The document discusses various risks and complications that can arise from soft contact lens wear, including hypoxia, desiccation, deposit buildup, mechanical issues, and inflammatory responses. It covers specific conditions like epithelial edema, stromal edema, microcysts, vascularization, polymegethism, endothelial blebs, dry eye, contact lens papillary conjunctivitis, contact lens superior limbic keratoconjunctivitis, acute red eye, sterile infiltrates and ulcers, and preservative allergies and sensitivities. Potential causes, symptoms, diagnoses, and treatment approaches are provided for each condition.

1. 소프트 콘택트렌즈 착용에 관한
부작용
Peter B. Lee, OD
121st General Hospital
Seoul, Korea

2. CL 부작용의 위험 요소
• Hypoxia (저산소증)
– virtually all CLs reduce O2 supply to cornea
• Desiccation / Alteration of tear
film(렌즈탈수/각막건조)
– CLs are much thicker than tear film
– SCLs evaporate to the atmosphere
• Deposit build-up(침전)
– SCL>RGP, but all develop deposits made of
proteins, mucous, lipids, dirt, and microbes

3. CL 부작용의 위험 요소
• Mechanical(물리적 요소)
– Tightness & looseness
– Abrasions & friction
• Inflammatory response(염증)
– Proteins and other surface deposits
– Microbes and their toxins
– Solution preservatives and other components

4. Contributory Factors
(문제가 될 수 있는 요소)
• Lens material
– Dk(산소 침투성)
– Wettability and deposit attraction
– Stiffness and other physical characteristics
• Lens design and fitting
– Lens-to-cornea relationship
– Position and movement
– Thickness profile

5. • Wearing time(착용 시간)
– DW vs. EW
– Daily vs. part-time
– Patient’s physiology
• Patient compliance(착용자의 순응도)
– Wear time
– Cleaning and disinfection
– Lens replacements
– Follow-up visits

6. Effects of Hypoxia
(저산소증에 인한
문제점)

7. Effects of Hypoxia
1. Epithelial and stromal edema(각막부종)
2. Decrease in epithelial mitosis(상피 분열)
3. Increase in stromal lactate
accumulation(유산 축적 in anterior
chamber)
4. Decrease in corneal sensitivity

8. Corneal Edema(각막부종)
• The cornea requires a certain amount of
oxygen to prevent swelling, or edema
• During sleep, the oxygen supply is reduced
to approx. 8%, compared to about 21%
during waking hours
• The cornea swells 3% to 4% overnight
• Therefore, it appears the cornea needs more
than 8% O2 to prevent swelling

9. Corneal sensitivity(각막 민감도)
» Millodot and O'Leary (1980) found that the cornea
needs at least 8% oxygen to prevent a reduction in
corneal sensitivity

10. Oxygen Requirements
• The cornea requires 8% to 13% O2 to
maintain normal corneal thickness,
metabolism, and sensitivity.
• What are today’s contact lenses able to
deliver?

11. Oxygen Requirements
• CLs are not rated by % O2 delivered
• Transmissibility (Dk/L) is a rough indicator
of how well a CL transmits oxygen
• Dk/L is the most common measure to rate
how well contact lenses deliver oxygen to
the cornea
• Other methods have also been developed
but are not in widespread use

12. Epithelial Edema(각막 부종)

13. • Epithelial edema manifests as clouding of
the epithelial tissue, usually centrally, with
associated punctate epithelial staining,
steepening of the corneal curvature and
possible irregularity of the corneal surface
Epithelial Edema(각막 부종)

14. 원인
• Low Dk(산소 침투성) contact lens wear
(PMMA more likely than soft lenses)
• Long-term, extended hours or extended
wear(연속 착용)

15. 증상과 진단
• Poor endpoint visual acuity
• Distorted keratometry mires, steepening of
K's
• Central circular clouding (CCC)
• Punctate epithelial staining centrally
• Increased minus on refraction

