Neovascular glaucoma and vitreous hemorrhage following cataract surgery in patients with diabetes mellitus

Intraocular lens selection in diabetic patients: How to increase the odds for success

The incidence of cataracts is significantly higher in diabetic individuals, particularly in younger age groups, with rates quadrupled in those under 65 and doubled in those over 65 compared to non-diabetics. Cataract surgery in diabetic patients poses many challenges: Poor epithelial healing, decreased corneal sensitivity, increased central corneal thickness, decreased endothelial cell count, variable topography, poor pupillary dilatation, anterior capsular phimosis, posterior capsular opacification (PCO), chances of progression of diabetic retinopathy (DR), zonular weakness, and vitreous prolapse and diabetic macular edema. Selection of an appropriate intraocular lens (IOL) is crucial for visual rehabilitation and monitoring DR. The choice of IOL in diabetic cataract patients is a challenging scenario. Square-edge IOLs are favored for their capacity to mitigate PCO, whereas hydrophilic counterparts may incur calcification in the setting of proliferative DR. The advisability of premium IOLs for achieving spectacle independence warrants judicious evaluation, particularly in the presence of advanced retinopathy. Optimal IOL placement within the capsular bag is advocated to minimize postoperative complications. Rigorous preoperative assessment and informed patient counseling regarding IOL options are indispensable for optimizing surgical outcomes. This review article covers various aspects regarding the choice of IOLs in different case scenarios and complications in the diabetic population.

Spectrum of eye disorders in diabetes (SPEED) in India: Eye care facility based study. Report # 1. Eye disorders in people with type 2 diabetes mellitus

Purpose

To document the spectrum of eye diseases in people with type 2 diabetes mellitus (T2DM) reporting to large eye care facilities in India.

Methods

The selection of eye care facilities was based on the zone of the country and robustness of the programs. Only people with known T2DM certified by internist, or taking antidiabetes medications, or referred for diabetes related eye diseases were recruited. The analysis included the demographic characteristics, systemic associations, ocular comorbidities, and visual status.

Results

People (11,182) with T2DM were recruited in 14 eye care facilities (3 in north, 2 in south central, 4 in south, 2 in west, and 3 in east zone); two were government and 12 were non-government facilities. Hypertension was the commonest systemic association (n = 5500; 49.2%). Diabetic retinopathy (n = 3611; 32.3%) and lens opacities (n = 6407; 57.3%) were the common ocular disorders. One-fifth of eyes (n = 2077; 20.4%) were pseudophakic; 547 (5.4%) eyes had glaucoma and 277 (2.5%) eyes had retinal vascular occlusion. At presentation, 4.5% (n = 502) were blind (visual acuity < 3/60 in the better eye) and 9.6% (n = 1077) had moderate to severe visual impairment (visual acuity <6/18-->3/60 in the better eye).

Conclusion

People with T2DM presenting at eye clinics in India have high rates of diabetic retinopathy and vision loss. Cataract is a very common occurrence. Advocacy, infrastructure strengthening, and human resource development are the key to address the growing threats of T2DM and eye care in India.

Severe Neovascular Glaucoma Exacerbation as a Complication of Carotid Artery Stenting: A Case Report

Introduction

Neovascular glaucoma (NVG) has been rarely reported as an acute complication of carotid endarterectomy, but there is scant literature available regarding this potential condition following carotid artery stenting (CAS). We present a case of severe worsening of NVG occurring after bilateral CAS with progressive deterioration of vision ultimately leading to blindness.

Case Description

A 66-year-old male with multiple stroke risk factors, bilateral cataract extraction, proliferative diabetic retinopathy of left eye, and nonproliferative diabetic retinopathy of right eye, and prior left eye pars plana vitrectomy presented with episodes of transient right eye vision loss in context of bilateral high-grade internal carotid artery stenoses. He underwent right CAS with subsequent elevation of bilateral intraocular pressures (IOPs) concerning for acute NVG. Over time, the patient had some interval improvement in IOPs and underwent planned left CAS. After the procedure, he again developed elevated IOPs, concerning for acute NVG which eventually led to right eye pars plana vitrectomy for vitreous hemorrhage and refractory IOP elevation. At 6-month follow-up from initial stenting, the patient was blind in both eyes.

