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Intercapsular Cataract Extraction with Intraocular Lens Implantation in Diabetes Mellitus
Intercapsular Cataract Extraction with Intraocular Lens Implantation in Diabetes Mellitust MOHINDER S. DANG* and PALANISWAMY SUNDER RAJ Department of Ophthalmology, Memorial Hospital, Darlington DL3 6HX, U. K.
A retrospective evaluation of intercapsular cataract extraction with 'in the capsular bag' Intraocular lens implantation (IOL) was carried out on 45 eyes of 34 diabetics and 200 non-diabetic eyes. This demonstrated no statistically significant difference in operative or postoperative complications (P>0.4). A postoperative corrected visual acuity of 6/12 or better was achieved in 80% of the operated diabetic eyes and 87% of the non-diabetic eyes. When eyes with preexisting diseases responsible for reducing vision were excluded, postoperative corrected visual acuity of 6/12 or better was seen in 92% of the diabetic eyes compared to 94% in non-diabetic eyes. These differences were not significant (P>0.2 and >0.7 respectively). Postoperative visualization of the fundus and retinal photocoagulation with Argon laser could be carried out through the intraocular lens without any significant problem. There was no deterioration in the diabetic retinopathy status after the surgery. Diabetes mellitus per se does not adversely affect the results of cataract-IOL surgery. Keywords: Cataract; Diabetes; Intraocular lenses; Laser therapy INTRODUCTION
PATIENTS AND METHODS
Diabetes is present in approximately 2% of the United Kingdom population. Affected individuals have an increased prevalence of degenerative or agerelated cataract [1] which will need surgery at some stage of their lives. However, some surgeons [2-5] consider diabetes as a contra-indication to IOL implantation especially if there is some form of retinopathy. Other reports suggest that IOL implantation in diabetics, with or without non-proliferative retinopathy, have been as successful as in nondiabetics [6-11]. Limited data are available regarding intercapsular cataract extraction and 'in-the-bag' IOL implantation in diabetic patients. Further, many studies of IOL implantation in diabetics [9-11] have not included a similar non-diabetic population for comparison purposes. Hence, we carried out a retrospective evaluation of IOL implantation in diabetic and non-diabetic patients to determine if there were any differences between the 2 groups in the visual outcome and frequency of complications.
A review of the records of all the eyes that underwent intercapsular cataract extraction with in-the-bag insertion of a reversed optic posterior chamber IOL between 1985 and 1988 revealed 54 eyes of 40 diabetic patients. Of these 6 patients (9 eyes) were lost to follow-up and therefore they have been excluded from this study. The remaining 34 patients (45 eyes) were retrospectively analysed, after a follow-up period ranging from 3 months to 34 months (Table 1) with a mean of24 months. We also analysed
* To whom all correspondence should be sent. t This paper is partly based on a report presented at a meeting of the European Intraocular Implant Council in Copenhagen, September 1988. 0955-3681/91/010035+05 $03.00/0 © 1991 Bailliere Tindall
Table 1 Duration of postoperative follow-up of the diabetic eyes Percentage Follow-up period (months) No. of eyes 11 3-6 5 7-12 20 9 13-24 16 36 >24 33 15 45
10
200 consecutive non-diabetic eyes which underwent the above procedure in the same period. Preoperative evaluation of all the patients included estimation of best corrected visual acuity, slit lamp examination, intraocular pressure measurement, ophthalmoscopy under mydriasis, ocular biometry with A scan ultrasonography and Eur J Implant Ref Surg, Vol 3, March 1991
M.S. Dang, P. Sunder Raj
36
