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

9 Medical Retina 261

spot s (periph eral hyperpigm en ted spots th at m ay be su rrou n ded by a sm all h alo of hypop igm en tat ion ). Siegrist st reaks are lin ear hyperpigm en ted areas directly over ch oroidal vessels th at m ay h ave a sim ilar path ophysiology as Elsch n ig spots. In ext rem e cases pat ien ts can presen t as hyper ten sive ch oroidopathy, serous ret in al detach m en t , an d hyp erten sive opt ic n eu ropathy (h em orrh ages at th e opt ic disk m argin , blurring of disk m argin s, congest ion of ret in al vein s, m acu lar exu dates, an d florid disk edem a) (Fig. 9.1).

Differential Diagnosis

Diabet ic ret in opathy, collagen vascu lar diseases, an em ia, radiat ion ret in opathy, bran ch ret in al vein occlusion (BRVO), cen t ral ret in al vein occlusion (CRVO), isch - em ic opt ic n eu ropathy, oth er cau ses of n eu roret in it is, papilledem a, an d ch err y-red spot

Management

Th e pat ien t is referred for a cardiological w orkup . Ph arm acoth erapy an d lifest yle ch anges are required to preven t fur th er en d organ dam age.

Diabetic Retinopathy

Ret in al vasculopathy affect s 25%of th e total diabet ic populat ion . Diabetes can affect eyes in various w ays, m ost com m on ly corn eal abn orm alit ies, glaucom a, iris n eovascularizat ion , cat aract s, an d n eu ropath ies. How ever, diabet ic ret in op athy is th e m ost com m on an d poten t ially th e m ost blin ding of th ese com plicat ion s. Na- t ive Am erican s an d African Am erican s are at in creased risk of developing diabet ic ret in opathy (Fig. 9.2A,B,C,D).

Presentation

Nonproliferat ive diabet ic ret inopathy (NPDR): Most com m on ly th e con dit ion is

detected in ciden t ally. How ever, sym ptom s can range from m ild blu rring vision to distor t ion to visu al acuit y loss. Com m on clin ical feat ures in clu de th e presen ce of m icroan eu r ysm s, dot/blot h em orrh ages, flam e-sh aped h em orrh ages, ret in al edem a, h ard exu dates, cot ton w ool spots, ven ous loops/beadings, in t raret in al m icroangiopath ies. On th e basis of clin ical pict ure, Early Treat m en t Diabet ic Ret in opathy St u dy (ETDRS) h as classified NPDR in to m ild, m oderate, an d severe t ypes.

Proliferat ive Diabet ic Ret inopathy (PDR): Th is is classified as early an d h igh -risk PDR. Un t reated PDR h as a 70% ch an ce of leading to tot al blin dn ess. Sym ptom s

can var y from m ild blurring of vision to severe vision loss. Com m on clin ical fea- t u res in clu de n eovascularizat ion of disk (NVD), n eovascularizat ion elsew h ere (NVE), p reret in al an d vit reous h em orrh age, fibrovascu lar t issu e proliferat ion , an d t ract ion or com bin ed ret in al det ach m en t s.

Maculopathy: Th is is th e leading cau se of vision loss in pat ien ts w ith diabet ic ret in opathy. It is du e to fu n ct ion al dam age an d n ecrosis of ret in al capillaries. Edem a can also be cau sed by t ract ion in th e case of PDR. Th e defin it ion of clin i- cally sign ifican t m acu lar edem a (CSME) is given by ETDRS (Fig. 9.2E,F,G,H).

262 Color Atlas of Ophthalm ology

A B

C D

E F

Fig . 9.2 (A) Severe nonproliferative diabetic retinopathy (NPDR) with diffuse diabetic m aculopathy. (B) Moderate NPDR. (C) Proliferative diabetic retinopathy (PDR) with clinically significant macular edema. (D) PDR–FFA. (E) PDR with preretinal hemorrhage– color fundus photo. (F) PDR with preretinal hemorrhage–FFA.