Discussion

We present a case of recurrent IOP elevations following CAS eventually resulting in bilateral eye blindness. This case is important not only as an illustration of an underrecognized postprocedural CAS complication but also as a demonstration of likely elevated risk of NVG following CAS for patients with other predisposing risk factors for ocular hypertension such as glaucoma, proliferative diabetic retinopathy, prior cataract extraction, and prior pars plana vitrectomy.

Association of Cataract Surgery With Risk of Diabetic Retinopathy Among Asian Participants in the Singapore Epidemiology of Eye Diseases Study

IMPORTANCE

Cataracts and diabetic retinopathy (DR) are the leading causes of acquired blindness worldwide. Although extraction is the standard treatment option for cataracts, it is also reported to increase the risk of developing DR among individuals with diabetes. Nevertheless, the association between cataract surgery and risk of DR is still not well understood, and there have been no prior population-based reports in this area.

OBJECTIVE

To assess the risk of developing DR after cataract surgery among individuals with type 2 diabetes.

DESIGN, SETTING, AND PARTICIPANTS

A population-based prospective cohort study was conducted among participants recruited from the Singapore Epidemiology of Eye Diseases Study. The baseline visit was conducted between June 1, 2004, and March 31, 2009, and the 6-year follow-up visit was conducted between June 1, 2011, and July 31, 2016. Statistical analysis was performed from October 1 to 31, 2019.

EXPOSURES

Cataract surgery performed before a follow-up visit, determined based on slitlamp evaluation of lens status at baseline and follow-up visits.

MAIN OUTCOMES AND MEASURES

Eyes with incidence of DR were defined as those with the presence of any DR (level ≥15 based on the modified Airlie House classification system, graded from retinal photographs) at 6-year follow-up with no DR at baseline. The association between cataract surgery and incidence of DR was evaluated using a multivariable Poisson regression model with a generalized estimating equation to account for correlation between both eyes.

RESULTS

A total of 1734 eyes from 972 participants with diabetes (392 Malay individuals and 580 Indian individuals; 495 men; mean [SD] age, 58.7 [9.1] years) were included in the analysis. A total of 163 study eyes had already undergone cataract surgery at baseline, and a total of 187 eyes (originally phakic at baseline) underwent cataract surgery any time during the follow-up period. Of these 350 eyes, 77 (22.0%) developed DR. Among the 1384 eyes that never underwent cataract surgery, 195 (14.1%) developed DR. After adjustments for age, sex, race/ethnicity, baseline hemoglobin A1c level, duration of diabetes, random blood glucose level, antidiabetic medication use, hypertension, body mass index, and smoking status, multivariable regression analysis showed that any prior cataract surgery was associated with incidence of DR (relative risk, 1.70; 95% CI, 1.26-2.30; P = .001). Subgroup analyses by race/ethnicity showed similar associations in both Malay individuals (relative risk, 1.73; 95% CI, 1.13-2.69; P = .02) and Indian individuals (relative risk, 1.93; 95% CI, 1.33-2.80; P < .001).

CONCLUSIONS AND RELEVANCE

The findings of this population-based cohort study suggest that prior cataract surgery was associated with a higher risk of developing DR among individuals with diabetes. Further validation is warranted to confirm this association.

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.

Diabetic Retinopathy Clinical Practice Guidelines: Customized for Iranian Population

PURPOSE

To customize clinical practice guidelines (CPGs) for management of diabetic retinopathy (DR) in the Iranian population.

