Intraocular lenses and diabetes mellitus

Cataract in diabetes mellitus

Diabetes mellitus (DM) is a chronic systemic disease that has increases in prevalence over time. DM can affect all ocular structures, with cataract being the most common ocular complication. Cataract is the leading cause of blindness worldwide. Due to several mechanisms, there is an increased incidence of cataract formation in the diabetic population. Advancements in technology have now made cataract surgery a common and safe procedure. However, the diabetic population is still at risk of vision-threatening complications, such as diabetic macular edema (ME), postoperative ME, diabetic retinopathy progression, and posterior capsular opacification.

Cataract Surgery in Patients with Diabetes: Management Strategies

Diabetes is a chronic systemic disease that affects nearly one in eight adults worldwide. Ocular complications, such as cataract, can lead to significant visual impairment. Among the worldwide population, cataract is the leading cause of blindness, and patients with diabetes have an increased incidence of cataracts which mature earlier compared to the rest of the population. Cataract surgery is a common and safe procedure, but can be associated with vision-threatening complications in the diabetic population, such as diabetic macular edema, postoperative macular edema, diabetic retinopathy progression, and posterior capsular opacification. This article is a brief review of diabetic cataract and complications associated with cataract extraction in this population of patients.

Phacoemulcification with intravitreal bevacizumab injection in patients with cataract and coexisting diabetic retinopathy: prospective randomized study

OBJECTIVE

To evaluate efficacy of intravitreal injection of bevacizumab at the time of cataract surgery on the postoperative progression of diabetic retinopathy (DR) and diabetic maculopathy.

METHODS

Patients were randomized to a standardized procedure of phacoemulsification with intraocular lens implantation alone (control group; 30 eyes) or to receive 1.25 mg intravitreal bevacizumab (0.05 mL of solution prepared from avastin, 100 mg/4 mL vial) at the end of surgery (IVB group; 27 eyes). Efficacy measures included best-corrected visual acuity (BCVA) testing, optical coherence tomography (OCT), and ophthalmoscopic examination at each postoperative visit during a 6-month follow-up.

RESULTS

There were no significant differences in central macular thickness (CMT), BCVA, or systemic condition between the control and IVB groups at baseline. Progression of diabetic maculopathy occurred in 15 eyes (50%) in the control group and 2 eyes (7.4%) in the intervention group (P = 0.0008). There was no statistically significant difference in postoperative visual acuity between the 2 groups after 6 months (P = 0.5). Five eyes in the control group and 1 eye in the intervention group progressed to neovascular glaucoma. Difference in mean postoperative CMT was not statistically significant between both groups (P = 0.54).

CONCLUSIONS

Intravitreal administration of 1.25 mg bevacizumab at the time of cataract surgery was safe and effective in preventing the progression of DR and diabetic maculopathy in patients with cataract and DR.

Comparison of Vitrectomy Alone and Combined Vitrectomy, Phacoemulsification and Intraocular Lens Implantation for Proliferative Diabetic Retinopathy

There have been concerns that there may be an increased incidence of iris neovascularization (NV) following lens removal in patients with proliferative diabetic retinopathy (PDR). In this study, we retrospectively compared vitrectomy alone and vitrectomy combined with phacoemulsification (phacovitrectomy) and intraocular lens implantation regarding both complications and results. Fifty-three eyes for vitrectomy group and 31 eyes for phacovitrectomy group were included. Postoperative iris and angle NV were found in eight (15.1%) eyes in the first group and no (0%) eyes in the second. The incidence was significantly lower (p < 0.05) in the phacovitrectomy group. The final vision gain of one or more lines was found in 17 (32.1%) and 21 (67.7%) eyes, respectively. There was significantly better vision improvement in the phacovitrectomy group. We consider the combined procedure to be useful as an alternative surgical treatment for patients with PDR and cataract formation.

Axial length measurement in eyes with diabetic macular edema: a-scan ultrasound versus IOLMaster

OBJECTIVE

To compare axial length (AL) measurements obtained with ultrasound (US) and IOLMaster (software version 3.01.0294; Carl Zeiss Meditec, Jena, Germany) in eyes with diabetic clinically significant macular edema (CSME) and to examine the correlation between measurement difference and foveal thickness.

DESIGN

Prospective nonrandomized clinical study.

PARTICIPANTS

Twenty-three healthy eyes of 23 participants and 21 eyes with CSME of 21 diabetic outpatients.

METHODS

The authors prospectively measured AL using US and IOLMaster in eyes of both groups. Foveal thickness was measured with optical coherence tomography. The difference between both methods was assessed using the t test, and its correlation to foveal thickness was evaluated by Pearson coefficient.

MAIN OUTCOME MEASURE

Difference in AL measurements between IOLMaster and US.

