Feline Corneal Sequestration: a Retrospective Case Study

Transcription

1 t:l~ ia Ujj,t Taiwan Vet J 31 (2): ,2005 Feline Corneal Sequestration: a Retrospective Case Study Hung-Fei LO, Lih-Seng YEH, and *Chung-Tien LIN Division of Ophthalmology, Department of Veterinary Medicine, College of Bio-Resource and Agriculture, National Taiwan University, Taipei, Taiwan. ( Received: April 15, Accepted: May 8, ) ABSTRACT Corneal sequestratio n is a disease unique to the cat characterized by a localized necrosis of the corneal epithelium and anterior stroma with accumulation of dark brown pigments in the affected tissue. In this paper, we analyze the clinical characteristics of seven cases of corneal sequestrum (ten affected eyes ) at our ophthalmology clinic from 2002 to Most of the affected cats were Persians (six Persians and one Domestic short hair ). The common clinical signs of all affected cats included a dark brown or black necrosis plaque (sequestrum ) surrounded by edematous cornea. Other clinical signs present in the affected eyes included lacrimation ( 5/10), purulent ocular discharge ( 5/10 ), blepharospasm (4/10 ), and photophob ia (4/10). Ophthalmic examination was performed wi th slit lamp biomicroscope and corneal fluorescein staining. We found that 4 cats had unilateral corneal vascularization and pigmentation, 3 cats had bilateral corneal vascularization and pigmentation, and all cats had corneal ulceration around the sequest rum ( ranged from superfic ial to descementocele ). All patients were treated by topical antibiotics and artificial tear ointment initially. Keratectomy surgery was performed in five cats to remove the corneal sequestrum with additional third eyelid or conjunctival flap. The affected cats were evaluated for a follow-up period of 4-15 weeks. Affected corneas and ocular discomfort were more quickly recovered more quickly in patients w ith keratectomy. Based on this study, surgical management of feline corneal sequestrum is a helpful procedure to remove corneal sequestru m and improve ocular signs. [LO HF, Yeh LS and Lin CT. Feline corneal sequestration: a retrospective case study. Taiwan Vet J 31(2): , *Corresponding author TEL : , FAX: , ctlin@ntu.edu.tw] Key words: Cat, Cornea, Keratectomy, Sequestration, Sequestrum INTRODUCTION Feline corneal sequestrum ( also called corneal necrosis, corneal sequestration, corneal mummification, corneal nigrum, necrotizing ) is a disease unique to cats [2,6]. Recently, a case of corneal sequestrum has been reported in the horse [7]. The disease is characterized by a localized necrosis ofthe epithelium and anterior stroma in the central or paracentral coroea. The disease is breed-predisposed and commonly affected breeds include Persian, Siamese, Burmese, Himalayan [2,7,9]. Feline corneal sequestrum is usually unilateral but may occur bilaterally either simultaneously or at different stage [6,7,9]. Corneal sequestrum can cause persistent pain, irritation, cor nea l ulcer, and descementocele. The exact etiology of the disease in the cat is still unknown. Previous ocular trauma, feline herpesvirus-i infection, keratoconjunctivitis sicca, and entropion are implicated to be the predisposing factors [6,9]. This retrospective study is to evaluate the clinical characteristics and treatment outcomes ofthe feline corneal sequestrum case at the National Taiwan University Veterinary Hospital from

2 98 Hung-Fei LO et al 2002 to CASE DESCRIPTION Analysis of details of feline corneal sequestrum patients Here we describe 7 cases with feline corneal sequestrum ( 10 affected eyes ) diagnosed and treated at the National Taiwan University Veterinary Hospital from 2002 to The details ofthese cases are summarized in the Table I. The ratio ofaffected males and females was 6:I (6 males and I females ). The leading affected breed was the Persian ( 6/7 ). The age of affected cats was from 2 months to 6 years. Ophthalmic examination The clinical signs and ocular lesions by ophthalmic examination with slit lamp biomicroscope and corneal fluorescein staining showed that four patients had unilateral lesion in one eye ( 4/7 ), and three patients presented bilateral corneal lesions ( 3/7 ). Common presenting clinical signs including lacrimation ( 5110 ) ( Fig. 1 and Fig. 3 ), watery or purulent ocular discharge ( 7/10 ) ( Fig. 2 ), blepharospasm ( 4/10 ), and photophobia ( 4/10 ). All of affected eyes presenting corneal ulceration ( superficial corneal ulcer to descementocele ), corneal neovascularizaion ( Fig. 3 ), and pigmentation ( Fig. I, Fig. 2 and Fig. 3 ). Managements and outcomes All patients received topical broad spectrum antibiotics, arti ficial tear ointment ( Duratear" ), and atropine eye drop to relieve blepharospasm and lesions. Five cats were given ora l medication at the same time and corneal surgery ( including keratectomy, punctate keratotomy, third eyelid or conjunctiva flap ) ( Fig. 4 ) about 2-3 weeks later. The patients with surgical treatments were found to recover more quickly ( 14 to 42 days, mean time of 19.6 days after surgery ) than the cases without surgery ( one cat had no improvement in the follow-up period of 15 weeks, and sequestrum slough offspontaneously 8 weeks later in another case ). The details of the management and outcome of treatment are summarized in the Table 2. DISCUSSION There was high incidence of feline corneal se- Table 1. Signalment and clinical findings on ophthalmic examinations in cats with feline corneal sequestration. No.1 No.2 No.3 No.4 No.5 No.6 No.7 Breed DSH Persian Persian Persian Persian Persian Persian Gender Female Male Male Male Male Male male Age 6 yrs 2ms 4yrs 2yrs 2yrs 3yrs 1.5yrs Affected eye (s ) unilateral ( Lt. ) bilateral bilateral unilateral unilateral unilateral bilateral ( Lt. ) ( Rt. ) ( Lt. ) Lacrimation Ocular discharge watery purulent purulent purulent watery Photophobia Corneal ulcer Superficial Moderate Moderate Descemen- Moderate Moderate Moderate stroma stroma tocele stroma stroma stroma Neovascularization Pigmentation DSH : Dome stic short hair cat; yrs: yea rs; ms: month s; Lt.: Lett; Rt.: Right