METHODS

Three DR CPGs (The Royal College of Ophthalmologists 2013, American Academy of Ophthalmology [Preferred Practice Pattern 2012], and Australian Diabetes Society 2008) were selected from the literature using the AGREE tool. Clinical questions were designed and summarized into four tables by the customization team. The components of the clinical questions along with pertinent recommendations extracted from the above-mentioned CPGs; details of the supporting articles and their levels of evidence; clinical recommendations considering clinical benefits, cost and side effects; and revised recommendations based on customization capability (applicability, acceptability, external validity) were recorded in 4 tables, respectively. Customized recommendations were sent to the faculty members of all universities across the country to score the recommendations from 1 to 9.

RESULTS

Agreed recommendations were accepted as the final recommendations while the non-agreed ones were approved after revision. Eventually, 29 customized recommendations under three major categories consisting of screening, diagnosis and treatment of DR were developed along with their sources and levels of evidence.

CONCLUSION

This customized CPGs for management of DR can be used to standardize the referral pathway, diagnosis and treatment of patients with diabetic retinopathy.

Paradoxical development of neovascular glaucoma following carotid angioplasty and stenting

This report describes a very rare ocular complication of carotid intervention. A 74-year-old patient presented with left-sided weakness and was diagnosed with right cerebral border-zone infarctions caused by severe stenosis of the right proximal internal carotid artery. Staged carotid intervention (balloon angioplasty followed by stenting) was successfully performed. However, neovascular glaucoma developed following carotid angioplasty and stenting. We concluded that although carotid angioplasty and stenting improves vision in patients with ischemic oculopathy, it can rarely induce paradoxical visual deterioration such as development or aggravation of neovascular glaucoma.

Intraocular surgery in a large diabetes patient population: risk factors and surgical results

The prevalence of diabetes is on the increase in developed countries. Accordingly, the prevention and treatment of vision-threatening diabetic eye complications is assuming greater importance. The overall aim of this thesis is to analyse risk factors for intraocular surgery in a large diabetes population and to report surgical results. The specific objectives are to (1) estimate the incidence of diabetic vitrectomy and analyse risk factors (Study I), (2) report long-term results, prognostic factors and incidence of cataract surgery after diabetic vitrectomy (Study II), (3) report results and prognostic factors after cataract surgery in diabetes patients (Study III) and (4) analyse risk factors for diabetic papillopathy with emphasis on metabolic control variability (Study IV). All studies are based on a close-to-complete national surgery register and a large, closely followed diabetic retinopathy screening population. Study I (cohort study, 3980 type 1 diabetes patients) illustrates that diabetic vitrectomy is rarely required in a diabetes patient population with varying degrees of diabetic retinopathy. The risk of reaching diabetic vitrectomy increases fourfold with poor metabolic control, defined as glycosylated haemoglobin A1c > 75 mmol/mol (~9%), which points to good metabolic control as an important preventive measure. Study II (cohort study, 167 diabetes patients) shows that most diabetic vitrectomy patients stand to gain visual acuity ≥0.3 after surgery. Visual acuity is stable after 1 year, and the stability is maintained through 10 years of follow-up. The use of silicone oil for endotamponade is a consistent long-term predictor of low vision after surgery. The risk of requiring cataract surgery after diabetic vitrectomy is substantial, and the risk increases if silicone oil is used. Study III (cohort study, 285 diabetes patients) shows, on the other hand, that diabetes patients can expect a significant improvement in visual acuity after cataract surgery, regardless of the degree of diabetic retinopathy. Poor preoperative visual acuity, a high degree of diabetic retinopathy and advanced age are predictors of a poor visual acuity after surgery. The risk of diabetic macular oedema after surgery is 4%. Finally, Study IV (case-control study, 2066 type 1 diabetes patients) demonstrates that diabetic papillopathy shares characteristics with diabetic retinopathy. The risk of experiencing diabetic papillopathy increases markedly with a drastic, recent reduction in glycosylated haemoglobin A1c and a small optic disc. This lends support to the theory that diabetic eye complications may occur in anatomically predisposed patients in response to metabolic control variability. Overall, results after intraocular surgery in diabetes patients are favourable. Surgery, however, is associated with costs to society, patient discomfort and risk of complications. This thesis provides an analysis of risk factors for intraocular surgery and identifies prognostic factors for visual acuity after surgery, which can be used for preventive purposes, surgical decision-making and patient counselling.

