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35
Conjunctiva
Anatomy and PhysiologyThe conjunctiva reacts promptly to
endogenous and exo-genous irritants and is thus a sensitive
indicator of con-tact lens complications. Practically any problem
causeddirectly or indirectly by contact lenses is
associatedwithconjunctival changes (though not all
conjunctivalchanges are due to contact lenses). Lid disease caused
bycontact lenses is associated with changes of the
tarsalconjunctiva, and corneal disease caused by contactlenses is
associated with changes of the bulbar conjunc-tiva.
Changes of the lids and cornea should be soughtwhenever a
contact lens wearer presents with con-junctivitis, because, in
contact lenswearers, the lids, cor-nea, and conjunctiva constitute
a functional unit. Thecomplications that arise are generally due to
a distur-bance of the physiological, metabolic, and
toxicologicalinterrelationship of these three structures. This
inter-relationship is the central theme of contactologicalresearch
and accounts for a major part of the ophthal-mologist’s work in
caring for the contact lens-wearingpatient.
The conjunctiva is a mucousmembrane that extendsfrom the lid
margins to the limbal region of the globe. Itis a well
vascularized, translucent membrane with twoportions, tarsal
(palpebral) and bulbar. The tarsal con-junctiva is tightly bound to
the underlying tissue on theinner surface of the lid, while the
bulbar conjunctiva ismore loosely applied to the sclera, except in
the limbalarea. The fornix (zone of transition between the
tarsaland bulbar conjunctiva) lies at the most remote area ofthe
surface of the eyeball and forms the base of the con-junctival sac
(cul-de-sac).
The conjunctiva is a mucous membrane containingmany secretory
cells; the most important of these forcontact lens wearers are the
goblet cells. When theirfunction is impaired, lacrimation becomes
deficient, theeye dries out, and a foreign body sensation ensues
thatmakes lens-wearing intolerable.
Tarsal Conjunctiva
Follicular Swelling, Papillary Hypertrophy,Giant Papillary
Conjunctivitis
Symptoms: Severe itching while wearing lenses; burn-ing;
increased secretions; impaired visual acuity (VA).
Clinical findings: Hyperemia, follicular swelling; papil-lary
hypertrophy of the tarsal conjunctiva; recurrentdeposition of
hydrophobic material on lens surfaces.
Hyperemia, follicular swelling, and papillary hyper-trophy of
the tarsal conjunctiva are the classic signs ofGPC in contact lens
wearers, a complication that is not atall rare inwearers of hard or
soft lenses. This condition isbecoming significantly more common,
not least becauseof air pollution.
Both in etiology and in phenotype, GPC resemblesvernal
conjunctivitis (vernal catarrh), a condition seen inthe springtime
in patients with an allergic predisposi-tion. GPC is caused by
proteins from the lacrimal fluidthat are presumably denatured by
lens-hygiene solu-tions and thereby become immunologically
active.Deposited on the surface of the lens, these proteins act
asantigens, towhich antibodies thenbind. The sandwichoflens,
antigen, and antibody rubs on the tarsal conjunc-tiva, causing
increased conjunctival swelling and secre-tions—the vicious cycle
of GPC.
The hallmark of GPC is the coating of the contact lenssurface
with a strongly adherent protein layer, whichpierces the film of
tear fluid over the lenswithin secondsof insertion, leading to
diminished visual acuity and in-creased glare. The case history
generally points to thediagnosis: The patient wears lenses without
complica-tions forweeks ormonths and then, suddenly, a
problemdevelops. A few minutes after lens insertion the
patientexperiences burning, chafing, and itching in the eyes.Tears
and a film deposited on the surface of the lens im-pair visual
acuity within a few seconds after the eyes areopened, and until the
next blink. Conjunctival secretionscause the eyelids to stick
together and limit the mobilityof the contact lens during blinking
and eye movements.
Examination reveals the following: the contact lensis barely
mobile or immobile on the surface of the eyeand is coated with a
grayish-white film that makes itlook dry and dull. The lids are
mildly swollen, and theirmargins are coated with dried
yellowish-white secre-tion. The bulbar conjunctiva is mildly
injected; evertingthe lids reveals a massive papillary swelling of
the tarsalconjunctiva, which is made even more evident
withfluorescein staining. GPC can be classified into fourstages
(Table 9).
Conjunctiva
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36
57
59
58
60
Fig. 55 Scarring of the tarsal conjunctiva of the lower lid
afterdecades of wearing hard PMMA lenses.
Fig. 56 Tarsal conjunctiva 1 hour after test wear of a rigid
con-tact lens for myopia; injection of conjunctival vessels.
