size of hollow part to the overall size of the nerve Written as decimal which represents percentage 10% of nerve is cup = 0.1 50% of nerve is cup = 0.5 Average nerve size is 0.4

20. Factors associated with glaucoma Elevated IOP > 21 HG the higher the pressure, the greater the risk Thinner Corneas (< 550)

21. گلوکوم

22. OPTIC DISC OCT

23. فشار نرمال چشم 10 تا 21 میلی متر جیوه است • ضخامت مرکز قرنیه 520 میکرون نرمال است • اگر ضخامت مرکزی بالاتر باشد فشار چشم بیشتر نشان میدهد و بر عکس • در هنگام صبح بیشترین فشار و در شب کمترین فشار است. • تا فشار 30 درمان لازم نیست. • دو فاکتور از فشار بالا-فیلد مشکل دار – آسیب سر عصب بینایی باید باشد تا گلوکوم تعریف شود.

24. در بعضی افراد فقط فشار بالای چشم دیده شده و فیلد و سر اعصاب نرمال اند که به این حالت هیپر تانسیون چشمی گویند. • در بعضی افراد فشار چشم در محدوده نرمال است ولی فیلد مختل است و سر اعصاب آسیب دیده اند.که اینها گلوکوم دارند . • در 24 ساعت حدود 6 میلی متر جیوه نوسان در میزان فشار داریم و نرمال است. زیر 10 هم خوب نیست.

25. WHAT IS GLAUCOMA? Glaucoma is a disease of the optic nerve It is caused by progressive optic nerve damage Glaucoma can progress to total loss of vision and can cause irreversible blindness

26. Glaucoma is usually ,but not always ,associated with elevated intraocular pressure(IOP) • The elevated IOP leads to damage of the optic nerve and visual field

27. Initially the damage to neural cells may go undetected as the disease is typically asymptomatic, but, left untreated, it can cause severe vision loss. • The damage to the optic nerve is irreversible: so far, regenerative attempts have been unsuccessful, so early diagnosis is essential .

29. Epidemiology • More than 64 million people globally are believed to have glaucoma. • it is expected that more than 111 million will have it by 2040, due to population aging.

30. In the US approximately 2.9 million individuals have glaucoma

31. Epidemiology • Most frequent cause for nonreversible blindness in blacks. • Throughout the world, approximately 8.4 million cases of irreversible bilateral blindness are attributed to glaucoma. • it accounts for an estimated 9% to 12% of all blindness in the United States.

33. 4.4 %

34. Glaucoma is more common than some people might think.

35. Prevalence • Whites>40 years : 1.1 – 2.1 % • Blacks : 3-4 times higher with 4 time higher likehood of blindness. • FH: polygenic inheritance • FH increases risk by 3 times

36. A multi-factorial disease Can be related to: Intraocular pressure Functioning of the eye’s drainage system Structure of the optic nerve Blood supply to optic nerve Underlying defects in eyes Genetics Previous trauma or inflammation Steroid use

37. Ocular Hypertension IOP consistently ≥ 21 mmHg WITHOUT damage to optic nerve IOP 20-24 = appox 2.5% prevalence IOP 25-29 = approx 10% prevalence IOP 30+ = approx 40% prevalence (1 in 2.5 people) Monitor closely, but don’t always treat

38. The optic nerve is the most susceptible part of the eye to high pressure because the delicate fibers in this nerve are easily damaged either by direct pressure on the nerve or decreased blood flow to the nerve.

41. Physiological Cupping If canal that optic nerve exits out through sclera is large in diameter, then fibers can spread out more Creates larger appearing cup even though there is same number of nerve fibers

42. Possible changes to optic nerve due to glaucoma Concentric enlarging of the optic cup Asymmetric cupping between eyes Notching/thinning of the rim tissue (usually happens at superior or inferior rim) Pallor of rim tissue Baring of blood vessels Parapapillary atrophy Nerve fiber layer hemorrhage (Drance heme)

45. Enlarging Cup over time

46. Asymmetric Cupping OS > OD

47. Inferior Notching, Baring of Vessels

49. رباعی زیبا از خیام: تا کی غم آن خورم که دارم یا نهوین عمر به خوشدلی گذارم یا نهپر کن قدح باده که معلوم نیستکاین دم که فرو برم بر آرم یا نه

50. Inferior notch