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比較眼科21，1－11，2002 Anim． Eye Res．21，1－11，2002

総 説 Review

Exotic Animal

Stacy E． ANDREW and Dennis E． BROOKS

Small Animal Clinical Sciences， Coliege of Veterinary Medicine， University of Florida PO Box 100126， Gainesville， FL 32610－0126， U．S．A．

This paper will serve as a basic overview of exotic merangiotic， since retinal blood vessels are present in a animal ophthalmology． It is not meant to be a complete limited portion of the ． The head of synopsis， but will try and address some of the more the rabbit is located superior and medial to the horizon－ common eye problems recognized in exotic animal spe－ tal midline． Rabbits also lack an organized Iamina cies． The reader is directed to various other more com－ cribrosa and the optic nerve head is thus normally deeply plete texts for additional information． cupped． Rabbits do not have a tapetum lucidum．

RABBITS Ophthalmic Proble〃ls Orbital disease is most commonly associated with Because of its popularity as a pet， the domestic retrobulbar or periorbital abscess， usually associated rabbit（Or），ctolagus cuniculus）is commonly presented with systemic infection such as Pasteurellosis． The pus fbr ocular problems． Rabbits are also very widespread is highly inspissated and dif臼cult to drain。6）With or－ laboratory research animals because they are easy to bital or periorbital abscessation， with ex－ handle， relatively inexpensive， and readily available． posure often occurs． Treatment requires drain－ Ocular lesions of all segments of the eye have been re－ age and systemic antibiotics． Oral antibiotics with pri－ ported in wild， pet and research animals． marily gram－positive spectrum sh皿ld not be used in rabbits because of their fragile gastrointestinal tract Ocular Anato〃ly flora． Establishing drainage may be difficult and dan－ Rabbits have prominent， laterally placed eyes．They gerous due to anatomy of the and prominent or－ have an upper ， a larger and thinner lower eyelid， bital venous sinus． The prognosis for this condition is and a third eyelid or nictitating membrane． Rabbits blink guarded because of the dif且culty in treatment． Enucle－ lO－ 12 times per hour．48）The lacrimal gland（located ven－ ation must be perfbrmed with caution because of the trally behind the lower eyelid and a（lj acent to the lower risk of excessive blood loss． Euthanasia is often chosen orbital rim）， Harderian gland（attached to the lower by owners because of the prognosis．65） medial orbital wall）， and gland of the third eyelid sup－ Bleph輌unctivitis， or in刊ammation and infec－ ply components of the precomeal tear film that are cru－ tion of the eyelid and co句unctiva， is uncommon， but cial to the health of the ．48）Schirmer tear test is may be caused by bacteria or viral myxomatosis．28・38） low（5．30±2．96 mm wetting／60 seconds）．2）The rab－ Clinical signs include swelling and closure of the eye－ bit is somewhat皿ique in having a single nasolacrimal lids and thick mucoid ocular discharge． Chronic cases punctum in the ventromedial conjunctival fornix． The exhibit swelling of the face and genital area， and』sub－ nasolacrimal duct fbllows a tortuous route with several cutaneous tumors can develop． There is a high mortal－ sudden constrictions that are often the site of obstruc－ ity rate associated with infection． has been tion．3）There is also a large venous sinus in each orbit． associated with刀reponema cuniculi， or rabbit syphi－ Rabbits have a shallow anterior chamber， slightly lis．65） is commonly associated with Pas－ oval pupi1， large and poorly developed teu「ella SP．， Staph）710coccus au．reus and Haemophilus