9 Medical Retina 263

G H

Differential Diagnosis

NPDR: CRVO, BRVO, ocu lar isch em ic syn drom e, hyper ten sive ret in opathy, radia-

t ion ret in opathy, sickle cell disease

PDR: Neovascu larizat ion due to vein occlusion , sickle cell ret in opathy, drug abu se, sarcoidosis, Valsalva ret in opathy

Maculopathy: Cystoid m acular edem a (CME), cen t ral serous ret in op athy (CSR), n euroret in it is, parafoveal telangiect asia, m acroan eu r ysm

Management

Fast ing glucose level an d th e h em oglobin A1c (HbA1c) levels are im por tan t in -

dicators to m on itor con t rol of diabetes m ellit us. HbA1c m ust be m ain tain ed be- t w een 6 an d 7%. Fun du s flu orescein angiography is don e to diagn ose st age an d for follow -u p of cases of diabet ic ret in opathy. B-scan is u sed in diagn osis an d follow -up of cases w ith vit reou s h em orrh age.

Laser photocoagulation form s the m ainstay of treatm ent . Focal and grid lasers are done to treat m acular edem a depending on the num ber and localization of the

leaks. Panretinal photocoagulation is done in PDR. W hen both the lasers need to be com bined, grid laser is done 2 to 3 w eeks prior to the PRP (Fig. 9.2I).

In t ravit real t riam cin olon e aceton ide an d bevacizum ab h ave been t ried for t reating m acu lar edem a. In t ravit real inject ion s of bovin e hyaluron idase are used in t reat m en t of vit reous h em orrh ages.

Vit rectom y is n ecessar y in cases w ith longst an ding vit reous h em orrh age, t rac- t ion , or com bin ed ret in al detach m en t .

264 Color Atlas of Ophthalm ology

Follow -u p depen ds on th e st age of th e diabet ic ret in opathy (diabet ic ret in o- pathy). Mild NPDR is follow ed u p on ce in 1 year, m oderate NPDR in 6 to 8 m on th s, severe NPDR in 3 to 4 m on th s, CSME in 2 to 3 m on th s, early PDR in 2 to

3m on th s, an d h igh -risk PDR ever y 1 to 2 m on th s.

Central Retinal Vein Occlusion

Th e et iology is th rom bus form at ion posterior to th e lam in a cribrosa of th e opt ic n er ve in th e predisposed popu lat ion . Here vessels lie in a com p ar t m en t w ith lim - ited sp ace for displacem en t . Ret in al vein occlu sion can be a cen t ral or a bran ch vein occlusion . Th e path ogen esis of th rom bosis can be an alyzed by th e classic Virch ow t riad: stasis of blood flow, hypercoagu lat ion , an d vessel w all abn orm alit ies. (Fig. 9.3A,B,C,D).

Presentation

A det ailed h istor y is t aken to rule out possible causes. Th e presen t ing pat ien t can be asym ptom at ic or w ith decreased vision , ph otoph obia, pain fu l blin d eye, an d redness. Visual loss can be sudden or gradual, over a period of days to w eeks. Visual loss ranges from m ild to severe. Pat ien t s can presen t w ith t ran sien t obscurat ion s of vision in it ially, later progressing to con st an t visual loss. Best-corrected vision is a ver y good progn ost ic in dicator. Conju n ct ival congest ion , corn eal edem a, relat ive afferen t pupillar y defect (RAPD), iris an d angle n eovascularizat ion , an d periph - eral an terior syn ech iae are im port an t associated fin dings. Fu n du s exam in at ion reveals su perficial, dot an d blot , an d/or deep ret in al h em orrh ages possible in all fou r qu adran t s. W h ole fu n du s gives a “blood an d th u n der” appearan ce. Vein s m ay be dilated an d tort u ous. Oth er associated fin dings can be opt ic disk edem a, cot ton - w ool spot s, NVD, NVE, optociliar y sh u n t vessels, m acular edem a w ith or w ith out exu dates, cystoid m acular edem a, lam ellar or fu ll-th ickn ess m acu lar h ole, opt ic at rophy, an d p igm en tar y ch anges in th e m acu la (Fig. 9.3E,F).