RESULTS

Mean+/-standard deviation foveal thickness in healthy and CSME eyes was 201+/-26 microm (range, 156-240) and 475+/-106 microm (range, 331-758), respectively. Mean AL by US and IOLMaster in healthy eyes was 23.17+/-1.07 mm (range, 21.17-25.18) and 23.25+/-1.10 mm (range, 21.17-25.26), respectively (P = 0.51); in CSME eyes, it was 23.02+/-0.97 mm (range, 21.53-24.81) and 23.27+/-0.924 mm (range, 21.9-25.13), respectively (P<0.001). Correlation between AL difference and foveal thickness was poor in both healthy (r = 0.18, P = 0.40) and CSME (r = 0.02, P = 0.93) eyes.

CONCLUSIONS

Axial length measurements using applanation A-scan US and IOLMaster in eyes with CSME differ statistically and clinically significantly. This is likely a result of the fundamentally different methodology of the 2 methods in measuring eyes with a pathologically thickened retina. A conversion formula based on foveal thickness can not be provided at present.

Does diabetic retinopathy increase the incidence of intraoperative complications of phacoemulsification surgery?

PURPOSE

To evaluate the rates of intraoperative and early postoperative complications (IEPC) and the duration of phacoemulsification (DOP) in the eyes with and without diabetic retinopathy and the effect of oral and topical nonsteroidal anti-inflammatory agents (NSAIDs) on surgically induced miosis (SIM).

MATERIALS AND METHODS

Phacoemulsification was applied to 50 eyes with proliferative diabetic retinopathy (PDR), 50 eyes with nonproliferative diabetic retinopathy (NPDR), and 50 eyes with no other ocular findings. NSAIDs were used perioperatively. The parameters evaluated were IEPC, DOP and the effect of NSAIDs on SIM.

RESULTS

The rates of IEPC and the DOP were significantly higher in the PDR group compared with the NPDR and control groups. Diabetes mellitus (DM) type had no significant effect on these parameters. The rate of SIM was higher in the eyes with PDR compared with the eyes with NPDR and the controls despite use of NSAIDs.

CONCLUSION

Our results indicates that eyes with PDR are significantly more prone to IEPC, while the type of DM is not a predictor factor. DOP is longer in the eyes with PDR. In spite of NSAID use, SIM is more commonly observed in eyes with PDR.

Clinical outcomes of phacoemulsification cataract surgery in diabetes patients: visual function (VF-14), visual acuity and patient satisfaction

PURPOSE

To evaluate the visual outcomes (visual acuity [VA] and visual function) after phacoemulsification cataract surgery in patients with diabetic retinopathy (DR), and assess patient satisfaction with final surgical outcome.

METHODS

This prospective study comprised 74 eyes of 74 patients with different stages of DR. One surgeon (AW) performed all cataract surgery in a standardized fashion. Patients were assessed using the VF-14 (Visual Function-14) questionnaire. The following groups of patients were compared: those with no apparent retinopathy; those with mild non-proliferative DR (NPDR); those with severe NPDR, and those with proliferative DR (PDR). Visual acuity and visual function questionnaire (VF-14) responses were recorded preoperatively and 3 months postoperatively, during which the non-operated fellow eye showed no progression in retinopathy.

RESULTS

Improvements in visual outcomes were significantly higher in groups 1 and 2 compared to groups 3 and 4 (Tukey-Kramer, p < 0.001). Comparisons between groups 1, 2 and 3, 4 showed significant differences in improvements in VA (Tukey-Kramer, p < 0.01), yet no statistically significant differences in functional (VF-14) improvements emerged between these groups.

CONCLUSIONS

Patients with more advanced levels of DR showed no functional improvements despite improvements in VA. This emphasizes the relevance of patient education prior to surgery. In particular, it should be explained to patients with more advanced DR that, although surgery may be required, their functional improvement may be limited.

A prospective, case controlled study of the natural history of diabetic retinopathy and maculopathy after uncomplicated phacoemulsification cataract surgery in patients with type 2 diabetes

AIM

To determine if uncomplicated phacoemulsification cataract surgery is associated with an accelerated rate of progression of diabetic retinopathy or maculopathy postoperatively.

METHODS

A prospective trial of 50 type 2 diabetics undergoing monocular phacoemulsification cataract surgery by a single consultant surgeon. The grade of diabetic retinopathy and diabetic maculopathy in the operated and non-operated fellow eye was assessed preoperatively and for 12 months postoperatively.

RESULTS

Overall, retinopathy progression was observed in 11 patients. In seven the retinopathy progressed in both eyes, in three it progressed in the operated eye alone, and in one it progressed in the fellow eye alone. Macular oedema was observed in 13 eyes postoperatively. Four had transient pseudophakic cystoid macular oedema and nine true diabetic maculopathy. Where maculopathy progressed it did so symmetrically in five patients, it progressed in the operated eye alone in four patients, and the fellow eye alone in two patients. There was no significant difference in the number of operated and fellow eyes whose retinopathy or maculopathy progressed postoperatively. In both the operated (OE) and non-operated (NoE) eyes retinopathy progression was associated with a higher mean HbA(1)C (OE p=0.003; NoE p=0.001) and insulin treatment (OE p=0.008, NoE p=0.04).