musculature．48）Their retinal vascular pattern is sp・

Recieved：Sep．17，2001 Address reprint requests to：Dr． Dennis E． BROOKS tel：（352）392－4700 fax：（352）392－6125 e－mail：brooksd＠mail．vetmed．ufl．edu Corneal occlusion or aberrant conjunctival over－ neal dystrophy has been reported in Dutch belted rab－ growth is a progressive ingrowth of co可unctival tissue bits．43）Rabbits are susceptible to atherosclerosis and hy－ over the comea．65）Any or all of the cornea can be af－ percholesterolemia induced by high fat diets．22・48）Cor－ fected， and the condition may be unilateral or bilateraL neal lipidosis may occur peripherally or centrally， and The conjunctival tissue is not attached to the cornea． is often associated with a high cholesterol diet． Other Affected animals are not painful and may not have any ocular structures（， ， ）can also be af－ perceptible vision impairmenしThe cause is unknown， fected．22・48） and inflammatory cells are not usually evident on his－ associated with Pasteure〃a multocida sep－ topathologic examination of excised tissue．65｝Surgical ticemia also occurs．65）Many uveitic rabbits have lens－ excision with limbal tacking has been perfbrmed suc－ induced uveitis caused by the protozoan infection En－ cessfully，2・4）but the lesion is likely to refb㎜．32）Tbpical cephalitozoon cuniculi．55）Iris abscessation may be seen therapy with cyclosporine A62）or an antimetabolite such with Pasteurella or Enc‘2phalitozoon． is in－ as mitomycin－C70）may help Prevent recurrence， but herited as a recessive semilethal trait in New Zealand there are currently no docurnented studies on the use of white rabbits．65）Adecreased facility of aqueous out－ these drugs for this condition． flow is seen by 1－3 months， and increased IOP by 3 （inflammation or infection of the months． Comeal edema is the primary clinical lesion， nasolacrimal system）is a very common problem in pet followed by buphthalmos． Medical treatment with and research rabbits． The practitioner must be aware of dorzolamide may be attempted．30）Surgical treatments the unique nasolacrimal duct anatomy of the rabbit in fbr glaucoma include laser cyclophotocoagulation or order to properly diagnose and treat these conditions． enUCIeatiOn．2832） Nasolacrimal duct obstruction and secondary Cata∫acts have been reported in rabbits． Congeni－ can be a sequel to chronic dacryocystitis， rhinitis or tal nuclear and persistent papillary membranes dental disease． The obstruction occurs at sites of natu－ have been reported．21）E． cμniculi， an obligate intracel－ ral narrowing of the nasolacrimal duct． There are two lular microsporidian parasite， is the most frequent cause sites of bending and tapering（proximal maxillary bend， of phacoclastic uveitis and ． The organism most bend at incisor tooth）as well as a small opening to the likely enters the lens in utero and only infrequently nasal cavity．1DPaぷtet〃’ella sp．， Staphylococcus sp．， causes overt cataract．65）However， intralenticular infec－ C121α〃～）；dia sp．， P∫〈eudomonas sp． andルfソxoma virus aエe tion and lens capsule rupture cause a profound the most frequent infectious causes． Clinical signs in． phacoclastic uveitis that can be blinding．69）Recom－ clude serous to mucopurulent ocular discharge with or mended treatment of this condition includes removal without co呵unctivitis． The condition may be chronic of all lens material with phacoemulsification and oral an（Yor recurrent with intermittent response to treatment． albendazole．55） Diagnosis is based on clinical and ocular signs． Fluo－ rescein applied topically to the cornea often fails to pass RODENTS to the nose． It is important to compare affected and normal sides． Inability to flush由e duct is common as well． If也e Rats are common laboratory animals and are also duct can be flushed， it is important to perform culture and kept as pets． Rats have a holangiotic retinal vascular sensitivity of the exudate． Dacryocystorhinography may pattem． There are many genetic mutants fbr ocular dis－ also be performed diagnostically． Treatment includes ease that are specific to a certain strain of rat． Posterior systemic antibiotics determined by culture and sensi－ segment examination requires dilation with l％ tivity． Tbpical antibiotic－colticosteroid solutions reduce tropicamide or 1％atropine． Pigmented rats require 1％ inflammation while controlling infection， and it is im－ atropine and 10％phenylephrine 3－4 doses at 3－5 minute portant to fluorescein stain the cornea to rule out cor－ intervalS． neal ulceration before using topical steroid． Repeated Environmental from ammo－ nasolacrimal flushes at 1－2 week intervals are often rec－ nia buildup in bedding is common． Red tears or ommended．49）Cannulating the duct with small suture chromodacryo皿hea are due to porphyrin secretion from left in place as a stent may be useful but is difficult to the Harderian gland into the tear film， and is a normal perfbrm． physiological process in many rodents．65）If excessive Corneal disease is common in pet and research or associated with stress， it can be caused by rabbits． The Draize eye test is still used in research set－ sialodacryoadenitis（SDA）， which is an epizootic ting， but is becoming less frequen仁It is a grading sys－ coronavirus infection in certain colonies．65）Clinical tem where ocular irritation is quantified based upon signs include exophthalmos， blinking， conjunctivitis， ， conjunctival hyperemia， chemosis and keratitis， keratoconjunctivitis sicca， rubbing eyes with iritis．63）The rabbit eye reacts more intensively than hu－ front legs， epiphora and ． The main man or nonhuman primates to ocular irritants．63）Cor－ differential diagnosis for the excessive tearing is mal－ neal ulceration can be caused by trauma or fbllowing fbrmed or overgrown lower incisor teeth that can ob－ general anesthesia．63）Corneal ulcers are treated with stmct the nasolacrimal duct． Ybung rats have also been topical broad spectrum antibiotics 3－4 times daily as reported to have subepithelial corneal mineralization．65） well as topical autologous serum 3－4 times daily． Cor一 and corneal ulceration］7（）llow一