Ranibizumab in patients with dense cataract and proliferative diabetic retinopathy with rubeosis

BACKGROUND

To evaluate the safety of ranibizumab as a surgical adjunct during cataract surgery in patients with proliferative diabetic retinopathy (PDR) with rubeosis, and to evaluate the efficacy and adverse effects of ranibizumab in treating PDR with rubeosis.

MATERIALS AND METHODS

Three intravitreal injections of 0.5 mg ranibizumab were administered on day-1, months-1 and -2 with cataract surgery 6-16 days after first injection. Retreatments with ranibizumab injections and pan-retinal photocoagulation (PRP) were given if recurrence or persistence of PDR was noted between months-3 and -11. Safety observation visits occurred at months-12, -18 and -24. Primary end points were incidence and severity of adverse events (AEs) that were related to both cataract surgery and treatment of PDR with rubeosis through month -12.

RESULTS

Of six patients screened, four (mean age 61.3 years) were enrolled. No AEs were noted with either cataract surgery or treatment of PDR. Neovascularization of iris (NVI) promptly regressed by 4 days after first ranibizumab injection, prior to cataract surgery in three of four patients (one had significantly regressed NVI by post-injection day-3 visit); NVI was not noted in any patient at 2 weeks after first ranibizumab injection. Recurrence of rubeosis or NVA after 3 monthly injections was not observed in any. At month-12, PDR was not present when assessed clinically and by fluorescein angiogram (FA). Only one patient developed neovascularization of disc and neovascularization elsewhere and required retreatments at months-5 and -9.

CONCLUSIONS

Multiple intravitreal injections of ranibizumab may be a safe, effective treatment adjunct for PDR and diabetes-related rubeosis.

Combined panretinal photocoagulation and cataract surgery in a patient with diabetes mellitus

A case is presented whereby a simple method of applying indirect laser during cataract surgery in the presence of retinal and iris neovascularization is described. The method involves placing an infusion cannula into the anterior chamber following standard phacoemulsification and soft lens matter removal. The main section is then sutured and indirect laser is delivered to the far retinal periphery with gentle manipulation of the eye. Successful delivery of indirect panretinal photocoagulation despite inadvertent vitreous loss in this case demonstrates the advantages of its use. Other advantages, including its use in previously vitrectomized eyes and allowing manipulation/indentation of the eye, control of bleeding, and better visualization, are discussed.

Surgery for diabetic retinopathy

Surgery for diabetic retinopathy addresses late secondary complications of a primary microvascular disease. Since surgery is not a causative therapy, the functional outcome of surgery depends on the degree of retinal ischemia and may be disappointing even in technically and anatomically successfully operated eyes. Typical indications for vitrectomy are vitreous hemorrhage, tractional retinal detachment, combined tractional rhegmatogenous retinal detachment and tractive macular edema. More recently diffuse diabetic macular edema has been shown to improve after removal of an attached vitreous in several cases. Neovascular glaucoma requires aggressive surgical intervention to salvage the eye. Cataract surgery is commonly performed in eyes with diabetic retinopathy. It may however deteriorate diabetic eye disease. Vitreous surgery also has a potential for severe complications in diabetic eyes which can be ameliorated but not eliminated by proper surgical strategies and techniques. The decision for an intervention in diabetic eyes always requires a careful weighing of risks and benefits of surgery.

The management of diabetic eye disease in the setting of cataract surgery

PURPOSE OF REVIEW

The increased incidence of diabetes mellitus worldwide is accompanied by an increased risk of co-morbid conditions, including the intersection of diabetes, diabetic retinopathy and cataracts. In an effort to improve the surgical outcomes for this population, it is necessary to understand the historical perspectives that have evolved into current treatment recommendations.

