Ординатура / Офтальмология / Учебные материалы / Color Atlas of Ophthalmology The Quick-Reference Manual for Diagnosis and Treatment
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5 Cornea 171
Fig . 5.23 Central corneal thinning and protrusion with keratoconus.
n ifican t factors. Th ere is a h igh associat ion w ith con dit ion s su ch as atopy, Dow n syn drom e, Marfan syn drom e, floppy eyelid syn drom e, an d Leber congen it al h e- reditar y opt ic n eu ropathy. Acu te hydrops can occur.
Presentation
Vision is decreased as a result of progressive m yopic ast igm at ism from alterat ion of th e sh ape of th e corn ea. Keratocon us t ypically develops in th e oblique axis an d is associated w ith irregular ast igm at ism . Exam in at ion sh ow s scissoring of th e red reflex an d apical corn eal th in n ing. Associated fin dings m ay in clude breaks in th e Descem et m em bran e, apical corn eal scarring, st ress lin es in th e st rom a (Vogt st riae), an d iron lin e form at ion (Fleisch er ring) (Fig. 5.23).
Differential Diagnosis
Con tact len s scarring, pellu cid, keratoglobus
Management
Corn eal topography, keratom et r y, or ph otokeratoscopy can im prove accu racy of diagn osis by dem on st rat ing in ferior corn eal steepen ing. Scissoring reflex on ret i- n oscopy is path ogn om on ic. Treat w ith spectacle correct ion of m yopic ast igm at ism or rigid gas perm eable or hybrid con tact len ses w h en spectacle correct ion is poor ow ing to irregu lar ast igm at ism . In tacs corn eal im plan t s (Addit ion Tech n ology, In c., Sun nyvale, CA) can h elp in som e cases of con tact len s in toleran ce an d poten t ially provide in creased corn eal stabilit y w ith or w ith ou t corn eal collagen cross-lin king. Pen et rat ing or deep an terior lam ellar keratoplast y provides th e u lt im ate cure.
Keratoglobus
Keratoglobus is a rare n on in flam m ator y con dit ion th at presen t s at bir th as op - posed to oth er corn eal ect at ic disorders w ith m idperiph eral corn eal th in n ing. Acute hydrops can occu r.
172 Color Atlas of Ophthalm ology
Fig . 5.24 Corneal hydrops in keratoglobus.
Presentation
Exam in at ion sh ow s a globular sh ape of both corn eas w ith large corn eal diam eters. Associated gen eralized th in n ing occu rs, m ore con cen t rated in th e m idperiph er y. Th e an terior ch am ber is ver y deep (Fig. 5.24).
Differential Diagnosis
Keratocon u s
Management
A lam ellar or pen et rat ing keratoplast y is u su ally required . Progn osis is gu arded becau se of th e n ecessar y large graft diam eter.
Pellucid Marginal Degeneration
Pellu cid m argin al degen erat ion is a n on h eredit ar y, bilateral, periph eral corn eal th in n ing disorder th at m ost often involves th e in ferior corn eal periph er y but m ay occur in th e superior periph eral corn ea. It presen t s in early adulth ood, t ypically bet w een 20 an d 40 years of age.
Presentation
Pat ien ts experien ce blurred vision as a resu lt of progressive, again st th e rule ast ig- m at ism or oblique ast igm at ism . Exam in at ion dem on st rates corn eal prot rusion above th e area of th in n ing. St rom al scarring can occur w ith in th e th in n ed areas, an d rarely p erforat ion m ay develop (Fig. 5.25).
Differential Diagnosis
Keratocon u s, Terrien m argin al degen erat ion , collagen vascular disease
5 Cornea 173
Fig . 5.25 Inferior corneal thinning with pellucid marginal degeneration.
Management
Rigid gas perm eable len ses are recom m en ded . Spect acle correct ion is often n ot h elpfu l. Crescen t ic lam ellar or pen et rat ing keratoplast y can occur in severe cases of vision loss or corn eal ectasia.