2 ing prolonged anesthesia is not uncommon． Eyes should sual pupillary light response． The retina is anangiotic， be well lubricated during anesthetic procedures to pre－ and retinal nutrition is accomplished by the choroidal vent this complication．65） vasculature． Birds have a pecten， which is a highly vas－ Cataracts have many experimental causes． Pro－ cular， pigmented structure that protrudes into the vitre－ longed non－closure of the during anesthetic pro－ ous and sits over the optic nerve． Over 30 fUnctions have cedures alters the aqueous humor and causes reversible been attributed to the pecten， but its absolute function lens opacities by dehydration． These cataracts occur remains unknown． Excellent review a由cles about avian fairly frequently when rats are anesthetized but are re－ ophthalmic examination：and ocular problems have re－ versible if anesthesia is of a short duration．20）Retinal cently been published．66・67） phototoxic can be induced by housing con－ ditions．65）Animals housed in cages on top shelves of Ophthalmic Probte〃zs facilities may be subject to light induced damage． There Congenital ocular problems reported most fre－ are also numerous retinal disease experimental models． quently in avian species include microphthalmos in rap－ The Royal College of Surgeons（RCS）rats have a he－ tors 12）and cryptophthalmos in cockatiels．13）PeriorbitaI reditary retinal degeneration and were the first lab ani－ （infraorbital）sinusitis occurs in psittacines and passe－ mal species used for retinal reseach．65） rines and can be caused by fUngi（particularly Asp〈～rgil－ Hamsters also possess a holangiotic retinal vascu－ lus）and bacteria（Chlamソdia andルfycoρlas〃za）． Sinusi－ lar pattern． They have been reported to have inherited tis can be a sequela to chronic upper respiratory tract microphthalmos or ．65）Guinea Pigs have disease．47）The main clinical sign is exophthalmos． The an anangiotic retina． All retinal nutrition is provided by disease frequently leads to keratoconjunctivitis and self－ the choroid． They have been reported to have several trauma． Macaw si皿sitis is a distinct type of sinusitis ophthalmic problems． Blepharitis can be caused by that results in sinking of the eyes into the orbiL26）Clini－ mites． Animals with、Pasttterella can cally it appears as a copious thick， mucoid to mucopu－ present with a profbund white ocular discharge．65）Con－ rulent discharge廿om the sinuses． E． coli， Klebsie〃o， junctivitis may be caused by Chlamydia sp．， Salmonella Pseudo〃lonas and Hemophilas have been cultured． sp・， Listeria monocytogenes or vitamin C deficiency．65） Treatment includes systemic antibiotics and daily si－ Heterotopic bone fbrmation or osseous metaplasia in nus flushing． Recovery is usually complete after two the ciliary body and iridocomeal angle， which may be weeks of vigorous treatment． A similar condition that related to the concentration of ascorbic acid in the guinea ls not responslve to therapy is observed in Amazons pig aqueous humor， is not uncommon．8）Cataracts are and cockatoos． Lacrimal sac abscesses are seen as an also seen in guinea pigs．」Ferrets may present with se－ area of swelling anteroventral to the medial canthus．26） rous to mucopurulent conjunctivitis due to canine dis－ This condition may be confused with periorbital ab－ temper or systemic salmonellosis．65）They frequently scesses． The cause is unknown， but it usually accompa－ have exoph中almos with lymphoma， as the orbit is com－ nies or fbllows sinusitis in psittacine birds． Treatment monly affected．34）The exophthalmos may be difficult with daily flushing and adequate topical and systemic to apPreciate early in the disease process because of the antibiotics， determined by culture and sensitivity， is of－ relatively deep orbit in ferrets． Anterior uveitis most ten required． frequently occurs secondary to trauma or corneal ul－ Eyelid diseases occur fairly丘equently in birds． ceration．42）Other causes of uveitis such as infection and Traumatic lacerations are the most common eyelid dis－ neoplasia probably occur in ferrets， although the diag－ order seen in raptors． Avian ocular dermoids and eyelid nosis and treatment are not currently reported in the agenesis are infrequently reported． Knemidokoptes mite literature． Ferrets have also been reported with corneal infection causes skin Iesions involving the periorbital dermoids， glaucoma and cataracts．42・65） area，40）Chronic infestation results in hyperkeratosis with build up of keratin and sebaceous material． Diagnosis AVIAN is by direct observation of the mite following skin scrapings． O」CySpirura is a nematode that may be found Ocutar Anatomy behind the nictitating membrane or in the conj unctival Avian eyes are relatively and absolutely large． Birds sac and lacrimal duct of birds， resulting in conjunctivi－ have scleral ossicles（10－18）that help maintain the var－ tis and blepharitis．40）Mite and nematode infections are ied shape of the （tubular， globose or flat）．31）The usually treated with systemic ivermectin． Nictitating iris and ciliary body contain striated muscle which membrane disorders have been reported in l 6 birds and makes pupil dilation di］fficult． Pupil dilatation with topi－ included trauma（7 birds）， neoplasia（3 birds）， inHam－ cal vecuronium has produced consistent in mation（3 birds）， and mineralization（3 birds）．29） psittacine species， with the fewest side effects of Keratoconjunctivitis is an important disease com－ mydriatics tested．36・50）Birds must be closely monitored plex in birds． Normal avian conjunctival fomix bacte－ during administration of these drugs because they are rial flora has been determined in captive cranes，41）psit－ absorbed systemically and may cause cessation of tacines，71）and captive exotic birds．68）Gram－positive or－ breathing． The optic nerve has lOO％decussation at the ganisms are more commonly isolated than gram－nega－ optic chiasm， consequently there is usually no consen一 tive organisms in most cases． Infectious keratitis and

