Graefe's Arch Clin Exp Ophthalmol (1986) 224:218-220 Graefe's Archive for Clinical and Experimental

Ophthalmology © Springer-Verlag 1986

Early pars plana vitrectomy in chronic endophthalmitis of toxocariasis* Alvaro Rodriguez Fundaci6n Oftalmol6gica Nacional, Bogotfi, Colombia

Abstract. Pars plana vitrectomy was performed in 12 eyes affected with chronic endophthalmitis in patients 4-38 years of age. In 3 cases the indication was severe vitreitis and the surgical response was excellent. The other 9 eyes were operated upon during the cicatricial and sequelae stages, and the results were better the earlier surgery was per- formed. Lensectomy was associated in 5 cases. Good ana- tomical results were obtained in 9 eyes (75%); the other 3 (25%) were failures because of complications. Visual acu- ity improved after vitrectomy in 8 cases (66%), remained the same in 1 and became worse in the 3 anatomical failures (25%). Early pars plana vitrectomy is indicated in the chronic endophthalmitis of toxocariasis to prevent develop- ment of complications leading to loss of the eye and in order to obtain good functional results with little risk of complications. The ELISA test was performed on 5 vitreous samples and was positive in all. Toxocariasis should be strongly suspected in cases of unilateral vitreitis and/or pars planitis.

Introduction

Infections caused by the larvae of Toxocara can& have a worldwide distribution and today are frequently intraocu- larly located where, mostly in children, the infections may produce multiform clinical pictures, especially posterior chorioretinal granuloma, peripheral granuloma and pars planitis, and chronic endophthalmitis. The diagnosis is made: (1) by clinical examination; (2) in accordance with Pollard et al., using of the Toxocara ELISA laboratory test, which is performed on blood and vitreous samples; (3) by removal of the complicating cataract. (Pollard et al. 1979).

Toxocara endophthalmitis is a chronic disease in the active or cicatricial stages, but spontaneous regression after the active phase of the disease does not mean visual recov- ery. Persisting inflammation leads to complications that may be mild or severe. Contracting vitreoretinal organiza- tion may develop tractional and/or rhegmatogenous retinal detachment, leukokoria, and phthisis.

In children under 10 years of age, there is frequently inflammation, and the vascular processes develop a vitreor-

* Presented at the 1984 meeting of the Club Jules Gonin in Lau- sanne, Switzerland

Offprint requests to: Alvaro Rodriguez, M.D., Carrera 15 No. 76-60, Apt. 201, Bogotfi, D.E., Colombia

etinal falciform fold as a result of dragging between the optic disc and the peripheral granuloma, with loss of vision and strabismus. Treatment with systemic steroids may be useful in a few cases. Therefore, vitrectomy has been sug- gested by many research teams: for diagnostic purposes; for optical reasons to remove opaque inflamed or hemor- rhagic vitreous; for mechanical reasons to remove vitreous traction bands and to avoid or treat retinal detachment; to prevent amblyopia in children; for immunological rea- sons, as the vitreous seems to be a reservoir for antigens; and to avoid leukokoria, ciliary body detachment, and phthisis (Biglan et al. 1979; Hagler et al. 1981; Belmont et al. /982).

Patients and methods

Retrospective analysis of the years between 1981 and 1984 showed that 89 patients from two local institutions had clinically presumed ocular toxocariasis, many with ELISA test confirmation (Table 1). All blood and vitreous samples were sent to the Parasitic Diseases Division in Atlanta, USA. Thirty of the 89 patients had chronic endophthalmi- tis; 16 of these eyes were in the partial or complete cicatri- cial stage, and 14 had active inflammatory disease. Of those in the active stage, 6 had severe vitreitis and 8 unilaterals pars planitis. The disease may be bilateral but, except for ] patient, only unilateral cases were included in this study.