CONCLUSION

Uncomplicated phacoemulsification cataract surgery does not cause acceleration of diabetic retinopathy postoperatively and any progression that is observed probably represents the natural history of the disease. Although macular oedema is common after cataract surgery it may follow a benign course and in many patients the development of clinically significant macular oedema postoperatively probably represents natural disease progression rather than being a direct effect of surgery.

Influence of phacoemulsification and intraocular lens implantation on the course of diabetic retinopathy

PURPOSE

To study the effect of phacoemulsification and posterior chamber intraocular lens implantation on the course of diabetic retinopathy using the nonoperated fellow eye as a control.

SETTING

Departments of Ophthalmology, Diabetes Center, Tokyo Women's Medical University, and University of Tokyo School of Medicine, Tokyo, Japan.

METHODS

One eye of 66 diabetic patients who preoperatively had a similar stage of retinopathy in both eyes or no retinopathy bilaterally had cataract surgery. The course of diabetic retinopathy was followed for 1 year postoperatively. Patients were placed into 1 of 2 groups: Group A, progression of retinopathy in the operated eye was attributable to the surgical invasion (i.e., there was progression of retinopathy only in the operated eye or more progression in the operated eye than in the nonoperated fellow eye); Group B, no deterioration of retinopathy bilaterally, comparable level of deterioration in both eyes, or greater progression in the nonoperated eye than in the operated eye.

RESULTS

Surgery resulted in retinopathy progression in 16 patients (24.2%, Group A): 13 with unilateral deterioration and 3 with greater progression in the operated than in the nonoperated fellow eye. Of the remaining 50 patients (75.8%, Group B), 39 presented no significant progression in either eye, 8 had bilaterally comparable progression, and 3 showed progression in the nonoperated fellow eye only. Retinopathy worsened in the operated eye in 24 cases (36.3%); of these, changes in 16 patients were attributed to surgical influence. There was no significant difference between Groups A and B in age, diabetes mellitus duration, diabetes treatment method, and preoperative and postoperative hemoglobin A1c levels. The distribution of preoperative retinopathy stage significantly differed between groups, with more patients without retinopathy in Group A and more patients with advanced retinopathy in Group B.

CONCLUSION

Factors such as age, diabetes mellitus duration, diabetes treatment method, and hemoglobin A1c level did not affect the progression of retinopathy; however, preoperative status of retinopathy may influence the susceptibility of the retinopathy to surgical invasion. A considerable proportion of eyes with aggravation of retinopathy would reflect the natural course of the disease, systemic factors, or both rather than the influence of cataract surgery.

Iris fluorescein angiography in clinical practice

Iris fluorescein angiography is a valuable technique for elucidating a wide range of eye pathologies, among them developmental anomalies, degenerative disease, retinal vascular occlusions, diabetic microangiopathy, uveitis of various etiologies, glaucoma, tumor, and surgical or accidental trauma. In fact, IFA is more sensitive than biomicroscopy in the evaluation of iris abnormalities. Moreover, it provides indirect but reliable information on the retinal circulation when this cannot be examined directly. Some of the most important clinical applications involve the early detection of iris new vessels, cataract management in diabetic patients, and monitoring of iris tumors. Equipment, procedures, and fluorescein angiography patterns in normal and disease states are described and extensively illustrated. More widespread use of this valuable technique is encouraged.

Diabetic retinopathy before and after cataract surgery

AIMS/BACKGROUND

Increased retinopathy progression has been reported after cataract surgery in patients with diabetes mellitus. To assess the influence of cataract surgery on visual acuity and retinopathy progression, all diabetic patients who were subjected to cataract surgery during 1991-3 have been followed up at the Department of Ophthalmology in Helsingborg. The average follow up time was 2 years.

METHODS

One eye of each of 70 patients was included in the study, 35 monocularly and 35 binocularly operated on. Sixteen of the 70 patients had proliferative diabetic retinopathy (PDR) at baseline. The Wisconsin scale was used for the grading of retinopathy. The degree of glycaemic control was assessed by measurements of HbA1c.

RESULTS

Most patients obtained improved visual acuity; a postoperative visual acuity of 0.5 or better was achieved in 89% of diabetic surgical eyes. Progression of the retinopathy occurred in 30 out of the 70 eyes, and was associated with mean level of HbA1c (p = 0.04), duration of diabetes (p = 0.02), insulin treatment (p = 0.001), and presence of retinopathy at baseline (p = 0.01). Patients who progressed had a significantly higher incidence of macular oedema (p = 0.006) than those who did not progress. No significant differences were found when operated and non-operated eyes were compared in the 35 patients with monocular surgery. Two patients in this group, however, ended up with macular oedema and worse vision in the operated eye than in the eye which was not operated on. Both patients had background retinopathy before surgery.