3 co可unctivitis are frequently reported in pet and wild Pseudomonas spP． is probably related to poor husbandry birds． Mycoplasmal co句unctivitis in house丘nches has with overcrowding． Comeal trauma（other birds， fenc－ recently been reviewed．23）Poxvirus causes caseous ing）followed by environmental infection is theorized． plaques of the eyelids and severe exudative conjunc－ Severe keratomalacia with secondary uveitis， globe rup－ tivitis with edema and ulceration， and severe infections ture and panophthalmitis are common． Diagnosis is can result in pneumonia and death．40｝Many species of based on culture and sensitivity， cytology with gram birds have been reported to be infected with poxvirus： stain and fluorescein stain． Treatment with topical fbr－ canary， conure， mynah， parrot， peacock， pheasant， pi－ tified antibiotics based on culture and sensitivity and geon， quail， raptor， and swan．3DTreatment includes pre－ autologous serum are recommended， and systemic an－ vention of secondary bacterial or fungal infections as tibiotics are used if the eye is ruptured． If a large area is well as supPortive care． Periocular lesions may be involved and there is obvious necrotic cornea， keratec－ treated with baby shampoo wash and chloramphenicol tomy with partial tarsorrhaphy may give better and omtment． Systemic vitamin A has been shown to be of quicker results． Sequelae include corneal scarring， glau－ some benefit．40｝Chlamydial and bacterial co可unctivi－ coma， and blindness from panophthalmitis． tis have been reported in birds． Lovebird is Amazon parrots with punctate keratitis have bilat－ asevere and highly fatal systemic disease．26）Affected eral mild blepharospasm and serous ocular discharge．40） lovebirds present clinically with depression， blephari－ No treated group has shown a significant improvement tis， co可unctivitis（serous ocular discharge）and weight over untreated control， but treatment is recommended loss． It is stress related（developing symptoms l to 2 f（）rbhlds with geographic comeal disease and those with weeks after stress such as shipping）and carries a poor concurrent sinusitis．40）Most cases improve without treat－ prognosis even in birds that receive supportive medical ment in l to 2 weeks．40）Mild residual blepharospasm treatment． may be evident for several weeks to months． Hypovitaminosis A can cause keratoco勾unctivi－ Uveitis occurs mainly in turkeys with／Aspergillus tis sicca or dry eye， blepharitis and ocular discharge fumigatus infection，46）but can also occur in birds with secondary to bacterial or fUngal infbction．67）Cockatiel infectious avian bronchitis or avian encephalomyelitis． conjunctivitis affects white or albino mutations of cock－ Panophthalmitis and conjunctivitis has also been re－ atiels．26）Blepharitis， serous ocular discharge， swelling ported in canaries infected with toxoplasmosis． Buph－ and protrusion of the from under the lids thalmia and glaucoma occur in chickens and turkeys are seen clinically． It may also be associated with upper with exposure to continuous light（fluorescent or in－ and lower respiratory tract infections．Treatment with candescent）or continuous dark conditions． There is also topical antibiotic ophthalmic preparations and systemic arelationship with increased glycine in diet． The slate chlortetracycline or doxycycline is recommended be－ turkey is a genetic line of turkeys with glaucoma．18） cause of a possible association withルtycoplasma in－ Cataracts due to numerous causes have been re－ fection．26）Recurrence is common． Chronic conjunctivitis ported in several bird species．lo）Penguins have been in Amazon Pa∬ots may be associated with upper respi－ reported to have nutritional cataracts． Ducks have nu－ ratory tract infbction and sinusitis．40）The conjunctiva tritional and toxic fOrms of cataracts．35）Canaries have becomes edematous， inflamed and infiltrated． Chronic an inherited form of cataract，52）and aged birds often or intermittent comeal ulcers may also be present． Treat－ have Iens lesions（cataract， nuclear sclerosis）． Trauma ment with topical broad－spectrum antibiotics with or is the most common cause of cataracts and lens lux－ without corticosteroid is indicated， depending on the ation in raptors．17）Phacoemulsification is routinely per－ absence or presence of comeal ulcers．40）Sometimes sur－ formed in pet birds and some raptors following evalua－ gical removal of excessive conjunctival tissue is re－ tion of the retina by ultrasound and electroretinogra－ quired． phy．10・27）Cataractous lenses in some birds may sponta－ Comeal diseases are fairly common in birds． My－ neously resorb．45〕 cobacterial keratitis has been reported in several spe－ Retinal disease is not appreciated very commonly cies， including a parrot．54）Inherited avian in pet and companion birds． However， there is an inher・ is a model fbr keratoconus in human beings．61）Fungal ited retinopathy causing blindness in the Rhode Island mynah bird eye disease occurs due to comeal scratches Red chicken．58）Retinal detachment， vitreal hemorrhage， during shipping．26）Keratitis is observed within a week and pecten tears fbllowing trauma are common poste－ and ranges from mild corneal edema to complete cor－ rior segment abnormalities related to ocular trauma in neal opacity with subsequent scarring． Chronic kerato－ raptors．17） conjunctivitis is a frequent sequela to the keratitis syn－ If ocular injury is severe enough or the avian eye drome． Large masses of infiltrated co可unctiva under painful en卯gh to warrant enucleation， care must be lower eyelid and corneal vascularization are fb皿d on taken in planning the surgical apProach depending on examination， and the entire comea is often ulcerated．26・40） the anatomical features of the species． In owls， both Systemic aspergillosis has been fbund in some chroni－ globe－collapsing and transaural techniques have been cally affected birds．26） case reports have described・44）For other bird species the globe－collaps－ been reported in many species of birds． ing procedure is recommended， although histopathol－ Infectious keratitis in ostriches caused by ogy is lost．

