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Persisting corneal oedema following intracapsular cataract extraction Kirsten Baggesen and Niels Ehlers

Department of Ophthalmology, Arhus University Hospital, Ahus , Denmark

ABSTRACT. Purpose: The purpose of this study was to reveal the frequency of persisting cor- neal oedema following intracapsular cataract extraction and at the same time to examine whether the survival rate after penetrating keratoplasty due to this diag- nosis differs from the survival rate following penetrating keratoplasty due to pri- mary Fuchs’ endothelial dystrophy. Methods and Material: A series of 2455 eyes underwent intracapsular cataract extraction between January 1,1986 and December 31,1988, at the Department of Ophthalmology, Arhus University Hospital. The medical files were examined to study the frequency of persisting corneal oedema. Patients with persisting cor- neal oedema were offered penetrating keratoplasty and the survival rate following this procedure was calculated. Results: The frequency of pseudophakic persisting corneal oedema was 5.3% in the group of patients who underwent intracapsular cataract extraction. The sur- vival of the following corneal transplantation was 54% after 2 years of follow-up. This is a low survival rate compared to the survival rate in primary Fuchs’ endo- thelial dystrophy, but there is a similarity to this disease in a development of a slowly progressive oedema in 17% compared to 13% in primary Fuchs’ endothelial dystrophy. Conclusion: 5.3% of a group of patients who underwent intracapsular cataract ex- traction developed persisting corneal oedema within a 5 to 7-year follow-up period. When these patients underwent penetrating keratoplasty the survival rate of the graft was 54% after 2 years of follow-up.

Key words: intracapsular cataract extraction - persisting corneal oedema - complications - pseu- dophakic - bullous keratopathy.

Acta ODhthalrnol. Scand. 1997: 75: 487-489

urgical techniques for cataract extrac- S tion have undergone a marked change from intracapsular to extracapsu- lar technique. During the last decades the extracapsular technique has replaced the intracapsular technique. Among the rea- sons for this change were the high in- cidence of aphakic retinal detachment, cystoid macular oedema and persisting corneal oedema after intracapsular cata- ract extraction (ICCE). The frequencies of complications are poorly documented when regarding long-term results. Powe et al. (1994) reviewed 90 studies pub-

lished between 1979 and 1991 that among other features addressed compli- cations following intracapsular cataract extraction. The authors did not report on any study addressing persisting corneal oedema following ICCE. The purpose of this study has been to reveal the fre- quency of persisting corneal oedema after ICCE and at the same time to examine whether the survival rate after penetrating keratoplasty due to this diag- nosis differs from the survival rate follow- ing transplantation due to primary Fuchs’ endothelial dystrophy.

Material Between January 1,1986 and December 31,1988,2455 intracapsular cataract ex- tractions (ICCE) with implantation of an anterior chamber IOL were performed at the Department of Ophthalmology, Arhus University Hospital. The indica- tions were mostly senile cataract, but also traumatic cataract, presenile cataract and secondary cataract were included.

By December 31, 1993, 718 patients, accounting for 733 eyes, were dead, leav- ing 1722 eyes for calculations. 66 patients underwent penetrating keratoplasty.

Methods All patients in this study underwent ICCE with implantation of an anterior chamber IOL. Pseudophakic corneal oedema was diagnosed either at the De- partment of Ophthalmology or by one of the ophthalmologists, who were asked to report all cases of pseudophakic corneal oedema to the authors.

All patients were offered penetrating keratoplasty if indicated, but some pa- tients were not interested in further surgery. The patients who accepted graft- ing were followed for at least 18 months. During surgery the anterior chamber lens was exchanged with another type of ante- rior chamber IOL if indicated. This was the case in 32 of the 66 patients. The IOL remained an anterior chamber IOL in all patients except one, who was left aphakic. The transplant was sutured by a single continuous 10-0 nylon. The postopera- tive treatment was systemic steroid dur- ing 3 months supplemented by topical steroid and antibiotics. If a rejection epi- sode occurred, the patient was referred to and treated at the Department of Oph-

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thalmology. The treatment was systemic prednison 30-60 mg (gradually tapered over weeks), subconjunctival injections of steroid, and topical steroid and anti- biotics.

A control group of patients operated during the same period under the same conditions as the grafted patients was sampled. In all cases of persisting corneal oedema the next patient operated was se- lected as a control. Operative complica- tions, type of intraocular lens and axial length, sex, age and additional ocular dis- eases were noted in the patients and in the control group.

The statistical method for comparing the control group to the patients with per- sisting corneal oedema was odds ratio. To calculate the survival rates for the pene- trating keratoplasty, Kaplan-Meiers sur- viva! curves were used.

Results During the study period 2455 eyes were operated by ICCE. When the follow-up began by December 1993, 718 patients (733 eyes) were dead without examin- ation, which left 1722 eyes for the study. Eighty-nine patients were admitted be- cause of persisting corneal oedema. This gives an overall frequency of 5.3% of pa- tients who experienced persisting corneal oedema, with a follow-up of 5-7 years.

Of the 89 patients, 66 accepted pene- trating keratoplasty. This group was com- pared to a case/control group without persisting corneal oedema.

The type of IOL implanted is listed in Table 1. No statistically significant in- fluence of the IOL type on persisting cor- neal oedema could be demonstrated.

Table 1. Type of IOL in the group with persist- ing corneal oedema compared to the control group. Chi-square: 1.81 (2 degrees of free- dom).

UV44B 3M Others

+Cornealoedema 27 32 7 - Cornealoedema 20 36 10

Table 2. Axial length in the group with persist- ing corneal oedema and the control group (P = 0.035).