Differential Diagnosis

Diabet ic ret in opathy, acute hyper ten sive ret in opathy, ocu lar isch em ic syn drom e, pap illedem a, p apillit is, radiat ion ret in opathy, acu te ret in it is

Management

Medical exam in at ion an d laborator y test s are don e to fin d th e system ic causes leading to th e episode. Ocu lar hyperten sion an d glaucom a m ust be ru led out . Dop - pler color im aging, opt ical coh eren ce tom ography (OCT), FFA, an d elect roret in o- gram (ERG) con firm th e stat us of th e disease an d th e likely progn osis. Aspirin , an - t iin flam m ator y agen ts, system ic an t icoagu lan t s, fibrin olyt ic agen t s, an d system ic cor t icosteroids are used as th e m edical lin e of t reat m en t .

In t ravit real inject ion of t riam cin olon e is th e th erapy of ch oice in pat ien t s w ith severe m acu lar involvem en t . Ch orioret in al ven ous an astom osis, radial opt ic n eu - rotom y, an d vit rectom y to rem ove th e posterior hyaloid ph ase are th e surgical ap - proach es u sed so far. Cen t ral vein obst ruct ion st udy (CVOS) advocated a frequ en t follow -up in th e early m on th s of th e episode to look for th e iris n eovascularizat ion . Neovascu larizat ion , m acular pu cker, m acular edem a, celloph an e m aculopathy, an d opt ic at rophy are th e com plicat ion s to be n oted in ever y visit .

9 Medical Retina 265

A B

C D

E F

Fig. 9.3 (A) Central retinal vein occlusion (CRVO)—color fundus photo. (B) CRVO—fun- dus fluorescein angiography (FFA) late phase. (C) Branch retinal vein occlusion (BRVO) involving the m acula—color fundus photo. (D) BRVO involving macula—FFA. (E) Macular retinal vein occlusion—color fundus photo. (F) Macular retinal vein occlusion—FFA.

Branch Retinal Artery Occlusion

Of all th e acu te ret in al arterial occlu sion s, 40%are bran ch ret in al arter y occlu sion s (BRAOs). Path ophysiologically, BRAO resem bles cen t ral ret in al ar ter y occlusion (CRAO), but it involves on ly a sector of th e ret in a. Isch em ia of th e in n er layers of th e ret in a leads to cellular injur y an d n ecrosis. It is m ost com m on in th e seven th decade of life. Ch olesterol em boli, called Hollen h orst p laqu es, are th e em boli m ost com m on ly associated w ith BRAO. Platelet fibrin em boli appear as w h it ish

266 Color Atlas of Ophthalm ology

gray p lugs an d in creases in n u m ber w ith repeated episodes. Calcific em boli ap - pear as large w h ite plaques an d u su ally involve th e large ar terioles arou n d th e disk. Oth er u n com m on sources of em boli are also fou n d, such as leukoem boli (vascu lit is, Pur t sch er ret in op athy, sept ic en docardit is), fat em boli follow ing longbon e fract u res, am n iot ic flu id em boli (com plicat ion of pregn an cy), t um ors (at rial m yxom a, m it ral valve papillar y fibroelastom a), talc em boli (long-term in t raven ous drug abusers), cort icosteroid em boli (com plicat ion of in t ralesion al or ret robulbar steroid inject ion ), air em boli follow ing t rau m a or surger y, syn th et ic m aterials u sed in cardiac an d vascular p rocedu res (e.g., syn th et ic par t icles from art ificial cardiac valves).

Cer t ain n on em bolic cau ses are also respon sible for th e arterial occlu sion s, for exam ple, th rom bosis associated w ith ath erosclerosis, vascu lit is (gian t cell ar terit is, system ic lu pus er yth em atosu s), posterior in flam m ator y con dit ion s (toxoplasm a ret in och oroidit is, Beh çet syn drom e).