16. 치료/처치법
• Discontinue lens wear or immediate refit to
higher Dk material
• Refit to higher Dk material
• Decrease wear time
• Looser fit for better tear exchange
• Monitor K and SR changes
– Prescribe new spectacles when stable to allow
decreased CL wear time

17. Stromal Edema(고유층 부종)
• Stromal edema manifests as fine wrinkling
(striae) or folds in Descemet's membrane
• Striae and folds appear with approx. 6%
stromal edema
• Stromal clouding requires extensive edema,
at least 15%, and is usually not induced by
contact lens wear

18. Stromal Edema

19. 원인
• Thick lens design (aphakic, prism ballast),
low Dk material or EW

20. 증상과 진단
• Mild edema: 6 to 7%
• Striae in deep stroma
• Moderate edema: 10 to 15%
• Folds in deep stroma
• Severe edema: > 18%
• Central haze on sclerotic scatter

21. 치료/처치법
• Increase Dk/L: higher water content, thinner
design
• Looser fit for better tear exchange

22. Microcysts(상피 미세낭종) /
Vacuoles(엑포)

23. Microcysts(상피 미세낭종) /
Vacuoles(엑포)
• Microcysts are tiny cystic bodies containing
cellular debris
• They form at the basal cells and slowly
migrate towards the corneal surface
• They are visible with reversed illumination,
indicating that the cystic material has a
higher index of refraction than the
surrounding corneal tissue

24. Microcysts / Vacuoles

25. Microcysts / Vacuoles
• Vacuoles form similarly to microcysts but
are fluid filled
• They are visible with unreversed
illumination, indicating that the cystic
material has a lower index of refraction than
the surrounding corneal tissue

26. Microcysts / Vacuoles
• Although they do not induce any
symptomalogy, the presence of microcysts
and vacuoles indicate a chronic hypoxic
condition and a resulting alteration of
corneal metabolism
• Removal of the offending contact lens will
result in their disappearance over the course
of several weeks

27. 원인
• Several weeks (6 to 12 or more) of low
Dk/L lens wear
• Extended Wear

28. 증상 및 진단
• Small cysts in epithelium visible with
retroillumination
• Microcysts: reversed illumination (higher
index than cornea)
• Vacuoles: unreversed illumination (lower
index than cornea)

30. 치료/처치법
• Increase Dk/L
• D/C extended wear
• D/C lens wear if more than 50 are observed
• Monitor for 3 to 6 months for resolution
– # may increase after d/c lens wear due to
abnormal processing of epithelial cells

31. Vascularization(혈관신생)
• Cellular debris and other metabolic by-
products may be other stimuli to vessel
growth
• Almost all soft lens patients will
demonstrate some amount of
vascularization

32. Vascularization(혈관신생)

33. Vascularization(혈관신생)
• In most cases, vascularization is
asymptomatic, but encroachment into the
visual axis may result in a reduction in
vision
• Vascularization can be graded according to
the number of quadrants and the extent to
which the vessels have grown into the
cornea

34. 원인
• Long-term wear of any soft lens, but
particularly lenses with low Dk/L (aphakic,
prism ballasted, etc.)
• Extended wear

35. 진단
• Varying degrees of vessels encroaching into
previously avascular cornea
– Grade 1: Sectorial or circumlimbal vessel
extension less than 0.5 mm, or 1 or 2 vessels
extending less than 1.5 mm into cornea.
– Grade 2: Sectorial or circumlimbal vessel
extension 0.5 to 1.5 mm into cornea.

