Vitrectomy in the management of diabetic eye disease

Long-Standing Macula-Involving Diabetic Tractional Retinal Detachments with Good Visual Acuity: How Should We Manage These Patients?

Purpose

We assess the merits of pars plana vitrectomy (PPV) in subjects with good visual acuity (VA) and a chronic macula-involving tractional retinal detachment (TRD) secondary to proliferative diabetic retinopathy (PDR).

Methods

A retrospective review of medical records was undertaken. Subjects were divided into 1) a Study Group of subjects who underwent prompt PPV and 2) a Control Group of subjects in which PPV was deferred in favor of less invasive treatment options or observations. Both study and control subjects had a baseline Snellen VA of ≥20/50 and a PDR-associated macula-involving TRD of >6 months duration with a minimum follow-up of 12-months.

Results

There were 58 patients analyzed over an average follow-up period of 27.6 (±7.1) months. The change in VA was similar in the Study Group compared to the Control Group (p=0.94) with both groups losing about three lines of VA during the study period (-0.30 ±0.52 logMAR). Although the rates of maintaining ≥20/200 Snellen VA and ≥20/50 Snellen VA were similar in the Study Group compared to the Control Group (p=0.55 and p=0.28, respectively), the Study Group had more subjects gaining ≥2 lines of VA during the study period (p=0.002).

Conclusion

Patients presenting with good VA and a PDR-associated macula-involving TRD of >6 months were more likely to gain ≥2 lines of VA when PPV was performed at baseline compared to PPV deferral until further deterioration occurred.

Anti-vascular endothelial growth factors in combination with vitrectomy for complications of proliferative diabetic retinopathy

BACKGROUND

Vitrectomy is an established treatment for the complications of proliferative diabetic retinopathy (PDR). However, a number of complications can occur during and after vitrectomy for PDR. These include bleeding and the creation of retinal holes during surgery, and bleeding, retinal detachment and scar tissue on the retina after surgery. These complications can limit vision, require further surgery and delay recovery. The use of anti-vascular endothelial growth factor (anti-VEGF) agents injected into the eye before surgery has been proposed to reduce the occurrence of these complications. Anti-VEGF agents can reduce the amount and vascularity of abnormal new vessels associated with PDR, facilitating their dissection during surgery, reducing intra- and postoperative bleeding, and potentially improving outcomes.

OBJECTIVES

To assess the effects of perioperative anti-VEGF use on the outcomes of vitrectomy for the treatment of complications for proliferative diabetic retinopathy (PDR).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; which contains the Cochrane Eyes and Vision Trials Register; 2022, Issue 6); Ovid MEDLINE; Ovid Embase; the ISRCTN registry; ClinicalTrials.gov and the WHO ICTRP. The date of the search was 22 June 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that looked at the use of anti-VEGFs and the incidence of complications in people undergoing vitrectomy for PDR.   DATA COLLECTION AND ANALYSIS: Two review authors independently assessed and extracted the data. We used the standard methodological procedures expected by Cochrane. The critical outcomes of the review were the mean difference in best corrected visual acuity (BCVA) between study arms at six (± three) months after the primary vitrectomy, the incidence of early postoperative vitreous cavity haemorrhage (POVCH, within four weeks postoperatively), the incidence of late POVCH (occurring more than four weeks postoperatively), the incidence of revision surgery for POVCH within six months, the incidence of revision surgery for recurrent traction/macular pucker of any type and/or rhegmatogenous retinal detachment within six months and vision-related quality of life (VRQOL) measures. Important outcomes included the proportion of people with a visual acuity of counting fingers (1.8 logMAR or worse), the number of operative retinal breaks reported and the frequency of silicone oil tamponade required at time of surgery.