RECENT FINDINGS

While cataract surgery in patients with no or mild retinopathy may result in minimal complications, a substantial minority of patients with diabetes and advanced retinopathy, including macular edema and a history of previous laser treatment, may require additional considerations when planning cataract surgery. Untreated retinopathy, insufficiently treated retinopathy or treatment failures can be challenging. In these instances, a paradigm shift may be indicated, and the occasion of cataract surgery may provide an opportunity to simultaneously treat retinopathy. By utilizing combined vitrectomy/cataract surgical techniques and/or pharmacologic interventions, improved results for a broader diabetic population may be attainable.

SUMMARY

Newer surgical and pharmacologic therapies may now allow for safe and effective surgery in individuals who were previously not candidates for surgery or who had a limited visual prognosis.

Trabeculectomy with mitomycin C for treatment of neovascular glaucoma in diabetic patients

BACKGROUND

To assess the efficacy and to determine the risk factors of trabeculectomy with mitomycin C (MMC) in eyes with neovascular glaucoma (NVG) secondary to diabetic retinopathy.

METHODS

Kaplan-Meier survival analysis of the surgical outcome was performed on 35 eyes with NVG. Age, extent of peripheral anterior synechia, surgical history (cataract, glaucoma, vitrectomy), and concurrent retinal cryotherapy were evaluated to determine factors influencing the surgical outcome. The main criterion for success was a postoperative intraocular pressure (IOP) of < or = 21 mm Hg.

RESULTS

The cumulative probability of success was 67.0% at 1 year and 61.8% after 2 to 3 years. The surgical outcome was significantly better in patients without a previous vitrectomy (p = 0.03). Extensive preoperative peripheral anterior synechia was also a risk factor for surgical failure (p = 0.013).

CONCLUSIONS

Trabeculectomy with MMC can effectively reduce the elevated IOP associated with NVG. The extent of peripheral anterior synechia and a history of vitrectomy are significant negative predictors of surgical outcome.

Chirurgie combinée phacoexérèse, vitrectomie et implantation chez le patient diabétique avec phacoémulsification versus phacophragmentation

INTRODUCTION

In diabetic patients, we often need to perform cataract and pars plana vitrectomy. Two different techniques are currently valid: 1) phacoemulsification and pars plana vitrectomy and 2)pars plana lensectomy and posterior vitrectomy.

METHODS

Retrospective study of two different groups of type 2 diabetic patients: those receiving 1) phacoemulsification and pars plana vitrectomy or 2) pars plana lensectomy and posterior vitrectomy.

RESULTS

On statistical analysis there were no differences in complications between the two groups. The effect on visual acuity was similar in both groups.

DISCUSSION

The association of cataract surgery and posterior vitrectomy is a valid technique for treating diabetic retinopathy complications. In the present study, the complications of the two techniques were similar, the most important concerning only anterior chamber opening in the first group.

CONCLUSION

The two techniques of cataract extraction and pars plana vitrectomy at the same time have no differences in their results and are valid for treatment of diabetic patients.

Combined Pars Plana Vitrectomy and Phacoemulsification With Intraocular Lens Implantation in Severe Proliferative Diabetic Retinopathy

BACKGROUND AND OBJECTIVE

To evaluate the results of combined vitrectomies and intraocular lens implantations in cases of proliferative diabetic retinopathy.

PATIENTS AND METHODS

Data from procedures on 117 eyes (91 patients) undergoing combined pars plana vitrectomy, phacoemulsification, and intraocular lens implantation for the complications of proliferative diabetic retinopathy were analyzed retrospectively. Follow-up ranged from 8 to 64 months (median = 25 months).

RESULTS

Retinal tears were the most frequent intraoperative problems (19%). Limited postoperative fibrin formation occurred in 22% of eyes. Within 6 months, 7% developed glaucoma and 2% showed new anterior segment rubeosis. Overall, 10% underwent secondary surgical procedures as follows: lavage for hemorrhage (n = 3), silicone oil exchange after 7 days for focal rebleeding (n = 1), silicone oil surgery for retinal detachment after gas resorption (n = 1), and lavage for late vitreous hemorrhage (7 to 13 months) (n = 4). Half of the secondary procedures were necessitated within 3 months of the original surgery.