4 FISH conus papillaris， which is a vascular tuft overlying the optlc nerve． A recent article reviewed normal ocular anatomy， examination techniques and ocular disorders of fish．an） Snakes Corneal disorders including ulcers，opacification， para－ Microphthalmos and anophthalmos are uncom－ sitic infection， and nutritional deficiencies are not un－ mon in snakes， but have been reported．37・40）Orbital ab－ common in fish．64）Cataract fbrmation may affect the scesses caused by Pseudomonas spP． or E．coli have animals ability to find food， and surgical removal has been reported in snakes．37・40）Affected animals present been successfu1．64）Causes of fish cataracts include lens with exophthalmos， and surgical drainage is usually invasi皿by Trematode larva（Diplostoma Spathecum） required．40） in trout．3）Gas bubble disease may also result in cataract Retained spectacle is a common problem in formation．53）Cold water fish maintained in warm water snakes．31・40）This refers to an abnormal shedding or will develop cataract formation．60）Nutritional causes of ecdysis in which the spectacle covering the cornea is fish cataracts include deficiencies of zinc， methionine， not shed with the remainder of the skin and remains in riboflavin and tryptophan．5・15’6”） The hepatic carcinogen place． Over several months， a thick layer of old spec－ thiacetarsamide is a toxic cause of fish cataracts．59）UI－ tacle accumulates， putting Pressure on the comea be－ traviolet light can also induce cataracts． neath． The etiology is thought to be low humidity in There are also many systemic diseases with ocu－ environment， inadequate nutrition， or systemic disease． lar manifestations in fish． They are often bilateral and Conservative treatment is usually recommended fbr affected animals may present with other signs．64）Ex－ multiple reasons．40）The owner should be instructed to ophthalmos may be seen with gas bubble disease；in－ moisten the snake frequently and wait for next shed if fection with bacteria， fungus， virus， protozoa or the spectacle is tightly adhered． Do not remove the spec－ metazoa；and neoplasia．〔id） tacle if it is tightly adhered because the new spectacle may also be removed inadvertently， resulting in expo－ MARINE MAMMALS sure keratitis and eye Ioss． Prevention of the problem is desirable． Increase environmental humidity and en－ The eyes of marine mammals are difficult to ex－ sure that the animal is well hydrated． Soak the spec－ amine because of the general problems with immobili－ tacle with water or saline to loosen it， and possible zation as well as their thick eyelids．24）Pinnipeds in cap－ manually remove the retained spectacle with small fbr－ tivity are often found to suffer from conjunctivitis and ceps． It is helpful apply a thick layer ophthalmic oint－ ulcerative keratitis． Corneal edema is reported fre－ ment several times a day fbr 3－5 days prior to trying quently， and may be due to confinement in fresh water removal． versus saltwater tanks， trauma， ultraviolet light expo－ Subspectacular abscess is also a fairly common sure， and brightly colored containment walls have all problem in snakes， and may be seen unilaterally or bi－ been speculated as causative factors．31）Sometimes， ad－ laterally． The etiology is uncertain， but frequently bac－ ministration of a topical hyperosmotic ointment（5％ terial in origin． Pseudomonas sp． is sometimes isolated． sodium chloride）will lessen or relieve comeal edema Penetrating injuries to the spectacle， ascent or bacteria in pinnipeds． Comeal scars are the most frequent ocu－ through the nasolacrimal duct from the mouth， or he－ lar lesion fbllowed by prominent lens sutures， cataracts matogenous extension of systemic disease have all been and iris depigmentation in Northem fur seals．56）Harbor proposed as theories．40）Observed clinical signs include seals have been reported to have cataracts（21／44 ani－ an exudates underneath the spectacle as well as cloud－ mals）， the cause of which was not determined．51）Cata－ ing and bulging of the spectacle． Treatment consists of ract extraction， while diflfTicult to perform， may be con－ controlling the underlying disease as well as perfbrm－ sidered in captive pinnipeds that depend on heavily on ing a ventral 30°wedge excision of the spectacle， cul－ their vision．19） turing the abscess material， and flushing with sterile isotonic saline．37・40）Gentocin ophthalmic ointment is REPTILES often applied 3－4 times daily if Pseudomonas spp． in－ fection is present． Ocular Anatomy Bulging of the spectacle is caused by an accumu－ The eyes of most reptiles are similar． Reptiles also lation of clear fluid in subspectaclar space． It is usually have hyaline cartilage in the anterior sclera， and stri－－ caused by oral cavity inflammation with blockage of ated iris musculatUre similar to birds． Some reptiles have the nasolacrimal duct or congenital absence of a naso－ well developed eyelids with the lower lid being more lacrimal drainage system．40）Differential diagnoses in－ movable． Snakes do not possess eyelids but instead have clude glaucoma and hydrophthalmos． An oral exami－ aspectacle， which is a fusion of clear eyelids， which nation should be perfbrmed to rule out stomatitis with lies anterior to the cornea． Most reptiles， except for blockage． Spontaneous resolution may occur， or surgi－ snakes， have a rapidly moving nictitating membrane． cal treatment such as spectacle wedge excision or Nasolacrimal ducts are reported to be absent in turtles． conj皿ctivoralostomy may be necessary．39’40） Reptiles have an avascular retina． Some reptiles have a Cataracts can occur and they may be皿ilateral or

5 bilateral， and congenital or acquired． They are most of－ can Veterinary Conference，821－823． ten diagnosed in older captive snakes．40）Acquired cata－ 7）Bonney， C．H．， Hartfiel， D．A．， and Schmidt， R．E． racts may also be caused by ocular penetrating trauma （1978）：Klebsiella pneumoniae infection with sec－ or persistent anterior uveitis． Posterior segment disease ondary in tokay gecko lizards．」． A〃z． Vet． ls reported uncommonly in snakes． Med． Assoc．，173：1115－1116． 8）Brooks， D．E， Ginn， PE， Miller， T．R．， et al．（1994）： Turtles Ocular fibropapillomas of green turtles（Chelonia Vitamin A deficiency or hypovitaminosis A is a mydas）．レ2τ．」Path．，31：335－339．

problem in young growing turtles fed a high protein 9）Brooks， D．E．， McCracken， M．D．， and Collins， B．R． diet of mostly insects and meatJnappropriate diet causes （1990）：Heterotopic bone formation in the ciliary squamous metaplasia of the renal， gastrointestinal and body of an aged guinea pig． Lab」Anim． Sci．，40：88－

respiratory epithelia， as well as the orbital glands． Clini－ 90．

cal signs in af飴cted turtles include orbital and eyelid 10）Brooks， DE．（1997）：Avian cataracts． Sem． Au Exot． edema， purulent ocular discharge， and secondary kera－ Petルled．，6：131－137．

toco可unctivitis and blepharitis．31）Treatment includes 11）Burling， K．， Murphy， CJ．， da Silva Curiel， J．， et al． improving the diet by feeding commercial trout pellets， （1991）：Anatomy of the rabbit nasolacrimal duct and dog fbod， or adding cod liver oil．31）Infectious kerato－ its clinical implications． Vet． Comρ． Ophthalmot．，

co可unctivitis is related to poor environmental housing 1：33－40．

conditions． The main differential diagnosis is infectious 12）Buyukmichi， N．C．， Murphy， CJ．， and Schulz， T． keratoconjunctivitis・Pasteurella spP． is frequently in－ （1988）：Developmental ocular disease of raptors．」． volved・Salmonellosis can also cause co可unctivitis． Wild． Dis．，24：207－213． Owners should be instructed to clean housing（bowl， 13）Buyu㎞ichi， N．C．， Murphy， CJ．， Paul－Mu叩hy，」．， tank）more frequently． et al．（1990）：Eyelid malfbrmation in fbur cockatiels． Herpesvirus infection or Grey patch disease is an 」．Am． Vet．ルled． Assoc．，196：1490－1492． ulcerative skin lesion， often observed periocularly in 14）Cooper， J．E．， McClelland， M．H．， and Needham， J．R． Green sea turtles（Chelonia mydaぷ）．25・33・40）It can be quite （1980）：An eye infection in laboratory lizards associ－ severe with comeal papillomas that are blinding．9・37） ated with an Aeromonas sp． Lab． Anim．，14：149－151．