Corneal Degenerations and Deposits
Arcus Senilis
Arcu s sen ilis is an accu m u lat ion of ext racellular lipid in th e periph eral corn eal st rom a. It can be associated w ith hyerlipidem ic states.
Presentation
Pat ien t s are asym ptom at ic, bu t th e con dit ion can be visible cosm et ically as a ring of periph eral opacificat ion th at begin s in th e su perior an d in ferior periph eral cor- n eal st rom a w ith a th in , clear zon e bet w een th e lim bu s. It t ypically presen ts in a 360-degree ring an d can be associated w ith correspon ding carot id ar ter y disease (Fig. 5.26).
Differential Diagnosis
Hyp erlipoprotein em ia, pseu dogeron toxin , arcu s juven ilis
Management
No ocu lar t reat m en t is n ecessar y. Con sider obt ain ing a lipid profile in you ng adu lt s.
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Fig. 5.26 Peripheral lipid deposition with arcus senilis.
Limbal Girdle of Vogt
An elastot ic degen erat ion of collagen develops in th e periph eral corn ea an d m ay con tain par t icles of calciu m .
Presentation
An asym ptom at ic, periph eral corn eal opacit y t yp ically begin s at 3 an d 9 o’clock along th e lim bu s. Th ere m ay be a clear lucid in ter val bet w een th e opacit y an d lim bus, depen ding on w h ich t ype of lim bal girdle develops. Ch alklike opacificat ion is com m on (Fig. 5.27).
Management
No t reat m en t is n eeded becau se visual fun ct ion is n ot affected .
Fig. 5.27 Vogt limbal girdle.
5 Cornea 175
Fig. 5.28 Dense primary lipid keratopathy.
Primary Lipid Keratopathy
A yellow - or cream -colored lipid deposit ion com posed of ch olesterol develops in th e su perficial or deep corn eal st rom a. Un like secon dar y lipid keratopathy w h ere an an teceden t corn eal in flam m ator y con dit ion such as h erpes sim plex, h erpes zoster, or t rach om a is presen t , prim ar y cases lack corn eal n eovascu larizat ion an d previou s in fect ion or in flam m at ion .
Presentation
Pat ien ts are asym ptom at ic un less decreased vision develops from obscu rat ion of th e visual axis. Cream or yellow deposits develop in th e paracen t ral or cen t ral cor- n ea (Fig. 5.28).
Differential Diagnosis
Crocodile sh agreen , cen t ral clou dy dyst rophy of Fran çois, Sch nyder corn eal dyst rophy, hyperlipoprotein em ia
Management
No t reat m en t is n ecessar y un less th e visual a xis causes decreased vision . A deep an terior lam ellar keratoplast y or pen et rat ing keratoplast y m ay be n eeded depen d - ing on th e depth of lipid deposit ion in th e corn eal st rom a.
Corneal Keloid
Corn eal opacit ies are com posed of irregu lar pat tern s of collagen ase bu n dles. Th ey can be associated w ith ocu locerebroren al (Low e) syn drom e, an autosom al dom i- n an t con dit ion in ch ildren , in w h ich th ey are bilateral. Adu lt cases t ypically occu r after previou s corn eal perforat ion or corn eal t rau m a.
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Fig . 5.29 Corneal keloid.
Presentation
Pat ien ts presen t w ith decreased visual acu it y an d foreign body sen sat ion . A w h ite, elevated, corn eal lesion can progressively en large an d cover th e visual axis of th e corn ea (Fig. 5.29).
Differential Diagnosis
Scar from in fect ious corn eal ulcer; derm oid
Management
If visu al acu it y is com prom ised, a lam ellar keratectom y or pen et rat ing keratop last y m ay be n eeded for vision reh abilit at ion . Bilateral cases in ch ildren sh ou ld receive a system ic evaluat ion for Low e syn drom e w ith referral to a pediat rician .
