The Aging Eye

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The Aging Eye

• January 5, 2004
• Dorothy D. Sherwood, M.D.

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Cataracts

• Cataracts are the leading cause of blindness
  world wide.
• Cataract surgery is the most frequently performed
  surgical procedure in the US with 1.5 million
  operations annually
• 50 of those over 65 develop vision impairing
  cataracts.

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Cataracts

• Definition and Symptoms of Cataracts.
• Clouding of the lens which prevents light from
  passing through properly to the retina
• Types -3

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Cataracts

• Nuclear Cataracts
• Most common age-related cataract
• Substantial genetic component
• Age, female sex, smoking are risk factors
• More common in white
• Cortical
• Related to sun exposure
• More common in blacks
• Posterior Subcapsular
• steroids

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Cataracts

• Symptoms
• Cloudy vision, glare, halos, decreased night
  vision, faded colors, double vision, need for
  brighter light when reading
• Treatment can neither be prevented or treated
  with medications surgical only
• Removal of lens and insertion of intraocular lens
  (permanent)

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Cataracts

• Indications for surgery
• When visual impairment interferes with ADLs,
  driving, working,
• Co-existing ocular conditions requiring removal
  for treatment such as macular degeneration,
  diabetic retinopathy, glaucoma
• Peri-operative evaluation- none
• 19000 cases no improved outcome with
  pre-operative evaluation, except MI within 3
  months
• No need to stop anticoagulants or ASA-Archives
  April 28, 2003 163(8)901-908

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Cataracts

• Peri-operative complications
• Hypertension
• Arrhythmia
• 31 complications per 1000 procedures

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Cataracts

• Surgical Strategies
• Dilate eye and wash with povidone-iodine solution
  
• Small self-sealing corneal or scleral incision is
  made for phacoemulsification tip and IOL
• Injection of viscous material into anterior
  chamber to maintain the stability of the eye
• Open the capsule with continuous tear
  capsulotomy, inject saline, separate lens from
  capsule with phacoemulsification

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Cataracts

• Phacoemulsification introduced by Kelman in 1967
• Ultrasound probe using piezoelectric crystals to
  convert electrical energy into mechanical energy
• Irrigation and aspiration of the cataract. The
  posterior capsule is kept intact.
• Anesthesia is usually 1 lidocaine topical

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Cataracts

• IOL
• First implanted by Ridley in 1949
• Currently it is a small, foldable silicone or
  acrylic material injected into the capsule.
• Monofocal or multifocal lens are available
• Monofocal distant vision only, near vision
  requires glasses
• Multifocal both however, halos and loss of
  clarity are down side

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Cataracts

• Postoperative Care
• Topical eye drops
• Antibiotics gatifloxacin or moxifloxacin
• Steroids for inflammation prenisolone acetate 1
• NSAI drops ketorolac tromethamine0.5 to
  prevent inflammation in the retinal
• Examined one day, one week, two weeks, 1 months
  and 3 months post op glasses can be prescribed
  in 2 weeks.

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Cataracts

• Risk Benefits
• Bleeding, infection, posterior dislocation of
  lens material- intraoperative
• Post operative -High-level of pressure in the
  eye, corneal swelling, retinal inflammation,
  dislocation of the IOL, retinal detachment,
  infection
• Posterior capsule opacifications (PCO)
  migration of lens remnants to the visual axis of
  the capsule less common with improved technique
  treat with laser

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Cataracts

• Future
• Laser, ultrasound less heat generated,
• Pulse phacoemulsification less heat less
  chance for wound burn

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Cataracts

• Take home
• Most common cause of blindness worldwide,
  affecting 50 of the over 65 population
• Clouding of the lens which impairs light travel
  to the retina.
• Age, female sex, smoking, white nuclear
• Black, sun exposure cortical
• Steroids subcapsular
• MI 3 months prior is only risk factor- no preop
  evaluation needed.
• Post op meds gatifloxacin or moxifloxacin,
  prenisolone acetate 1, and ketorolac
  tromethamine0.5)

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Glaucoma

• The triad of increased intraocular pressure,
  degeneration of the optic nerve head, restricted
  visual field open angle glaucoma
• Visual impairment in 0.7 of those over 60, 4 of
  those over 90
• IOP greater than 17.5 mmHg is associated with a
  persistent loss of vision and underscores the
  need to aggressively treat intraocular pressure

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Glaucoma

• Diagnosed before loss of vision by
  ophthalmoscopic examination of the optic nerve to
  detect cupping.
• Blacks
• Advanced age
• Family history
• Elevated intraocular pressure- Goldmans
  tonometer is gold standard but the Schiotz
  indentation tonometer is cheap and easy to use
  normal pressure is 15 to 16 mmHg those with
  pressures over 21 are considered to have ocular
  hypertension

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Glaucoma

• Dynamics of aqueous humor
• Produced by ciliary body, circulates around lens,
  through pupil, and anterior chamber
• Flows out through the trabecular meshwork into
  the venous system here-in lies the problem

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Glaucoma

• Treatment is started when there is optic disc
  cupping or even when there is just elevated
  pressure gt21 (normal 15).
• The remainder of this discussion on glaucoma will
  cover the drugs used to treat this problem

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Glaucoma

• Pharmacopoeia
• Topical inhibition of carbonic anhydrase
• Agonism of the alpha-adrenoceptor
• Safer beta-adrenoceptor antagonist
• Prostaglandin Analogues
• Enhancement of trabeuclar outflow and uveoscleral
  outflow

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Glaucoma

• Carbonic Anhydrase Inhibitors-sulfonamides- 1
  drop tid
• Inhibition of carbonic anhydrase in the eye
  results in decreased fluid transport across the
  ciliary body resulting in decreased formation of
  aqueous humor
• Dorsolamide (Trusopt), brinzolamide (Azopt)- as
  effective as timolol, additive to timolol,
  brinzolamide is less irritant as its pH is 7.5 vs
  5.6
• Burning, stinging, bitter taste, 15 - allergic
  conjunctivitis

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Glaucoma

• beta-Adrenoceptor Antagonist-
• Timolol (Timoptic) used since 1979- lowers
  intraocular pressure the method of action is
  unknown, but may be related to decrease in
  aqueous humor production
• Contraindicated in asthma, severe COPD,
  bradycardia, third degree heart block, CHF
• Betaxolol (Betoptic or Kerlone)- may have
  decreased bronchoconstriction and causes
  increased retinal blood flow.