Mean Range IllIll mm

+ Corneal oedema 22.7 20.84 - 26.78 - Corneal oedema 23.04 21.82 - 25.66

100 I I

"1 N=66

70i I

N=121

: : I , , , , I I I I 1 0 0 100 200 300 400 500 600 700 800 900 1000

Days Fig. 1. The survival rate of penetrating corneal keratoplasty in persisting corneal oedema follow- ing intracapsular cataract extraction.

The influence of axial length is listed in Table 2. There is a significantly shorter axial length in the group of patients who later developed corneal oedema.

There were no significant differences between the two groups with regard to sex, age, operative complications or addi- tional ocular diseases.

The survival rate of the 66 eyes who had penetrating keratoplasty is shown in Fig. 1. The grafts were mainly lost due to decompensation and only 7 of the cor- neas were lost due to irreversible rejec- tion.

Discussion Clinical studies reporting the frequency of pseudophakic corneal oedema follow- ing ICCE are rare, although most sur- geons believe that it was one of the major reasons for changing to extracapsular cataract surgery. In the present study the medical reports of 1722 eyes that under- went ICCE have been reviewed to ex- plore the frequency of persisting corneal oedema. The overall frequency of persist- ing corneal oedema was 5.3%. No similar studies of this frequency have, to the au- thors' knowledge, been published. Pseu- dophakic corneal oedema has been ex- posed as a major indication for corneal transplantation in several studies (Easty et al. 1989; Haamann et al. 1994). These authors base their conclusions on a group of corneal graft patients and do not dis- cuss the number of cataract extractions laying behind.

In a number of studies, different types of anterior chamber IOLs have been dis-

cussed as a cause of persisting corneal oedema. Insler et al. (1989) performed penetrating keratoplasty on 32 eyes that developed pseudophakic bullous kerato- pathy associated with closed loop ante- rior chamber intraocular lenses. This type of lens was widely used in the United States until 1985, and the authors do not give the number of ICCE performed, re- sulting in 32 eyes for penetrating kerato- plasty. Also Smith et al. (1987) reported on 53 eyes with corneal oedema or per- sisting macular oedema, which at surgery received a semiflexible, closed loop ante- rior chamber lens, without accounting for the underlying number of cataract extrac- tions.

During the study period two major types of anterior chamber IOLs were in- serted at the Department of Ophthalmo- logy in h h u s . Although there was a dif- ferent frequency of persisting corneal de- compensation between the two types of IOLs, this was not statistically significant.

The pathoanatomical explanation for the development of persisting corneal oedema following ICCE with anterior chamber IOL is still controversial. Sev- eral factors have been suggested as major risk factors including preoperative Fuchs' endothelial dystrophy, surgical complica- tions and age at cataract surgery. Among the patients in this study none of the risk factors was present at a significantly higher degree among the patients with decompensated corneas compared to the case control group. However, short axial length seems to be a risk factor for de- veloping persistent corneal oedema. Among patients with corneal oedema the mean axial length was 22.7 mm (20.84-

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26.78) compared to 23.08 mm (21.82- 25.66) in the control group. This might be explained by the relatively flat anterior chamber in the short eye compared to the longer eye, with the anterior chamber IOL situated closer to the corneal endo- thelium.

The clinical course in persisting cor- neal oedema bears similarity to Fuchs’ endothelial dystrophy. Olsen et al. (1 984) published long-term results of corneal grafting in Fuchs’ endothelial dystrophy. Of 33 cases thirteen (39%) had de- veloped irreversible corneal oedema after a follow-up of 50 months (range 3-136). 12% of all cases developed a quiet, slowly progressive oedema without any obvious aetiology. In this study the 50-month survival rate of the corneal graft is 54%, and 17% of the corneas were lost due to a similar quiet, slowly pro- gressive oedema. The primary Fuchs’ dystrophy has a higher survival, but there

might be a common factor for the devel- opment of quiet, slowly progressive oedema.

References Easty DL, Armitage WJ, Moss SJ, Rogers CA,

Gore SM & Bradley BA (1989): Corneal grafting. In: Leslie Brent & Robert A Sells (eds.) Organ transplantation: Current clini- cal and immunological concepts. Bailliere Tindall.

Haamann P, Jensen OM & Schmidt P (1994): Changing indications for penetrating kera- toplasty. Acta Ophthalmol (Copenh) 72:

Insler MS, Kook MS & Kaufmann HE (1989): Pentrating Keratoplasty for Pseudophakic Bullous Keratopathy Associated With Semiflexible, Closed-Loop Anterior Chamber Interocular Lenses. Am J Oph- thal 107: 252-256.

Olsen T, Ehlers N & Favini E (1984): Long

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term results of corneal grafting in Fuchs‘en- dothelial dystrophy. Acta Ophthalmol (Co- penh) 62: 445-452.

Powe NR, Schein OD, Gieser SC, Tielsch JM. Luthra R, Javitt J & Steinberg E P for the Cataract Patient Outcome Research Team (1994): Synthesis of the Literature on visual Acuity and Complications Following Cata- ract Extraction With Intraocular Lens Im- plantation. Arch Ophthalmolll2: 239-252.

Smith PW, Wong SK, Stark WJ, Gottsch JD, Terry AC & Bonham RD (1987): Compli- cations of Semiflexible, Closed-Loop Ante- nor Chamber Interocular Lenses. Arch Ophthalmol 105: 52-57.

Received on October 7th. 1996.

Corresponding author: Kirsten Baggesen Department of Ophthalmology Arhus University Hospital DK-8000 Arhus C, Denmark.

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