Fig. 57 Isolated hyperemia of the upper lid conjunctiva causedby
protein deposits on the anterior surface of a soft contactlens.
Fig. 59 Injection of the upper lid conjunctiva; focal
conjuncti-val atrophy after 18 years of wearing hard lenses for
kerato-conus; tear deficiency.
Fig. 58 Mild hyperemia of the tarsal conjunctiva;
mechanicalirritation of the conjunctiva on the initial fitting of a
hard lens.
Fig. 60 Upper-lid hyperemia and edema; allergic reaction
tochlorhexidine.
3 Pathologic Findings
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37
61
63
62
64
Fig. 61 Upper-lid hyperemia; mild cockscomb swelling of
theconjunctiva indicating chronic irritation; hard contact lens
wornfor 6 years.
Fig. 63 GPC reaction on upper lid; marked hypertrophy of
thepapillae; hyperemia.
Fig. 62 Early GPC, characterized by hyperemia and
moderatepapillary hypertrophy; soft hydrophilic lens.
Fig. 64 GPC stage 1–2; isolated tarsal conjunctival
hyperemia;papillary hypertrophy in the region of the fold.
Conjunctiva
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38
Fig. 65 GPC stage 2–3; papillary hypertrophy; identical pic-ture
to vernal conjunctivitis.
Fig. 66 GPC in a CAB lens wearer; stage 2; fluorescein
staining.
Fig. 67 GPC follicular swelling in the region of the lower
con-junctival fold; soft contact lens worn for 3 months.
3 Pathologic Findings
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39
Fig. 68 GPC stage 3; fluorescein staining; PMMA lens worn for11
years.
Fig. 69 Marked GPC, stage 3; fluorescein staining; gel
contactlens worn for 4 months.
Fig. 70 GPC; scarring; 9 months of wearing a
fluorosiliconecarbonate lens.
Conjunctiva
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40
Table 9 Stages of giant papillary conjunctivitis
Stage Papillaryappear-ance
Mucus Lenswearingcomfort
Visualacuitywith lens
1 Littlechange
Minimal Good Very good
2 Diameterup to0.5 mm
Moderate Slightlydecreased
Still good
3 Diameterup to0.7 mm
Moderate Markedlydecreased
Variable
4 Diametergreaterthan0.7 mm
Copious Lenses un-wearable
Markedlydiminished
Differential diagnosis: Other conditions resembling GPCinclude
other allergic reactions of the conjunctiva, auto-immune
conditions, and (typically in the springtime)primary vernal
conjunctivitis independent of the wear-ing of contact lenses.
Prevention: Meticulous daily lens hygiene, frequent useof
protein removers, and a temporary cessation of lenswearing during
critical seasons will reduce the risk ofGPC.
Note: Patients with pollen allergy should be instructednot to
wear contact lenses during the hay fever season.
Bulbar Conjunctiva
Conjunctival Edema and Acute Chemosis
Symptoms: Severe itching and tearing; difficulty closingthe
lids.
Clinical findings:Marked swelling of the conjunctiva thatmay
project beyond the lid margin, with clear or san-guineous
secretion. Mild proptosis.
Conjunctival edema in contact lens wearers is usuallydue to
lens-cleaning solutions, or to wetting solutions orartificial tears
that are supposed to enhance wearingcomfort. Acute conjunctival
edemamay occur as early as
the fitting phase, particularly when relevant details ofthe case
history are not obtained or disregarded, such asa previous episode
of allergic blepharitis or conjunctivi-tis requiring treatment.
Patients with certain types of al-lergies, for example to
thiomersal, a common constitu-ent of eye drops and contact lens
solutions, also tend todevelop acute conjunctival reactions when
contactlenses are fitted.
Acute chemosis is a complication that usually ap-pears within a
few minutes of the initial insertion of alens or the initial use of
a lens care product or variety ofeye drops. Most of the affected
patients were previouslytreated at some time with eye drops or
ointments andwere presumably sensitized in this way. An
adequatehistory helps to identify and prevent this problem:patients
should be asked at the initial prefitting visitwhether they have
ever had complications from the useof eyedrops or ointments, or
difficulty tolerating them. Ifso, the risk is high that the initial
insertion of contactlenses will cause marked conjunctival swelling
withinminutes, so that the fitting will have to be terminated.
One can also use the Ophthalmotest to predict ad-verse reactions
in advance and determine the offendingsolution constituent (cf. p.
80, 86).