3 Feline Corneal Sequestration: a Retrospective Case Study 99 (a) Fig. 1 Unilatera l corneal sequestrum in a 6-year-old. Domestic short hair cat. ( a ) A brown-black pigmented area was noted on the cornea. The patient showed a moderate lacrimation but had no obvious ocular discomfort. ( b ) Ophthalmic examination with corneal fluo rescein staining. Moderate corneal ulceration was noted around the pigmented sequestrum lesion. Fig. 2 A 6-year-old Persian cat. Unilateral corneal sequestrum with extensive stromal ulceration and cornea edema was noted. Pain and purulent ocular discharge were present in the cat. (a) '-- ~=_ ~ (b) Fig. 3 Bilateral corne al sequestrum in a 2-month-old Persian cat. ( a) Bilateral corne al sequestra were noted. The patient showed watery ocu lar discharge and obvious neovascularization around the corneal sequestrum. ( b ) Ophthalmic examination with corne al fluorescein stain ing was perfo rmed. Moderate corneal ulceration was noted around the pigmented sequestrum lesion. (a) (b) L Fig. 4 Keratectomy surgery in a 1.5-year-old Persian cat. ( a) Unilateral corneal sequestrum affecting the left eye. A black pigmented area and obv ious neovascularization was noted on the cornea. ( b ) Corneal sequestrum was removed by keratectomy surgery. (c ) Immediate postoperative appearance. ( d) Fluorescein stain of immediate post-operative cornea. A moderate ulce r in the corneal stroma was noted. The corneal ulcer was then protected with a third eyelid flap. (d) (c)

4 100 Hung-Fei LO et al Table 2. Topical eye drop Management and outcome of treatment s of cats with feline corneal sequestrum. No.1 No.2 No.3 No.4 No.5 No.6 No.7 Statrol" 1,2 1,2,3 1,2,3 1,2,3 1,2 1,2,3 Duratear" 1,2 1,2,3 1,2 1,2,3 1,2 1,2,3 Gentamicin 1,2 Atropine 3 3 Fusidic acid 3 Oral medication Cephalexin Surgery Keratectomy Punctate keratotomy Linear grid keratotomy Third eyelid flap Conjunctiva flap Outcome Corneal healing time 14days 17days I: The first week of therapy. 2: The secondweek of treatment. 3: Post-operative medication. not healed in follow-up period 42days 28days slough off 8wks later 14days questration in the Persian cat in our cases. This is consistent with that corneal sequestrum is a breed-predisposed disease in cats [4, I0]. Most of the affected cats had a history of chronic ocular problem noted by the owners. Reported clinical signs include lacrimation, purulent ocular discharge, blepharospasm, photophobia, chemosis, elevation of the nictitating membrane, chemosis, conjunctiva hyperemia, and decreased appetite and activity due to pain. The sequestrum usually appears as an oval to round, dark brown or black necrosis plaque surrounded by corneal ulceration [3,4]. In this study, 100% ofthe affected eyes had various degrees of corneal ulceration around the sequestrum plaque ( one superficial, eight moderate stromal, and one descementocele). Both medical and surgical management are available for feline corneal sequestrum. Surgical treatment for feline corneal sequestrum depends on the severity and depth ofthe lesions [1,5,8]. In this study, one patient received only topical medical treatment ofanti biotics and Duratear ointment, while 6 other patients received both medical and surgical management ( ineluding keratectomy, punctate keratotomy, third eyelid or conjunctiva flap). The patients with keratectomy were found to make affected corneas and ocular discomfort recovered more quickly (mean time of 19.6 days after surgery ) than two cases without surgery ( one case had no improvement in the follow-up period of 15 weeks, and sequestrum slough offspontane ously 8 weeks later in another case ).Surgical management of feline corneal sequestrum is found to be a helpful procedure to remove corneal sequestrum, improve ocular signs, relieve pain and improve healing of the affected corneas. In conclusion, corneal sequestrum is a painful ocular disorder predisposed in several purebreeds of cats. It can be managed by a similar treatment protocol as used for treating corneal ulcer. In the cases of persistent painful corneas, surgery is a good option to facilitate the recovery of the affected corneas. REFERENCES 1. Andrew SE. Tou S. Brooks DE. Corneoconjunctival