CONCLUSIONS

Patients in this study, also those with PDR, obtained good visual acuity, better than in most previous studies. Poor glycaemic control was a factor of importance for the progression of diabetic retinopathy after cataract surgery.

Colour vision in diabetic and normal pseudophakes is worse than expected

Automated colour vision testing in pseudophakes showed unexpected results. Chromatic discrimination sensitivity was measured in 22 diabetic pseudophakes with no retinopathy, 23 diabetic pseudophakes with background retinopathy and 34 non-diabetic pseudophakes. These results were compared with those in age-matched normal and diabetic phakic subjects, all of whom had good vision. The diabetics were also matched for retinopathy grading and duration of diabetes. In all three groups, red-green discrimination sensitivity was worse in the pseudophakes when compared with the corresponding phakic subjects (normals, p < 0.001; no retinopathy, p = 0.467; background retinopathy, p = 0.057). However, tritan vision was marginally worse in the normal pseudophake group but was better in the two diabetic pseudophake groups, when compared with phakic controls. This may be due to a reduction in tritan sensitivity in age-matched phakic controls from the effects of increased lens yellowing with age.

Visual acuity following extracapsular cataract extraction in diabetes: a meta-analysis

Although pre-operative retinopathy severity appears to be a major factor in determining the visual outcome of diabetic extracapsular cataract extraction, its precise relationship to post-operative visual acuity is ill defined. A meta-analysis was therefore carried out, and studies were included if pre-operative maculopathy and retinopathy status was sufficiently defined to permit discrimination of visual outcome between subgroups. Weighted mean proportions of eyes achieving a post-operative visual acuity > or = 6/12 were as follows: no retinopathy, 87%; non-proliferative retinopathy with no maculopathy, 80%; quiescent proliferative retinopathy with no maculopathy, 57%; non-proliferative retinopathy with maculopathy, 41%; quiescent proliferative retinopathy with maculopathy, 11%; active proliferative retinopathy, 0. Differences in visual outcome between groups were significant (chi 2 = 119.9, p < 0.0005), attributable mostly to the trend across groups (chi 2 for trend = 115.4, p < 0.0005). Logistic regression indicated that maculopathy was a more potent predictor of post-operative visual acuity < or = 6/12 (odds ratio 6.4, 95% CI 4.13-9.94, p < 0.0005) than quiescent proliferative retinopathy (odds ratio 3.33, 95% CI 2.04-5.42, p < 0.0005). The severity of retinopathy and maculopathy prior to cataract surgery in diabetics are the major determinants of post-operative visual acuity. Further study of the relationship between pre-operative retinopathy severity and the incidence of post-operative complications, progression of retinopathy and maculopathy is required to optimise the management of cataract in diabetes.

Relation between iridopathy and retinopathy in diabetes

In order to assess the relation between diabetic iridopathy (DI) and retinopathy (DR), 225 eyes of 117 diabetics with clear media were evaluated. Each patient underwent iris and retinal fluorescein angiography, which was used to classify DI and DR. DI was classified as: absence of DI; non-proliferative DI; proliferative DI; neovascular glaucoma. DR was classified as: absence of DR; background DR; pre-proliferative DR; proliferative DR. The sensitivity of iris fluorescein angiography in assessing DR was 44.5%, the specificity 88%, the positive predictive value 92.8%, and the negative value 31.2%. In pre-proliferative and proliferative DR, fluoroiridographic detection of iris neovessels gave a sensitivity of 56% and a specificity of 100%. The positive predictive value was 100% and the negative value 65%. In conclusion, iris fluorescein angiography yields valuable information on DR and is a helpful basis for avoiding complications when scheduling eyes with dioptric media opacities for surgery.

Severe diabetic retinopathy after cataract surgery

We retrospectively compared the visual acuity and degree of background diabetic retinopathy in 32 consecutive patients with diabetes who had cataract surgery in one eye (study group) and compared them with the visual acuity and degree of diabetic retinopathy in 32 patients with diabetes who had not had cataract surgery (control group) to determine if the retinopathy was asymmetric and worse in the operated-on eye. Twenty-three (72%) of the 32 study patients had asymmetric retinopathy (with the more severe retinopathy in the eye that underwent cataract surgery in each case) compared with three (9%) of the control group (P < .0005). The eyes that had cataract surgery did poorly in terms of visual acuity with no eyes achieving 20/20 or 20/25, only three eyes achieving 20/30 or 20/40, and 16 achieving 20/100 or worse.