Presentation

Th e pat ien t usually presen ts w ith acu te, u n ilateral, pain less, par t ial loss of vision . Many t im es it can be an in ciden t al fin ding. A h istor y of associated risk factors like sm oking, hyper ten sion , hyperch olesterolem ia, diabetes, coron ar y ar ter y disease, or h istor y of st roke or t ran sien t isch em ic at t ack an d am aurosis fugax m ay be presen t . Th ere m ay be a part ial field loss respect ing th e h orizon t al m eridian .

Fu n du s exam in at ion reveals a grayish w h ite ret in a along th e dist ribut ion of th e affected vessel. An em bolus can be seen in th e vessel involved, usu ally at th e bifu r- cat ion s. A n arrow ed bran ch ret in al ar ter y, boxcarring, segm en t at ion of th e blood colum n s, an d cot ton -w ool spot s are th e com m on associated fin dings.

Differential Diagnosis

CRAO, cilioret in al ar ter y occlu sion , ret in it is, ret in al con t usion , n eoplasia, an d m y- elin ated n er ve fiber layer

Management

Th e con dit ion is broadly invest igated an d t reated along th e sam e lin es as CRAO. All th e t reat m en t m odalit ies used in th e case of CRAO h ave been t ried but w ith ver y lit tle success. Prop er system ic invest igat ion s are don e frequen tly to diagn ose an d elim in ate th e et iological factors. FFA an d elect roret in ography (ERG) play a role in diagn osis of th e con dit ion , localizat ion of n onperfu sion areas, an d viabilit y of th e involved ret in a. An t icoagulan ts, th rom bolysis, an d carot id en dar terectom y form th e t reat m en t opt ion s, depen ding on th e resu lt s of various invest igat ion s.

Central Retinal Artery Occlusion/Ophthalmic

Artery Occlusion

Vision loss du e to CRAO is at t ributed to isch em ia of th e in n er ret in al layers an d pykn osis of th e ganglion cell layer. Subsequ en t isch em ic n ecrosis of th e ret in a cau ses opacificat ion . Fou rteen percen t of th e popu lat ion h as a cilioret in al ar ter y th at is a com pon en t of ch oroidal circulat ion an d supplies th e m acu la w ith all th e com pon en t s of th e m acu lopapillar y bu n dle. Men in th eir early sixt ies are m ost com m on ly involved (Fig. 9.4A,B,C,D).

9 Medical Retina 267

A B

C D

Fig . 9.4 (A) Central retinal artery occlusion (CRAO) showing cherry-red spot.

(B) CRAO—color fundus photo. (C) CRAO fundus fluorescein angiography showing poor filling even after 6 minutes. (D) CRAO FFA showing poor filling even after 10 m inutes.

Presentation

CRAO presen ts as u n ilateral, acu te, persisten t , pain less loss of vision . It can be bilateral in 2% of th e p opulat ion . Am au rosis fugax an d oth er sym ptom s of tem poral ar terit is are oth er associated fin dings. A h istor y of drug in t ake an d em bolic ph en om en a are com m on ly presen t . Visu al acu it y m ay var y from h an d m ovem en t s to a few m eters. Th e presen ce of a cilioret in al ar ter y por ten ds a bet ter progn osis becau se th e cen t ral vision in th ese pat ien t s is w ell preser ved . Afferen t pup illar y defects, pale disk w ith splin ter h em orrh ages, ch err y-red spot , grou n d -glass ap - pearan ce of th e ret in a, boxcar segm en t at ion of th e arteries an d vein s, an d em bolu s in ~20% of pat ien ts are com m on fin dings. A cardiac exam in at ion can reveal th e presen ce of a bru it or m urm urs. A h istor y of tem poral ten dern ess, jaw clau dica- t ion , m u scle w eakn ess, raised er yth rocyte sedim en t at ion rate (ESR), an d fever m ay be associated .