Ophthalmologists periodically see an emergencycase of acute
chemosis referred by a contact-lens-fittingoptician. The problem
typically arises during a fittingsession, for example on initial
application of a wettingsolution to improve lens-wearing comfort.
Within a fewminutes, massive conjunctival swelling in both
eyesmaycompletely occlude the palpebral fissure andmake it
dif-ficult to close the lids. A retrospectively obtained
historyusually reveals that the patient has been using
non-prescription eye drops irregularly over the years,without
medical supervision, to treat hay fever or otherallergic symptoms.
Acute chemosis can occur even ifeyedrops were last used years
earlier.
Slit-lamp examination in acute chemosis revealsslightly
thickened lids with mildly erythematous mar-gins. The bulbar
conjunctiva is severely swollen, andthere is a large volume of
clear or sanguineous secretion.The swelling extends beyond the lid
margins, hinderinglid closure. Corneal changes are only mild: there
may bemild edema, and slit-lamp examination after
fluoresceininstillation may reveal fine stippling of the
epithelium.The anterior chamber is usually normal, and,
unlesshindered by the swollen lids, vision is normal but for
aslight increase in glare.
3 Pathologic Findings
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41
73
75
74
76
Fig. 71 Acute chemosis 45 seconds after insertion of a
softcontact lens stored in Polyquad; known allergy to
quaternaryammonium bases.
Fig. 72 Acute hemorrhagic chemosis after the application ofan
artificial tear solution to a dry eye; hard lens; BAC allergy.
Fig. 73 Acute bulbar conjunctival injection; immediate reac-tion
to PMMA lens; because of the pressure exerted by the con-tact lens,
the edema is limited to the area not covered by thelens.
Fig. 75 Jelly-like swelling of the tarsal and bulbar
conjunctivaafter many years of astringent eye drop abuse while
wearingsoft contact lenses.
Fig. 74 Acute bulbar conjunctival injection; immediate reac-tion
to chlorhexidine and thiomersal; the lens contact zone re-mains
visible for a few minutes after the lens is removed.
Fig. 76 Acute chemosis in a gel lens wearer with known
aller-gies to various plant species, after a brief stay in a
garden. Rem-nants of organic foreign matter in the cul-de-sac,
pollen dust onthe lens surface.
Conjunctiva
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42
Table 10 Causes of conjunctival hemorrhage in contactlens
wearers
A Related to contact lensesMaterial defects, inadequate
polishing, edge defectsImproper lens insertion or removalSurface
deposits
B Not related to contact lensesMechanical irritation, strong
eye-rubbingVascular sclerosisCoagulopathy, leukemiaIatrogenic
(anticoagulation)Tear deficiency syndrome
Differential diagnosis: Acute chemosis can also occur asan
allergic reaction to pollen, environmental pollutants,or other
substances. Other causes include retrobulbarmasses, severe
intraocular infections, and radiation in-jury to the eyes.
Prophylaxis: Acute chemosis can often be prevented bymeticulous
history-taking.
Note: When acute chemosis occurs, its cause must bedetermined
before the lenses are worn again or newlenses are fitted;
otherwise, a recurrence is likely.
Subconjunctival Hemorrhage
Symptoms: Usually no pain or discomfort, but patientsare highly
distressed by the prominently visible abnor-mality.
Clinical findings: Deep-red hematoma under the con-junctiva,
which is usually somewhat raised.
Multiple microhemorrhagic spots are often present inthe
conjunctiva of contact lens wearers, usually in theperilimbal
region where the lens rests, but occasionallyin the tarsal
conjunctiva. These easily visible lesions ap-pear spontaneously,
often sending the highly distressedpatient to the emergency service
of the eye clinic. Thereis usually no pain or impairment of visual
acuity.
Blood begins to pool under the bulbar conjunctivashortly after
lens insertion, usually arising from a site ofinjury near the
limbus and spreading out evenly underthe conjunctiva of the lower
half of the eye. When a softlens is still on the eye, the hematoma
in the area coveredby the lens is somewhat compressed and thus
paler thanelsewhere. There is no pain, discomfort, or cornealedema,
unless the eyes are rubbed.
High-power slit-lamp examination reveals thesource of the
bleeding as a small tear of the bulbar con-junctiva, rarely more
than 1mm long. Such tears oftenresult from improper lens insertion
or removal. Othercauses are long fingernails or devices used for
lens inser-tion or removal. Another common cause is a defect of
therim of the lens, for example, a sharp-edged lens tear,breakage,
or deposit. Such lesions are usually caused byhard lenses but can
also be caused by inadequately rehy-
drated soft lenses, or by disposable lenses that are wornfar
beyond the recommended period, until they physi-cally deteriorate.