15）Cowey， C．B．， Cho， C．Y， Sivak， J．G．， et al．（1992）： 、Lizards Methionine intake in rainbow trout（Oncorhynchus Most reports of ocular disease in lizards are case mykiss）， relationship to cataract fbrmation and the reports． A fluctuant swelling of the eyelid of a chame－ metabolism of methionine．」．」V協κ，122：1154－1163． leon caused by a nematode has been reported．57）Con－ 16）Cullen， A．P， Monteith－McMaster， C．A．， and Sivak， junctivitis is infrequent but may be caused by J．G．（1994）：Lenticular changes in rainbow trout fbl－ Aeromonas liquefaciens or 1）seudomonas sp．14・37）Uvei－ lowing chronic exposure to UV radiation． Curn Eye tis and hypopyon caused by respiratory infection with Res．，13：731－737． Klehsie”a 1フ12（？unzonia《3 and subspectacle infection 17）Davidson， M．（1997）：Ocular consequences of caused by Protetイ∫sp． in Tbkay geckos have been re－ trauma m raptors． Sem．、4v． Exot． petルfed．，6：121－ ported．7・37） 130． 18）de Kater， A．W．， Smyth， J．R Jr．， Rosenquist， R．C， REFERENCES et aL（1986）：The Slate turkey：amodel for second－ ary angle CIOSUre glaUCOma． Invest． Ophthalmol． Vis． 1）Abrams， K．L．，Brooks， D．E．， Funk， R．S．， et al．（1990）： Sci．，27：1751－1754． Evaluation of the Schirmer tear test in clinically nor－ 19）Dutton， A．G．（1991）：Cataract extraction in a fur mal rabbits．んη．」． Vet． Res．，51：1912－1914． seal．」． A〃z． Vet．ルled． Assoc．，198：309－311． 2）Arnbjer， J．（1979）： in a pygmy rab－ 20）Fraunfelder， FT． and Bums， R．R（1970）：Acute re－ bit． Vet．ルled．∫ノη、 Aninz． Clin．，74：737－738． versible Iens opacity：caused by drugs， cold， anoxia， 3）Ashton， N．， Brown， N．， Easty， D．（1969）：Trematode asphyxia， stress， death and dehydration． Exp． Eye cataract i吐esh water丘sh．・」．・Sm． Anim． Pract．，10： 1～es．，10：19－30． 471－478． 21）Gelatt， K．N．（1975）：Congenital cataracts in a litter 4）Bagley， L．H． and Lavach， D．（1995）：Ophthalmic dis－ of rabbits．」． A〃z． Vet．ルled． Assoc．，167：598＿599． eases of rabbits． Cal． Vet．，49：7－9． 22）Gwin， R．M． and Gelatt， K．N．（1977）lBilateral ocu－ 5）Barash， H．， Poston， H．A．， and Rumsey， G．L．（1982）： lar lipidosis in a cottontail rabbit fed an all－milk diet．

Differentiation of soluble proteins in cataracts caused ／．Am．レとτ．ルled． A∫ぷoc．，171：887－889． by deficiencies of methionine， riboflavin or zinc in 23）Hartup， B．K．， Kollias， G．V．（2000）：Mycoplasmal diets fed to Atlantic salmon， Salmo salar， rainbow conjunctivitis in wild house finches． Comp． Cont． trout， Salmo gairdneri， and lake trout， Salvelinus Educ．1）ract． Vet．，22：1001－1005． namaycush． Corne〃Vet．，72：361－371． 24）Hirst， LW．， Stoskopf， M．K．， Graham， D．， et al． 6）Bennett， A．（1999）：Management of abscesses of the （1983）：Pathologic findings in the anterior segment head in rabbits． In Proceedings of the North Ameri一 of the pinniped eye．」． A〃1． Vet．ルled． Aぷぷoc．，

6 183：1226－1231． K．N． ed．）。680－705．Lea＆Febiger， Philadelphia． 25）Jacobson， ER．， Gaskin， J．M．， Roelke， M．， et al． 41）Miller， PE， Langenberg， J．A．， and Hartman， FA． （1986）：Conjunctivitis， tracheitis， and pneumonia （1995）：The normal conjunctival aerobic bacterial associated with herpesvirus infection in green sea flora of three species of captive cranes．」． Zoo Wild． turtles．」． Am． Vet．ルled． Assoc．，189：1020－1023． ルfed．，26：545－549． 26）Karpinski， L．G． and Clubb， S．L．（1986）：Clinical 42）Miller， PE（1997）：Ferret ophthalmology． Sem． Au aspects of ophthalmology in caged birds． In Cun’ent Exot． Petルted．，6：146－151． Veterinary Therapy IX．（Kirk， R．W．， et al． ed．）．616－ 43）Moore， C．P， Dubielzig， R．， and Glaza， S．M．（1987）： 621．WB． Saunders Co．， Philadephia． Anterior of American Dutch belted 27）Kem， T．J．， Murphy， C．J．， and Riis， R．C．（1984）：Lens rabbits：biomicroscopic and histopathologic findings． extraction by phacoemulsification in two raptors．」． Vet． Path．，24：28－33．

Am． Vet．ルfed． Assoc．，185：1403－1406． 44）Murphy， CJ．， Brooks， D．E， Kem， TJ．， et al．（1983）：

28）Kern， T．J．（1989）：Ocular disorders of rabbits， ro－ Enucleation in birds of prey．」．んn． Vet．ルTed． A∬oc．， dents， and ferrets． In Current Veterinary Therapy X， 183：1234－1237． （Kirk， R．W．， et al． ed．）．681－685．WB． Saunders Co．， 45）Ofri， R． and Horowitz， L（1995）：Spontaneous cata－