MAIN RESULTS

The current review includes 28 RCTs that looked at the pre- or intraoperative use of intravitreal anti-VEGFs to improve the outcomes of pars plana vitrectomy for complications of PDR. The studies were conducted in a variety of countries (11 from China, three from Iran, two from Italy, two from Mexico and the remaining studies from South Korea, the UK, Egypt, Brazil, Japan, Canada, the USA, Indonesia and Pakistan). The inclusion criteria for entry into the studies were the well-recognised complications of proliferative retinopathy: non-clearing vitreous haemorrhage, tractional retinal detachment involving the macula or combined tractional rhegmatogenous detachment. The included studies randomised a total of 1914 eyes.  We identified methodological issues in all of the included studies. Risk of bias was highest for masking of participants and investigators, and a number of studies were unclear when describing randomisation methods and sequence allocation. Participants receiving intravitreal anti-VEGF in addition to pars plana vitrectomy achieved better BCVA at six months compared to people undergoing vitrectomy alone (mean difference (MD) -0.25 logMAR, 95% confidence interval (CI) -0.39 to -0.11; 13 studies, 699 eyes; low-certainty evidence). Pre- or intraoperative anti-VEGF reduced the incidence of early POVCH (12% versus 31%, risk ratio (RR) 0.44, 95% CI 0.34 to 0.58; 14 studies, 1038 eyes; moderate-certainty evidence). Perioperative anti-VEGF use was also associated with a reduction in the incidence of late POVCH (10% versus 23%, RR 0.47, 95% CI 0.30 to 0.74; 11 studies, 579 eyes; high-certainty evidence). The need for revision surgery for POVCH occurred less frequently in the anti-VEGF group compared with control, but the confidence intervals were wide and compatible with no effect (4% versus 13%, RR 0.44, 95% CI 0.15 to 1.28; 4 studies 207 eyes; moderate-certainty evidence). Similar imprecisely measured effects were seen for revision surgery for rhegmatogenous retinal detachment (5% versus 11%, RR 0.50, 95% CI 0.15 to 1.66; 4 studies, 145 eyes; low-certainty evidence).  Anti-VEGFs reduce the incidence of intraoperative retinal breaks (12% versus 31%, RR 0.37, 95% CI 0.24 to 0.59; 12 studies, 915 eyes; high-certainty evidence) and the need for silicone oil (19% versus 41%, RR 0.46, 95% CI 0.27 to 0.80; 10 studies, 591 eyes; very low-certainty evidence). No data were available on quality of life outcomes or the proportion of participants with visual acuity of counting fingers or worse.

AUTHORS' CONCLUSIONS

The perioperative use of anti-VEGF reduces the risk of late POVCH, probably results in lower early POVCH risk and may improve visual outcomes. It also reduces the incidence of intraoperative retinal breaks. The evidence is very uncertain about its effect on the need for silicone oil tamponade. The reported complications from its use appear to be low. Agreement on variables included and outcome standardisation is required in trials studying vitrectomy for PDR.

Current management of diabetic tractional retinal detachments

Twenty-five percent of diabetes-related vision loss stems from complications of proliferative diabetic retinopathy (PDR). Panretinal photocoagulation has been the preferred treatment of high-risk PDR for decades and more recently intravitreal injections of drugs that inhibit the actions of vascular endothelial growth factor have become popular. But despite these treatments PDR may progress uncontrollably to advanced pathologies such as traction retinal detachments (TRDs), combined traction/rhegmatogenous retinal detachments (TRD/RRDs), vitreous hemorrhages, rubeosis iridis, and traction maculopathies, which produce mild-to-severe loss of vision. TDR have long been the most common indication for PDR-related vitreoretinal surgery. Vitrectomy surgery is indicated for recent (<6 months duration) TRD involving the macula, progressive TRD that threatens the macula, and recent data suggest that chronic macula-involving TRDs (>6 months duration) may also benefit. Combined TRD/RRD represents a particularly challenging surgical condition but advances in surgical instrumentation, dissection techniques, and post-operative tamponade have produced excellent success rates. The recent development of small-gauge vitrectomy systems has persuaded most surgeons to switch platforms since these appear to produce shorter surgical times and quicker post-operative recoveries. Pre-operative injections of bevacizumab are frequently administered for persistent neovascularization to facilitate surgical dissection of pre-retinal fibrosis and reduce the incidence of post-operative hemorrhages. Recent trends toward earlier surgical intervention and expanded indications are likely to continue as surgical instrumentation and techniques are further developed.

