Complications 1+2 Flashcards
Name 5 effects of CL wear on the anterior seg (7 possible):
- hypoxia
- desiccation
- debris entrapment
- microbial attachment
- mechanical effects
- surface deposits
- solution sensitivities
major effect of hypoxia on the cornea:
-other significant effects?
hypoxia causes corneal EDEMA
-others: increased BACTERIAL ADHERENCE, debris accumulation (microcysts), increased acidity (lactate accumulation), decreased healing and corneal sensitivity
What molecule is needed by the cornea to PREVENT swelling?
-how much does it swell overnight w/ nml lid closure?
oxygen
2-4% (not enough to cause clouding/epi swelling)
13% O2 to maintain nml mitosis
8% to prevent decreased corneal sensitivity
Use of WHICH lens type (broad category) with WHICH solution does NOT result in increased bacterial binding over 1 year?
SiHy lenses with UNpreserved solution; OR CLEARCARE soln
-use of any other lens type w/ PRESERVED soln resulted in increased bacterial binding
Define: COR (Critical Oxygen Requirement)
minimum Dk/t level required to prevent measurable corneal changes - different for DW and EW
i.e., for NO additional corneal swelling; DW = 23, overnight = 87
Mertz study also says a minimum 10% oxygen is needed to prevent swelling
Most common reason why pts drop out of CL wear?
dry eye/desiccation
Which bacteria are most common in normal cases of microbial keratitis? How about in CL-induced MK?
nml - staphlococcus
CL-induced - pseudomonas
What does an infiltrate with feathery borders and satellite lesions most likely indicate regarding its origin?
Most COMMON type of this organism?
it’s probably FUNGAL - ABx won’t work.
Fusarium. Also, could be candida, aspergillus, cephalosporin
Which type of microbe will cause pain out of proportion to the corneal findings, pseudodendrites, and a late ring infiltrate (and may originate from a water source)?
Acanthamoeba
What type of reaction do solutions yield in solution sensitivity CL reactions?
Type 4 hypersensitivity - to thimerosal, polyquad, etc. Certain combos of Sihy lens and soln may result in this more frequently
CC: vision is blurry/cloudy AFTER LENS REMOVAL. Doctor finds temporary shift toward MINUS power - what condition is this?
- also: distorted Ks, poor acuity endpt
- Tx?
epithelial edema
Tx: D/C lens wear, switch to higher Dk
CC: “mild haze/haloes” - but none rly.
Sx: DESCEMET’S STRIAE, FOLDS, CENTRAL HAZE (>18%)
stromal edema
Difference between microcysts and vacuoles?
- what do they indicate?
- note: both start @ basal cells initially
Microcysts: contain CELLULAR DEBRIS. Viewable with REVERSED illum.
Vacuoles: FLUID-FILLED. Viewable with UNREVERSED illum.
-both will cause SPK once they reach the surface
-both are 2’ CHRONIC HYPOXIA
Tx: D/C lenses if >50 present, will go away w/i several weeks
What percent oxygen is required to:
- prevent changes in epithelial mitosis and lactate accumulation?
- prevent decreased corneal sensitivity?
13% (lactate)
8% (sensitivity)
Non-compliance rate vs manufacturer recommendations? Vs doctor recommendations?
manufacturer - 67%
doctor - 60%
2-week replacement: 82!!!
1-month: 53%
Most common grading of NEOVASCULARIZATION? What are the other gradings?
Tx?
Grade 1: 2.5 (or any ONE w/i 3mm of corneal apex)
If grade 4: refit to Sihy…WATCH ALL STAGES for GHOST vessels
Polymegethism: change in ___
Pleomorphism: change in ___
-both are caused by what?
-Tx?
mega: size
morph: shape
HYPOXIA to ENDOthelial cells
Tx: change to Sihy or GP
CC: severe spectacle blur and PAIN x2-3 hrs after lens removal, lens intolerance, central SPK/clouding
- what condition is this? Hint: it’s secondary to increased PLIABILITY (2’ to increased edema)
- Tx?
SLACH - SL-Associated Chronic Hypoxia
-aka OVERWEAR SYNDROME
-Tx: D/C lens wear, Rx ATs, prophylactic ABx if necessary, or bandage CL (low water)
name the changes to each layer of the tear film w/ SCL and GP lenses
-lipid, aqueous, mucoid
lipid: thin or NONE
aqueous: present on SCL, dries quickly on GP
mucoid: loose attachment over SCL, NONE on GP
Pt presents w/ nonspecific complaints of CL dryness. Doctor notes a HIGH water content lens being used, and INFERIOR CENTRAL ARCUATE** staining
-what’s the diagnosis?
soft lens dessication
What’s the condition similar in appearance/complaint to soft lens desiccation, in GP LENSES?
-Tx?
Peripheral 3+9 staining (peripheral corneal desiccation)
Tx: refit the GP lens
CC: dry, gritty, decreased WT, REDNESS. Signs: (+)INFILTRATE w/ epi defect and accommpanying neo, (+)bulbar injection, (+)3+9 staining -what's the diagnosis? -cause? -Tx?
VLK - vascularized limbal keratitis
- cause: CHRONIC hypoxia (eventual epi/stromal hypertrophy allowing effects)
- Tx: D/C lens, TOPICAL ABx, STEROID to prevent scarring (infiltrate)
CC: dry, gritty, decreased WT, REDNESS.
Signs: **peripheral corneal desiccation w/ adjacent conj elevation. Also, excavation @ 3+9 and poor lens mvmt.
-Tx?