Steroid treatment was successful in 3 cases of vitreitis. Twelve eyes of 11 patients with chronic endophthalmitis were subjected to pars plana vitrectomy because of: (a) vitreous inflammation that progressively and rapidly wors- ened; (b) severe vitreitis unresponsive to steroids; (c) vision decrease of below 20/100; (d) early onset of retinal detach- ment; (e) dragging retina near the optic disc, leading to strabismus and amblyopia; (f) before other threatening ci- catricial complications, such as cataract, macular epiretinal membrane proliferation, hypotony, and phthisis. Leukok- oria occurs at too late a stage for surgery. Occasionally, the simultaneous lensectomy of total or partially clear lenses may be advisable to facilitate peripheral vitrectomy. The presence of a cataract or its late development requires its removal at the same time as the vitrectomy or in an addi- tional procedure.

Results and discussion

Of the 11 patients, 6 were women and 5 men; their ages ranged from 4 to 38 years, with an average of 13. Both

110

Table 1. Suspected clinical ocular toxocariasis (89 cases)

ELISA test (75 patients)

Titer Serum Vitreous

Negative 1 1:2 2 1:4 28 2 1:8 7 1:16 9 1:32 13 1:64 6 t 1:128 7 1 1:256 2 2 1:2048 1

Courtesy of Dr. Peter Schantz

Table 2. Toxocara chronic endophthalmitis: early pars plana vitrec- tomy (12 cases), pre- and postoperative visual acuity

Preoperative Postoperative

Active

Cicatricial

LP 20/400 20/200 20/25 (aphakia) 20/100 20/25 LP 20/30 20/400 20/40 20/100 20/80 20/200 20/200 CF 20/20 (aphakia) CF 20/30 (aphakia) CF LP (aphakia) CF LP HM LP (aphakia)

LP = light perception; CF = counting fingers; HM = hand motion

eyes were equally affected. Preoperatively, visual acuity ranged from 20/25 to light perception (Table 2).

Regarding motility, exotropia was found in 5 and eso- tropia in 2 eyes. Intraocular pressure was normal in all eyes. Biomicroscopy indicated keratic precipitates in 1 case, lens changes in 4, and cyclitic membranes in 2.

Inflammation was present in all eyes and was a severe vitreitis in 3; the vitreous in I case was filled with a fibrinous hemorrhage. Six cases presented a typical path of organized vitreous condensation between the optic disc and the pe- ripheral granuloma.

Ophthalmoscopy revealed two main pictures (Table 3): 1. Active endophthalmitis accompanied by severe mem-

branoid vitritis, cystoid macular edema, papillitis, peripher- al active granuloma or snowbanks in pars plana, usually inferiorly located.

2. Cicatricial endophthalmitis with complicating seque- lae, such as vitreous hemorrhage, contracting vitreous orga- nization, surface epiretinal proliferation, papillitis, traction retinal detachment, and dragged retina, was found in chil- dren under 10 years of age.

It was difficult to assess the visual fields. Fluorescein angiography was of no help, but ultrasound helped make an evaluation.

According to Belmont et al. (1982), any ELISA serum- positive titer is significant in the presence of a characteristic

Table 3. Toxocara chronic endophthalmitis

Ophthalmoscopy

Vitreitis 3 Papillitis-pallor 2 Periphlebitis 4 Peripheral granuloma 4 Pars planitis 4 Vitreous hemorrhage 1 Contracting vitreous bands 7 Epiretinal membranes 2 Traction retinal detachment 5 Dragging retina 6 Cystoid macular edema 4

219

Table 4. Toxocara chronic endophthalmitis

ELISA test titers

Case Serum Vitreous

1 1:32 2 1:64 1:64 3 1:4 1:128 4 1:4 5 1:4 6 1:128 7 1:16 8 1:4 9 Pending

10 1:4 1:256 11 1:4 1:256 12 1:128 1:2048

clinical picture. Others (e.g., PM Schantz, personal commu- nication 1984) believe that because of the exposure of indi- viduals to visceral larvae migrans, the incidence of positive- serum ELISA tests is high in populations of some countries around the world. Therefore, in some areas the serum EL- ISA test would appear to be unreliable. On the other hand, if the ELISA is positive in vitreous samples, this is definitely significant in the presence o f intraocular larvae.