The effect of bevacizumab before vitrectomy for diabetic tractional retinal detachment demonstrated on optical coherence tomography angiography

Purpose

To demonstrate the effect of intravitreal bevacizumab (IVB) on the size and vascularity of the fibro-vascular complex with the optical coherence tomography angiography (OCTA) before pars plana vitrectomy (PPV).

Methods

Observational case series of three eyes with active diabetic fibro-vascular complex and tractional retinal detachment (TRD) who underwent IVB (1.25 mg/0.05 ml) two days before proceeding to PPV. OCTA was carried out prior to IVB, two days after IVB and six weeks after PPV.

Results

OCTA showed a reduction in the size and calibre of the diabetic fibro-vascular complex two days after IVB in all the cases. Consequently, there was less traumatic dissection of the fibro-vascular membranes during PPV and thus reduced chances of intraoperative and postoperative vitreous cavity bleeding. One case showed mild hemorrhage in the posterior vitreous on the second day post-injection which implies the increased traction caused by IVB.

Conclusions

In this case series, we have used OCTA to demonstrate how IVB is highly effective in reducing the vascularity of diabetic fibro-vascular membranes. This finding also suggests that the use of IVB before PPV in the management of diabetic TRD could also be much shorter than the advocated standard practice of one week in most institutions.

Neovascular glaucoma after vitrectomy in patients with proliferative diabetic retinopathy

To evaluate the prevalence and risk factors of neovascular glaucoma (NVG) after vitrectomy in patients with vitreous hemorrhage associated with proliferative diabetic retinopathy (PDR). This retrospective, noncomparative, observational study included 127 eyes of 127 patients with PDR who received vitrectomy with a follow-up period of at least 6 months. The prevalence of NVG and associated risk factors were assessed including sex, age, previous panretinal photocoagulation, baseline intraocular pressure, combined phacovitrectomy, and pretreatment with intravitreal bevacizumab (IVB) before vitrectomy for the treatment of vitreous hemorrhage. NVG developed in 15 (11.8%) of 127 patients. Of the 15 eyes with NVG, 11 cases (73.3%) postoperatively developed NVG within 6 months. Postoperative NVG was associated with preoperative IVB treatment (odds ratio, 4.43; P = 0.019). The prevalence of NVG after vitrectomy was 11.8%, and an associated risk factor for NVG was preoperative IVB for the treatment of vitreous hemorrhage.

Role of bevacizumab in the prevention of early postoperative haemorrhage after 25-gauge microincision vitrectomy surgery

Objective:

To evaluate the effect of preoperative intravitreal bevacizumab injection on the incidence of postoperative haemorrhage and visual prognosis, in patients undergoing 25-gauge micro incision vitrectomy surgery (MIVS) for diabetic vitreous haemorrhage.

Methods:

One hundred and twenty two eyes of 122 patients of diabetic retinopathy of both genders and aged over 18 years, who presented with non-resolving vitreous haemorrhage were enrolled for this study. All patients received an intravitreal injection of 1.25 mg/0.05 mL bevacizumab (Avastin) which was followed one week later by 25-gauge sutureless micro incision vitrectomy surgery. Main outcomes measured were best corrected visual acuity (BCVA) assessed with logMAR and post-operative vitreous haemorrhage. Follow ups were up to six months post-operatively. IBM SPSS 21 was used for data analysis.