Plasma glucose levels, postoperative complications, and progression of retinopathy in diabetic patients undergoing intraocular lens implantation

Of 220 patients (250 eyes) who underwent extracapsular cataract extraction with implantation of a posterior chamber intraocular lens, 36 (45 eyes) with non-insulin-dependent diabetes mellitus had no retinopathy, simple, or preproliferative retinopathy. They were divided into group A patients who underwent diet therapy or were treated with oral agents and group B patients who were given insulin therapy. The 184 patients (205 eyes) without diabetes mellitus served as control (group C). Transient elevation of intraocular pressure and cystoid macular edema were observed more frequently in diabetic patients (groups A and B). Progressive retinopathy occurred more frequently in group B than in group A patients, and it correlated with increased levels of plasma glucose. Unilateral cataract surgery was performed on 27 diabetic patients. Nine (33%) operated eyes showed progressive retinopathy, while one (4%) fellow eye worsened. It is possible that both increased levels of plasma glucose and surgical procedures may participate in the progression of retinopathy.

Biomicroscopy versus fluorescein angiography of the iris in the detection of diabetic iridopathy

Iris fluorescein angiography is not commonly employed in clinical practice, but it is the most sensitive technique for the evaluation of iris vessel abnormalities. We used iris fluorescein angiography as the gold standard against which to test the ability of iris biomicroscopy to demonstrate diabetic iridopathy (DI). One hundred and fourteen eyes of 63 diabetic patients affected by preproliferative or proliferative diabetic retinopathy (DR) (the DR groups at high risk of developing DI) were considered. The DI fluorangiographic classification used was: (1) absence of DI; (2) nonproliferative DI; (3) proliferative DI. The sensitivity of biomicroscopy in detecting DI turned out to be 57%, while the specificity was 94%. The positive predictive value was 93% and the negative predictive value 50%. Our study proved that biomicroscopy can accurately judge when DI is absent. When it is present, however, there is a high probability that biomicroscopy will be less precise in the detection of iris lesions.

Modulation of interferon-gamma-induced major histocompatibility complex class II and Fc receptor expression on isolated microglia by transforming growth factor-beta 1, interleukin-4, noradrenaline and glucocorticoids

Interleukin-4 (IL-4) enhances Fc receptor (FcR) expression on isolated rat brain microglia and peritoneal macrophages but has little effect on major histocompatibility complex (MHC) class II antigen expression. In contrast transforming growth factor-beta 1 (TGF-beta 1) causes a reduction in expression of MHC class II on macrophages and of FcR on both cell types. Both microglia and peritoneal macrophages demonstrate enhanced expression of FcR and MHC class II on treatment with interferon-gamma (IFN-gamma). The effect of IL-4 or TGF-beta 1 in combination with IFN-gamma, added either sequentially or simultaneously, has been investigated. TGF-beta 1 down-regulates IFN-gamma-induced effects in both microglia and macrophages when present before or during the activation stage. In combination, IL-4 and IFN-gamma can be additive or antagonistic, depending on their concentrations and the sequence in which cells are exposed to the cytokines. Non-cytokine mediators present during stimulation, such as noradrenaline, dexamethasone and corticosterone, are also potent inhibitors of IFN-gamma-induced activation of microglia and macrophages.

Extracapsular cataract extraction with placement of a posterior chamber lens in patients with diabetic retinopathy

PURPOSE

The authors evaluated factors that might influence the outcome of extracapsular cataract extraction with placement of a posterior chamber lens in patients with diabetic retinopathy. The factors included patient age and sex, severity of the retinopathy, preoperative laser photocoagulation, vitrectomy, and posterior capsulotomy.

METHODS

The records of 109 patients who had been examined by the authors before cataract surgery were retrospectively reviewed.

RESULTS

The final visual acuity in only 48% of the eyes was 20/40 or better, and 28% had 20/200 or worse visual acuity. Only 65% had an improvement in visual acuity of two or more Snellen lines. Eyes with preoperative macular edema had a poorer visual outcome than eyes without. Macular edema and ischemia accounted for 70% of the eyes with a final visual acuity of 20/50 or worse. The authors found that age was a strong predictor of final visual acuity and chances of improvement. In patients 63 years of age and younger, 58% had 20/40 or better and 81% had improved visual acuity. In patients 64 years of age and older, only 38% had 20/40 or better and only 54% were improved. Supplementary panretinal photocoagulation was required in 37% of patients who had received it preoperatively. Neovascularization of the iris developed in 6% of patients. Posterior capsulotomy did not cause an increased incidence of neovascularization of the iris or in the development or progression of proliferative retinopathy or macular edema.

CONCLUSION

The prognosis of patients with diabetic retinopathy about to undergo cataract surgery, even extracapsular cataract extraction with placement of a posterior chamber lens, is guarded.

Extracapsular cataract extraction in proliferative diabetic retinopathy

PURPOSE

To establish the visual prognosis, prevalence of complications, and optimal strategy for management of proliferative diabetic retinopathy (PDR) in isolated extracapsular cataract extraction (ECCE).

METHOD

This is a retrospective review of 56 patients with PDR who underwent ECCE with lens implantation. Results were compared with 64 patients with background diabetic retinopathy (BDR) operated on during the same time period.