CONCLUSIONS

Combined surgery in proliferative diabetic retinopathy is safe and effective. It should be considered when lens opacities are either present or likely to develop soon.

Cataract surgery and diabetic retinopathy

Diabetes is a risk factor for the development of cataracts. Studies have shown an increased risk of ocular complications in diabetics after cataract surgery, but modern surgical techniques have minimized them, leading to an overall good visual outcome. Macular edema before surgery is the most common condition that limits post-operative visual recovery. Thus, pre-operative laser treatment is needed. Photocoagulation of preproliferative or early proliferative diabetic retinopathy is also advisable, due to the increased risk of iris neovascularization or retinopathy progression after surgery.

INCIDENCE OF CATARACT EXTRACTION AFTER DIABETIC VITRECTOMY

PURPOSE

To determine the frequency of visually significant cataracts after vitrectomy for complications of diabetic retinopathy.

METHODS

We studied 40 patients and 56 concurrent control patients in a retrospective, consecutive, comparative case series in an institutional setting. Entry criteria included phakic patients with a clear lens or mild lens opacity undergoing anatomically successful diabetic vitrectomy, without lens removal at the time of vitrectomy, without intraocular gas or silicone oil use, and with at least 1 year of postoperative follow-up examination information. Two comparative phakic control groups with the diagnosis of macular hole or epiretinal membrane were selected, also with follow-up examination information of at least 1 year postoperatively. The occurrence of cataract extraction was the principal outcome measure. Its validity as a measure of cataract formation was evaluated by ascertainment of improved visual acuity after cataract extraction. A secondary endpoint analysis included eyes that needed cataract extraction at the final follow-up examination.

RESULTS

For the primary analyses (clear lens preoperatively), there were 26 patients in the study group, 38 in the macular hole control group, and 18 in the epiretinal membrane control group. The cumulative cataract extraction rates at 2 years were 15%, 66%, and 53% respectively. By using multivariate survival analysis, the patient age was an important factor, with a younger age associated with a lower rate of progression to nuclear sclerosis. After controlling for age, the difference in these three groups was still statistically significant. In the four patients with diabetes undergoing cataract surgery, the visual acuity improved at least two lines in only one of the eyes and did not change in three eyes. After expanding the outcome measures to include study patients with mild lens opacities at baseline or those judged to be in need of cataract surgery at the final follow-up examination, there was still a strongly statistically significant difference between the three groups.

CONCLUSION

The rate of cataract extraction after vitrectomy in patients with diabetes is lower than in patients without diabetes undergoing vitrectomy and suggests a lower rate of cataract formation. This inference should be considered when attributing subnormal vision in a patient who has had a diabetic vitrectomy to a cataract. This is especially significant because the risk ratio in patients with diabetes in general and in patients with a previous vitrectomy is likely less favorable compared with the general population.

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.

Evidence-based recommendations for the diagnosis and treatment of neovascular glaucoma

PURPOSE

To succinctly update information on the pathogenesis, etiology, diagnosis, and treatment of neovascular glaucoma based on a systematic review of available literature and to provide summary recommendations rated for their importance to clinical outcome.

CLINICAL RELEVANCE

Neovascular glaucoma is a devastating ocular disease that often results in loss of vision. The current standard of care includes retinal ablation and control of increased intraocular pressure with medical and surgical therapy. LITERATURE REVIEW METHODOLOGY: The authors conducted a MEDLINE literature search of articles published in English from 1966 to the present. Each article reviewed was rated as to the strength of evidence it provided, and summary ratings for the strength of evidence supporting clinical recommendations were generated.