Result:

A total of 122 patients were included; 78 (63.9%) males and 44 (36.1%) females. Mean age at the time of surgery was 51.4 ± 13.66 years. The mean preoperative BCVA was 1.64 ± 0.427 logMAR which improved to 0.57 ± 0.253 logMAR at 12 months post-operatively (p-value < 0.001). Recurrent vitreous haemorrhage was seen in four patients (3.28%).

one1 week before 25-gauge vitrectomy helps to reduce the incidence of early post-vitrectomy haemorrhage in diabetic 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.

Surgery for Proliferative Diabetic Retinopathy: New Tips and Tricks

Over the recent years, retina specialists have enjoyed significant improvements in the surgical management of proliferative diabetic retinopathy including improved preoperative planning, vitreoretinal instrumentation and new surgical maneuvers. In this review, we present new tips and tricks such as preoperative pharmacotherapy approaches including pegaptanib injection and biodegradable dexamethasone implantation, bimanual vitrectomy techniques and the concept of mixing small gauges as well as valved cannulas and intraoperative optical coherence tomography. With advanced surgical planning and sophisticated operative maneuvers tailored to the individual patient, excellent outcomes can be achieved even in severe cases of diabetic tractional detachment.

Clinical biomarkers and molecular basis for optimized treatment of diabetic retinopathy: current status and future prospects

Diabetic retinopathy is a highly specific microvascular complication of diabetes and a leading cause of blindness worldwide. It is triggered by hyperglycemia which causes increased oxidative stress leading to an adaptive inflammatory assault to the neuroretinal tissue and microvasculature. Prolonged hyperglycemia causes increased polyol pathway flux, increased formation of advanced glycation end-products, abnormal activation of signaling cascades such as activation of protein kinase C (PKC) pathway, increased hexosamine pathway flux, and peripheral nerve damage. All these changes lead to increased oxidative stress and inflammatory assault to the retina resulting in structural and functional changes. In addition, neuroretinal alterations affect diabetes progression. The most effective way to manage diabetic retinopathy is by primary prevention such as hyperglycemia control. While the current mainstay for the management of severe and proliferative diabetic retinopathy is laser photocoagulation, its role is diminishing with the development of newer drugs including corticosteroids, antioxidants, and antiangiogenic and anti-VEGF agents which work as an adjunct to laser therapy or independently. The current pharmacotherapy of diabetic retinopathy is incomplete as a sole treatment option in view of limited efficacy and short-term effect. There is a definite clinical need to develop new pharmacological therapies for diabetic retinopathy, particularly ones which would be effective through the oral route and help recover lost vision. The increasing understanding of the mechanisms of diabetic retinopathy and its biomarkers is likely to help generate better and more effective medications.

Visual outcome of 25-gauge microincision vitrectomy surgery in diabetic vitreous haemorrhage

Objective:

To assess the visual outcome and complications of 25-gauge micro incision vitrectomy surgery (MIVS) in diabetic vitreous haemorrhage.

Methods:

This Quasi Experimental study was conducted at LRBT, Tertiary eye care hospital Karachi, from February 2012 to January 2013. Sixty eyes of sixty patients with uncontrolled type II diabetes mellitus (DM) were included. There were 43 (71.7%) males and 17 (28.3%) females. Age range was 40 – 60 years. All randomly selected patients underwent 25-gauge sutureless micro incision vitrectomy surgery for diabetic vitreous haemorrhage. Main outcomes measured were best corrected visual acuity (BCVA) assessed with logMAR and post-operative complications. Follow ups were at one day, one week, one month, three months and six months post-operatively.

Result:

Best corrected visual acuity (BCVA) gradually improved in majority of subjects in each subsequent follow up visit. Preoperative visual acuity was 1.023 ±0.226 logMAR, which was improved after final follow up to 0.457±0.256 and P-value was < 0.001. Five patients developed recurrent vitreous haemorrhage during study period, one patient developed cataract (1.7%), one (1.7%) had ocular hypotony defined as intraocular pressure < 5 mmHg and one (1.7%) developed endophthalmitis.

