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

7 Lens and Cataract 231

A B

Fig. 7.16 (A) One haptic of the IOL is grasped by an end-gripping 23-gauge micro rhexis forceps (f) passed through sclerotomy wound. The haptic (h) is then externalised under the scleral flap (sf). (B) The second haptic is also externalized in a similar manner.

Fig . 7.17 (A) The haptics are externalized and a 26-gauge needle is taken to create a scleral tunnel. (B) 26-gauge needle is seen making a scleral tunnel near the edge of the flap, parallel to the limbus. (C) The haptic is tucked into the tunnel made with the 26gauge needle. This provides it additional stabilit y.

A B

Fig . 7.18 (A) Reconstituted fibrinogen and thrombin preparation of fibrin glue (FG) injected beneath the scleral flaps. (B) Scleral flaps (arrow) sealed well with the scleral bed.

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Fig . 7.19 Conjunctiva closed with fibrin glue.

described earlier are m ade an d th e lu xated IOL h apt ic is th en grasped w ith th e 23gauge m icro rh exis forceps an d extern alized, t ucked in to th e scleral t u n n el m ade at th e edge of th e flaps, an d th en glu ed un der th e scleral flaps. Th e in fu sion can n ula is th en rem oved . Conjun ct iva is also closed w ith th e sam e fibrin glu e (Fig. 7.19).

Th is tech n ique is u seful in a m yriad of clin ical sit uat ion s w h ere scleral-fixated IOLs are in dicated, such as a lu xated IOL, dislocated IOL, zon ulop athy, or secon d - ar y IOL im plan t at ion . In dislocated posterior ch am ber polym ethyl m eth acr ylate (PMMA) IOL, th e sam e IOL can be reposit ion ed, th ereby redu cing th e n eed for furth er m an ipu lat ion . It can be perform ed w ell w ith a rigid PMMA IOL, IOLs w ith m odified PMMA h apt ics, or m u lt ifocal glued IOLs. On e th erefore does n ot n eed to h ave special scleral fixated IOLs w ith eyelet s or n ew er h apt ic design s. Becau se

Fig . 7.20 Im age of the scleral flap as seen by anterior seg - ment optical coherence tomography on day 1 (above) and well sealed scleral flaps at 6 weeks (below).

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Fig . 7.21 Postoperative anterior segm ent optical coherence tomography showing 360 degrees well-centered intraocular lens at 6 weeks.

th e h apt ic is being placed in its n orm al cur ved con figu rat ion w ith ou t any t ract ion , th ere is n o distort ion or ch ange in sh ape of th e IOL opt ic. Extern alizat ion of th e greater par t of th e h apt ics along it s cu r vat u re stabilizes th e a xial posit ion ing of th e IOL an d th ereby preven ts any IOL t ilt (Figs. 7.20 an d 7.21).

Temporary Haptic Externalization

On e of th e m ost difficult steps of reposit ion ing a dislocated posterior ch am ber IOL is secu ring a sut u re on th e h apt ics. In 1992, Clem en t Ch an first in t roduced th e con - cept of tem porar y h apt ic extern alizat ion to en h an ce th e ease of su t ure placem en t an d ch anged IOL reposit ion ing from an un con t rolled to a h igh ly con t rolled set t ing th at allow s fixat ion of th e dislocated IOL in th e ciliar y su lcu s on a con sisten t basis (Fig. 7.22).

A th ree-port pars p lan a vit rectom y is perform ed for th e rem oval of th e an terior an d cen t ral vit reou s adjacen t to th e dislocated IOL to p reven t any vit reoret in al t ract ion during th e process of m an ipu lat ing th e IOL. Tw o diam et rically opposed lim bal-based part ial-th ickn ess t riangu lar scleral flaps are prepared along th e h orizon tal m eridian s at 3 an d 9 o’clock. Cau terizat ion is don e to preven t any bleeding An terior sclerotom ies w ith in th e beds un der th e scleral flaps are m ade at 1 to 1.5 m m from th e lim bus. As an altern at ive to th e scleral flaps, th e an terior scleroto- m ies m ay be m ade w ith in th e scleral grooves at 1.0 to 1.5 m m from th e h orizon tal lim bu s.