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Glaucoma

• Combination therapy
• Dorsolamide and timolol (Corsopt) decreases
  pressure by 50
• alpha-Adrenoceptor Agonists
• Stimulate presynaptic feedback inhibition of
  norepinephrine and reduce aqueous humor
  formation.
• .125 clonidine tid equal to pilocarpine, the
  standard
• Doses of .25 or .5 produced hypotension
• Brimonidine-(Alphagan)- reduces AH production,
  but also increases uveoscleral outflow - .2 tid
  as effective as timolol
• Headache, dry mouth, fatigue, ocular discomfort

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Glaucoma

• Prostaglandin Analogs
• Latanoprost (Xalatan) approved in 1996 more
  effective than timolol bid and is only dosed qd.
  Causes increased pigmentation, growth of
  eyelashes, conjuctival hyperemia
• Enhance uveoscleral outflow
• Other drugs in same class
• Unoprotatone(Rescula), travoprost (Travatan),
  bimatoprost (Lumigan)

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Glaucoma

• Muscarinic agents parasympathomimetic drugs
  have been used since 1870s.
• Contraction of the muscle of the ciliary body
  pulls scleral spur, opens trabecular meshwork,
  and increases aqueous flow form the eye
• These agents are anticholinesterases
• Pilocarpine -.25 to 4 every 4 to 8 hours as
  needed
• Cause miosis and cataracts
• Ocusert- wafer placed under the lid once a week
  less side effects.

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Glaucoma

• Cannabinoids
• 1971- smoking marijuana lowers intraocular
  pressure by 45
• No successful topical form and systemic causes
  too many side effects

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Glaucoma

• Take home points
• DX and TX early Schiotz tonometer, cupping of
  disc.
• Risk Age, black, family history
• Drugs CAI decrease AH Dorsolamide
• Alpha agonist decrease AH - Brimonidine
• Beta blocker unknown- Timolol
• Prostaglandin analog- scleral-uveal Lantaoprost
• Muscarininc- opens the trabecula - Pilocarpine

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Macular Degeneration

• Most common cause of blindness in the Western
  World 8 million people world wide.

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Macular Degeneration

• Macula is 5.5 mm in diameter, fovea is at its
  center located temporally from the optic disc.
  
• Fovea is thinnest part of the retina no blood
  vessels
• Preponderance of cone cells detailed central
  vision

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Macular Degeneration

• The retina is functionally 2 layers
• Rods and cones connected to the optic nerve
• Retinal pigment epithemlium and its basal lamina
  called Bruchs membrane maintains the integrity
  of the barrier between the choroid and the retina
• The choroid is between the retinal and the sclera

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Macular Degeneration

• Causes
• Risk factors age, soft drusen, macular
  pigmentary change, chorioidal neovascularisation
  in the other eye, hypertension, smoking, family
  history
• The retinal pigment epithelium becomes less
  efficient results in accumulation of waste
  material called drusen. The retinal pigment cells
  degenerate and central vision is lost
• This is dry type age related MD slowly
  progressive 5 to 10 years to blindness

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Macular Degeneration

• Geographic pattern of retinal pigment epithelial
  atrophy

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Macular Degeneration

• Disruption of Bruchs membrane-
• Choroidal neovascularization- edema disruption
  of visual function wet type or exudative age
  related MD

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Macular Degeneration

• Clinical features
• Blurring of the central vision
• Reduced vision, metamorphopsia
• The lines on graph paper will appear wavy or
  distorted
• Ophthalmoscopic examination chorioretinal
  atrophy on dry or macular edema on wet type,
  associated with retinal hemorrhages and lipid
  exudate

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Macular Degeneration

• Retinal and choroidal angiography
• Intraretinal hemorrhage and edema of macula
• Fluorescein angiogram with leakage
• Indocyanine green angiogram choroidal
  vasculature

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Macular Degeneration

• Clinical Advances
• Laser treatments for choroidal neovascularization
• Radiation treatment may preserve near vision and
  contrast sensitivity
• Prevention High dose Zn and Vit A,C,E
• Lutein and zeaxanthin carotenoids potent
  native-antioxidants found in high concentration
  in the macula needs to be studied
• Suppression of vascular endothelial growth factor
  or other antiangiogenic agents

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Macular Degeneration

• Take Home Points
• Risk age, soft drusen, htn, smoking, family
  history
• Retina retinal pigmented epithelium and rods
  and cones
• Dry failure of the RPE to remove waste products
  results in accumulation of stuff-atrophy
• Wet- neovascularization of the Choroid breaks
  Burchs membrane-edema

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The Aging Eye

• References
• Age related macular degeneration BMJ Volume
  326(7387) March 1 2003 pp 485-488
• Recent Advances and Future Frontiers in Treating
  Age-Related Cataracts JAMA volume 290(2) July
  9, 2003 pp248-251
• Drug Therapy-Medical Management of Glaucoma
  volume 339(18) October 29 1998 pp1298-1307
• New Glaucoma Medications in the Geriatric
  Population Efficacy and Safety JAGS volume
  50(5) May 2002 pp 956-962