RESULTS

Final visual acuity (67% > or = 20/40) was better in BDR eyes compared with PDR eyes (21% > or = 20/40; P < 0.001). In eyes without maculopathy, 94% with BDR achieved a final visual acuity of at least 20/40 compared with 52% with quiescent proliferative retinopathy (P < 0.001). Final visual acuity in eyes with maculopathy was better in BDR eyes (36% > or = 20/40) than in PDR eyes (5% > or = 20/40) (P < 0.02). No patient with active proliferative or preproliferative retinopathy achieved a final visual acuity of more than 20/80. Postoperative deterioration of retinopathy occurred in 50% of patients with active proliferative retinopathy compared with 10% with quiescent proliferative retinopathy (P < 0.01) and 3% with BDR (P < 0.001). Immediate postoperative fibrinous anterior uveitis, which prevented early panretinal photocoagulation, developed in over half the patients with active proliferative retinopathy.

CONCLUSIONS

Final visual acuity after cataract extraction in diabetic patients with proliferative retinopathy is generally poor; however, in patients with quiescent proliferative retinopathy and no maculopathy, visual acuity may be good. Active proliferative retinopathy at the time of surgery is a poor prognostic indicator for final visual acuity and is associated with postoperative deterioration of retinopathy and fibrinous uveitis, which may preclude immediate postoperative panretinal photocoagulation.

Progression of nonproliferative diabetic retinopathy and visual outcome after extracapsular cataract extraction and intraocular lens implantation

Twenty-one patients with symmetric nonproliferative retinopathy who underwent extracapsular cataract extraction and intraocular lens implantation were followed up postoperatively for an average (+/- standard deviation) of 18 +/- 7 months to determine the incidence of progression of diabetic retinopathy, the final visual acuity, and factors predictive of progression of retinopathy and final visual acuity. Progression of retinopathy, defined as the development of clinically significant macular edema, an increase in intraretinal hemorrhages or hard exudate, or the development of proliferative diabetic retinopathy, was assessed in both eyes of 19 patients; in two remaining patients, dense preoperative cataract in the fellow eye precluded comparison of retinopathy progression in the operated-on eye to progression in the fellow eye. Overall, retinopathy progressed in 14 of 19 operated-on eyes (74%). Cataract extraction was highly associated with asymmetric progression of nonproliferative retinopathy; it progressed only in the operated-on eye in seven of 19 patients (37%), but in no patients did progression occur in the fellow eye alone (P = .0078). Women had a significantly increased risk of progression of retinopathy in the operated-on eye compared to men (P = .005). Visual acuity improved in 19 of 21 operated-on eyes (86%); however, only 11 eyes (52%) achieved a visual acuity of 20/50 or better and only six eyes (14%) achieved a visual acuity of 20/25 or better. In only five eyes was the final visual acuity in the operated-on eye more than two lines better than the final visual acuity in the fellow eye.(ABSTRACT TRUNCATED AT 250 WORDS)

Extracapsular cataract extraction in diabetics with rubeosis iridis

We reviewed thirteen operated eyes (twelve diabetic patients) with rubeosis iridis who underwent extracapsular cataract extraction and intraocular lens implantation. Prior to surgery five had active proliferative retinopathy (APR), and eight had non-proliferative retinopathy (NPR), either quiescent proliferative retinopathy (QPR) or background retinopathy (BR). No case with APR was visually improved by surgery. Three cases with NPR achieved a visual acuity of 6/12. After surgery, vitreous haemorrhage or progression of proliferative retinopathy occurred in three cases with APR. Early postoperative fibrinous uveitis was severe in eyes with APR, resulting in permanent fibrin membrane formation in four. We suggest a significant prognostic indicator in diabetic cataract extraction with rubeosis iridis is the status of the underlying retinopathy. With NPR, postoperative visual acuity may be good and early postoperative complications less severe. In the presence of APR the visual outcome is poor, progression of retinopathy likely and early postoperative fibrinous uveitis may be severe enough to prevent postoperative panretinal photocoagulation. Maximum preoperative panretinal ablation is essential in these cases.

Progression of diabetic retinopathy after cataract extraction

The course of diabetic retinopathy following cataract extraction was studied retrospectively in 89 patients (89 eyes). Cataract extraction was extracapsular in 12 eyes (13.5%), extracapsular with intraocular lens implantation in 37 (41.6%), and intracapsular in 40 (45%). In 55 eyes (61.8%) there was no change in the retinal status after surgery, and in 34 (38.2%) there was progression of diabetic retinopathy. In the eyes showing progression there was appearance or aggravation of non-proliferative changes in 85.3% and development of proliferative diabetic retinopathy in 14.7%. Most of these eyes (91%) deteriorated within six months of surgery. Risk factors for the progression of diabetic retinopathy were the preoperative existence of diabetic retinopathy (p less than 0.005) and the need for antidiabetic agents in addition to dietary control in the management of diabetes (p less than 0.025).

