Ординатура / Офтальмология / Учебные материалы / Color Atlas of Ophthalmology The Quick-Reference Manual for Diagnosis and Treatment

182 Color Atlas of Ophthalm ology

Fig. 5.35 Mooren ulcer.

in fect ion ; th is form is m ore com m on in en dem ic areas of Africa w ith h igh popula- t ion s of parasitem ia. Th is form is often bilateral an d h igh ly associated w ith corn eal perforat ion . Mooren u lcer can be associated w ith con curren t h epat it is C in fect ion (Fig. 5.35).

Differential Diagnosis

Perip h eral u lcerat ive kerat it is, in fect iou s kerat it is, rosacea, st aphylococcal m argin al ulcerat ion

Management

A conjun ct ival recession can be ut ilized for in it ial t reat m en t of ulcerat ion , perh aps by severing con n ect ion of th e lim bal vasculat ure an d associated in flam m ator y cells from th e region of u lcerat ion . Lam ellar keratoplast y is often n eeded in cases w ith im p en ding or fran k perforat ion . System ic im m un osuppressive agen t s such as oral cort icosteroids, m eth ot rexate, cyclosporin e, an d cycloph osph am ide h ave sh ow n prom ise in t reat m en t . Hep at it is C–associated cases h ave sh ow n im prove- m en t w ith in terferon th erapy. Despite t reat m en t opt ion s, th is form of ulcerat ion often h as a poor progn osis w ith a h igh corn eal perforat ion rate.

Peripheral Ulcerative Keratitis

A periph eral corn eal u lcerat ion is associated w ith epith elial breakdow n an d keratolysis. Th e con dit ion can be associated w ith any con n ect ive t issue disorder (collagen vascu lar disease) bu t is m ost com m on ly seen w ith rh eu m atoid ar th rit is.

Presentation

Presen tat ion in cludes pain , redn ess, an d decreased vision in th e set t ing of a con - n ect ive t issu e disorder. Periph eral corn eal in filt rat ion is presen t w ith an associated epith elial defect except in th e early st ages. St rom al m elt ing m ay be th e first sign of system ic disease an d is correlated w ith exacerbat ion s of system ic disease act ivit y. Sym ptom s are u sually u n ilateral but m ay be bilateral in presen t at ion . Associated lim bal vaso-occlu sion can be seen w ith th e adjacen t lim bal vessels (Fig. 5.36A,B).

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A

B

Fig . 5.36 (A) Peripheral ulcerative keratitis from rheumatoid arthritis. (B) Peripheral corneal ulcer associated with system ic lupus erythem atosis.

Differential Diagnosis

In fect ious kerat it is, Mooren ulcer, Terrien m argin al degen erat ion , furrow degen - erat ion , rosacea, exposu re kerat it is

Management

Th e goal of th erapy is to preven t corn eal m elt ing an d p rom ote reepith elializat ion . Surface lu brican t s su ch as art ificial tears, gels, or oin t m en t s sh ould be u sed ever y 1 to 2 h ours w ith or w ith ou t a blan d oph th alm ic an t im icrobial an t ibiot ic such as er yth rom ycin to t reat th e im m un e-m ediated dr y-eye disease. Tem porar y or perm an en t pu n ctal cau ter y can also in crease th e su rface m oist u re. System ic collagen ase in h ibitors (m acrolides) m ay be u seful. Con t rol of system ic in flam m at ion is essen t ial w ith im m u n osu ppression m edicat ion s such as predn ison e, cyclosp o- rin e, azath iop rin e, cylcoph osph am ide, or m eth ot rexate; th is can be adm in istered in con cer t w ith a rh eum atologist depen ding on th e oph th alm ologist’s com fort w ith system ic th erapy. Cyan oacr ylate glu e or th erapeu t ic ban dage len ses m ay be

184 Color Atlas of Ophthalm ology

n eeded in cases of severe st rom al th in n ing. A conju n ct ival recession of adjacen t lim bal conju n ct iva can prom ote h ealing of th e adjacen t periph eral st rom al m elt ing an d ulcerat ion , perh ap s becau se of elim in at ion of a sou rce of in flam m ator y cells an d collagen olyt ic en zym es from severing th e con n ect ion to th e lim bal vessels. Lam ellar an d pen et rat ing keratoplast y m ay be n eeded in cases of im pen ding or fran k perforat ion .

Terrien Marginal Degeneration

Th is is an idiopath ic periph eral corn eal th in n ing disorder th at can be localized or diffuse. Th e ocu lar surface t ypically sh ow s on ly m ild in flam m at ion in associat ion w ith th e periph eral corn eal th in n ing. Th e con dit ion is u sually bilateral but m ay be un ilateral or asym m et rical in presen tat ion . Elect ron m icroscopy reveals th e p resen ce of h ist iocytes in th e corn eal lam ellae, in dicat ing a possible im m u n e-m ediated role.