IOL power calculations. Diabetic retInal status was determined preoperatively as far as possible but had to be done postoperatively where lens opacities precluded a reasonably good view of the fundus. All the operations were performed by the same surgeon (MSD) usually under general anaesthesia. The basic surgical technique adopted was the intercapsular or endocapsular method of Baikoff [12] and Galand [13]: corneo-scleral two step incision, linear anterior capsulotomy between two and ten o'clock, nucleus expression, manual infusion/aspiration of the cortex, insertion of a reversed optic IOL 'in-thebag', a small anterior capsulectomy and closure of section with 10'0 nylon sutures followed by a subconjunctival injection of Gentamycin and Beta-methasone. Sodium hyaluronate was used at various stages of the above procedure. Postoperatively all the eyes routinely received a topical antibiotic-steroid combination 3 times daily and cyclopentolate hydrochloride 1% once or twice daily for 2 weeks; the former alone was continued for another 4 weeks. Follow-up examination was carried out at 2 weeks, 6 weeks, 3 months and then every 6 months postoperatively. At each follow-up best corrected visual acuity, refraction, intraocular pressure, complications and treatment, if any, were recorded. The significance of the difference in the frequency of operative and postoperative complications and in best corrected visual acuity between operated diabetic and non-diabetic eyes was assessed with the Chi -squared (X 2 ) test. RESULTS
The mean duration offollow-up was 22 months in the diabetic patients compared to 24 months for the nondiabetic group. Table 2 shows the age and sex distribution of the study patients. The average age of the diabetic patients was 65 years while that of the non-diabetic patients was 74 years. Table 2 Age and sex distribution ofthe diabetic patients (N =34) Age (years) Percentage Sex Total No. ofpatients Male Female 41-50 1 2 3 9 51-60 2 5 15 3 ·4 61-70 6 10 30 71-80 5 7 12 35 >81 2 4 12 2 14 (41%)
20 (59%)
34
101
All the diabetic patients were either suffering from maturity onset or non-insulin-dependent diabetes mellitus (NIDDM) which was controlled by diet and
oral hypoglycaemic drugs in 25 patients or were insulin dependent (9 patients). Evaluation of the retinal status of the diabetic patients using ophthalmoscopy and fluoroscein angiography revealed that 58% of the eyes exhibited retinal changes due to diabetes (Table 3). Table 3 Retinal status of the diabetic eyes (N = 45) No. of eyes Percentage Retinal status Normal 19 42 13 28 Background Maculopathy 10 22 Pre-proliferative 2 5 Proliferative 1 3 45 100
Preexisting ocular disease other than diabetic retinopathy included 4 eyes with age-related macular degeneration (ARMD) and one each with open angle glaucoma, amblyopia and cornea guttata. Tables 4 and 5 list the frequency of operative and Table 4 Peroperative complications in diabetic (N = 45) and non-diabetic eyes (N = 200) Complication Non-diabetic e~es Diabetic e~es No. Percent. No. Percent Surgical hyphaema 3 6.7 6 3 Extension of anterior caps ulotomy to the equator 1 2.2 3 1.5 Posterior capsule tear (a) Minor 1 2.2 2 1 (b) Major 2 1 Incomplete clearance of the cortex 2 4.4 10 5 x2 test = 0.57; P>O.4 not significant. Table 5 Postoperative complications in diabetic (N = 45) and non-diabetic (N = 200) eyes
Complication No. (a) Early Soft lens matter in the anterior chamber Hyphaema Fibrin in the pupillary area and/or anterior uveitis Vitreous haemorrhage Raised intraocular pressure (b) LATE Posterior capsular thickening Lens decentration (a) Minor (b) Major Persistent anterior uveitis Pupil distortion Cystoid macular oedema X2 test = 0.59; P>Q.4 not significant.
Diabetic ~es Percent
2 3
4.4 6.6
1 1
2.2 2.2
Non-diabetic e~es No. Percent 10 6
5 3
4
2 5
3
6.6
10
1
2.2
6 1
3 0.5
1 1 -
2.2 2.2
1 4 1
0.5 2 0.5
Eur J Implant Ref Surg, Vol 3, March 1991
IntraOcular Lenses in Diabetics
postoperative complications in 45 diabetic eyes and 200 non-diabetic eyes. There was no statistically significant difference between the two groups (P>O.4). A final corrected visual acuity of more than 6/12 was achieved in 80% of the diabetic eyes (Table 6) which rose to 92% when eyes with preexisting causes of reduced visual acuity were excluded (Table 7). Table 6 Corrected postoperative visual acuity in operated diabetic (N = 45) and non-diabetic (N = 200) eyes Visual acuity Non-diabetics Diabetics No. of eyes Percent No. of eyes Percent >6/12 36 80 174 87 6/18-6/24 4 9 6 3 6/36-6/60 3 7 8 4 < 6/60 2 4 12 6 45 100 200 100 x2 test = 1.52; P>0.2 not significant. Table 7 Corrected postoperative visual acuity in operated diabetic and non-diabetic eyes after excluding eyes with preexisting disease affecting vision Visual acuity Non-diabetics Diabetics No. of eyes Percent No. of eyes Percent > 6/12 36 92 172 94 6/18-6/24 1 8 5 3 2 6/36-6/60 1 1 3 1 1 1 < 6/60 3 183 39 101 101 x2 test = 0.13; P>0.7 not significant.