Conclusion:

25-gauge micro incision vitrectomy surgery (MIVS) is an effective sutureless parsplana vitrectomy surgery which has good visual outcome in diabetic vitreous haemorrhage with minimum manageable complications.

Anti-vascular endothelial growth factor for prevention of postoperative vitreous cavity haemorrhage after vitrectomy for proliferative diabetic retinopathy

BACKGROUND

Postoperative vitreous cavity haemorrhage (POVCH) is a significant complication following vitrectomy for proliferative diabetic retinopathy (PDR). It delays visual recovery and can make further treatment difficult if the view of the fundus is significantly obscured. A number of interventions to reduce the incidence of POVCH have been proposed, including the perioperative use of anti-vascular endothelial growth factor (anti-VEGF). Anti-VEGFs reduce vascular proliferation and the vascularity of neovascular tissue, which is often the source of bleeding following vitrectomy.

OBJECTIVES

This updated review aimed to summarise the effects of anti-VEGF use to reduce the occurrence of POVCH after vitrectomy surgery for PDR.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2015, Issue 4), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to May 2015), PubMed (January 1966 to May 2015), EMBASE (January 1980 to May 2015), Latin American and Caribbean Health Sciences (LILACS) (January 1982 to May 2015), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov), and the the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 26 May 2015.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) and quasi-RCTs that looked at the use of anti-VEGFs and the incidence of POVCH in people undergoing vitrectomy for PDR.

DATA COLLECTION AND ANALYSIS

Both review authors independently assessed and extracted the data. We used standard methodological procedures expected by Cochrane.The primary outcomes of the review were the incidence of early and late POVCH following perioperative anti-VEGF administration. Secondary outcomes included best-corrected visual acuity at six months following surgery, the incidence of vitreous cavity washout or revision vitrectomy at six months, adverse effects of intervention (cataract, iris rubeosis and rubeotic glaucoma, retinal detachment, increased inflammation and systemic side effects), quality of life measures performed at least six months following vitrectomy, and density of POVCH.

MAIN RESULTS

The current review included 12 RCTs that looked at the pre- or intraoperative use of intravitreal bevacizumab to prevent postoperative vitreous haemorrhage during pars plana vitrectomy for complications of PDR. The studies were conducted in a variety of countries (three from Iran, two from Italy, two from Egypt, and the remaining from South Korea, USA, Mexico, Pakistan, and Japan). The inclusion criteria for entry into the studies were standard complications of proliferative retinopathy: non-clearing vitreous haemorrhage, tractional retinal detachment involving the macula, or combined tractional rhegmatogenous detachment. The included studies randomised a total of 654 eyes. The average age of the participants was 54 years.We identified methodological issues in all included studies. Risk of bias was highest for masking of participants and investigators (four studies were an 'open label' design), and a number of studies were unclear when describing randomisation methods and sequence allocation.Participants receiving intravitreal bevacizumab in addition to pars plana vitrectomy were less likely to experience early POVCH (grade 2) compared to people undergoing pars plana vitrectomy alone (risk ratio (RR) 0.28, 95% confidence interval (CI) 0.08 to 0.96, 2 studies, 144 eyes, high-quality evidence). This corresponds to an absolute effect of 130 fewer people (95% CI 167 fewer to 7 fewer) with early POVCH per 1000 people when treated with intravitreal bevacizumab. We saw similar results for all grades of POVCH (RR 0.35, 95% CI 0.23 to 0.53, 9 studies, 512 eyes) and when excluding cases where assessment of outcome was impossible due to presence of silicone oil (RR 0.34, 95% CI 0.19 to 0.60, 6 studies, 302 eyes).The effect of pre- or intraoperative intravitreal bevacizumab on the incidence of late postoperative haemorrhage was uncertain (RR 0.72, 95% CI 0.30 to 1.72, 3 studies, 196 eyes, low-quality evidence). The absolute effect was 55 fewer people (95% CI 138 fewer to 143 more) with late POVCH per 1000 people when treated with intravitreal bevacizumab. This outcome was rarer and was only reported in a few studies. We are currently unable to provide an estimate of the effect of intravitreal bevacizumab on postoperative visual acuity due to significant study heterogeneity.No local or systemic complications of intravitreal bevacizumab were reported by the RCTs. The risk of postoperative retinal detachment was lower in the participants treated with pre- or intraoperative bevacizumab (RR 0.46, 95% CI 0.19 to 1.08, 7 studies, 372 participants, low-quality evidence); the absolute effect was 49 fewer people (95% CI:73 fewer to 8 more) with postoperative retinal detachment per 1000 people when treated with intravitreal bevacizumab.