Presentation

Sym ptom s in clude foreign body sen sat ion , blurred vision , an d on ly m in im al sign s of redn ess or conju n ct ival inject ion . Periph eral corn eal th in n ing occu rs m ost often su periorly an d p rogresses in an an n ular pat tern w ith an overlying in t act epith e- lium . Th e th in n ing is accom pan ied by an an terior lipid border an d bridging vessels exten ding tow ard th e lipid base. Th e an terior lipid border is often steep, w ith slop - ing of th e lim bal border. Again st-th e ru le-ast igm at ism often develops as th e th in - n ing progresses. Spon tan eous perforat ion is rare bu t m ay occu r, especially w ith ocu lar t rau m a (Fig. 5.37).

Differential Diagnosis

Perip h eral ulcerat ive kerat it is, fu rrow degen erat ion , at ypical pellucid m argin al degen erat ion , Fu ch s su perficial m argin al kerat it is

Fig . 5.37 Terrien marginal degeneration.

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Management

Man agem en t often con sists of suppor t ive care w ith lu brican t tears, gels, or oin t- m en ts. Topical cyclosporin e m ay add ben efit in som e cases. Lam ellar corn eal patch graft s can be useful in cases of im pen ding perforat ion . An n u lar lam ellar graft s h ave also been used in severe cases w ith 360 degrees of progressive p eriph eral th in n ing.

Furrow Degeneration

Th is m ay be an opt ical illu sion , th ough som et im es t ru e th in n ing does occur.

Presentation

Th e pat ien t is u su ally asym ptom at ic. Th is m ay occu r as an idiopath ic con dit ion in th e elderly as a lu cid area separat ing th e corn eal arcu s from th e lim bu s. Corn eal th in n ing is eviden t . Th e ep ith eliu m is in tact w ith n o vascularizat ion .

Differential Diagnosis

Terrien m argin al degen erat ion

Management

No t reat m en t is requ ired .

Aphakic and Pseudophakic Bullous Keratopathy

Refer to th e ch apter 7 sect ion on corn eal edem a as a com plicat ion of cataract su r- ger y.

Corneal Surgery

Penetrating Keratoplasty

Pen et rat ing keratoplast y con sists of a fu ll-th ickn ess replacem en t of diseased cor- n ea using a don or corn ea h ar vested from a h ealthy corn eoscleral don or rim . In dicat ion s for surger y in clu de corn eal edem a, corn eal scarring, corn eal dyst roph ies, keratocon u s, corn eal u lcerat ion or perforat ion , in fect ion , an d failed corn eal t ran s- plan ts, am ong oth ers. Th e don or t issue is secu red to th e periph eral h ost corn eal rim w ith a variet y of su t ure p lacem en t tech n iques, in cluding in terrupted su t ures, a con t in uous r un n ing sut ure, or com bin ed tech n iqu es.

Risks of su rger y in clu de but are n ot lim ited to sut u re in fect ion s an d graft rejec- t ion . Graft reject ion m ay be epith elial, subepith elial, or en doth elial in n at ure (Fig. 5.38A,B).

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A

Fig . 5.39 Lam ellar keratoplast y for recurrent pterygium .

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Lamellar Keratoplasty

Th is is a part ial replacem en t of th e corn ea w ith don or corn eal t issue. Th e procedu re can be u sed in keratocon us, an terior corn eal dyst roph ies, an terior corn eal scars, recurren t pter ygia, an d corn eal m elt s. Lam ellar grafts can be perform ed using an ar t ificial an terior ch am ber an d m icrokeratom e or using a w h ole globe w ith h an dh eld p ar t ial-th ickn ess don or t issu e dissect ion (Fig. 5.39).

Endothelial Keratoplasty

Th is corn eal t ran splan t tech n iqu e replaces th e diseased en doth eliu m w ith a posterior don or corn eal but ton con sist ing of en doth elium , Descem et m em bran e, an d a th in layer of posterior corn eal st rom a. It is used for diseases of th e en doth eliu m w h en th e epith eliu m an d st rom a are essen t ially n orm al, su ch as Fuch s dyst rophy, bullous keratopathy, en doth elial graft failu re, an d iridocorn eal en doth elial syn - drom e. Tissue can be prepared u sing an ar t ificial an terior ch am ber an d m icrokeratom e or by h an dh eld dissect ion . Descem et st ripp ing en doth elial keratoplast y (DSEK) h as becom e a popu lar m eth od of perform ing th is tech n iqu e w ith st ripping of th e Descem et m em bran e an d en doth elium , follow ed by replacem en t w ith a th in don or posterior corn ea. Th e part ial-th ickn ess don or corn ea is h eld in place w ith air t am pon ade (Fig. 5.40A,B).