There was no statistically significant difference when this was compared with a similar analysis of the 200 non-diabetic eyes which gave figures of 87% (P>0.2) and 94% (>0.7) respectively. Diabetic maculopathy, either alone or in combination with some other ocular pathology, was the commonest non-operative cause of reduced visual acuity in operated diabetic eyes (Table 8). Table 8 Preexisting eye disease causing reduced visual acuity in operated diabetic eyes (N = 6) Number of eyes Ocular disease Percent Diabetic maculopathy (a) alone 2 33 (b) with branch vein occlusion 1 17 (c) with ARMD 1 17 1 17 ARMDalone 1 Amblyopia 17
The best corrected postoperative visual acuity was less than 6/12 in three diabetic eyes after preexisting ocular disease affecting vision had been excluded. This was due to one case each of vitreous haemorrhage, thickened posterior capsule (awaiting YAG laser capsulotomy) and persistent anterior uveitis with pigment deposition on the IOL implant. However, we are not certain if the vitreous haemorrhage Eur J Implant Ref Surg, Vol 3, March 1991
37
occurred in the postoperative period since the fundal view was not possible either preoperatively or during the surgery. A final visual acuity of 6/24 was achieved in this patient after vitrectomy and endo-coagulation. All the patients underwent postoperative fundal examination and fluoroscein angiography where necessary, at regular intervals. Of the 15 diabetic eyes which were followed up for more than 2 years, two eyes (13%) had a change of retinal status with both developing minimal background retinopathy. Six study eyes (13%) required Argon laser photocoagulation in the post-IOL period due to diabetic retinopathy. No particular problem was encountered in the above eyes during fundus examination or laser photo-coagulation except in one patient who had moderate posterior capsular opacification. DISCUSSION
Diabetes mellitus is a common disorder with earlier and increased prevalance of cataractous changes [1]. At the same time, the life expectancy of diabetics is increasing due to improvements in medical management and is only slightly lower than that of the general population [14]. This means that compared to a non-diabetic, it is not only more likely that a diabetic will need cataract extraction at a younger age but also that he will have to wear his aphakic correction for longer. Visual demands are greater in younger patients and an IOL implant offers the maximal benefit in these patients particularly those with macular pathology. However some surgeons consider diabetes mellitus as a relative contraindication to IOL implantation [3-5] mainly because of the view that: (i) complications are more frequent during and after implant surgery in diabetics; (ii) an IOL implant makes evaluation and treatment of diabetic retinopathy either difficult or impossible. The frequency of operative and postoperative complications in cataract surgery is difficult to establish and compare because of varying surgical techniques and non-standardization of complications. With this limitation in mind, the frequency of complications in our diabetic eyes, as in previous reports, was not significantly different from those in non-diabetic eyes [2, 6, 15]. This may be due to the obvious advantages of using the intercapsular technique: (i) retention of the anterior capsule during expression of the nucleus, infusion and aspiration of lens matter and IOL insertion allows these manoeuvres to be done within the bag, thus protecting the endothelial cells from damage [16];
38
M.S. Dang, P. Sunder Raj
The less favourable visual outcome ofIOL implantation in diabetic eyes as compared to' non-diabetics was due to the greater occurrence of preexisting ocular disease in diabetics, especially diabetic maculopathy. This became evident when eyes with preexisting ocular pathology affecting visual acuity were excluded (Table 7). Visual outcome was then similar among diabetics and non-diabetics. This indicates that diabetes mellitus per se does not have an adverse influence on the visual results following Previous reports have documented an increased cataract-IOL surgery. frequency of vitreous haemorrhage [18], neovascular Consistent with experience of other authors [7, 8, glaucoma [19] and cystoid macular oedema (CMO) 10,11,21], we did not face any significant problems in [11] after cataract surgery in diabetic patients either visualizing the postimplant diabetic fundus or especially if associated retinopathy is present. We treating it with Argon laser. Capsular opacification experienced one case of vitreous haemorrhage but it which was a problem in some cases was easily solved is possible that this was present preoperatively. No by performing N d: YAG posterior capsulotomy. case of CMO was noticed in our study. The discrepIt appears from our experience and that of other ancy between our study and that of Cheng and reports [6-8, 10, 11] that IOL implantation does not Franklin [11] may be due to differences in surgical have a deleterious effect on the progress of retintechnique. All our diabetic eyes with retinopathy opathy in diabetic eyes. In one of the two patients in underwent intercapsular cataract extraction with whom deterioration of the retinopathy status the insertion of a posterior chamber IOL while Cheng occurred after surgery, similar changes were noticed and Franklin [11] did not mention the surgical techin the unoperated fellow eye. However, this stresses nique adopted and type of IOL implanted in the 18 the importance of close post-IOL follow-up and coneyes with diabetic retinopathy. All the operated tinued monitoring of the retinal status. diabetic eyes in this study, except one with a