A fiberopt ic ligh t pipe is in serted th rough on e of th e posterior sclerotom ies, w h ile a pair of fin e, n on angled posit ive-act ion forceps (e.g., Griesh aber 612.8, Alcon Griesh aber, Ltd ., Sch affh au sen , SZ) is in ser ted to h old th e IOL an d bring it an teriorly. A forceps is th en passed th rough th e an terior sclerotom y of th e oppos-

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A B

C

Fig . 7.22 (A) A forceps is passed through a sclerotomy made under a scleral flap in the opposite quadrant and one haptic of the dislocated IOL is caught for temporary externalization. (B) A double -armed 9–0 or 10–0 polypropylene suture is tied around the externalized haptic to make a secured knot and it is re -introduced into the vitreous cavit y. The same process is then repeated for the other haptic. (C) The internalized haptics are anchored securely in the ciliary sulcus by taking scleral bites with the external suture needles.

ing quadran t to engage on e h apt ic of th e dislocated IOL for th e tem porar y exter- n alizat ion . A dou ble-arm ed 9–0 (Eth icon TG 160–8 plus, Som er ville, NJ) or 10–0 polypropylen e sut u re (Eth icon CS 160–6, Som er ville, NJ) is t ied arou n d th e extern alized h apt ic to m ake a secured kn ot . Th e sam e process is repeated for th e oth er h apt ic after th e su rgeon sw itch es th e in st ru m en ts to th e opposite h an ds. Th e extern alized h apt ics w ith th e t ied sut u res are rein tern alized th rough th e corresp on ding an terior sclerotom ies w ith th e sam e forceps. Th e in tern alized h apt ics are an ch ored securely in th e ciliar y sulcus by taking scleral bites w ith th e extern al su t u re n eedles on th e lips of th e an terior sclerotom ies. By adjust ing th e ten sion of th e op posing sut u res w h ile t ying th e polypropylen e sut u re kn ot s by th e an terior sclerotom ies, th e opt ic is cen tered beh in d th e p upil, an d th e h apt ics are an ch ored in th e ciliar y sulcus.

Intraoperative Complications

Posterior Capsular Rupture

If a capsular tear does occu r, several steps can h elp m in im ize vit reou s loss. A closed system sh ould be m ain t ain ed by inject ing viscoelast ic before w ith draw ing th e ph aco t ip . Th is h elps to tam pon ade th e vit reou s backw ard w h ere a capsu lar deh iscen ce is presen t . Cor t ical rem oval sh ould th en proceed w ith eith er low in fu - sion or by a dr y tech n ique filling th e ch am ber w ith viscoelast ic m aterial an d us-

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Fig. 7.25 Torn intraocular lens.

Torn Intraocular Lens

An IOL can get torn during im plan t at ion . In such a case it sh ould be explan ted an d replaced (Fig. 7.25).

Postoperative Complications

Corneal Edema after Cataract Extraction

Corn eal edem a after a cataract surger y can be iden t ified im m ediately after th e cataract su rger y. It is best appreciated a few h ou rs after th e cataract surger y. Most com m on causes th at lead to epith elial or st rom al edem a after th e cataract surger y are m ech an ical t rau m a, prolonged in t raocular irrigat ion , in flam m at ion , in creased in t raocular pressu re (IOP), Descem et m em bran e det ach m en t , in t raocu lar toxin s, an d a com p licated cataract su rger y.

