Simultaneous Bilateral Cataract Extraction: ECCE versus ICCE

Simultaneous Bilateral Cataract Extraction: ECCE versus ICCE PER JULIUS NIELSEN Eye Department, Hjorring Hospital, DK-9800 Hjorring, Denmark

OBJECTIVE: To evaluate the differences in visual rehabilitation between intracapsular (ICCE) and extracapsular (ECCE) cataract surgery as well as the significance for visual performance of the position of an intraocular lens in the eye. STUDY DESIGN: Prospective study of simul· taneously performed cataract extraction in both eyes, with evaluation at 3 days, 6 weeks, 3 and 6 months after surgery. PATIENTS: Ten adult patients severely visually handicapped from equally advanced cataract in both eyes had simultaneous cataract surgery performed under general anaesthesia with an ECCE with a posterior chamber lens (PCL) in one eye and an ICCE with an anterior chamber lens (ACL) in the other eye. MAIN OUTCOME MEASURES: Refraction and visual acuity (VA) were obtained unbiased by a trained nurse with an autorefractor and with the same instrument a value for contrast (CS) and glare (GS) sensitivity were obtained, expressed as the numerical drop in Snellen lines from the best visual acuity obtained at the same time. RESULTS: After 6 months all patients seemed to have benefited almost equally in both eyes (mean VA/ECCE 0.72 ± 0.15); and mean VA (ICCE 0.80 ± 0.16). No subjective differences in visual performance was noticed between the eyes except in one of the ECCE patients, who experienced the beginnings of opacification in the posterior capsule. There were no significant differences in either CS (ECCE: 2. 7 ± 1.8 and ICCE: 3.4 ± 1.3; P = 0.37) or GS
INTRODUCTION

Implantation of an intraocular lens (IQL) was introduced during the era of intracapsular cataract extraction IICCEl but gradually a change has occurred to almost exclusively extracapsular cataract extraction
eye (anterior chamber and iris fixation: bullous keratopathy, secondary glaucoma) have favoured the transition to ECCE, where the posterior lens capsule is preserved and the IOL is positioned in the posterior chamber [1-3]. On the other hand ECCE, in contrast to ICCE, is rather often followed by some degree of opacification in the preserved posterior capsule, which may or may not lead to a gradual deterioration of visual performance necessitating yet further treatment [4]. Comparisons between ICCE and ECCE in the past have always been by retrospective study of different patients operated by different surgeons by different Eur J Implant Ref Surg, Vo/4, September 1992

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Bilateral Cataract: ECCE versus ICCE

microsurgical techniques and for different observation periods [3, 5]. To investigate further the differences between ICCE and ECCE as well as the significance of a different IOL position in the eye patients who had simultaneous cataract surgery in both eyes were chosen prospectively to have ICCE with an ACL in one eye and ECCE with a PCL in the other eye. Subjective as well as objective measures were taken (visual acuity, contrast and glare sensitivity) 3 days, 6 weeks, 3 months and 6 months after surgery. MATERIAL AND METHODS

During a condensed period of about 9 months (1989/ 90), ten patients severely visually handicapped from almost equally developed cataract in both eyes were chosen prospectively to have simultaneous cataract surgery on both eyes under general anaesthesia. One eye was allocated to have an intracapsular cryoextraction (ICCE) with a modern open loop ACL (Pharmacia Symflex), and the other eye an extracapsular cataract extraction (ECCE) with a PCL (Allergan PC57). The initial operation was performed as the ECCE on the patient's best eye (objective and/or subjective) and if uncomplicated was intended to be followed by an ICCE on the other eye. All coverings, clothes and instruments were changed between the two operations and surgery was performed by the same.surgeon (experienced with both techniques) in all patients. The eyes were prepared for operation in the same manner, the same corneoscleral incisions were used and the same suturing techniques with a 10.0 Nylon doublecross continuous suture and postoperative treatment regimens were used. Healon was used for inserting the lens in the ECCE group, whereas only a plastic glide was used in the ICCE group. An envelope capsulotomy was used in the ECCE group. The ICCE, but not the ECCE, patients had an iridectomy performed. Refraction and visual acuity (VA) were obtained unbiased by a trained nurse with an AllerganHumphrey Autorefractor (Model 570), and with the same instrument simple values for contrast- and glare-sensitivity (CS and GS) were obtained; both values are expressed as the numerical drop from the best Snellen visual acuity obtained at the same time (3 days, 6 weeks, 3 months and 6 months after surgery). In addition the patients had an ophthalmological investigation with slitlamp examination, lOP measurement and fundus evaluation. Statistical analysis was done using two-tailed, paired and unpaired t-tests. P values < 0.05 were considered statistically significant. Eur J Implant Ref Surg, Vol4, September 1992