Differential Diagnosis

An terior isch em ic opt ic n eu ropathy, in adver ten t in t raocu lar inject ion of gen tam i- cin , blun t t raum a, an d oth er cau ses of ch err y red spot like Tay-Sach s disease, oth er sph ingolipidoses, qu in in e toxicit y, m acular h em orrh age, hyper ten sion , Hurler syn - drom e, m acular h ole, steroid inject ion s

268 Color Atlas of Ophthalm ology

Management

(PT/aPTT), seru m protein elect rop h oresis, fast ing blood sugar, lipid profile, an d blood cult ures are h elpful in th e et iological diagn osis. Im aging tech n iqu es such as carot id u lt rasou n d, w h ich is su pposedly m ore specific th an carot id Doppler; m agn et ic reson an ce im aging; an d FFA h elp in diagn osing th e site of occlu sion an d th e progn osis. FFA sh ow s a gen eralized delay in th e dye flow in all th e ph ases of angiogram . Elect rocardiography an d ech ocardiography are in dicated to ru le ou t cardiac causes. ERG sh ow s a dim in ish ed B-w ave respon se.

CRAO w ith durat ion of onset less than 24 hours: Treat as an em ergen cy.

Ocular m assage: Apply direct pressure over the eye digitally or w ith a fundus con - tact lens. The em bolus can lodge dow n, giving a better perfusion to the retina.

Anterior cham ber paracentesis: In t raocu lar pressu re (IOP) is ch ecked before th e procedu re. Topical an esth esia an d a topical an t ibiot ic are given to th e pat ien t .

After w ith draw ing 0.1 to 0.2 m L of aqueous from th e an terior ch am ber th e IOP is rech ecked . Th e procedure is repeated u n t il th e pat ien t’s IOP is n ot less th an 10 m m Hg.

Acetam ide: 500 m g in t raven ou s

Topical drugs: To low er IOP

Carbogen therapy (5%CO2 w ith 95%O2): Carbon dioxide dilates th e ret in al ar terioles. Oxygen in creases th e viabilit y of th e isch em ic t issues. It is given for 10

m in utes ever y 2 h ou rs for 48 h ou rs.

Hyperbaric oxygen: Most usefu l if started w ith in 2 h ou rs of th e episode; 100%

oxygen at 2 at m osph eric absolute provides an arterial PO2 of 1000 to 1200 m m Hg resu lt ing in a th reefold in crease in th e oxygen su pply to th e isch em ic t is-

su es. St u dies sh ow a t w o-lin e im provem en t in 40%of th e pat ien t s subjected to hyperbaric oxygen .

Int raarterial fibrinolysis: Tissu e plasm in ogen act ivator is preferred .

Approxim ately 20%of pat ien t s presen t w ith n ew vessels of iris w ith in a period of 4 to 5 w eeks. To preven t th is com p licat ion th e pat ien t h as to be review ed ever y 2 w eeks after th e episode. If any eviden ce of develop m en t of n ew vessels elsew h ere or n ew vessels at th e disk is n oted, PRP is don e to preven t n eovascular glau com a.

Ocular Ischemic Syndromes

Th is ch ron ic vascular in su fficien cy occurs secon dar y to ath erosclerot ic disease of th e in tern al or com m on carot id ar ter y. Gian t cell arterit is leads to a state of hypoxia to th e ocu lar st ru ct ures, w h ich causes n eovascu larizat ion an d oth er sym p - tom s (Fig. 9.5).

Presentation

Pat ien ts presen t largely in th eir fift ies an d sixt ies w ith t ran sien t obscu rat ion of vision (am au rosis fugax) or w ith gradu al or abru pt loss of vision an d ocu lar pain . An terior segm en t exam in at ion sh ow s sign s of congest ion , an terior uveit is, iris n ew vessels, an d cat aract . Posterior segm en t exam in at ion sh ow s n arrow ing of th e ret i- n al ar teries, dilated ret in al vein s, dot an d blot h em orrh age, cot ton -w ool spots, an d opt ic n er ve or ret in al n ew vessels.

9 Medical Retina 269

Fig . 9.5 Anterior segm ent neovascularization in ocular ischemic syndrome seen on anterior segment fluorescein angiography.