Presentation

An associated en doth elial abn orm alit y or decom p en sat ion h as to be ruled out preoperat ively. Th ere is an associated in crease in th e corn eal th ickn ess. An in creased epith elial th ickn ess w ith associated h azy corn ea, irregu lar surface, an d epith elial defect form th e h allm arks of epith elial edem a. Th e th ickn ess ret urn s to n orm al after a few h ou rs of su rger y. St rom al edem a is associated w ith a m arked in crease in th e corn eal th ickn ess, corn eal h aze, an d en doth elial folds involving m ain ly th e cen ter of th e corn ea (Fig. 7.26). Brow n -McLean syn drom e, a clin ical con dit ion arising after cat aract surger y, is ch aracterized by periph eral corn eal edem a w ith a clear cen ter.

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A

Management

As a r ule, if th e corn eal p eriph er y is clear, th e corn eal edem a reduces in a few h ou rs. Cases w ith epith elial edem a requ ire a m edical reduct ion of IOP if th e edem a does n ot resolve in a few h ou rs. A st rom al corn eal edem a p ersist ing for a few days is requ ired to be m an aged w ith hyper ton ic eyedrops an d steroids. A vit rectom y is in dicated in pat ien t s w ith exist ing vit reocorn eal adh eren ce w ith associated cor- n eal edem a. A Descem et m em bran e detach m en t can be h an dled by inject ing air or gas (C3F8 or SF6). Edem a exist ing for m ore th an 3 m on th s u sually requ ires a p en et rat ing keratoplast y.

Hypotony and Wound Leak after Cataract Extraction

Hyp otony due to w ou n d leak after cataract su rger y is a com m on com plicat ion of th e cat aract surger y. Th e leakage can occur from th e in cision site, th e side por t , or th e bleb in cases w ith th e com bin ed t rabecu lectom y su rger y.

Presentation

Wou n d leakage can be picked u p on slit lam p an d by em ploying a Siedel test . Mild to m oderate leaks presen t w ith a sh allow an terior ch am ber, leaking w oun d, irriga- t ion , tearing, con t act len s in toleran ce, in fect ion , an d sign ifican t hypotony. Severe leaks m ay be associated w ith iridocorn eal touch w ith severe corn eal edem a.

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Management

Most of th e leaks are self-lim it ing an d requ ire obser vat ion w ith patch ing an d use of topical an d system ic aqu eou s suppressan ts. Tem porar y redu ct ion of th e topical steroids h elps in prom pter h ealing by in creasing in flam m at ion . In ch ron ic cases use of cyan oacr ylate glu e, sim ple w oun d sut uring, an d an terior ch am ber reform a- t ion w ith salin e or air follow ed by w ou n d sut u ring h elps.

Elevated IOP after Cataract Extraction

An IOP fluct uat ion im m ediately after cataract surger y is a com m on bu t self-lim - it ing p roblem in m ost of th e cases. Reten t ion of viscoelast ic m aterial in th e eye du ring th e su rger y is on e of th e m ost com m on cau ses of p ostop erat ive in flam - m at ion an d IOP rise. Oth er cau ses of in creased IOP after cat aract su rger y in clude pupillar y block, hyph em a, ciliar y block, en doph th alm it is, retain ed len s m aterial, iris pigm en t release, preexist ing glaucom a, use of steroids, an d periph eral an terior syn ech iae.

Presentation

Th e pat ien t u sually com plain s of h azy vision an d pain . Hazy corn eas du e to epith elial or st rom al edem a an d associated an terior ch am ber in flam m at ion are com - m on .

Management

Most of th e cases are m ild an d self-lim it ing an d requ ire on ly m on itoring. A rise in IOP n oted in t raoperat ively can be m an aged by depressing th e low er lip of th e paracen tesis site to evacuate som e of th e fluid out of th e eye. How ever, a sign ifican t an d su stain ed rise in IOP m ay n ecessitate t im ely an d specific m an agem en t of several circu m stan ces. Secon dar y glau com as are h an dled by t reat ing th e u n derlying cau se.