RESULTS

Ten patients were studied: six women and four men. The mean age was 82 (age range 73-90). The preoperative visual acuity in the better eye, which had an ECCE, was 0.12 ± 0.13 (mean± S.D.) and in the qther eye, which had an ICCE, 0.11 ± 0.11 (mean± S.D.). One of the ICCE patients had an anterior vitrectomy, but still did as well with this eye as with the ECCE eye (VA was 1.0 in both eyes at 6 months). Otherwise, no complications occurred during surgery. In the early postoperative period, one patient accidentally fell on the floor resulting in an iris prolapse in the ECCE eye. Resuturing was done under local anaesthesia and no further trouble was experienced with the patient. At 6 months VA was 0.5 in both eyes and macular degeneration was observed to be the same in both eyes. The visual performance of the two eyes developed almost in parallel at all investigation times, as determined by patient questioning as well as with the autorefractor . There were no significant differences in the responses to CS and GS between ICCE and ECCE operated eyes at any time during the 6 months of observation (Fig. 2), the response being significantly more pronounced at all times, when glare was added, than when only low contrast was used, both in ECCE and ICCE
P.J. Nielsen

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Fig. 1 Mean visual acuity in patients who had simultaneous bilateral cataract surgery performed. Visual rehabilitation developed with the same speed and equally in eyes operated with an ECCE/PCL or with an ICCE/ACL with no significant differences occurring at any time

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Fig. 2 The sensitivity to low contrast and glare is shown for eyes that had either an ECCE/PCL (E; left columns) or an ICCE/ACL (J; right columns). There was no significant difference between the two operations or between different measuring times

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Fig. 3 Mean intraocular pressure iiOPI was not affected by whether an ECCE/PCL or an ICCE/PCL was performed, though a slight decrease in lOP in ECCE/PCL and a slight increase in lOP in ICCE/ACL early postoperatively (P < 0.171 was observed Eur J Implant Ref Surg, Vo/4, September 1992

Bilateral Cataract: ECCE versus ICCE

DISCUSSION

The introduction ofiOLs and, later, the change from ICCE to ECCE has been followed by an almost explosive development in microsurgical technique. The need to explain the more expensive surgery may have forced many to exaggerate the advances of ECCE compared with ICCE (faster visual rehabilitation, quieter eyes, lower complication rate especially for cystoid macular oedema and retinal detachment) [1-3]. A major problem has been the retrospective nature of the studies comparing ICCE and ECCE, where the observation periods and surgeons are often not the same and more advanced microsurgical techniques have been used in the ECCE groups [1-3, 5, 6]. Although in this study the sample is small (N = 10) and the observation period is short (6 months), several important points may be noted. First, visual rehabilitation developed in parallel regardless of whether the eyes had an ECCE or an ICCE operation performed (Fig. 1). No discomfort could be registered from leaving a posterior lens capsule in the ECCE group as long as it remained clear, the responses to low contrast and glare being comparable at all times to the ICCE-operated eyes (Fig. 2). These results are in accordance with another recent investigation where only ACLs were implanted and where no differences in colour vision, dark adaptation, contrast and glare sensitivity were found between ICCE and ECCE operated patients [5].