AUTHORS' CONCLUSIONS

The use of pre- or intraoperative bevacizumab lowers the incidence of early POVCH. The reported complications from its use appear to be low. Futher randomised studies that look at other anti-VEGF medications are ongoing and will strengthen the current review findings, giving both surgeons and patients evidence to guide treatment choices in the management of proliferative retinopathy.

Perfluorocarbon in vitreoretinal surgery and preoperative bevacizumab in diabetic tractional retinal detachment

AIM: To describe the en bloc perfluorodissection (EBPD) technique and to demonstrate the applicability of using preoperative intravitreal bevacizumab during small-gauge vitreoretinal surgery (23-gauge transconjunctival sutureless vitrectomy) in eyes with advanced proliferative diabetic retinopathy (PDR) with tractional retinal detachment (TRD).

METHODS: This is a prospective, interventional case series. Participants included 114 (eyes) with advanced proliferative diabetic retinopathy and TRD. EBPD was performed in 114 eyes (consecutive patients) during 23-gauge vitrectomy with the utilization of preoperative bevacizumab (1.25 mg/0.05 mL). Patients mean age was 45 years (range, 21-85 years). Surgical time had a mean of 55 min (Range, 25-85 min). Mean follow up of this group of patients was 24 mo (range, 12-32 mo). Main outcome measures included best-corrected visual acuity (BCVA), retinal reattachment, and complications.

RESULTS: Anatomic success occurred in 100% (114/114) of eyes. Significant visual improvement [≥ 2 Early Treatment Diabetic Retinopathy Study (ETDRS) lines] was obtained in 69.2% (79/114), in 26 eyes (22.8%) BCVA remained stable, and in 8 eyes (7%) BCVA decreased (≥ 2 ETDRS lines). Final BCVA was 20/50 or better in 24% of eyes, between 20/60 and 20/400 in 46% of eyes, and worse than 20/400 in 30% of eyes. Complications included cataract in 32 (28%) eyes, iatrogenic retinal breaks in 9 (7.8%) eyes, vitreous hemorrhage requiring another procedure in 7 (6.1%) eyes, and phthisis bulbi in 1 (0.9%) eye.

CONCLUSION: This study demonstrates the usefulness of using preoperative intravitreal bevacizumab and EBPD during small-gauge vitreoretinal surgery in eyes with TRD in PDR.

Targeting Neovascularization in Ischemic Retinopathy: Recent Advances

Pathological retinal neovascularization (RNV) is a common micro-vascular complication in several retinal diseases including retinopathy of prematurity, diabetic retinopathy, age-related macular degeneration and central vein occlusion. The current therapeutic modalities of RNV are invasive and although they may slow or halt the progression of the disease they are unlikely to restore normal acuity. Therefore, there is an urgent need to develop treatment modalities, which are less invasive and therefore associated with fewer procedural complications and systemic side effects. This review article summarizes our understanding of the pathophysiology and current treatment of RNV in ischemic retinopathies; lists potential therapeutic targets; and provides a framework for the development of future treatment modalities.