minor Several previous studies on cataract-IOL surgery tear, had an intact posterior capsule, which is protecin diabetics [2, 6-8, 10, 11] are in general agreement tive against the development of pseudophakic CMO with our findings regarding visual outcome, fre[19] perhaps by preventing backward diffusion of quency of complications, visualization of the fundus, prostaglandins or by scattering ultraviolet energy photo-coagulation therapy, laser and effect on retinoaway from the macula [20]. It is well known that pathy. This study also shows that intercapsular inflamed eyes are much more likely to develop cataract extraction with in-the-bag implantation of pseudophakic CMO [19]. Capsular fixation of the an IOL in diabetic patients helps to achieve results IOL, as performed in our patients, minimizes uveal comparable to those attained in non-diabetics. contact [17] and consequent inflammation. It must be emphasized that undue occurrence of hyphaema, fibrin in the pupillary area, anterior uveiREFERENCES tis or raised intraocular pressure was not observed in our diabetic eyes when compared with non-diabetics. 1 F. Ederer, R. Hiller and H.R. Taylor. Senile lens changes and diabetes in two population studies. Am. J. Ophthalmol., 91, The visual outcome of cataract-IOL surgery in our (1981). group of diabetic patients is comparable to similar 2 381-395 B.R. Straatsma, T.H. Pettit, N. Wheeler and W. Myamasu. previous studies [2, 6-8, 10]. Reports vary from 65% Diabetes mellitus and intraocular lens implantation. Ophthalmology, 90, 336-343 (1983). [2] of the diabetic patients achieving a postoperative D. Wong and MeG. Steele. A Survey of Intraocular Lens visual acuity of6/12 or better to 88.5% [6] of the eyes 3 Implantation in the United Kingdom. Trans. Ophthalmol. achieving a visual acuity of similar magnitude. This Soc. UK, 104, 760-765 (1985). 4 A. Platz. Photo-coagulation of Retinal, Vascular and Macular wide range is mainly due to the differences in fredisease through Intraocular Lenses. Ophthalmology, 88, 398quency of preexisting ocular pathology including 406 (1981). diabetic maculopathy and ARMD in operated 5 J. Francois. Ethics in Cataract Surgery edited by J. Francois, A.E. Maumenee, I. Esente. In: Cataract Surgery and Visual diabetic eyes [10]. Rehabilitation. Second International Congress on Cataract Cheng and Franklin [11] reported that eyes with Surgery and Visual Rehabilitation ofthe Aphakic Eye. Flordiabetic retinopathy achieved significantly worse ence 1981. Milano Libreria Scientifica (1982) pp. 19-22. visual results when compared with eyes without 6 H.M. Clayman, N.S. Jaffe and D.S. Light. Lens implantation and diabetes mellitus. Am. J. Ophthalmol., 88, 990-992 diabetic retinopathy. We did not perform such a (1979). differential analysis as it was felt that the number of 7 M.S.H. Ngui, A.8.M. Lim and A.B. Chong. Posterior chamber intraocular lenses in diabetics. Int. Ophthalmol., 8, 257-259 eyes in the two groups were too small to permit any (1985). meaningful statistical comparison. (ii) IOL is placed within the capsule bag under direct visual control and since this insulates the IOL from contact with adjacent structures [17], chafing of the pigment from the posterior surface of the iris and other related complications are avoided. These advantages are of particular importance in diabetes mellitus where increased frequency of pigment dispersion, inflammation and bleeding during surgical manipulation of the iris is possible.
Eur J Implant Ref Surg, Vol 3, March 1991
Intraocular Lenses in Diabetics
8 P.M. Hart, A.S.M. Lim, B.C. Ang, J.E. Kennedy and M.8.H. Ngui. Posterior Chamber Intraocular Lenses in Diabetics-A review of 126 cases. Implants Ophthalmol., 1, 55-58 (1987). 9 S.M. Thompson, E.E. Kritzinger and M.J. Roper-Hall. Should diabetes be a contra-indication for an intraocular lens? Trans. Ophthalmol. Soc. UK, 103, 115-117 (1983). 10 J.G. Sebestyen. Intraocular lens and diabetes mellitus. Am. J. Ophthalmol., 101,425-428 (1986). 11 H. Cheng and S.L. Franklin. Treatment of cataract in diabetics with and without retinopathy. Eye, 2, 606-614 (1988). 12 G. Baikoff. Insertion ofthe simcoe posterior chamber lens into the capsular bag. Am. Intra-Oc. Implant Soc. J., 7, 267-269 (1981). 13 A. Galand. A simple method ofimplantation within the capsular bag. Am. Intra-Oc Implant Soc. J., 9, 330-332 (1983). 14 P.S. Entmacher and G.S. Bale. Insurability and life expectancy in diabetics. Diabetes Mellitus, 5, 341 (1981). 15 B. Biedner, E. Bessler and Y. Yassur. Iritis after cataract extraction in diabetic patients. Eur. J. Implant Ref Surg., 1, 13-14 (1989). 16 P.I. Condon, G.D. Barrett and M. Kinsella. Results of the
Eur J Implant Ref Surg, Vol 3, March 1991
39
17 18
19 20 21 22
Intercapsular Technique with the IOGEL Lens. J. Cataract Refract. Surg., 15,495-503 (1988). R. Champion, P.J. McDonnell and W.R. Green. Intraocular lenses. Histopathologic characteristics of a large series of autopsy eyes. Surv. Ophthalmol., 30, 1-32 (1985). L.M. Aiello, M. Wand and G. Liang. Neovascular glaucoma and vitreous haemorrhage following cataract surgery in patients with diabetes mellitus. Ophthalmology, 90, 814-820 (1983). L.M. Jampol, D.R. Sanders and M.C. Kraff. Prophylaxis and Therapy of aphakic cystoid macular edema. Surv. Ophthalmol., 28 (Suppl), 535-539 (1984). L.M. Jampol. Aphakic cystoid macular edema. (Editorial) Arch. Ophthalmol., 103, 1134-1135 (1985). J.G. Sebestyen and M.Z. Wafai. Experience with intraocular lens implants in patients with diabetes. Am. J. Ophthalmol., 96,94 (1983). J.G. Jaffe and T. Burton. Progression of non-proliferative diabetic retinopathy following cataract extraction. Arch. Opthalmol., 106, 745-749 (1988).