Posterior chamber intraocular lens implantation in eyes with inactive and active proliferative diabetic retinopathy

We reviewed the records of 2,100 consecutive eyes that had undergone extracapsular cataract extraction with intraocular lens implantation between January 1981 and December 1989. Of these eyes, 21 had inactive and four had active proliferative diabetic retinopathy at the time of cataract extraction. Twenty-one eyes with inactive proliferative diabetic retinopathy received extracapsular cataract extraction with posterior chamber intraocular lens implantation, and four eyes with active proliferative diabetic retinopathy had both extracapsular cataract extraction with posterior chamber intraocular lens implantation and pars plana vitrectomy with endophotocoagulation. The mean follow-up period was 27 months. Final visual acuity was 20/40 or better in 12 of 25 eyes (48%). Of 25 eyes, five (20%) showed progression of the retinopathy after the operation, and two (8%) developed macular edema. Extracapsular cataract extraction and posterior chamber intraocular lens implantation was well tolerated in most eyes.

Extracapsular cataract surgery with lens implantation in diabetics with and without proliferative retinopathy

In a retrospective study we have examined all diabetics (66 operated eyes) and an equal number of non-diabetic matched controls who underwent extracapsular cataract extracation (ECCE) with intraocular lens (IOL) implantation over a two-year period ending in December 1987. Of the diabetic patients' 76% eyes improved by at least two lines of Snellen acuity postoperatively. Of these patients 68% eyes and of the control eyes 83% achieved an acuity of 6/12 or better. In the diabetics the visual outcome depended on the state of the retinopathy and in particular the maculopathy. The diabetic group had a greater incidence of postoperative inflammation, but the major complications were related to continuing neovascularisation. Early postoperative laser photocoagulation may help to prevent these proliferative complications, and, provided a large, adequate capsulotomy is performed for capsular thickening, the presence of an IOL does not interfere with this photocoagulation. We also advise early postoperative assessment, and treatment if necessary, of any maculopathy. Diabetic retinopathy should no longer be regarded as a contraindication to intraocular lens insertion.

Corneal endothelial changes after posterior chamber intraocular lens implantation in patients with or without diabetes mellitus

We examined 96 patients (111 eyes) who underwent extracapsular cataract extraction with the implantation of a posterior chamber intraocular lens. Of 96 patients 24 (29 eyes) with non-insulin-dependent diabetes mellitus had no or simple retinopathy; 72 patients (82 eyes) served as non-diabetic controls. The central corneas of all subjects were photographed by a specular microscope preoperatively and three, six, and 12 months postoperatively. No significant differences in the endothelial cell density, coefficient of variation, or cell loss were noted between diabetic patients and age matched non-diabetic subjects during the observation period.

Posterior chamber intraocular lens implantation during diabetic pars plana vitrectomy

Combined cataract removal, posterior chamber intraocular lens (PC IOL) implantation, and pars plana vitrectomy were performed in 15 diabetic patients who presented with coexisting cataract and vitreoretinal complications from proliferative diabetic retinopathy (PDR). Posterior chamber IOLs were placed anterior to the anterior lens capsule after pars plana lensectomy and vitrectomy in nine eyes, whereas extracapsular cataract extraction (ECCE) with PC IOL placement was performed before vitrectomy in six eyes. Panretinal laser endophotocoagulation was applied in 13 of the 15 eyes as an important part of the operative procedure. Because of inactive diabetic retinopathy or satisfactory preoperative panretinal photocoagulation, 2 of the 15 eyes did not receive laser endophotocoagulation. Visual acuity was improved in 12 eyes and was similar to preoperative vision in 3 eyes. After a minimum of 6 months and a maximum of 28 months of follow-up, the visual results are the following: 20/40 or better (4 eyes), 20/50 to 20/200 (5 eyes), 20/400 to 5/200 (5 eyes), and hand motions (1 eye). Although 5 of the 15 eyes required secondary vitreoretinal procedures, neovascular glaucoma and complications attributable to the IOL did not occur. A recurrent postoperative retinal detachment (RD) developed with subsequent hypotony and rubeosis iridis in 1 of the 15 eyes.

Posterior chamber intraocular lens implantation during pars plana lensectomy and vitrectomy for diabetic complications

Ten eyes had posterior chamber lenses implanted in the ciliary sulcus in front of the anterior lens capsule during diabetic pars plana lensectomy and vitrectomy. Six months later, nine eyes had improved vision and one had the same vision as compared with preoperative acuity levels. Two eyes had 0.5 and eight eyes had 0.1 or better acuity. None of the eyes developed iris or angle neovascularization or glaucoma, and all ten eyes had clear vitreous cavities with attached maculas. The posterior chamber lenses were well tolerated and provided good visual rehabilitation.