Philadelphia． ract resorp“on ln an ostrich． Vet． Rec．136：276． 29）Kern， T．J．， Paul－Murphy， J．， Murphy， C．J．， et aL 46）Olson， L．D．（1981）：Ophthalmia in turkeys infected （1996）：Disorders of the third eyelid in birds：17cases． with Pasteurella multocida． Av． Dis．，25：423－430． 」二Av．ルfed． Surg．，10：12－18． 47）Pass， D．A． and Riddell， C．（1987）：Chronic rhinitis 30）Kern， TJ．（1997）Rabbit and rodent ophthalmol－ and sinusitis in budgerigars（Melopsittacus ogy． Sem．／lv． Exot． Petルfed．，6：138－145． undulatus）．Aソian Dis．，31：425－427． 31）Kenl， TJ．（1999）：Exotic animal ophthalmology． In 48）Peiffer， R．L， Pohm－Thorsen， L．， and Corcoran， K． Veterinary Ophthalmology，3rd． ed．（Gelatt， K．N． ed．）． （1994）：Models in ophthalmology and vision re－ 1287－1305．Lippincott Williams＆Wilkins， Phila－ SearCh． ln The BiOIOgy Of the LabOratOry Rabbit．2nd． delphia． ed．（Manning， PJ．， et al． ed．）．409－433． Academic 32）Kirschner， S．E．（1997）：Ophthalmologic diseases Press， Inc．， San Diego． in small mammals． In Ferrets， Rabbits， and Rodents． 49）Petersen－Jones， S．M． and Carrington， S．D．（1988）： Clinical Medicine and Surgery．（Hillyer， E．V．， et aL Pasteurella dacryocystitis in rabbits．レlet． Rec．， ed．）．339－345．WB． Saunders Co．， Philadelphia． 122：514－515． 33）Lackovich， J．K．， Brown， D．R．， Homer， B．L．， et aL 50）Ramer， J．C．， Paul－Murphy，」．， Brunson， D．， et aL （1999）：Association of herpesvirus with （1996）：Effects of mydriatic agents in cockatoos， fibropapillomatosis of the green turtle Chelonia A丘ican gray parrots， and Blue－fronted Amazon par－ mydas and the loggerhead turtle Caretta caretta in rots．」． Am． Vet．ルled． Assoc．，208：227－230． Florida． Dis． A4uat． Organ．，37：89－97． 51）Schoon， H．A． and Schoon， D．（1992）：Lenticular 34）McCalla， T．L， Erdman， S．E．， Kawasaki， T．A．， et al． lesions in harbour seals（Phoca vitulina）．」． Comp． （1997）：Lymphoma with orbital involvement in two Path．，107：379－388．

ferrets． Vet． Co，ηρ． Ophthalmol．，7：36－38． 52）Slatter， D．H．， Bradley， J．S．， Vale， B．， et al．（1983）：

35）Meteyer， C．U， Dubielzig， R．R， Dein， FJ．， et al． Hereditary cataracts in canaries．」． Am． Vet．ルfed． （1997）：Sodium toxicity and pathology associated Assoc．，183：872－874． with exposure of waterfbwl to hypersaline playa lakes 53）Speare， DJ．（1990）：Histopathology and ultrastruc－ of southeast New Mexico．」肱Diα8． Invest．，9：269－ ture of ocular Iesions associated with gas bubble dis－ 280． ease in salmonids訊Comp． Path．，103：421－432． 36）Mikaelian，1．， Paillet，1．， and Williams， D．（1994）： 54）Stanz， K．M．， Miller， PE．， Cooley， AJ．， et al．（1995）： Comparative use of various mydriatic drugs in Mycobacterial keratitis in a parrot．」．んn． Vet．ルled． kestrels（Falco tinnunculus）． A〃z．」． Vet． Res．，55：270－ Assoc．，206：1177－1180． 272． 55）Stiles， J．， Didier， E， Ritchie， B．， et al．（1997）：En－ 37）Millichamp， N．J．， Jacobson， E．R．， and Wolf， E．D． cephalitozoon cuniculi in the lens of a rabbit with （1983）：Diseases of the eye and ocular adnexae in phacoclastic uveitis：con丘rmation and treatment． Vet． reptiles． J． Am． Vet．ルted．．Assoc．，183：1205－1212． Comp． Ophthalmol．，7：233－238． 38）Millichamp， N．J． and Collins， B．R．（1986）： 56）Stoskopf， M．K．， Zimmerman， S．， Hirst， L．W．， et al． Blepharoconjunctivitis associated with Staphylococ－ （1985）：Ocular anterior segment disease in northern cus aureus in a rabbit．」． Am．レ診τ．ルled． Assoc．， fUr seals．ヱAm． Vet．ルled． Assoc．，187：1141－1144． 189：1153－1154． 57）Thomas， C．L， Artwohl， J．E， Pearl， R．K．， et al． 39）Millichamp， N．J．， Jacobson， E．R．， and Dziezyc， J． （1996）：Swollen eyelid associated with Foleyella sp （1986）：Conjunctivoralostomy for treatment of an oc－ infection in a chameleon．」．んn． Vet．ルfed． A∬oc，， cluded lacrimal duct in a blood python． J．んn． Vet． 209：972－973． Med． Assoc．，189：1136－1138． 58）Ulshafer， RJ．， Allen， C．， Dawson， W．W．， et al． 40）Millichamp， N．J．（1991）：Exotic animal ophthal－ （1984）：Hereditary retinal degeneration in the Rhode mology． ln Veterinary Ophthalmology，2nd． ed．（Gelatt， Island Red chicken．1． Histology and ERG． EXp． Eye