Received December 1989
A retrospective evaluation of intercapsular cataract extraction with 'in the capsular bag' Intraocular lens implantation (IOL) was carried out on 45 eyes of 34 diabetics and 200 non-diabetic eyes. This demonstrated no statistically significant difference in operative or postoperative complications (P>0.4). A postoperative corrected visual acuity of 6/12 or better was achieved in 80% of the operated diabetic eyes and 87% of the non-diabetic eyes. When eyes with preexisting diseases responsible for reducing vision were excluded, postoperative corrected visual acuity of 6/12 or better was seen in 92% of the diabetic eyes compared to 94% in non-diabetic eyes. These differences were not significant (P>0.2 and >0.7 respectively). Postoperative visualization of the fundus and retinal photocoagulation with Argon laser could be carried out through the intraocular lens without any significant problem. There was no deterioration in the diabetic retinopathy status after the surgery. Diabetes mellitus per se does not adversely affect the results of cataract-IOL surgery. Keywords: Cataract; Diabetes; Intraocular lenses; Laser therapy INTRODUCTION
PATIENTS AND METHODS
Diabetes is present in approximately 2% of the United Kingdom population. Affected individuals have an increased prevalence of degenerative or agerelated cataract [1] which will need surgery at some stage of their lives. However, some surgeons [2-5] consider diabetes as a contra-indication to IOL implantation especially if there is some form of retinopathy. Other reports suggest that IOL implantation in diabetics, with or without non-proliferative retinopathy, have been as successful as in nondiabetics [6-11]. Limited data are available regarding intercapsular cataract extraction and 'in-the-bag' IOL implantation in diabetic patients. Further, many studies of IOL implantation in diabetics [9-11] have not included a similar non-diabetic population for comparison purposes. Hence, we carried out a retrospective evaluation of IOL implantation in diabetic and non-diabetic patients to determine if there were any differences between the 2 groups in the visual outcome and frequency of complications.
A review of the records of all the eyes that underwent intercapsular cataract extraction with in-the-bag insertion of a reversed optic posterior chamber IOL between 1985 and 1988 revealed 54 eyes of 40 diabetic patients. Of these 6 patients (9 eyes) were lost to follow-up and therefore they have been excluded from this study. The remaining 34 patients (45 eyes) were retrospectively analysed, after a follow-up period ranging from 3 months to 34 months (Table 1) with a mean of24 months. We also analysed
* To whom all correspondence should be sent. t This paper is partly based on a report presented at a meeting of the European Intraocular Implant Council in Copenhagen, September 1988. 0955-3681/91/010035+05 $03.00/0 © 1991 Bailliere Tindall
Table 1 Duration of postoperative follow-up of the diabetic eyes Percentage Follow-up period (months) No. of eyes 11 3-6 5 7-12 20 9 13-24 16 36 >24 33 15 45
10
200 consecutive non-diabetic eyes which underwent the above procedure in the same period. Preoperative evaluation of all the patients included estimation of best corrected visual acuity, slit lamp examination, intraocular pressure measurement, ophthalmoscopy under mydriasis, ocular biometry with A scan ultrasonography and Eur J Implant Ref Surg, Vol 3, March 1991
M.S. Dang, P. Sunder Raj
36
IOL power calculations. Diabetic retInal status was determined preoperatively as far as possible but had to be done postoperatively where lens opacities precluded a reasonably good view of the fundus. All the operations were performed by the same surgeon (MSD) usually under general anaesthesia. The basic surgical technique adopted was the intercapsular or endocapsular method of Baikoff [12] and Galand [13]: corneo-scleral two step incision, linear anterior capsulotomy between two and ten o'clock, nucleus expression, manual infusion/aspiration of the cortex, insertion of a reversed optic IOL 'in-thebag', a small anterior capsulectomy and closure of section with 10'0 nylon sutures followed by a subconjunctival injection of Gentamycin