Home » Ophthalmology » Introduction to Glaucoma and Measurement of Intraocular Pressure

Introduction to Glaucoma and Measurement of Intraocular Pressure

Glaucoma is the progressive and characteristic optic neuropathy which is associated with visual field loss as damage progresses and in which intraocular pressure is usually a key modifying factor.

It can also be defined as normal or raised intraocular pressure leading to cupping to optic disc and optic neuropathy along with visual field defects.

Triad of Glaucoma
Triad of Glaucoma

 

Classification
  1. Congenital or acquired
  2. Open angle or angle closure
  3. Primary or secondary
Normal Intraocular Pressure Range

Normal intraocular pressure is between 11-21 mmHg (mean is 16 mmHg; with 2 standard deviations on either side of it)

Glaucomatous damage with intraocular pressure less than 21 mmHg is normal tension glaucoma.

4-7% of population over age of 40 years has intraocular pressure greater than 21 mmHg without detectable glaucomatous damage.

Intraocular Pressure Measurement

1. Goldmann applanation tonometry (GAT)

It is the gold standard based on Imbert Fick Principle which states that for an ideal, dry, thin walled sphere, the pressure inside the sphere equals the force necessary to flatten its surface divided by the area of flattening.

P = F/A

2. Pneumotonometers

Time required by jet of air to flatten the central part of cornea is directly proportional to the level of intraocular pressure.

3.       Perkins applanation tonometer
4.       Tono pen
5.       Schiotz tonometer

Management

Aim of treatment is to prevent functional impairment of vision within patient’s lifetime by slowing the rate of ganglion cell loss closer to that of the normal population (approximately 5000 per year). Currently the only proven method of achieving this is the lowering of intraocular pressure. Each 1mmHg reduction in intraocular pressure leads to a 10% reduction in rate of RNFL loss.

Ocular Receptors
Receptors Location
Alpha 1 Dilator papillae/muller muscle/arterioles
M3 Ciliary muscles/Sphincter papillae
Alpha 2 Ciliary epithelium (inhibitory receptors)
Beta 2 Ciliary processes/ trabecular meshwork/bronchi
Beta 1 Myocardium

 

Check Also

Extraocular muscles

Examination of Extraocular Movements of Eye

Examination of extraocular movements may be carried out in the steps given below: Introduction and …

7 comments

  1. If some one desires to be updated with newest technologies afterward
    he must be pay a visit this web page and be up to date everyday.

  2. I am really delighted to read this webpage posts which contains
    plenty of helpful data, thanks for providing these kinds of data.

  3. だいたい成立した時期に比例してんじゃね、ファソの数は。
    ミミ       / (_r-、r-_)    |彡三-
    いい年こいて身の程知らずの夢を見てるとしか思えない

    There are wide ranging issues you really should take under consideration when founding a content marketing news site.
    http://Www.Opusfx.Coom Also whenever we
    look for the most popular articles or news,
    sadly, but mainly these articles usually are
    not positive.

  4. 再婚の結婚式にまた呼ばれた、今度は一万にしてやったよ。 でも一度こういう経験すると婚活に身が入らなくてね。
    ごめんなさいした方から恨み言メールが来て凄く怖いです泣。助けて~>< ありがとうございました。短い間でしたがお世話になりましたp(^-^)q 株式会社メッセージ

    消しても受信箱に100通以上はあるけどな 週末多忙でしたのでお返事遅れました。きちんと拝読してお返事いたします。 結婚式
    メッセージ 英語
    招待するのに2~3万かかるのはわかるが、だからってくる人に3万包めっておかしくないか?
    低収入な脳足らずに「先生」と言われても、

    As also the after invest tensions is going to be solved because of the latest news available inside whole
    country. 結婚 メッセージ 芸能人 結婚指輪 Because
    news becomes old fast, often within hours, keeping a
    directory of news links current is often a
    major difficulty set for Drudge-style news portals.

  5. The alarm system of CCTV is a bit more secure than any internet-based camera monitoring.
    Since it’s freezeproof, taking this camera along on a skiing trip is fine.
    Waterproof camera bag nikon Over the years, I learned that in the event the camera is
    the ‘correct’ my hand it worked well for me.

    For instance, users can make a different record rate for each CCTV surveillance system camera along with set each camera to record in time-lapse mode, event mode or both.
    At up to $300, yourrrre still getting an outstanding camera, especially with this variety of reviews we’ve assembled for you.

    Take China, whose bauxite import prices have quietly risen from
    52 dollars to 60 dollars per ton. Waterproof housing
    cameras another Overall Scientific Technical
    Medical publishing industry grew 4.

  6. An HDTV feature responsible for simultaneous utilization of Television and computer performance will be the ‘PIP’ mode (picture in picture).

    You may also search for suppliers and corporations
    that sell refurbished TVs on the internet. Insignia tv used as monitor The TV adds
    an element of elegance to any room; guests are
    going being impressed with it.

    On the Horde side, “Freedom from the Horde” is earned for obtaining an Insignia or Medallion with the Horde.

    The sides of a Special Forces ring often contain a symbol or emblem of your
    specific military campaign the Green Beret were a part of or even an comcast remote codes insignia tv/dvd that few would understand.

  7. Several of us will not know the way to purchase a mobile computer
    for gaming purposes. Size from the gaming notebook that you just pick matters a whole
    lot as you has got to settle for something that appears stylish and
    will not be that bulky. Msi g series gt70 0ne-452us
    laptop review Of course, in order to experience the current games, you ought to have good gaming laptops under 600 hardware.

    The laptop includes Internet Explorer installed, nevertheless, you can also download Chrome, Firefox,
    or another browsers of your respective choice. Mostly folks who are inside the business use laptops computers for presentations.

Leave a Reply

Your email address will not be published. Required fields are marked *