A

B

Fig. 5.40 (A) Endothelial keratoplast y. Preoperative corneal edema from Fuchs dystrophy. (B) Endothelial keratoplast y. Postoperative Descemet stripping auto- m ated endothelial keratoplast y.

188 Color Atlas of Ophthalm ology

Fig . 5.41 Khodadoust line with endothelial rejection of penetrating keratoplast y.

Graft Rejection

Th e 5-year failu re rate for corn eal graft s is ~35%across th e Un ited States. Corn eal graft reject ion is th e m ost com m on cau se of graft failure in th e late postoperat ive period . Diagn osis of corn eal graft reject ion sh ould be m ade on ly in graft s th at h ave rem ain ed clear for at least 2 w eeks follow ing keratoplast y.

Presentation

Pat ien ts m ay com p lain of a decrease in visu al acuit y, redn ess, ph otoph obia, p ain , an d irrit at ion . Epith elial reject ion is m arked by an elevated epith elial reject ion lin e th at stain s w ith flu orescein or rose bengal or by th e presen ce of subepith elial in - filt rates. St rom al reject ion is ch aracterized by periph eral full-th ickn ess h aze w ith lim bal inject ion in a previou sly clear graft . An arc-sh aped in filt rate m ay be n oted periph erally at th e graft–h ost ju n ct ion th at progresses cen t rally. Classic en doth e- lial reject ion presen ts w ith an en doth elial reject ion lin e (Kh odadoust lin e) th at usually begin s at a vascularized por t ion of th e perip h eral graft–h ost ju n ct ion an d progresses (Fig. 5.41). Th e com bin at ion of kerat ic precipit ates, an an terior ch am - ber react ion , circu m corn eal inject ion , an d region s of corn eal edem a sh ould be diagn osed as corn eal graft reject ion .

Management

Reject ion m ay be preven ted w ith steroids, cyclosporin e A, an d oth er im m u n o- m odu lators.

Keratoprosthesis

An ar t ificial device is u sed to restore vision in con dit ion s of corn eal blin dn ess. Com m on ly u sed devices in clu de th e Boston Doh lm an Keratoprosth esis an d Alph a- Cor (Addit ion Tech n ology, In c., Des Plain es, IL; th e Type I device is m an u fact u red an d curren tly available th rough th e Massach u set t s Eye an d Ear In firm ar y at cost: h t t p://w w w .m asstech por tal.org/IP1416.aspx). In dicat ion s in clu de m u lt iple failed cadaveric allograft su rgeries w ith lit tle h ope for su ccess u sing fut u re cadaveric t issu e. Th is m eth od avoids allograft reject ion , bu t corn eal m elt ing, in fect ion s, an d glaucom a rem ain a con cern w ith th is device. It can also be u sed for stem cell disease in pat ien t s w h o are poor can didates for im m un osupp ression (Fig. 5.42A,B).

5 Cornea 189

A

B

Fig . 5.42 (A) Dense corneal opacification prior to Dohlman keratoprosthesis placement. (B) Postoperative Dohlman keratoprosthesis with 20/40 uncorrected Snellen visual acuit y.

Anterior Staphyloma Managed by Anterior Segment Transplantation

An an terior staphylom a is a ch allenging en t it y. Mult ip le causat ive factors h ave been n oted in th e literat u re, th e com m on on es being kerat it is an d congen ital m alform at ion s, w ith sp oradic report s of disorders su ch as n eu rofibrom atosis an d sarcoidosis .Th e surgical opt ion s for an terior st aphylom a an d sim ilar diffu se cor- n eal lesion s in clu de a conven t ion al kerat roplast y, overlay graft s, an d par t ialor full-th ickn ess sclerokeratoplast y. How ever, an terior st aphylom a is associated w ith addit ion al p roblem s oth er th an corn eal ectasia. Th e len s is often cataractous w ith com prom ised zon ules, w h ich h as to be t aken care of at th e t im e of th e surger y. In addit ion , staphylectom y leads invariably to loss of iris t issue, creat ing an iat rogen ic an iridia. Th erefore, an ideal t ran splan t for an an terior staphylom a or a sim ilar diffuse an terior path ology sh ould address th ese issues. Soosan Jacob h as develop ed a n ew m eth od of an terior segm en t t ran splan t at ion th at can be u sed to t reat a m alform ed an terior segm en t an d t ran splan t a n ew, bioprosth et ic graft sim u lat ing th e an terior segm en t (Figs. 5.43A,B). Th is tech n iqu e is an exten sion of th e glu ed in t raocu lar len s (IOL) tech n iqu e inven ted by Am ar Agar w al.

190 Color Atlas of Ophthalm ology

A

Presentation

Diffuse corn eal involvem en t an d cicat rizat ion of th e uveal t issu e along w ith h igh in t raocular pressu re resu lts in a large ect at ic area of th e corn ea an d lim bus.

Differential Diagnosis

Peters an om aly, diffuse corn eoscleral kerat it is