and Beta-methasone. Sodium hyaluronate was used at various stages of the above procedure. Postoperatively all the eyes routinely received a topical antibiotic-steroid combination 3 times daily and cyclopentolate hydrochloride 1% once or twice daily for 2 weeks; the former alone was continued for another 4 weeks. Follow-up examination was carried out at 2 weeks, 6 weeks, 3 months and then every 6 months postoperatively. At each follow-up best corrected visual acuity, refraction, intraocular pressure, complications and treatment, if any, were recorded. The significance of the difference in the frequency of operative and postoperative complications and in best corrected visual acuity between operated diabetic and non-diabetic eyes was assessed with the Chi -squared (X 2 ) test. RESULTS
The mean duration offollow-up was 22 months in the diabetic patients compared to 24 months for the nondiabetic group. Table 2 shows the age and sex distribution of the study patients. The average age of the diabetic patients was 65 years while that of the non-diabetic patients was 74 years. Table 2 Age and sex distribution ofthe diabetic patients (N =34) Age (years) Percentage Sex Total No. ofpatients Male Female 41-50 1 2 3 9 51-60 2 5 15 3 ·4 61-70 6 10 30 71-80 5 7 12 35 >81 2 4 12 2 14 (41%)
20 (59%)
34
101
All the diabetic patients were either suffering from maturity onset or non-insulin-dependent diabetes mellitus (NIDDM) which was controlled by diet and
oral hypoglycaemic drugs in 25 patients or were insulin dependent (9 patients). Evaluation of the retinal status of the diabetic patients using ophthalmoscopy and fluoroscein angiography revealed that 58% of the eyes exhibited retinal changes due to diabetes (Table 3). Table 3 Retinal status of the diabetic eyes (N = 45) No. of eyes Percentage Retinal status Normal 19 42 13 28 Background Maculopathy 10 22 Pre-proliferative 2 5 Proliferative 1 3 45 100
Preexisting ocular disease other than diabetic retinopathy included 4 eyes with age-related macular degeneration (ARMD) and one each with open angle glaucoma, amblyopia and cornea guttata. Tables 4 and 5 list the frequency of operative and Table 4 Peroperative complications in diabetic (N = 45) and non-diabetic eyes (N = 200) Complication Non-diabetic e~es Diabetic e~es No. Percent. No. Percent Surgical hyphaema 3 6.7 6 3 Extension of anterior caps ulotomy to the equator 1 2.2 3 1.5 Posterior capsule tear (a) Minor 1 2.2 2 1 (b) Major 2 1 Incomplete clearance of the cortex 2 4.4 10 5 x2 test = 0.57; P>O.4 not significant. Table 5 Postoperative complications in diabetic (N = 45) and non-diabetic (N = 200) eyes
Complication No. (a) Early Soft lens matter in the anterior chamber Hyphaema Fibrin in the pupillary area and/or anterior uveitis Vitreous haemorrhage Raised intraocular pressure (b) LATE Posterior capsular thickening Lens decentration (a) Minor (b) Major Persistent anterior uveitis Pupil distortion Cystoid macular oedema X2 test = 0.59; P>Q.4 not significant.
Diabetic ~es Percent
2 3
4.4 6.6
1 1
2.2 2.2
Non-diabetic e~es No. Percent 10 6
5 3
4
2 5
3
6.6
10
1
2.2
6 1
3 0.5
1 1 -
2.2 2.2
1 4 1
0.5 2 0.5
Eur J Implant Ref Surg, Vol 3, March 1991
IntraOcular Lenses in Diabetics
postoperative complications in 45 diabetic eyes and 200 non-diabetic eyes. There was no statistically significant difference between the two groups (P>O.4). A final corrected visual acuity of more than 6/12 was achieved in 80% of the diabetic eyes (Table 6) which rose to 92% when eyes with preexisting causes of reduced visual acuity were excluded (Table 7). Table 6 Corrected postoperative visual acuity in operated diabetic (N = 45) and non-diabetic (N = 200) eyes Visual acuity Non-diabetics Diabetics No. of eyes Percent No. of eyes Percent >6/12 36 80 174 87 6/18-6/24 4 9 6 3 6/36-6/60 3 7 8 4 < 6/60 2 4 12 6 45 100 200 100 x2 test = 1.52; P>0.2 not significant. Table 7 Corrected postoperative visual acuity in operated diabetic and non-diabetic eyes after excluding eyes with preexisting disease affecting vision Visual acuity Non-diabetics Diabetics No. of eyes Percent No. of eyes Percent > 6/12 36 92 172 94 6/18-6/24 1 8 5 3 2 6/36-6/60 1 1 3 1 1 1 < 6/60 3 183 39 101 101 x2 test = 0.13; P>0.7 not significant.