Excessively long wear of disposablelenses regularly produces breaks
and tears in the lens,which can injure the lids, conjunctiva, and
cornea; simi-lar defects can be produced by improper handling,
in-adequate hygiene, or storage under excessively dry con-ditions.
The most common causes of subconjunctivalhemorrhage are listed in
Table 10.
Tominimize the risk of subconjunctival hemorrhage,the contact
lenses should be inspected under a dissect-ing microscope, or a
slit lamp fitted with a contact-lens-holding device, at every
follow-up visit.
Differential diagnosis: Subconjunctival hemorrhage hasa unique
appearance and is hardly likely to be confusedwith any other
disorder. It may, however, appear for rea-sons unrelated to the
wearing of contact lenses.
Prophylaxis: Patients should be instructed to discard
anylenseswith visible defects, and to take care not to cut theeye
when inserting and removing the lens. Persons withhemorrhagic
disorders of any kind should not wear con-tact lenses.
Note: Whenever conjunctival hemorrhage occurs, thecontact lenses
should be inspected for defects. Patientswith recurrent hemorrhages
should undergo medicalevaluation for a bleeding disorder.
3 Pathologic Findings
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43
79
81
80
82
Fig. 77 Hyperacute, severe conjunctival edema; hemorrhagicform;
immediate reaction after the initial insertion of a hardcontact
lens wetted with an artificial tear solution; longstandingabuse of
astringent eye drops, known thiomersal allergy.
Fig. 78 Perilimbal hemorrhage of the bulbar conjunctivacaused by
wearing a soft lens with edge defects.
Fig. 79 Conjunctival lesion caused by wearing a disposablesoft
lens with an edge defect for several months longer than
therecommended time.
Fig. 81 Extensive bleeding into the conjunctiva at the 6
o’clockposition caused by an edge defect of a gel contact lens.
Fig. 80 Figure 79, enlarged; the haptic of the gel lens acts as
atamponade for the hyposphagma.
Fig. 82 Massive conjunctival bleeding after wearing a
hardcontact lens with edge defects; 42-year-old patient with
coagu-lopathy. Further wearing of contact lenses is
contraindicated.
Conjunctiva
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44
83
85
84
86
Fig. 83 Cutting injury of the bulbar conjunctiva from a
defec-tive lens edge; disposable gel contact lens; prescribed
wearingtime exceeded.
Fig. 85 Perilimbal, superficial conjunctival bleeding caused
byimproperly processed edge of a PMMA lens.
Fig. 84 Cutting injury of the conjunctiva and cornea; 8-year-old
soft hydrophilic corneoscleral lens in situ; large,
sharp-edgeddefect.
Fig. 86 Conjunctival hemorrhage in the sulcus region;
me-chanical irritation due to poor fitting.
3 Pathologic Findings
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45
Table 11 Causes of mechanical irritation in contact
lenswearers
Material defects, inadequate polishingFlat fitting,
decentrationSurface depositsLesion of the lid marginLesion of the
corneaTear deficiency syndrome
Generalized Conjunctival Hyperemia
Conjunctival hyperemia in contact lens wearers has avariety of
causes, which can often be distinguished fromone another by the
location and appearance of hyper-emia. Focal conjunctival hyperemia
is most often due tomechanical irritation of the conjunctiva in a
circum-scribed area from a dried-out, ill-fitted, defective,
ordeposit-coated lens; annular perilimbal injection is usu-ally of
toxic or allergic etiology. Generalized conjunctivalhyperemia
(i.e., of the entire conjunctiva, including thearea under the
contact lens) is usually caused by me-chanical irritation or
infection; other causes include in-adequate lacrimation, allergic
or toxic processes, andradiation injury. Whether focal or
generalized, thehyperemic area is superficially discolored
(brick-red);the reactively dilated vessels of the conjunctiva are
al-ways bright red and freely mobile over the scleral sur-face.
(This is not so in cases of conjunctival hyperemiasecondary to
underlying deep or scleral infection.)
Mechanical Irritation and Injury
Symptoms: Eye-rubbing; foreign body sensation; tear-ing.
Clinical findings: The entire bulbar conjunctiva is in-jected
and appears brick-red.
Conjunctival vasodilatation as a rapidly occurring re-sponse to
a foreign body is routinely observed when apatient first starts
towear contact lenses. Surface vesselsof the bulbar conjunctiva are
greatly enlarged duringthis period. This response is normal in the
initial phase ofcontact lens wear, but pathological at later
times.
The causes of mechanical irritation of the conjunc-tiva in
contact lens wearers are listed in Table 11.