37. 치료/처치법
• Grade 1 or 2: monitor Q6mos
• Grade 3: decrease wear time, increase Dk/L
or refit to RGP material
• Grade 4: refit to RGP material or D/C lens
wear
• Though vasc may regress, vessel walls do
not disappear
– Watch for development of ghost vessels

38. Polymegethism(폴리메가티즘)
• A permanent condition of endothelial
cell(내피) change such that the cells are no
longer uniform but are of varying sizes

39. Endothelial blebs(내피 물집)
• Transient, small, dark, non-reflective areas
that appear shortly after lens insertion

40. 원인
• Long-term wear of any soft lens, but
particularly lenses with low Dk/L (aphakic,
prism ballasted, etc.), extended wear

41. 치료/처치법
• Change to higher Dk or RGP
• Monitor for further cellular changes,
corneal edema

42. DRY EYE / DESICCATION

43. Soft Lens Desiccation(탈수)
• Soft lenses dehydrate when exposed to the
atmosphere
• As the lens dehydrates, it draws water from
the post-lens tear film, resulting in dryness
of the cornea in these areas
• Tear flow dynamics from tight or high
modulus soft lenses may contribute to this
staining pattern

44. 원인
• Thin, high water soft lens
• Borderline dry eye
• Extended wear
• Incomplete / infrequent blink
• Dry environment
• Heavy protein deposition

45. 진단
• Inferior central arcuate punctate staining

46. 치료/처치법
• Lubricating drops: unpreserved
• Thicker lens design, prism ballast
• Lower water content, non-ionic (group 1)
• Lenses that have high water retention
(Proclear, Extreme H20, Soflens 66)
• Frequent replacement (if deposited with
protein)
• Punctal plugs

47. INFLAMMATION /
INFECTION

48. Contact Lens-Induced
Papillary Conjunctivitis
(GPC)-유두상결막염
• Typical symptoms
– Itchiness
– Stringy mucous discharge
– Lens intolerance
• Hallmark sign is large papillae on the
superior palpebral conjunctiva

49. • A combined immunological and
mechanical response to denatured tear
proteins that have adhered to the lens
surface(렌즈의 침전물에 의한 일종의
알레르기성 반응)

50. 원인
• Aged soft lens
– high water content
– ionic
• Aged rigid lens
– silicone acrylate
• Poor compliance to cleaning regimen
• No enzymatic cleaning

51. 증상
• Itchiness
• Mucous discharge: white ropy
• Lens awareness / intolerance

52. 진단
• Large papillae on upper tarsal conjunctiva
– SCL: diffuse distribution
– RGP: more common along lid margin (zone 3)
• Heavily protein coated contact lens
• Poorly designed lens edge
• White, ropy mucous discharge

53. Diagnosis / Treatment: Stage 1
• Itching
• Mucous discharge
• Upper tarsus
hyperemic but
relatively normal
• Discontinue lens wear
or immediate refit in
new lens
• Unpreserved lubricants

54. Diagnosis / Treatment: Stage 2
• Enlarged papillae on
upper tarsus
• Hyperemic and
edematous upper tarsal
conjunctiva
• Increased itching and
mucous
• Mild blurring of vision
• Reduced wear time
• Discontinue lens wear
• Unpreserved lubricants

55. Diagnosis / Treatment: Stage 3
• Large, clover-like
papillae that may stain
with fluorescein
• Increase in tarsal
hyperemia
• Increased itching and
mucous
• Lens discomfort
• Discontinue lens wear
• Topical antihistamine
• Topical vasoconstrictor
• Topical NSAID
• Refit to disposables or
RGPs

56. Diagnosis / Treatment: Stage 3

57. Diagnosis / Treatment: Stage 4

58. Diagnosis / Treatment: Stage 4
• Larger, more
numerous papillae
• Exacerbation of
symptoms
• Lens intolerance
• Discontinue lens wear
• Topical steroid
• Topical NSAID
• Topical mast cell
stabilizer / combo
• Refit to disposables or
RGPs

59. Contact Lens Superior Limbic
Keratoconjunctivitis

60. Contact Lens Superior Limbic
Keratoconjunctivitis
(상윤부각결막염)
• Immunological response to lens surface
deposits and solution preservatives
• Its superior location suggests that there may
be a hypoxia component
• May also have a mechanical component