Feasibility of telemedicine in detecting diabetic retinopathy and age-related macular degeneration

Age-related macular degeneration and diabetic retinopathy are important causes of visual impairment and blindness in the world. Because of recent advances and newly available treatment modalities along with the devastating consequences associated with late stages of these diseases, much attention has been paid to the importance of early detection and improving patient access to specialist care. Telemedicine or, more specifically, digital retinal imaging utilizing telemedical technology has been proposed as an important alternative screening and management strategy to help meet this demand. In this paper, we perform a literature review and analysis that evaluates the validity and feasibility of telemedicine in detecting diabetic retinopathy and age-related macular degeneration. Understanding both the progress and barriers to progress that have been demonstrated in these two areas is important for future telemedicine research projects and innovations in telemedicine technology.

Faster recovery after 25-gauge microincision vitrectomy surgery than after 20-gauge vitrectomy in patients with proliferative diabetic retinopathy

Background and methods

We compared surgical procedures and outcomes, including duration of recovery period, in eyes with proliferative diabetic retinopathy that underwent 25-gauge microincision vitrectomy surgery with those that underwent 20-gauge vitrectomy. Seventy-two eyes from 53 patients that underwent 20-gauge vitrectomy in 2006 and 87 eyes from 55 patients that underwent 25-gauge vitrectomy in 2010 were studied. The surgical procedures, ie, number of vitreous procedures, operating time, and ratio of type of intraocular tamponade were compared between the two groups. In addition, the outcomes, ie, postoperative complications, anatomical success, postoperative best-corrected visual acuity (BCVA), and duration of hospitalization as an indicator of the postoperative recovery period were also compared.

Results

There were no significant differences in surgical procedures or ratio of cases with postoperative complications between cases with 20-gauge and 25-gauge vitrectomy. The final anatomical success rate was 100% in the two groups. BCVA at 6 months after the final vitrectomy was significantly better than the preoperative BCVA for both types of vitrectomy (P < 0.05), and was not significantly different between the two groups. The average duration of hospitalization was 19.5 days after 20-gauge vitrectomy, which was significantly longer than the 11.0 days after 25-gauge vitrectomy (P < 0.001).

Conclusion

These results indicate that the anatomical and functional improvements after 25-gauge microincision vitrectomy surgery are not significantly different from those after 20-gauge vitrectomy in eyes with proliferative diabetic retinopathy. However, the significantly shorter recovery period after 25-gauge microincision vitrectomy surgery suggests that it is less traumatic than 20-gauge vitrectomy.

Perfluorocarbon-perfused 23 gauge three-dimensional vitrectomy for complicated diabetic tractional retinal detachment

Background

Perfluorocarbon liquid (PCL)-perfused vitrectomy has been shown in previous studies to be feasible, safe, and to have advantages in managing complicated cases of tractional retinal detachment. The present study had the objectives of describing the anatomical results and measuring surgical time and PCL consumption when combining PCL-perfused techniques with modern vitrectomy equipment.

Methods

A prospective, interventional consecutive case series was investigated. We enrolled patients with diabetic tractional retinal detachment, complicated by proliferative vitreoretinopathy and poor vision. A 23 gauge PCL-perfused vitrectomy was done with three-dimensional settings. During the procedure, we assessed the degree of surgical bleeding, visualization quality, and difficulty of membrane dissections. Visual acuity, intraocular pressure, and anatomical success were assessed at one and 3 months of follow-up.

Results

Twelve patients were enrolled in this study. There were no statistical significant changes in intraocular pressure and visual acuity throughout the follow-up period. Surgery was performed in a hemorrhage-free environment in almost all cases, with good visualization and low technical difficulty. The mean complete surgical time was 94.92 ± 25.03 minutes. The mean effective vitrectomy time was 22.50 ± 19.04 minutes and the mean PCL consumption was 25.08 ± 9.76 mL, with a speed of 1.11 mL/minute. Anatomical success was 67% at 3 months.