If a lens is fitted too flatly, its edge does not lie se-curely
on the limbus and can rub against the conjunctiva.Lens cracks,
fractures, or polishing defects, as well assurface deposits due to
inadequate cleaning are othercauses of mechanical irritation.
Injury of the conjunctivafrom an exogenous foreign body looksmuch
the same asinjury from a contact lens; the two situationsmay be
dif-ficult to distinguish. It may be useful to remove the lensand
examine the conjunctiva with fluorescein or rosebengal staining;
distinctive traces of the foreign bodymay become evident.
A common cause of generalized conjunctival hyper-emia in contact
lens wearers is inadequate lacrimation.Any qualitative or
quantitative, primary or secondaryimpairment of lacrimation impairs
the ability of the lensto glide without friction over the cornea
and conjunc-tiva. The unlubricated lens acts as a foreign body
andcauses mechanical conjunctivitis. The symptoms in-clude burning,
foreign body sensation, rubbing of theeye, and epiphora. Defects in
the conjunctival and cor-neal epithelium can be detected with rose
bengal.
Infection
Symptoms: Burning; eye-rubbing; foreign body sensa-tion;
epiphora.
Clinical findings: Injection and chemosis of the
entireconjunctiva; secretions.
Conjunctivitis with generalized injection is certainly themost
common complication of contact lenswearing. Thesymptoms include
burning, foreign body sensation, eye-rubbing, and epiphora.
1. Bacterial Conjunctivitis
Symptoms: Burning; eye-rubbing; foreign body sensa-tion;
tearing.
Clinical findings: Generalized injection and chemosis;secretions
in the cul-de-sac.
Conjunctiva
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46
89
91
90
92
Fig. 87 Severe conjunctival hemorrhage after a punch in theeye;
the gel lens remained intact.
Fig. 88 Conjunctival hyperemia; mechanical irritation from ahard
contact lens characterized by an even, brick-red discolora-tion of
the entire bulbar conjunctiva.
Fig. 89 Focal lateral bulbar conjunctival hyperemia from
aforeign body reaction; hard contact lens; typical brick-red
color.
Fig. 91 Focal limbal conjunctival hyperemia from a foreignbody
reaction; gel contact lens.
Fig. 90 Focal lateral conjunctival hyperemia from a foreignbody
reaction; rigid contact lens.
Fig. 92 Focal conjunctival hyperemia with accentuation nearthe
limbus, due to a foreign body reaction; soft contact lens.
3 Pathologic Findings
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47
95
97
96
98
Fig. 93 Diffuse conjunctival injection from a foreign body
re-action to a rigid contact lens; tear deficiency.
Fig. 94 Severe conjunctival swelling; erythema from a
foreignbody reaction in a patient wearing gel contact lenses.
Eversionof the lower lid reveals an insect wing as the cause.
Fig. 95 Diffuse conjunctival injection as a foreign body
reac-tion to a hard contact lens worn for many hours.
Fig. 97 Mild, diffuse conjunctival hyperemia; tear
deficiency;gel contact lens with desiccated anterior surface.
Fig. 96 Diffuse conjunctival irritation after test wear of a
gelcontact lens for 4 hours; tear deficiency.
Fig. 98 Marked, deep-red conjunctival discoloration due toboth
superficial and deep vasodilatation; mechanical irritation;soft,
hydrophilic contact lenses.
Conjunctiva
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48
Fig. 99 Marked, diffuse brick-red coloration of the
conjunctivain bacterial conjunctivitis.
Fig. 100 Bacterial conjunctivitis due to Haemophilus in a
pa-tient wearing gel contact lenses.
Fig. 101 Massive conjunctival injection, mildly accentuated
inthe area contacted by the (soft, hydrophilic) contact
lens;bacterial conjunctivitis due to Pseudomonas.
3 Pathologic Findings
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49
Table 12 Causes of conjunctivitis in contact lens wearers
Altered ocular floraEpithelial defectsFaulty lens cleaningFaulty
lens disinfectionTear deficiencyElevated temperature of the corneal
surfaceImpaired immune competenceChronic hypoxiaOverwearingWearing
deteriorated lensesSystemic infectionWearing lenses during
sleepParasitic infection
Table 13 The organisms that most frequently cause
con-junctivitis in contact lens wearers
Adenovirus Herpes simplex virus Pneumococcus
Aspergillus Haemophilus Pseudomonas
Candida Klebsiella Staphylococcus
Chlamydia Moraxella
Infectious conjunctivitis is among the more commonconditions
treated by the ophthalmologist, affectingboth contact lens wearers
and the general population.Improper lens wear (Table 12)
predisposes to its occur-rence; it is caused by a broad spectrum of
micro-organisms—bacteria, viruses, and occasionally fungi
orAcanthamoeba.