Effect of cataract surgery and intraocular lenses on diabetic retinopathy

We reviewed a series of 137 cataract extractions with intraocular lenses (IOLs) in patients with diabetes, mellitus between 1977 and 1983. All patients were followed for an average of 36 months to determine if they subsequently showed progression of diabetic retinopathy. Divided into groups according to the type of procedure and IOL received, they were compared for age, sex, duration of diabetes, treatment required for the diabetes, intraoperative complications, and follow-up period. Patients who had intracapsular cataract extractions with anterior chamber IOLs were three times as likely to show proliferative retinopathy as those who had extracapsular cataract extractions with posterior chamber IOLs. Insulin-dependent patients were three to four times more likely to show progression to proliferation than noninsulin dependent patients. We conclude that, while some procedures are riskier for the diabetic eye, extracapsular lens extraction with implantation of a posterior chamber lens does not imply an increased risk of development of proliferative retinopathy.

Treatment of cataract in diabetics with and without retinopathy

The results of cataract surgery in diabetic patients was reviewed. The visual outcome was good in the absence of retinopathy and was not significantly different from that of non-diabetic patients. Eyes with retinopathy achieved significantly worse visual results and the prognosis was related to the severity of retinopathy. Clinical cystoid macular oedema occurred significantly more frequently in eyes with retinopathy than without and there were significantly more eyes with retinopathy which became blind or partially sighted. The use of a Projectoscope for assessing the amount of degradation of an image was tested. A good correlation was found between the amount of blurring of the test target and the drop in visual acuity. The optimal type of cataract surgery is discussed and lines of management outlined.

Cataract extraction in the diabetic eye after vitrectomy

We examined 289 phakic, diabetic eyes for evidence of cataract formation after a successful vitrectomy. Of 289 eyes, 107 (37%) developed or had significant progression of a cataract over a follow-up period of 16 to 108 months. Postvitrectomy hemorrhage and vitreous lavage were associated with an increased rate of cataract formation. Of the 107 eyes, 33 (31%) subsequently had cataract extraction, with 24 eyes (73%) treated by extracapsular cataract extraction and nine eyes (27%) with intracapsular surgery. A posterior chamber lens was used in 11 of the 24 eyes that underwent extracapsular surgery. Of the 33 eyes, 31 (94%) had improved visual acuity after cataract extraction. Intraoperative and postoperative complications were minimal and did not result in permanent reduction of vision. Intraocular lenses were well tolerated in the 11 patients in whom they were used.

Phacoemulsification and implantation of posterior chamber intraocular lens in eyes with quiescent proliferative diabetic retinopathy

A phacoemulsification procedure, combined with an "in-the-bag" lens implantation, was performed on ten eyes that once had proliferative diabetic retinopathy (PDR). The ten eyes were in eight patients who had a 20-plus year history of either type I or type II diabetes mellitus. All eyes had reached the "quiescent" state of diabetic retinopathy 2-13 years before the cataract surgery through either argon laser pan retinal photocoagulation and/or pars plana vitrectomy. Nine of ten eyes remained completely free of retinal neovascularization and rubeosis iridis, with follow-up periods between 1.5 and 5 years. One eye has been lost to recurrent vitreous hemorrhages and an inoperable retinal detachment.

Cataract and retinopathy: screening for treatable retinopathy

Diabetes causes cataract and certain physical changes in the lens. The diabetic lens is larger than the non-diabetic and shows greater light scatter and fluorescence. Both hyperglycaemia and lowering of blood glucose case refractive changes and hypermetropia is the most common. Classical 'snow-flake' juvenile cataract associated with hyperglycaemia is now rare. It has an osmotic mechanism. Diabetes is a risk factor for cataract in adults which is duration dependent, more frequent in women and leads to earlier surgery. It resembles non-diabetic senile cataract. Extracapsular cataract extraction is the method of choice for diabetic cataract with a better visual result and less risk of rubeosis iridis. A posterior chamber implant may still permit retinal photocoagulation if necessary. Diabetic retinopathy is still the leading cause of blindness in the working age group. The beneficial effect of photocoagulation has been shown by randomized controlled trials to be long-lasting for both proliferative retinopathy and maculopathy. Therefore there is a need for screening, especially for those with proliferative disease which may be present without symptoms. A knowledge of risk factors will enhance detection rate with duration as the strongest determinant for retinopathy. Any screening modality should be highly sensitive as well as specific. The role of different professionals as potential screeners should be considered. Adequate provisions include facilities for checking vision and for dimming ambient lighting. Mydriasis and a good ophthalmoscope light will increase detection rate. The use of a 45 degrees non-mydriatic camera is unlikely to supplant the use of an ophthalmoscope as a single field is likely to miss important lesions. A 60 degrees camera may confer a large enough field and the use of transparencies will provide magnification when films are projected but the camera is more difficult to use. A list of features chosen by a recent study to characterize sight-threatening retinopathy is included and their presence indicates the need for referral to an ophthalmic clinic for treatment or close observation.