With a longer observation period, an increased opacification of the posterior lens capsule can be expected in the ECCE-operated eyes, which could affect not only visual outcome, but glare and contrast sensitivity in the ECCE group [4, 5]. Whether this condition can be fully or only partially equalized again after YAG-laser treatment remains to be determined. In this study only one of the ECCE-operated eyes had a drop in VA, from 0.8 at 3 months to 0.5 at 6 months due to capsular opacification. At all measuring times during the 6 months of observation, the drop in CS and GS remained constant and with no differences between ICCE- and ECCE-operated eyes, the sensitivity to glare always being most pronounced (Fig. 2). The responses to glare and contrast seem unrelated to whether an ACL or an PCL is implanted, although there was a slight, though non-significant, tendency (P = 0.21) for the eyes with an ACL to be more affected by glare than the eyes with a PCL. The responses to glare and contrast should be evaluated carefully when these parameters are used to assist the indication of a cataract extraction in a patient with a Eur J Implant Ref Surg, Vo/4, September 1992

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good visual acuity, as almost identical responses may be registered in the pseudophakic eye. No differences in lOPs were found, except just after surgery, where a slightly higher pressure profile was measured in ICCE-operated eyes, but none of the patients needed antiglaucomatous treatment. After 6 months none of the ECCE- or ICCE-operated eyes had pressures higher than 19 mmHg; there was no significant difference between the two. There were also no significant changes (increase or reduction) from preoperative values in either ECCEor ICCE-operated eyes (Fig. 3). No differences were observed between the corneas in the ICCE-operated eyes with ACLs and the ECCE-operated eyes with PCLs although an endothelial cell count was not done. No retinal or macular changes were noticed between the two. The complication rate in both ECCE and ICCE has been reported as being low [3], and complications occurring due to ACLs may be overestimated when modern flexible open loop designs are used, as in this study [6]. However, the present investigation gives no conclusions on possible differences between ICCE and ECCE in the occurrence of complications such as secondary glaucoma, corneal decompensation, cystoid macular oedema and retinal detachment, all of which have been reported to occur at an increased rate in ICCE/ACL eyes [1-3]. This study is probably also the first to compare ICCE with a modern ACL and ECCE with a PCL, as all earlier studies [1-3, 5] have used ACLs with a reported higher complication rate [6]. It is still possible to find patients, even in developed countries such as Denmark, who may become almost blind from advanced cataract in both eyes before any desire or, less likely, possibility has arisen for treatment. In some of these patients it may be practical, justified and even safe to perform simultaneous cataract surgery on both eyes during the same operative session, after the patient has been informed of possible risks and advances and when safety measures can be taken as described in this and other similar studies [7]. In the present study, no complications occurred which could be ascribed to simultaneous cataract surgery performed on both eyes; however, the number of patients was small and allows no conclusions to be derived on the possibility and risk of bilateral panophthalmitis. Panophthalmitis is considered by some to be a major risk and a possible contraindication of bilateral cataract surgery, at least in congenital and juvenile cataracts [6]. In conclusion, bilateral cataract surgery may be safe and justified in selected patients. The magnitude of the present study allows no definite conclusions considering a possible difference in compli-

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cation rate between ICCE/ACL- and ECCE/PCLoperated eyes, although visual rehabilitation seems to develop with the same speed and to the same extent, when evaluated by visual acuity, contrast and glare in the same patient, having both types of operation performed at the same time.

REFERENCES NS Jaffe, HM Clayman, MS Jaffe. Cystoid macular edema after intracapsular and extracapsular cataract extraction with and without an intraocular lens. Ophthalmology, 1982; 89:25-29. 2 NS Jaffe, HM Clayman, MS Jaffe. Retinal detachment in

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myopic eyes after intracapsular and extracapsular cataract extraction. Am. J. Ophthalmol., 1984; 97: 48-52. K Nreser, TE Hansen, NE Nielsen. Visual outcome and complications following intracapsular and extracapsular cataract surgery. Acta Ophthalmol., 1991; 68: 733-738. SPB Percival, SS Setty. Analysis of the need for secondary capsulotomy during a five-year follow-up. J. Cataract Refract. Surg., 1988; 14: 379-382. B Calissendorff, S B~s. Visual function after cataract surgery with intraocular lenses: ECCE compared with ICCE. Eur. J. Implant Ref Surg., 1991; 2: 185-189. ES Lim, DJ Apple, JC Tsai, RB Morgan, D Wasserman, EI Assia. An analysis of flexible anterior chamber lenses with special reference to the normalized rate of lens explantation. Ophthalmology, 1991; 98: 243-246. 8 Guo, LB Nelson, J Calhoun, A Levin. Simultaneous surgery for bilateral congenital cataracts. J. Paediatr. Ophthalmol. Strabismus, 1990; 27: 23-25.

Eur J Implant Ref Surg, Vol 4, September 1992