5 Feline Corneal Sequestrat ion: a Retrospecti ve Case Study 101 transposition for the treatment of feline corneal sequestra: a retrospective study of 17 cases ( ). Vet Ophthalmol 4: Blogg JR. Stanley RG. Dutton AG. Use of conjunctival pedicle grafts in the management of f eline keratitis nigr um. J Small Anim Pract 30: Featherstone HJ. Sansom J. Feline corneal sequestra: a review of 64 cases ( 80 eyes ) from 1993 to Vet Ophthalmol 7 : Gelatt KN. Peiffer RL. Stevens J. Chronic ulcerat ive keratit!s and suquestrum in the domestic cat. J Am Ani m Hosp Assoc 9: Hansen PA. Guandalini A. A retrospective study of 30 cases of frozen lamellar corneal graft in dogs and cats. Vet Opht halmol 4: Morgan RV. Feline corneal sequestration: a retrospective study of 42 cases. J Am Anim Hosp Assoc 30: McLellan GJ. Archer FJ. Corneal stromal sequestration and keratoconjunctivitis sicca in a horse. Vet Ophthaimol 3: Pena Gimenez MT. Farina im. Lamellar keratoplasty for the treatment of feline corn eal sequestrum. Vet Ophthalmol 2: Pentlarge VW. Corneal seq uestration in cat s. Compend Contin Educ Pract Vet 11: Wolfer J. Grahn B. Diagnostic ophthalmology. Can Vet J 32:

6 102 Hung-Fei LO et al 貓壞死性角膜炎 : 回溯性之病例研究 駱虹霏莘力森 * 林中天 國立台灣大學獸醫學系眼科研究室 台北市 ( 收稿日期 : 94 年 4 月 15 日 接受日期 : 94 年 5 月 8 日 ) 摘要壞死性角膜炎是一種特發於貓隻的眼睛疾病, 主要特徵是角膜上皮及淺層基質出現局部性的壞死, 伴隨著咖啡色或黑色色素的堆積 本篇我們分析於 2002 至 2004 年間至台大動物醫院眼科門診就診之壞死性角膜炎的病例 ( 共 7 隻貓, 10 個眼睛 ). 壞死性角膜炎的病例中絕大部分都是波斯貓 ( 共有 6 隻波斯貓及 1 隻 短毛家貓 ), 所有病患的角膜都出現深咖啡色或黑色壞死的斑塊, 病社周圍伴隨著角膜水腫.其餘臨床症狀 還包括淚溢 (5/10 ) 臉樣眼分泌物 (5/10 ) 眼臉瘟? (4/10) 和畏光 (4/10). 使用裂隙燈及角膜螢光染色 進行眼科學檢查, 我們發現其中三隻病患雙眼角膜都出現色素堆積及血管新生, 所有的病患都在病社周圍出 現程度不 的角膜潰房 ( 程度從淺層的角膜潰蕩至後彈力層脫出 ) 所有病患都先接受局部抗生素和淚膜藥 膏點眼治療後, 其中 5 隻病患選擇局部角膜切除術以切除壞死性角膜炎之病社區域, 並視情況以第三跟臉瓣 或結膜瓣輔助角膜的修復.追蹤的時間約為 4-15 週 ' 發現接受局部角膜切除手術的病患其角膜修復的速度和 病畜眼部臨床症狀緩解之時間, 都明顯較未接受手術之病患縮短許多.根據本篇研究, 可推論對於貓壞死性 角膜炎的病患而言, 使用手術方式移除壞死性角膜炎之病位區域為 有效的治療方法, 可加速角膜癒合並快 速緩解不適的臨床症狀 I 酪虹霏 葉力森 林中天 貓壞死性角膜炎.回溯性之病例研究 台灣獸醫誌 31(2): , * 聯絡人 TEL: , FAX: , h 個.edu.tw] ifj, 訝 : 貓, 跟角膜, 角膜切獻仿, 壞 7f1 全局鹿三在