7 Res．，39：125－135． 59）Vbn Sallmann， L， Halver， JE．， and Collins， E．， et al．（1966）：Thioacetamide－induced cataract with in－ vasive proliferation of the lens epithelium in rain－ bow trout． CancerRes．，26：1819－1825． 60）Wata， S．（1985）：Effect of temperature on the rain－ bow trout lens． Curn Eye Res．，4：441－446． 61）Whitley， RD．， Garcia A．， Samuelson D．A．， et al． （1987）：Histology of keratoconus in the chicken rnodel． Invest． OphthalmoZ． Vis． Sci．，29：29． 62）Whitley， R．D． and Gilger， B．C．（1999）：Diseases of the canine comea and sclera． In Veterinary Ophthal－ mology，3「d． ed．（Gelatt， K．N． ed．）．635－673． Lippincott Williams＆Willdns， Philadelphia． 63）Wilhelmus， K．R．（2001）：The Draize eye test． Surv． Ophthalmol．，45：493－515． 64）Williams， CR． and Whitaker， B．R．（1997）：The evaluation and treatment of common ocular disor－ ders in teleosts． Sem． Av． Exot． Petルfed．，6：160－169． 65）Williams， D．L．（1999）：Laboratory animal ophthal－ Inology． In Veterinary Ophthalmology，3「d． ed．（Gelatt， KN ed．）．1209－1236． Lippincott Williams＆Wilkins， Philadelphia． 66）Willis， A．M． and Wilkie， D．A．（1999）：Avian oph－ thalmology， part 1：anatomy， examination， and diag－ nostic techniques．」二Av．ルled． Surg．，13：160－166． 67）Willis， A．M． and Wilkie， D．A．（1999）：Avian oph－ thalmology， part 2：review of ophthalmic diseases． J． Av．ルted． Surg．，13：245－252． 68）Wolf， E．D．， Amass， K．， and Olsen， J．（1983）：Sur－ vey of conjunctival flora in the eye of clinically nor－ mal， captive exotic birds．」． Am． Vet．ル1ed． A∬oc．， 183：1232－1233． 69）Wolfer， J．， Grahn， B．， Wilcock， B．， et al．（1993）： Phacoclastic uveitis in the rabbit． Vet． ComJフ． （）phthalmol．，3：92－97．

70）Yata， S．， Hara， H．， Kitano， H．， et al．（1995）：Treat－ ment of a rabbit with pseudosymblepharon．」． Jap． Vet． Med． Assoc．，48：335－337． 71）Zenoble， R．D．， Griffith， R．W．， and Clubb， S．L． （1983）：Survey of bacteriologic flora of conjunctiva and cornea in healthy psittacine birds．Am．」． Vet． Res．， 44：1966－1967．

8 ivr一否」 、

是・ Fig． 2 Corneal occlusion or overgrowth of aberrant conjunctiva is seen in the left eye of this young adult New Zea］and white rabbit．

j 肇 ▲＿、，｛

・ ．．．’．…．．．．．．．－．．i．

ニ t ’ i．』’．．．1’・；．』．胆．「1・1．．’．∴・．∴．．．、．1ジ．1：㌧1 ， tt

．∋’ 一 ． ， r1 －’ － Fig．1Retrobulbar abscess behind the right eye of this adult New Zealand white rabbit． Treatment by surgical drainage and systemic antibiotics was attempted prior to enucleation．

Fig．31）acryocystitis in the rabbit is often treated by cannulation the single yentral nasolacrimal punctum and flushing of the nasolacrimal system．

Fig．4Asuperficial， non・infected Fig．5Uveitis and iris abscessation are pmsent in the following general anesthesia is seen in this middle right eye of this rabbit． The organisms Pas旋mrella or aged lop rabbit． Encephaltrozoo〃are・Often・inCriminated．

Fig．6 A hypermature cataract With anterior lens Fig．7 Mature cataract formation in a young albino capsule rupture in a rabbit determined by rat． The cause is unknown． polymerase chain ieaction testing to have E．cuniculi．

9 Fig．9The left eye of an adult guinea pig with cataract and heterotopic bone formation． The other eye was similarly affected．

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Fig． 8 White ocular discharge is often observed in guinea pigs with PastuereUa dacryoadenitis．

工日∵匡L ° ． （Photograph courtesy of Dr． Darryl Heard．） ．㍉、．」 O

ぽ 聾 演薇． 一・tt，t・i． ．11憧

ノ’ ，1．‘ 斗 ，、．ー

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lr プ 継1 ．． ． ．川

． ゴ i べ 9 、ン ， ’ i ・ ご﹈ ’ ． ㍉ S． Fig．10 Right・sided infraorbital sinusitis in a 這 domestic chicken．（Photograph courtesy of Dr． ．二≡

‘ ．2．． Darryl Heard．） ト． ． ． ． ． 一一 ；4Lt鷲 Fig．1 1 Unilateral conj unctiVitis in a young parakeet （Photograph courtesy of Dr． Noelle McNabb．）

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Fig・13 Pseudomonas sp． keratitis and conjunctiVitis in an ostrich chick．（Photograph courtesy of Dr． Darryl Heard．）

Fig・12 Poxvirus infection in a pigeon causing caseous eyelid plaques．

10 ． A－ F． 『．三，プ．… tts z ざ一鞭・ ，〆㌧ ノ

’ ／1，タ’ ド

恒 “三 ・ン 違三≦

＾：1、eヘニ 義 蔭蒙．靖

’ 卓 夕獅パ斌蕊巡 】 ピ’ ．酋 Adult owl with ， anteriorFig．14 synechiae and cataract｛formation． The most likely cause is trauma． Fig． 15 Retinal detachment can be seen adjacent to the pecten in this adult screech owl．

Fig．16 Cataract formation in an adult Talipia fish． Fig．17 Retained spectacle量bllowing ecdysis in this The cause is unknown． adult snake． The rema緬ng spectacle is opaque and overlies the new spectacle and the cornea． （Photograph courtesy of Dr． Darryl Heard．）

Fig．18 Subspectacular abscess secondary to Fig．19 Corneal and conjuntiva1 fibropapillomas stomatitis in a 7 year old albino Burmese python・ in an adUlt Green sea turtle．（Photograph courtesy Note the pink exudates underneath the spectacle． of Dr． Noelle McNabb．）

11