The characteristic signs of bacterial conjunctivitis areswelling
of the lids and generalized injection of thebulbar and tarsal
conjunctivae. The cul-de-sac containscopious mucous or
proteinaceous secretions. As long asthe infection is limited to the
conjunctiva, the cornea isclear and visual acuity is unaffected;
the anterior cham-ber is normal. Excessive tearing may affect
vision. If theinterior of the eye is inflamed, changes in the
refractivemedia may impair visual acuity, but this is rare.
Cultureof the secretions in the cul-de-sac may reveal the
etio-logic organism; Pseudomonas, Staphylococcus, Haemo-philus, and
Pneumococcus commonly cause conjunctivi-tis in contact lens wearers
(Table 13).
Bacterial conjunctivitis is often the result of inade-quate lens
hygiene. The biofilm in the lens case providesan excellent breeding
ground for bacteria and fungi; soft,
hydrophilic lenses are more commonly the vector of in-fection
than hard lenses because their aqueous portioncan act as a culture
medium for microorganisms.
In patients with infectious conjunctivitis, samplesfor culture
should be obtained not only from the cul-de-sac, but also from the
surfaces of the contact lenses, andfrom the lens case, for
identification of the organism anddetermination of its pattern of
antibiotic sensitivity andresistance. The latter is particularly
important, not onlyfor the choice of the best antibiotic, but also
for assess-ment of the efficacy of the various contact lens
hygienesystems currently available on the market.
Differential diagnosis: Bacterial conjunctivitis is a
clini-cally distinctive entity. It should not be forgotten,however,
that conjunctivitis can be caused by foreignbodies of various kinds
in the cul-de-sac, including “lost”contact lenses or lens
fragments. Recurrent conjunctivi-tis may be due to an
immunodeficient state, a metabolicdisorder, or repeated reinfection
from the throat, nose,skin, or ear (transfer of organisms by way of
the pillow).
Prophylaxis: Two basic steps will minimize the risk
ofconjunctival inflammation: first do careful lens hygiene,second
stop all lens wearing during an infection.
Note: Bacterial conjunctivitis in contact lens wearers isalmost
always due to poor lens hygiene. If lens-wearingis not
discontinued, corneal infection may ensue.
Conjunctiva
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50
102
104
103
105
Fig. 102 Bacterial conjunctivitis; gel contact lens; diffuse
con-junctival hyperemia without accentuation in the area
contactedby the lens.
Fig. 104 Toxic hyperemia, most severe in the perilimbal
area;thiomersal reaction; standard aphakic fitting.
Fig. 103 Bacterial conjunctivitis; soft contact lens;
streptococ-cal infection.
Fig. 105 Mechanical hyperemia; perilimbal white ring of
com-pression from steeply fitted lens; tear deficiency.
3 Pathologic Findings
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51
Fig. 106 Bacterial conjunctivitis; pus in the lower
cul-de-sac;staphylococcal infection.
Fig. 107 Diffuse conjunctival infection and hemorrhage;
viralconjunctivitis; hard contact lens.
Fig. 108 Viral conjunctivitis; diffuse brick-red to deep-red
dis-coloration of the conjunctiva, with hemorrhage; soft
contactlens wearer.
Fig. 109 Fungal conjunctivitis; diffuse vasodilatation with
mildparalimbal accentuation; soft contact lens; candidiasis in
adiabetic patient.
Conjunctiva
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52
2. Viral Conjunctivitis
Symptoms: Burning; itching; foreign body sensation;tearing.
Clinical findings: Marked injection; microhemorrhages;swelling
of the plicae; minimal secretion.
Unlike bacterial conjunctivitis, viral conjunctivitis israrely
related to contact lens wearing; it is usually amanifestation of
systemic viral infection, for example in-fluenza. Nonetheless,
though primary viral conjunctivi-tis is the most common type,
fitters of contact lensesmust be aware that poor hygiene on their
partmay causean outbreak of iatrogenic epidemic
keratoconjunctivitis(EKC).
Differential diagnosis: Viral conjunctivitis is distin-guished
from bacterial conjunctivitis by the waterysecretion in the
cul-de-sac, and by the swollen plicae(particularly in EKC). Signs
of infection often involve thecornea as well. Cases that fail to
improve with treatmentshould arouse suspicion of another type of
infection,such as fungal or parasitic. Foreign body reactions
aswell as toxic and allergic processes must be excluded.