Dellen
Tx: D/C and focus on hydration therapy (ATs), Rx ABx if necessary
Pt presents for CL eval. Notes reuse of lenses, poor care lately, mild/moderate irritation, redness, tearing (OR NONE).
Signs: small, single or multiple NON-STAINING infiltrates seen in anterior stroma w/ (+) conj injection.
-what’s the diagnosis?
-Tx?
Infiltrative Keratitis
- cause: INFLAMMATORY; something on corneal surface (endotoxin, preservative).
- Tx: modify lens habits
Pt calls you first thing in the MORNING complaining of a PAINFUL, RED EYE. Woken up in the middle of the night by it. Redness, tearing, etc.
Signs: (+)trapped debris b/w lens and cornea, possible infiltrates.
-what’s the diagnosis? Type of bacteria involved?
-Tx?
CLARE - contact lens acute red eye
-inflammatory response 2’ to gram-NEGATIVE toxins**
Tx: prophylactic ABx (fluoroquinolone), steroid if NO staining present (ie you’re sure it’s not an ulcer)
CC: mild irritation, itching, (+)FBS, bulbar redness
Signs: (+)SEI w/ overlying epi defect. (+)sectoral injection, (+)necrosis 2’ to immunological or microbial invasion, (+/-)AC rxn.
-what’s the diagnosis? Offending organism type?
-Tx?
CLPU - CL Peripheral Ulcer
- Gram-POSITIVE (only one)(if microbial); began as an infiltrate and progressed.
- Can be sterile or microbial
- Tx: HARD ABx (fluoroquin) q1h x24h, then QID until resolution
- steroid only AFTER epi has healed
Pt calls w/ severe pain, redness, photophobia, discharge.
Signs: severe injection, corneal/lid edema, stromal/epi involvement, hypopyon, mucopurulent discharge.
-Offending organism?
-what’s the diagnosis?
-Tx?
MICROBIAL KERATITIS* - what you NEVER want.
- pseudomonas (or serratia); Gram NEGATIVE
- NOTE: STAPH is actually the MAIN cause of MK; pseudomonas causes
- Tx: LOAD-DOSED** Q15-30 MINS x6 hrs, then q24h BIG FLUOROquin. Cyclo/RTC 24h
- Note: acanthamoeba is the SECOND most common cause of MK in hong kong
tendencies: STERILE VS MICROBIAL
STERILE: peripheral, small, local, mild/no pain, serous discharge, mild/no AC rxn
MICROBIAL: central, larger, diffuse, severe pain, mucopurulent discharge, (+)AC rxn
Classic appearance of fungal infection? Most common fungal organism?
- fungal keratitis: causes a ____ infiltrate @ late stage.
- Tx?
infiltrate w/ FEATHERY borders
- ACANTHAMOEBA, FUSARIUM
- RING infiltrate**
- Natamycin q30-60 mins
- hospitalize if it’s acanthamoeba (causes pain OUT OF PROPORTION to clinical findings)
CC: itchy, stringy discharge, lens intolerance.
Signs: LARGE PAPILLAE*
-which zones are the papillae in SCL and GP?
-what’s the diagnosis?
-Tx/STAGES?
CLPC (GPC)
zones 1-3 if SCL, zone 3 if GP
Tx: dependent on stage
1: D/C wear, refit
2: (enlarged papillae, milld blurry VA) - refit
3 (clover-like papillae): antihistamine, vasoconstrictor, NSAID, refit - NO ABx, this is INFLAMMATORY!!!
4: STEROID*, NSAID, MC stabilizer
Pt calls complaining of burning, tearing, itching, and superior bulbar redness*
- what’s the diagnosis?
- cause??*
- Tx?
Superior limbic keratoconjunctivitis
- superior suggests HYPOXIA
- hypoxia is 2’ to lens deposits of soln preservative, THIMEROSAL
- Tx: D/C soln w/ thimerosal, Rx steroid
If all you see is DIFFUSE bulbar injection/SPK, what’s the most likely diagnosis?
SICS - solution-induced corneal staining
Note: SEI are possible - if persistent x2 wks, Rx steroid qid x2 wks full course
Difference between SLK and SLK of theodore?
SLK - anyone. FINE papillae
SLK of Theodore - middle-age females w/ thyroid problems. DENSE papillae
Pt complains of acute, sharp pain after getting something in their eye.
- what’s the diagnosis?
- greater chance of infection by gram ____ bacteria
- Tx? (esp for large abrasions?)
corneal abrasion/FB tracking
- increased chance of gram NEGATIVE infection
- if LARGE (>6mm) DO NOT PATCH. Instead, use BANDAGE CL w/ ABx (fluoro), NOT to be worn overnight - use ABx ointment qhs, RTC 24h
Mucin balls** are seen in what condition?
- indentations of what corneal layer? (d/t air bubbles)
- how should you change the lens to reduce the ball count?
dimple veiling
- epithelium
- STEEPEN the lens (to decrease lens mvmt which is causing the balls), DECREASE the modulus
Pt in for CL PE, notes very mild lens awareness.
- doctor sees faint linear break/split toward superior cornea*, and notes the lens is fit tightly
- what’s the diagnosis?
- Tx?
SEAL: superior epithelial arcuate lesion
- cause: high-modulus lens causing epithelial splitting
- Tx: remove lens, refit to lower mod, lubricate
T/F: GPs can cause a ptosis
True; 2’ to decreased lid sensitivity and possibly 2’ to tug-and-blink lens removal. (SCL won’t cause a ptosis)