RESULTS

Level A (most important to patient outcome) recommendations for the diagnosis of neovascular glaucoma include a high index of suspicion, a full ocular examination including undilated gonioscopy, and pupil examination. In regard to treatment, Level A recommendations include treatment of the underlying disease origin, complete panretinal photocoagulation (if retinal ischemia is a factor), and medical control of both elevated intraocular pressure and inflammation. Level B recommendations (moderately important to patient outcome) encompass glaucoma surgery to control intraocular pressure when medical therapy is unsuccessful, although the ideal surgical procedure is unknown. Currently, trabeculectomy with antimetabolite therapy, aqueous shunt implants, and diode laser cyclophotocoagulation are the preferred surgical treatment options.

CONCLUSIONS

The current literature on neovascular glaucoma has few articles that provide strong evidence in support of therapy recommendations (level I). Future research studies are needed to address areas in which the current evidence is moderately strong (level II) or weak, consisting only of a consensus of expert opinion (level III). Whenever practicable, these studies should be prospective, randomized clinical trials.

Vitrectomy in the management of diabetic retinopathy

According to the Early Treatment Diabetic Retinopathy Study, at least 5% of eyes receiving optimal medical treatment will still have progressive retinopathy that requires laser treatment and pars plana vitrectomy. During the past decade, improvements in instrumentation and surgical techniques have allowed more difficult cases of diabetic retinopathy to be candidates for vitrectomy. However, although the thresholds for performing surgery within established indicated situations have been lowered, only a few additional indications have been established. Although vitrectomy improves the prognosis for a favorable visual outcome, preventive measures, such as improved control of glucose levels and timely application of panretinal photocoagulation, produce better results. The authors review the indications, techniques, and results of vitrectomy in the management of diabetic retinopathy.

Panretinal photocoagulation during cataract extraction in eyes with active proliferative diabetic eye disease

PURPOSE

Cataract surgery in the presence of active proliferative diabetic eye disease carries a high risk of progression of retinopathy and neovascular glaucoma. Lens opacities may prevent panretinal photocoagulation (PRP) before surgery, and applying PRP in the immediate post-operative period can be difficult. The purpose of this study is to report results of cataract extraction combined with per-operative indirect laser PRP in a group of these patients.

METHODS

Nine eyes of 9 diabetic patients with active retinal or iris neovascularisation in which lens opacities prevented adequate pre-operative PRP underwent cataract surgery combined with indirect laser PRP after cortex aspiration and before intraocular lens implantation.

RESULTS

Regression of neovascularisation with this combined procedure alone was achieved in 5 eyes, 3 responded to further PRP, and 1 developed neovascular glaucoma. Visual acuity improved in all eyes, 4 achieving > or = 6/12. Four patients developed increased post-operative uveitis. One developed clinically significant macular oedema.

CONCLUSIONS

The method described has definite practical advantages over PRP attempted in the immediate post-operative period, when many factors can prevent its application or reduce its effectiveness, and when neovascularisation may be progressing rapidly. In addition, adjunctive per-operative indirect laser PRP appears to improve the outcome of cataract surgery in eyes with active proliferative diabetic eye disease.

The visual results and changes in retinopathy in diabetic patients following cataract surgery

INTRODUCTION

A study was designed to investigate the visual improvement and incidence of progression of retinopathy in diabetic patients following extracapsular cataract extraction or phacoemulsification. They were compared to a matched group of non-diabetic patients.

METHODS

A retrospective analysis of all diabetic patients (118) undergoing ECCE (90) or phacoemulsification (28) in 1995. These patients were operation and age matched with 118 non-diabetic patients who underwent surgery during the same year.

RESULTS

There was no statistically significant difference in complications following ECCE in diabetic and non-diabetic patients (p = 0.2). Complications were however more common in non-diabetic patients undergoing phacoemulsification compared to diabetics undergoing the same procedure (p = 0.046). Although consultants performed 42% of the surgery in diabetics compared to 31% in non-diabetics, there was no significant difference in the rate of complications between consultants and residents (p = 0.8). Overall the visual improvement in non-diabetics was better than diabetic patients (p = 0.006). This was due to a better improvement amongst non-diabetic patients undergoing phacoemulsification (p = 0.02). Overall, cataract surgery was found to lead to a worsening in retinopathy in 19 operated eyes (15 had no retinopathy preoperatively) compared to a worsening in 8 fellow eyes. This was statistically significant (p = 0.04). However, ECCE was no more likely to cause worsening of retinopathy than phacoemulsification (p = 0.87).