61. 원인
• Soft contact lens wear
• Protein deposition
• Use of solutions containing thimerosal

62. 증상
• Burning, itching
• Superior bulbar redness
• Photophobia, tearing

63. 진단

64. 치료/처치법
• Discontinue lens wear until resolution
• Lubricants
• Topical steroid if severe
• Refit to different material
• Patient education on compliance with lens care
• Discontinue use of thimerosal preserved
solutions

65. Acute Red Eye/급성충혈
(Tight Lens Syndrome)

66. 원인
• Extended wear of soft lenses, particularly
tightly fitting lenses
• Extended wear of rigid lens with lens
adherence

67. 증상
• Awaken with unilateral discomfort or pain
• Redness
• Tearing
• Photophobia

68. 진단
• Subepithelial infiltrates
• Conjunctival and limbal hyperemia
• Minimal epithelial staining
• Debris trapped between lens and cornea

69. 치료/처치법
• Discontinue lens wear until infiltrates resolve
• Lubricants
• Prophylactic broad spectrum antibiotic drops
if epithelial defect or infiltrates are present
(fluoroquinolones, Polytrim)
• Change wearing schedule to daily wear

70. Case example
• 26 세, 남
• Sx of moderate irritation and localized
redness OD for 4 days
• No pain, discharge, photophobia, blurry
vision
• SCL wearer for 10 years
– Focus Monthly: replaces Q2mos
– 16 hrs/day
– Renu MPS

72. Sterile Infiltrate / Ulcer
(무감염성 각막궤양)
• An infiltrate is a localized collection of
white blood cells
• An ulcer is an excavated area of the cornea
that has undergone necrosis due to
immunological or microbial invasion

73. 원인
• Extended wear, long wear times
• Low Dk material
• Preserved solutions
• Poor compliance with care regimen

74. 증상
• Mild irritation, tearing
• Foreign body sensation
• Localized bulbar redness

75. 진단
• Peripheral, small diameter white
subepithelial fuzzy lesions
• Overlying epithelial defect / disruption may
be present
• Mild to moderate sectoral injection
• None to moderate anterior chamber reaction

77. 치료/처치법
• Discontinue lens wear
• Culture if epithelial defect present: cannot
diagnose as sterile until culture is done
• Artificial tears if no epithelial defect present
• Topical broad spectrum antibiotic if
epithelial defect present
– Fluoroquinolone (Ciloxan, Ocuflox)
– Fortified aminoglycoside

78. • Continue antibiotic therapy until culture
results are in, or until re-epithelialization
– qh for 24 hours, then taper
• Topical steroid possible after
re-epithelialization if infiltrates are
central and persistent

79. SOLUTION RELATED
COMPLICATIONS(보존액에
의한 부작용)

80. Preservative Allergies
and Sensitivities (방부제에
의한 앨러지)
• Chemical care systems provide convenient
disinfection with little damage to the
contact lenses. However, many of the
preservatives in use today are capable of
inducing a Type IV delayed hypersensitivity
response.

81. 원인
• Long-term use of preserved soaking/rinsing
solution
• Potential offending agents:
– Polyquaternium-1 (Alcon)
– Polyaminopropyl biguanide (B&L)
– Polyhexamethylene biguanide (Allergan)
– Polyhexanide (Ciba)
– Chlorhexidine (Boston, Claris)
– Benzalkonium chloride (Allergan Wet n Soak)
– Thimerosal

82. 증상
• Redness, itchiness, tearing
• Irritation with lens wear

83. 진단
• Diffuse bulbar injection
• Diffuse SPK
• Possible subepithelial infiltrates

84. 치료/처치법
• Discontinue lens wear if infiltrates or
moderate to severe SPK are present
• Change preservative system or change to
unpreserved care system
• If infiltrates persist after 2 weeks, consider a
steroid
• Steroid Tx should be aggressive and of
sufficient duration