Table 4 shows the ELISA titers in sera of 11 of the 12 vitrectomized patients, as well as the titers found in pa- tients in whom vitreous samples were also tested: all 5 were definitely found to be positive. In some cases, we were un- able to obtain this information, as some samples were lost in the operating room or in the foreign mailing process.

Trea tmen t

An initial course of systemic steroids was given to 6 cases. Five eyes required lens removal, which was combined with vitrectomy in 2 patients and postvitrectomy in the other 3. Pars plana vitrectomy was performed in 12 eyes of 11 patients, all having chronic endophthalmitis with the fol- lowing indications:

1. Severe active vitreitis (3 eyes) 2. Chronic inflammation because of sequelae and cica-

tricial lesions (7 eyes): massive vitreous hemorrhage and macular epiretinal membrane (1 case); the presence of vi- treoretinal traction, dragged retina; partial tractional reti- nal detachment (other 6 eyes)

111

220

Table 5. Toxocara chronic endophthalmitis: early pars plana vitrec- tomy (12 cases)

Postoperative functional results

20/20-20/40 6 20/80 20/200 1 20/400 1 Light perception 3 Improved, 8 (66%); same, 1; worse, 3 (25%)

3. Late operations because of advanced tractional reti- nal detachment with leukokoria (2 eyes)

The complications were: transient exacerbation of in- flammation in 2 cases; cataract in 3 cases, which later re- quired removal; cystoid macular edema in 2 cases; 3 cases in which the tractional retinal detachment developed a rheg- matogenous component because of iatrogenic retinal tears formed during surgery. Therefore, we advise sectioning of the vitroretinal bands with scissors and not with vitreo- phages, as the latter technique tends to develop retinal tears in weak areas of long-standing inflammation.

Five eyes were reoperated upon. Three eyes underwent operations to remove the developing cataract, which also facilitated the excision of very peripheral vitreoretinal trac- tion bands. Two eyes required reoperation with scleral buckling to treat iatrogenic rhegmatogenous retinal detach- ments with retinal breaks created during vitrectomy: buck- ling was successful in one peripheral retinal dialysis of late postoperative onset, but reoperation failed in the other pa- tient. There were two more failures: the detachments pres-

ent in the two leukokoria cases, in spite of intravitreal sili- cone used in one eye, which was removed later on, together with cataract extraction.

Excellent anatomical results were obtained in 9 eyes (75%), with 3 failures (25%). I f the vitrectomy is performed very early in affected children, it may be possible to prevent dragging of the retina.

The functional results after vitrectomy are shown in Ta- bles 2 and 5. Eight eyes (66%) showed improved visual acuity, 6 of them above 20/40; 3 eyes required contact lens correction of aphakia. One eye still had the same vision. Three eyes became worse (the same anatomic failures) with only light perception remaining. However, one has to take into consideration the fact that the preoperative vision test was "counting fingers" to "hand motion." In conclusion, early pars plana vitrectomy provides fewer complications and better visual results.

References

Belmont JB, Irvine A, Benson W, O'Connor GR (1982) Vitrectomy in ocular toxocariasis. Arch Ophthalmol 100:1912-1925

Biglan AW, Glickman LT, Lobes LA (1979) Serum and vitreous toxoeara antibody in nematode ophthalmitis. AM J Ophthal- mol 88 : 898

Hagler WS, Pollard ZF, Jarrett WH, Donnelly EH (1981) Results of surgery for ocular toxocara canis. Ophthalmology 88:1081-1086

Pollard ZP, Jarret WH, Hagler WS (1979) ELISA diagnosis of ocular toxocariasis. Ophthalmology 86:743-749

Accepted July 24, 1985

112