CONCLUSIONS

Diabetic patients due to undergo cataract surgery a) have a good chance of visual improvement but to a level less than if they were not diabetic, b) have a greater chance of visual loss, c) surgery may initiate or worsen any pre-existing retinopathy and this may affect their vision in the future.

Vascular endothelial growth factor and severity of nonproliferative diabetic retinopathy mediate retinal hemodynamics in vivo: a potential role for vascular endothelial growth factor in the progression of nonproliferative diabetic retinopathy

PURPOSE

To determine the effect of vascular endothelial growth factor and retinopathy level on retinal hemodynamics in nondiabetic and diabetic rats and to evaluate retinal hemodynamics in nondiabetic and diabetic patients.

METHODS

Forty-eight diabetic and 22 nondiabetic patients had their diabetic retinopathy levels determined from fundus photographs according to Early Treatment Diabetic Retinopathy Study (ETDRS). Fluorescein angiograms were recorded from the left eye by video fluorescein angiography. Retinal blood flow was calculated from the digitized angiograms. Human recombinant vascular endothelial growth factor or vehicle alone was injected intravitreally into 13 nondiabetic and 11 diabetic rats.

RESULTS

Retinal blood flow decreased 33% in patients with ETDRS retinopathy level 10 compared with control patients (P = .001) and increased sequentially in more advanced stages of retinopathy, with a strong correlation between retinal blood flow and retinopathy level (r2 = 0.434, P = .001). In the diabetic rats, retinal blood flow was decreased 35.6% (P = .01). Vascular endothelial growth factor maximally increased retinal blood flow by 36.1% in nondiabetic rats after 25 minutes (P = .001) and by 73.7% in diabetic rats after only 5 minutes (P = .01) and caused a greater response in diabetic than in nondiabetic rats.

CONCLUSIONS

Retinal blood flow increases with advancing nonproliferative diabetic retinopathy in humans, and diabetes accentuates the vascular endothelial growth factor-induced increase in retinal blood flow and venous dilation in rats. Vascular endothelial growth factor may contribute to the changes in retinal hemodynamics and morphology observed in early diabetic retinopathy.

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.

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.

Extracapsular cataract extraction in diabetic eyes. The role of YAG laser capsulotomy

Cataract surgery may exacerbate preexisting diabetic retinopathy. Especially diabetics with active retinal neovascularisation are at high risk of rubeosis iridis after intracapsular cataract extraction. Thirty-five eyes previously treated with panretinal photocoagulation underwent extracapsular cataract extraction with posterior chamber lens implantation. Twenty-eight eyes with retinal neovascularisation required further Argon laser PRP after surgery. Fourteen eyes required YAG-laser capsulotomy. From the group of eyes without YAG-laser capsulotomy none developed neovascular glaucoma. From the YAG laser capsulotomy group six eyes developed rubeosis iridis and neovascular glaucoma. Our results indicate that eyes in which PRP has been performed, have an excellent prognosis after ECCE with posterior chamber lens implantation only if YAG Laser posterior capsulotomy is not performed.

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.

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.

Anterior hyaloidal fibrovascular proliferation after extracapsular cataract extraction in diabetic eyes

Four patients with proliferative diabetic retinopathy developed anterior hyaloidal fibrovascular proliferation after extracapsular cataract extraction and posterior chamber lens implantation. This complication of cataract extraction has been described after vitrectomy in diabetic eyes. Risk factors for this entity after extracapsular cataract extraction include proliferative diabetic retinopathy, iris neovascularization, and anterior ischemic retina. Anterior hyaloidal fibrovascular proliferation was observed an average of 12 months postoperatively and affected vision in one of four patients. No progression was seen within an average of six months of follow-up, and no complications such as traction retinal detachment and vitreous hemorrhage developed.