Differential Diagnosis

CRVO, diabet ic ret in opathy, pan uveit is, an d vasculit is

Management

Cardiac w orku p, ESR, an d C-react ive protein (CRP) to exclude gian t cell arterit is, FFA, an d oph th alm odyn am om et r y

Macroaneurysm

Macroan eur ysm is an acqu ired saccu lar dilatat ion of th e large ar terioles of th e ret in a due to w eaken ing of th e ar teriolar w all seen com m on ly in w om en aged 60 to 70 years. Hyper ten sion , arteriosclerosis, an d seru m lipid abn orm alit ies are th e com m on cau ses. Oth er cau ses are radiat ion ret in op athy, ven ou s occlu sive disease, sickle cell, an d diabetes.

Presentation

Pat ien ts presen t w ith an asym ptom at ic, sudden , pain less decrease in vision du e to vit reous h em orrh age, ret in al h em orrh age, or lipid exu dates in to th e m acu la. Th e fun du s sh ow s an eur ysm al dilat ion of ret in al arterioles, circin ate exu dates, h em orrh age, m acu lar edem a, an d serou s ret in al det ach m en t .

Differential Diagnosis

Age-related m acular degen erat ion (ARMD), parafoveal telangiect asis, diabet ic m acu lopathy, ret in al capillar y h em angiom a, BRVO

270 Color Atlas of Ophthalm ology

Management

Evalu ate cardiovascular disease, con t rol hyper ten sion , low er seru m lipids. Fu n dus flu orescein angiograp h ic evaluat ion m ust be don e. Spon t an eou s resolu t ion follow - ing th rom bosis is th e n at u ral cou rse. Lipid exu dates an d h em orrh age th reaten ing th e fovea m ay be t reated w ith argon laser or yellow -dye laser applied arou n d th e an eur ysm . Com p licat ion s in clu de h em orrh age an d occlusion of th e arteriole.

Vitreous Hemorrhage

Vit reous h em orrh age (VH) is th e ext ravasat ion of blood from th e ret in al vessels or n ew vessels in to th e vit reous cavit y. Causes in clu de diabet ic ret in opathy, posterior vit reous det ach m en t (PVD) w ith or w ith out a ret in al break, hyper ten sion , ret in al vein occlu sion , exu dat ive age-related m acu lar degen erat ion (ARMD), proliferat ive sickle cell ret in opathy, t raum a, in t raocular t u m or, an d Eales disease.

Presentation

Pat ien ts exp erien ce a su dden pain less loss of vision , floaters, an d cobw ebs. Den se VH m ay redu ce th e visu al acuit y to th e percept ion of ligh t . On exam in at ion , th ere is n o fun du s view w ith absen t red reflex. Ch ron ic vit reou s h em orrh age h as a ch icken -fat app earan ce ow ing to organ ized blood .

Differential Diagnosis

Oth er causes of sudden loss of visu al acu it y

Management

Ult rason ography is don e w h en th e view of th e fu n dus is obst ru cted by VH. Histor y an d physical exam in at ion are im por tan t , as w ell as exam in at ion of th e oth er eye. If system ically feasible, an t icoagu lan t s an d oth er an t iplatelet agen t s m ay n eed to be stopped . Treat m en t in clu des lim it ing physical act ivit y, bilateral patch ing, an d sleeping in an u prigh t posit ion . Par t ial clearan ce of th e VH w ith som e ret u rn of vision m ay occur over a few m on th s. Pars plan a vit rectom y m ay be requ ired if spon tan eous clearing doesn’t occur.

Angioid Streaks

Angioid st reaks represen t deh iscen ces in th e Br uch m em bran e an d ap pear as dark red ban ds of irregular con tour th at radiate from th e opt ic n er ve h ead . Angioid st reaks are associated w ith Pseudoxanthom a elast icum (Grön blad -St ran dberg syn - drom e), osteit is deform an s (Paget disease), sickle cell an em ia, hyper ten sive cardiovascu lar disorders, an d Eh lers-Dan los syn drom e (Fig. 9.6A,B).

Presentation

Th e pat ien t is asym ptom at ic. St udies repor t th at ch oroid n eovascularizat ion m em bran e (CNV) occurs in 42 to 86%of pat ien ts during follow -u p, w ith m ost eyes