There was no statistically significant difference when this was compared with a similar analysis of the 200 non-diabetic eyes which gave figures of 87% (P>0.2) and 94% (>0.7) respectively. Diabetic maculopathy, either alone or in combination with some other ocular pathology, was the commonest non-operative cause of reduced visual acuity in operated diabetic eyes (Table 8). Table 8 Preexisting eye disease causing reduced visual acuity in operated diabetic eyes (N = 6) Number of eyes Ocular disease Percent Diabetic maculopathy (a) alone 2 33 (b) with branch vein occlusion 1 17 (c) with ARMD 1 17 1 17 ARMDalone 1 Amblyopia 17
The best corrected postoperative visual acuity was less than 6/12 in three diabetic eyes after preexisting ocular disease affecting vision had been excluded. This was due to one case each of vitreous haemorrhage, thickened posterior capsule (awaiting YAG laser capsulotomy) and persistent anterior uveitis with pigment deposition on the IOL implant. However, we are not certain if the vitreous haemorrhage Eur J Implant Ref Surg, Vol 3, March 1991
37
occurred in the postoperative period since the fundal view was not possible either preoperatively or during the surgery. A final visual acuity of 6/24 was achieved in this patient after vitrectomy and endo-coagulation. All the patients underwent postoperative fundal examination and fluoroscein angiography where necessary, at regular intervals. Of the 15 diabetic eyes which were followed up for more than 2 years, two eyes (13%) had a change of retinal status with both developing minimal background retinopathy. Six study eyes (13%) required Argon laser photocoagulation in the post-IOL period due to diabetic retinopathy. No particular problem was encountered in the above eyes during fundus examination or laser photo-coagulation except in one patient who had moderate posterior capsular opacification. DISCUSSION
Diabetes mellitus is a common disorder with earlier and increased prevalance of cataractous changes [1]. At the same time, the life expectancy of diabetics is increasing due to improvements in medical management and is only slightly lower than that of the general population [14]. This means that compared to a non-diabetic, it is not only more likely that a diabetic will need cataract extraction at a younger age but also that he will have to wear his aphakic correction for longer. Visual demands are greater in younger patients and an IOL implant offers the maximal benefit in these patients particularly those with macular pathology. However some surgeons consider diabetes mellitus as a relative contraindication to IOL implantation [3-5] mainly because of the view that: (i) complications are more frequent during and after implant surgery in diabetics; (ii) an IOL implant makes evaluation and treatment of diabetic retinopathy either difficult or impossible. The frequency of operative and postoperative complications in cataract surgery is difficult to establish and compare because of varying surgical techniques and non-standardization of complications. With this limitation in mind, the frequency of complications in our diabetic eyes, as in previous reports, was not significantly different from those in non-diabetic eyes [2, 6, 15]. This may be due to the obvious advantages of using the intercapsular technique: (i) retention of the anterior capsule during expression of the nucleus, infusion and aspiration of lens matter and IOL insertion allows these manoeuvres to be done within the bag, thus protecting the endothelial cells from damage [16];
38
M.S. Dang, P. Sunder Raj
The less favourable visual outcome ofIOL implantation in diabetic eyes as compared to' non-diabetics was due to the greater occurrence of preexisting ocular disease in diabetics, especially diabetic maculopathy. This became evident when eyes with preexisting ocular pathology affecting visual acuity were excluded (Table 7). Visual outcome was then similar among diabetics and non-diabetics. This indicates that diabetes mellitus per se does not have an adverse influence on the visual results following Previous reports have documented an increased cataract-IOL surgery. frequency of vitreous haemorrhage [18], neovascular Consistent with experience of other authors [7, 8, glaucoma [19] and cystoid macular oedema (CMO) 10,11,21], we did not face any significant problems in [11] after cataract surgery in diabetic patients either visualizing the postimplant diabetic fundus or especially if associated retinopathy is present. We treating it with Argon laser. Capsular opacification experienced one case of vitreous haemorrhage but it which was a problem in some cases was easily solved is possible that this was present preoperatively. No by performing N d: YAG posterior capsulotomy. case of CMO was noticed in our study. The discrepIt appears from our experience and that of other ancy between our study and that of Cheng and reports [6-8, 10, 11] that IOL implantation does not Franklin [11] may be due to differences in surgical have a deleterious effect on the progress of retintechnique. All our diabetic eyes with retinopathy opathy in diabetic eyes. In one of the two patients in underwent intercapsular cataract extraction with whom