Note: Viral conjunctivitis is highly contagious. Thepatient’s
family and acquaintances are at risk, as are thepersonnel and
patients of the lens-fitting practice.
3. Fungal Infection
Symptoms: Foreign body sensation; eye-rubbing; sensa-tion of
heat and dryness.
Clinical findings:Marked surface injection accompaniedbymarked,
generally livid, deep injection;whitish secre-tions in the
cul-de-sac.
Fungal infection is rare in healthy contact lens wearersand is
usually seen in those suffering from immune com-promise, diabetes,
or other metabolic disorders. Candidaalbicans and Aspergillus niger
are often the cause. Fungalinfections are difficult to treat.
Corneal involvement orinfiltration into the interior of the globe
poses a majorthreat to vision.
Fungal infections are much more common in softlens wearers than
in hard lens wearers, as the soft lens isan ideal fungal culture
medium. The organisms take thewater they need from the aqueous
compartment of thelens, and nutrients and electrolytes from the
lacrimalfluid.
Fungal infections are best diagnosed by microbialculture of the
secretions from the cul-de-sac. Micro-scopic examination of
secretions and of the contact lensitself may reveal fungal hyphae.
Demonstration of theresponsible fungal organism serves to exclude
otherpossible causes of conjunctivitis, for example GPC.
Differential diagnosis: Fungal infections of the anteriorsegment
are not always readily distinguishable frombacterial or viral
infections, particularly because mixedflora may be present.
Microbial culture is required.
Prophylaxis: In general, patients at risk of fungal infec-tion
should not wear contact lenses. Those who do wearlensesmust comply
rigidlywith the recommended lens-care routine.
Note: The diagnosis of a fungal infection in a contactlens
wearer should prompt medical evaluation for latentor active
diabetes or an immunocompromised state.
Focal Conjunctival Hyperemia
Focal conjunctival hyperemia is due to a spatially re-stricted
process; thus, in contact lens wearers, it is usu-ally found in the
limbal area, (i.e., at the periphery of thecontact lens). The
etiology of hyperemia in contact lenswearers (as in other
persons)may be toxic, allergic, met-abolic, mechanical, or
inflammatory.
3-O’Clock and 9-O’Clock Limbal Hyperemia
Symptoms: Increased foreign body sensation; increasedtear
flow.
Clinical findings: Marked dilatation of the vessels at
the3-o’clock and 9-o’clock positions. These sites are oftencovered
with a mildly raised, yellowish deposit.
Conjunctival injection near the limbus at the 3-o’clockand
9-o’clock positions in a hard lens wearer implies aninadequate
cushion of tear fluid between the lens andthe eye. The lens
mechanically irritates the conjunctivaand cornea during horizontal
saccades. The problemmay be caused by inadequate lacrimation or by
poor fit-ting. Diagnostic assessment includes quantitative
tearanalysis, inspection of the sit of the lens, and
slit-lampexamination of the cornea after staining.
Differential diagnosis: Conjunctival injection near thelimbus
can also result from local lesions of the conjunc-tiva and
cornea.
Note: Check for corneal defects in all cases of
localizedconjunctival injection.
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Fig. 110 Marked deep-red discoloration of the conjunctiva dueto
candidiasis in a soft contact lens wearer with AIDS.
Fig. 111 Marked conjunctival vasodilatation at the
3-and9-o’clock positions in a hyperopic wearer of hard contact
lenseswith tear deficiency.
Fig. 112 Focal conjunctival hyperemia at the 4-to 5-o’clock
po-sition; injury of the edge of the cornea through improper
fitting.
Fig. 113 Isolated perilimbal conjunctival hyperemia under ahard
corneoscleral contact lens. Mechanical irritation by exces-sively
tight fitting in the haptic zone.
Conjunctiva
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Table 14 Differential diagnosis of perilimbal hyperemia
incontact lens wearers
Color Location Cause
Brick-red Conjunctivalsurface
Mechanical irritation,fitting error
Bluish-red Superficial anddeep conjunctiva
Toxic, allergic reaction
Livid blue Deep conjunctiva,sclera
Intraocular complication,iritis, iridocyclitis, uveitis
Perilimbal and Limbal Injection
Symptoms: The discomfort is rarely severe and is usuallylimited
to itching and a feeling of dryness.
Clinical findings: Markedly dilated vessels in the para-limbal
or perilimbal region.
Isolated, superficial perilimbal injection is a
pathologicalfinding seen almost exclusively inwearers of soft
contactlenses. It is easily mistaken for ciliary injection,
whichindicates an intraocular process. The affected vessels
inciliary injection are livid in color, more deeply situated,and
more finely reticulated.