Calcific Band Keratopathy
Th is con dit ion con sist s of calcific degen erat ion of th e su perficial corn ea involving th e Bow m an layer. System ic cau ses m ay in clu de ren al disease, hypercalcem ic states, gou t , sarcoidosis, an d elevated p h osph oru s levels. Con dit ion s of ch ron ic ocu lar disease such as glau com a, kerat it is, uveit is, an d th e p resen ce of in t raocular silicon e oil m ay also cau se th is con dit ion . A h eredit ar y form is presen t . Ch ron ic m ercur y exposure m ay be an oth er cause.
Presentation
Fin e gray-w h ite du stlike opacit ies develop in th e Bow m an layer in th e periph eral corn ea, t ypically at 3 an d 9 o’clock. A lu cid in ter val separates th e opacit ies from th e adjacen t lim bu s. Th e dep osits t ypically coalesce to form a h orizon tal ban d of corn eal op acificat ion in th e in terpalp ebral zon e of th e corn ea (Fig. 5.30).
Management
Determ in e th e un derlying cause. Any un derlying elect rolyte or ren al disease m u st be corrected . If pain or foreign body sen sat ion is sign ifican t , a lam ellar keratectom y w ith adju n ct disodium ethylen ediam in etet raacet ic acid (EDTA) (1, 1.5, or 2%) can be u sed to rem ove calcific deposit s. If un derlying con dit ion s are n ot corrected,
5 Cornea 177
Fig . 5.30 Band keratopathy.
th e calcific deposits w ill recur. Ph ototh erapeu t ic keratectom y m ay also be u sed to rem ove th e dep osits.
Salzmann Nodular Degeneration
A n on in flam m ator y corn eal degen erat ion develops eith er from idiopath ic cau ses or as a sequela of prior ch ron ic kerat it is. Som e causes m ay in clu de ph lycten ulosis, bleph arit is, t rach om a, con tact len s kerat it is, or in terst it ial kerat it is. It m ay also be associated w ith recurren t corn eal erosion s an d ep ith elial basem en t m em bran e dyst rop hy.
Presentation
Pat ien ts eith er m ay be asym ptom at ic or m ay presen t w ith foreign body sen sat ion , tearing, an d decreased vision . Elevated gray-w h ite or blu ish n odules develop rep - resen t ing fibrillar m aterial th at h as replaced th e Bow m an layer. Th e n odules often develop in a circu lar fash ion in th e cen t ral or paracen t ral corn ea, alth ough th ey m ay also be presen t ing adjacen t to th e lim bus (Fig. 5.31).
Differential Diagnosis
Ph lycten u losis, keloid, staphylococcal m argin al u lcer, corn eal scar from in fect ious kerat it is
Fig . 5.31 Salzmann’s nodular de - generation.
178 Color Atlas of Ophthalm ology
Management
Support ive care w ith art ificial tears, gels, or oin t m en t can h elp . If recurren t erosion s are presen t , a tem porar y ban dage len s or topical osm ot ic agen t su ch as sodiu m ch loride drops m ay im prove th e sym ptom s. If visual acu it y is decreased or sign ifican t discom fort develops, a su perficial keratectom y can be perform ed to rem ove th e n odules. Recurren ce m ay develop despite debridem en t . Pen et rat ing procedu res are n ot com m on ly n eeded for th is con dit ion .
Spheroidal Degeneration
Sph eroidal degen erat ion is also referred to as corn eal elastosis, Labrador keratop - athy, clim at ic droplet keratopathy, an d Biet t i n odu lar dyst rop hy. It is a bilateral con dit ion seen m ain ly in m en , kn ow n to h ave an associat ion w ith ult raviolet exposure.
Presentation
Th e pat ien t presen ts w ith irrit at ion an d foreign body sen sat ion . In ext rem e cases visu al im pairm en t m ay occur. Clin ical exam in at ion reveals sm all am ber-colored gran ules in th e su perficial st rom a of th e periph eral in terpalpebral corn ea. In - creased opacificat ion , coalescen ce, an d cen t ral spread occur in th e late presen t a- t ion s.