Cystoid Macular Edema after Cataract Extraction

Cystoid m acu lar edem a (CME) is a pain less con dit ion in w h ich cyst ic sw elling or th icken ing occurs of th e cen t ral ret in a (m acu la) an d is u su ally associated w ith blurred or distor ted vision . W h en CME develops follow ing cat aract su rger y an d its cau se is th ough t to be directly related to th e surger y, it is referred to as Ir vin e- Gass syn drom e. Th e Mü ller cells in th e ret in a becom e over w h elm ed w ith fluid, leading to th eir lysis. Th is result s in an accu m ulat ion of fluid in th e ou ter plexiform an d in n er n u clear layers of th e ret in a. Usual cau ses of CME are vascu lar in st abilit y, in t raocular in flam m at ion , an d m ech an ical forces (e.g., epiret in al m em bran e, vitreom acu lar t ract ion ). Th e in ciden ce of CME is 1% after ph acoem u lsificat ion an d 20%after ext ra-capsular cat aract ext ract ion (ECCE).

Presentation

Pat ien ts w ith CME u sually presen t w ith decreased or blurr y vision . Slit-lam p bio- m icroscopy reveals blun ted or irregu lar foveal ligh t reflex, ret in al th icken ing, an d/ or in t raret in al cyst s in th e foveal region . Opt ic disk edem a, epiret in al m em bran e/ m acu lar pu cker, diabet ic ret in opathy, an d uveit is m u st be looked for to rule out oth er causes. On fu n dus fluorescein angiograp hy a pet aloid pat tern of leakage in th e m acu la occurs. Opt ical coh eren ce tom ography (OCT) is h elpful in establish ing a diagn osis an d in m easu ring th e th erapeut ic respon se (Fig. 7.27).

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Fig . 7.28 Aphakic retinal detachment.

th at 20 to 40% of RRDs occur in eyes th at h ave un dergon e cataract ext ract ion . Aph akia an d p seu doph akia, especially after YAG capsulotom y, predispose to p osterior vit reou s det ach m en t (PVD). Previou s st u dies h ave sh ow n th at th e in ciden ce of PVD in creased w ith age an d w ith durat ion of th e aph akia. In pseudoph akic pa- t ien t s, perip h eral capsu lar op acificat ion , len t icular rem n an t s, an d opt ical effects in duced by th e rim of th e IOL m ay im pair visu alizat ion of th e sm all periph eral ret in al breaks by in direct oph th alm oscopy, leading to m issed breaks during su rgical repair.

Presentation

Because m ost postoperat ive ret in al detach m en ts are rh egm atogen ous in n at u re, sim ilar sym ptom s, such as ph otopsias, floaters, visual-field defects, an d cen t ral visu al loss are experien ced by p at ien t s. Th e ret in al breaks are often sm all, difficu lt to visu alize, an d located along th e posterior border of th e vit reous base. RRD is often exten sive an d com m on ly involves th e m acu la. Th e m ost im p or tan t p ostop erat ive factor is YAG capsu lotom y. An terior ch am ber IOL an d iris clip len ses in duce m ore in flam m at ion , resu lt ing in a h igh er in ciden ce of p roliferat ive vit reoret in opathy (Fig. 7.28).

Differential Diagnosis

IOL dislocat ion , lat t ice degen erat ion , an d oth er t ypes of ret in al detach m en t

Management

B-scan u lt rasou n d is th e m ain invest igat ion . As w ith all RRDs, th e goal is to iden t ify an d close all th e ret in al breaks. Vit rectom y w ith fluid -air exch ange, vit rectom y an d scleral bu ckling, an d pn eum at ic ret in opexy are som e of th e t reat m en t m odalit ies.

Endophthalmitis after Cataract Extraction

Postoperat ive en doph th alm it is is defin ed as severe in flam m at ion involving both th e an terior an d p osterior segm en t s of th e eye after in t raocu lar surger y. Typically, postoperat ive en doph th alm it is is cau sed by th e perioperat ive in t rodu ct ion of m i-