deterioration of the retinopathy status the insertion of a posterior chamber IOL while Cheng occurred after surgery, similar changes were noticed and Franklin [11] did not mention the surgical techin the unoperated fellow eye. However, this stresses nique adopted and type of IOL implanted in the 18 the importance of close post-IOL follow-up and coneyes with diabetic retinopathy. All the operated tinued monitoring of the retinal status. diabetic eyes in this study, except one with a minor Several previous studies on cataract-IOL surgery tear, had an intact posterior capsule, which is protecin diabetics [2, 6-8, 10, 11] are in general agreement tive against the development of pseudophakic CMO with our findings regarding visual outcome, fre[19] perhaps by preventing backward diffusion of quency of complications, visualization of the fundus, prostaglandins or by scattering ultraviolet energy photo-coagulation therapy, laser and effect on retinoaway from the macula [20]. It is well known that pathy. This study also shows that intercapsular inflamed eyes are much more likely to develop cataract extraction with in-the-bag implantation of pseudophakic CMO [19]. Capsular fixation of the an IOL in diabetic patients helps to achieve results IOL, as performed in our patients, minimizes uveal comparable to those attained in non-diabetics. contact [17] and consequent inflammation. It must be emphasized that undue occurrence of hyphaema, fibrin in the pupillary area, anterior uveiREFERENCES tis or raised intraocular pressure was not observed in our diabetic eyes when compared with non-diabetics. 1 F. Ederer, R. Hiller and H.R. Taylor. Senile lens changes and diabetes in two population studies. Am. J. Ophthalmol., 91, The visual outcome of cataract-IOL surgery in our (1981). group of diabetic patients is comparable to similar 2 381-395 B.R. Straatsma, T.H. Pettit, N. Wheeler and W. Myamasu. previous studies [2, 6-8, 10]. Reports vary from 65% Diabetes mellitus and intraocular lens implantation. Ophthalmology, 90, 336-343 (1983). [2] of the diabetic patients achieving a postoperative D. Wong and MeG. Steele. A Survey of Intraocular Lens visual acuity of6/12 or better to 88.5% [6] of the eyes 3 Implantation in the United Kingdom. Trans. Ophthalmol. achieving a visual acuity of similar magnitude. This Soc. UK, 104, 760-765 (1985). 4 A. Platz. Photo-coagulation of Retinal, Vascular and Macular wide range is mainly due to the differences in fredisease through Intraocular Lenses. Ophthalmology, 88, 398quency of preexisting ocular pathology including 406 (1981). diabetic maculopathy and ARMD in operated 5 J. Francois. Ethics in Cataract Surgery edited by J. Francois, A.E. Maumenee, I. Esente. In: Cataract Surgery and Visual diabetic eyes [10]. Rehabilitation. Second International Congress on Cataract Cheng and Franklin [11] reported that eyes with Surgery and Visual Rehabilitation ofthe Aphakic Eye. Flordiabetic retinopathy achieved significantly worse ence 1981. Milano Libreria Scientifica (1982) pp. 19-22. visual results when compared with eyes without 6 H.M. Clayman, N.S. Jaffe and D.S. Light. Lens implantation and diabetes mellitus. Am. J. Ophthalmol., 88, 990-992 diabetic retinopathy. We did not perform such a (1979). differential analysis as it was felt that the number of 7 M.S.H. Ngui, A.8.M. Lim and A.B. Chong. Posterior chamber intraocular lenses in diabetics. Int. Ophthalmol., 8, 257-259 eyes in the two groups were too small to permit any (1985). meaningful statistical comparison. (ii) IOL is placed within the capsule bag under direct visual control and since this insulates the IOL from contact with adjacent structures [17], chafing of the pigment from the posterior surface of the iris and other related complications are avoided. These advantages are of particular importance in diabetes mellitus where increased frequency of pigment dispersion, inflammation and bleeding during surgical manipulation of the iris is possible.
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8 P.M. Hart, A.S.M. Lim, B.C. Ang, J.E. Kennedy and M.8.H. Ngui. Posterior Chamber Intraocular Lenses in Diabetics-A review of 126 cases. Implants Ophthalmol., 1, 55-58 (1987). 9 S.M. Thompson, E.E. Kritzinger and M.J. Roper-Hall. Should diabetes be a contra-indication for an intraocular lens? Trans. Ophthalmol. Soc. UK, 103, 115-117 (1983). 10 J.G. Sebestyen. Intraocular lens and diabetes mellitus. Am. J. Ophthalmol., 101,425-428 (1986). 11 H. Cheng and S.L. Franklin. Treatment of cataract in diabetics with and without retinopathy. Eye, 2, 606-614 (1988). 12 G. Baikoff. Insertion ofthe simcoe posterior chamber lens into the capsular bag. Am. Intra-Oc. Implant Soc. J., 7, 267-269 (1981). 13 A. Galand. A simple method ofimplantation within the capsular bag. Am. Intra-Oc Implant Soc. J., 9, 330-332 (1983). 14 P.S. Entmacher and G.S. Bale. Insurability and life expectancy in diabetics. Diabetes Mellitus, 5, 341 (1981). 15 B. Biedner, E. Bessler and Y. Yassur. Iritis after cataract extraction in diabetic patients. Eur. J. Implant Ref Surg., 1, 13-14 (1989). 16 P.I. Condon, G.D. Barrett and M. Kinsella. Results of the
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Received December 1989