An arc-shaped, superficial perilimbal area of injec-tion
(sometimes accompanied by fine microhemor-rhages) is usually due to
faulty lens fitting. If the edge ofthe lens is too steep or too
firmly applied to the conjunc-tival surface, it can compress the
bulbar conjunctiva inthe region of the corneal sulcus. On the other
hand, if thelens is too flat, its edges can scrape the perilimbal
con-junctiva. The differential diagnosis is straightforward: Ifthe
perilimbal redness disappears within 10 minutes oflens removal, the
lens was too flat; if in the same periodof time a reactive
hyperemia appears, the lens was toosteep.
Redness from wearing lenses with abrasive edgesor edge defects
disappears within 1–2hours after thelenses are removed. Hyperemia
of this type is only rarelyassociated with corneal injury.
Deep perilimbal vasodilatation indicates an entirelydifferent
situation. Deep-red or livid vessels, locatedbelow the surface and
parallel to the limbus, are a defi-nite indication of corneal
damage or an intraocularprocess. The usual cause in contact lens
wearers is toxickeratopathy in reaction either to the lensmaterial
or to alens care product.
A finding of deep and livid (rather than superficialand
brick-red) vasodilatation limited to the limbal re-gion is
classically termed “ciliary injection.” The dilatedvessels are
located in the perilimbal sclera and are an in-dication of deep
corneal and intraocular changes, such asiritis or uveitis, which
are very rarely related to thewear-ing of contact lenses. It may
prove difficult to determineby examination whether the finding is
superficial (peri-limbal) or deep (ciliary), particularly in
protracted cases.A rule of thumb for the crucial differentiation of
primaryintraocular problems from contact lens complications isthat
the latter, unlike the former, generally resolve afterthe lenses
are removed.
It is not always easy to classify limbal hyperemia orto
determine whether it is due to the wearing of contactlenses. A
thorough history and a meticulous slit-lampexamination of the
limbus under highest power aremandatory. The most important
criteria for differentialdiagnosis are listed in Table 14.
The Ophthalmotest is an excellent aid to the exami-nation of
conjunctival changes, especially perilimbal re-actions, and enables
differentiation of improper lens fit-ting from a toxic or allergic
reaction (pp. 80, 86).
Differential diagnosis: In summary, perilimbal and
limbalinjection must be distinguished from scleral and in-traocular
processes, which cause deep perilimbal (par-ticularly ciliary)
vasodilatation and thereby produce alivid (bluish-purple)—rather
than brick-red—perilimbalring.
Prophylaxis: Immediate ophthalmological examinationin the early
phase of perilimbal injection can preventfurther injury.
Note: Intraocular disease must be ruled out wheneverperilimbal
vasodilatation is found.
3 Pathologic Findings
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116
115114
117
Fig. 114 Focal conjunctival hyperemia at the limbus; hard
con-tact lens; tear deficiency.
Fig. 116 Diffuse vasodilatation of the bulbar conjunctiva
withaccentuation at the limbus; dry eye; gel contact lens.
Fig. 115 Marked, diffuse conjunctival hyperemia; tear
defi-ciency; soft contact lens; marked drying of the anterior
surfaceof the lens.
Fig. 117 Diffuse bulbar conjunctival vasodilatation with
accen-tuation at the limbus at the area of contact of the soft
contactlens; deposits on the lens surface; tear deficiency.
Conjunctiva
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119
121
120
122
Fig. 118 Brick-red perilimbal injection from poorly seated
softcontact lens; hyperopia + 6.5 D.
Fig. 119 Limbal hyperemia; diffuse bulbar conjunctival
vaso-dilatation due to a toxic keratopathy; gel lenses; PMMA
intoler-ance.
Fig. 121 Fire-red limbal hyperemia in toxic keratopathy;
reac-tion to lens cleaning agents; gel contact lens.
Fig. 120 Limbal injection in toxic keratopathy; hyperemia ofthe
bulbar and tarsal conjunctiva. Soft hydrophilic contact lens.
Fig. 122 Enlargement of Figure 121.
3 Pathologic Findings
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57
Fig. 123 Toxic conjunctival hyperemia, especially marked atthe
limbus, caused by PMMA allergy.
Fig. 124 Perilimbal hyperemia from toxic damage to the
con-junctiva and cornea; thiomersal allergy; soft contact lens.
Fig. 125 Pseudoepiscleritic irritation after several weeks
ofwearing a defective contact lens.
Conjunctiva