Management
Lam ellar keratoplast y an d pen et rat ing keratoplast y are opt ion s w h en th ere is visu al im pairm en t .
Polymorphic Amyloid Degeneration
Bilateral corn eal opacit ies con tain ing am yloid develop in late adu lth ood w ith in th e corn eal st rom a.
Presentation
Pat ien ts are often asym ptom at ic w ith n o vision reduct ion . Gray to w h ite polym orph ic an d/or filam en tous flecks appear in th e m id - to deep st rom a w ith in th e cen - t ral or paracen t ral corn ea. Th e dep osits appear refract ile bu t are t ran slu cen t on ret roillu m in at ion . Th e in ter ven ing st rom a is clear (Fig. 5.32).
Differential Diagnosis
Corn eal gu t t ae, corn eal farin at a, lat t ice dyst rophy
Management
Visual acu it y is t ypically n ot involved so n o t reat m en t is n ecessar y.
5 Cornea 179
Fig . 5.32 Polym orphic amyloid deposits seen on retroillumination.
Iron Lines
Iron deposit ion occu rs in th e epith eliu m as a result of tear pooling abn orm alit ies from asperit y of th e corn eal su rface (Fig. 5.33).
Presentation
Hudson-Stähli line: A h orizon t al lin e at th e ju n ct ion of th e low er th ird an d upper
t w o th irds of th e corn ea
Ferry line: A lin e an terior to th e edge of th e conju n ct iva from a filtering bleb
Stocker line: A lin e an terior to th e h ead of a pter ygiu m
Fleischer ring: A con t in uous circular or ellipt ical pat tern surroun ding th e area of corn eal steepen ing in keratocon us
Mannis line: A con t in uous 360-degree ring ju st an terior to th e sut u res of a cor- n eal graft
Fig . 5.33 Fleischer ring from keratoconus outlined with cobalt blue light filter.
180 Color Atlas of Ophthalm ology
Management
No m an agem en t is n ecessar y.
Kayser-Fleischer Ring
Th is is a rare au tosom al recessive disorder in w h ich copp er deposit ion occu rs th rough out th e body, in clu ding th e Descem et m em bran e. It is also kn ow n as h epatolen t icular degen erat ion .
Presentation
Corn eal fin dings are asym ptom at ic, but exam in at ion by gon ioscopy or slit lam p reveals a Kayser-Fleisch er ring (a golden brow n to green 360-degree ring pat tern at th e lim bu s w ith in th e Descem et m em bran e).
Management
System ic pen icillam in e causes th e ring to disappear gradu ally. Liver t ran splan ta- t ion is often requ ired .
Corneal Verticillata
Lysosom al or lipid deposits occur in th e basal epith elial layer of th e corn ea in associat ion w ith several system ic m edicat ion s. Th is can also occu r in Fabr y disease.
Presentation
Pat ien ts are u sually asym ptom at ic but m ay experien ce blurred vision .
Differential Diagnosis
Fabr y disease (Fig. 5.34A), am iodaron e (Fig. 5.34B), ch loroquin e, hydroxych loroqu in e, ph en oth iazin es, in dom eth acin , n aproxen , st riate m elan okeratosis (Fig. 5.34C)
Management
Obser ve or perform epith elial debridem en t if vision is decreased . If th e con dit ion is severe, con sider discon t in u at ion of system ic m edicat ion un less it is essen t ial for t reat m en t of system ic disease.
Peripheral Thinning
Mooren Ulcer
Th is is an aggressive p eriph eral u lcerat ive kerat it is w ith a h igh risk of corn eal m elt ing an d perforat ion n ot associated w ith system ic collagen vascular disease. An au toim m un e role is th ough t to play a role in th e developm en t of u lcerat ion an d st rom al m elt ing based on kn ow n su ppressor T-cell deficien cy, in creased im - m u n oglobu lin A an t ibody levels, an d in creased levels of plasm a cells, lym ph ocytes, im m u n oglobu lin s, an d com p lem en t factor in th e periph eral corn ea an d adjacen t