Conclusion

Although the technique proved to have some advantages in managing complicated cases of diabetic tractional retinal detachment, there was a high consumption of PCL. A redesign of the entire system is needed in order to decrease the amount of PCL needed for the technique.

Anti-vascular endothelial growth factor for prevention of postoperative vitreous cavity haemorrhage after vitrectomy for proliferative diabetic retinopathy

BACKGROUND

Postoperative vitreous cavity haemorrhage (POVCH) is a significant complication following vitrectomy for proliferative diabetic retinopathy (PDR). It delays visual recovery and can make further treatment difficult if the view of the fundus is significantly obscured. A number of interventions to reduce the incidence of POVCH have been proposed, including the perioperative use of anti-vascular endothelial growth factor (anti-VEGF). Anti-VEGFs reduce vascular proliferation and the vascularity of neovascular tissue, which is often the source of bleeding following vitrectomy.

OBJECTIVES

The review aims to assess the effect of perioperative anti-VEGF in reducing the incidence of POVCH.

SEARCH STRATEGY

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2011, Issue 2), MEDLINE (January 1950 to March 2011), PubMed (10 March 2011), EMBASE (January 1980 to March 2011), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to March 2011), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com) and ClinicalTrials.gov (www.clinicaltrial.gov). There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 10 March 2011.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) that looked at the use of anti-VEGFs and the incidence of POVCH in people undergoing vitrectomy for PDR.

DATA COLLECTION AND ANALYSIS

Both review authors independently assessed and extracted the data using a standardised form based on the CONSORT statement.

MAIN RESULTS

We included four studies (202 eyes of 198 participants) in this review. The four RCTs met the inclusion criteria, but we were unable to conduct a meta-analysis due to methodological issues in three of the trials. We have provided a summary of the effects of the interventions. We have also provided a summary of the current literature addressing each primary and secondary outcome.

AUTHORS' CONCLUSIONS

Results from one of the included studies support the use of preoperative intravitreal bevacizumab to reduce the incidence of early POVCH. There are currently no other high quality RCTs that support the use of anti-VEGF agents perioperatively to reduce the incidence of early or late POVCH. The remaining studies identified by the search suggest that the preoperative use of bevacizumab may reduce the incidence of early POVCH, but it should be recognised that there are a number of significant methodological issues in these studies that lead us to be cautious when interpreting their findings and make any definitive conclusions unwarranted.

Individualised treatment of proliferative diabetic retinopathy: optimal surgical timing improves long-term outcomes

Ocular treatment of progressing proliferative diabetic retinopathy is based on retinal laser photocoagulation and pars plana vitrectomy. Improvements in instrumentation and advances in techniques and procedures have increased indications for vitrectomy. These include vitreous haemorrhage preventing laser photocoagulation, severe nonclearing vitreous haemorrhage, subhyaloid and premacular haemorrhage, tractional retinal detachment involving or threatening the macula, combined tractional and rhegmatogenous retinal detachment, progressive fibrovascular proliferation, clinically significant macular oedema and rubeosis iridis. Together with the increasing number of indications, timing for vitrectomy has also changed. The beneficial effect of early vitrectomy for these indications has been clinically shown and supported by several studies. The benefit is evident in case of type I diabetes and when the duration of the diabetes is less than 20 years. Long-term outcomes can therefore be improved when individualised treatment algorithms are applied.

Panretinal photocoagulation induces pro-inflammatory cytokines and macular thickening in high-risk proliferative diabetic retinopathy

PURPOSE

To investigate whether pan-retinal photocoagulation (PRP) affects vitreous levels of cytokines and macular thickening in patients with high-risk proliferative diabetic retinopathy (PDR).

METHODS

Fourteen patients with bilateral high-risk PDR--which requires pars plana vitrectomy (PPV)--but without a history of retinal photocoagulation participated in this study. Before PPV, one eye received PRP, and the other eye did not. The concentrations of cytokines of vascular endothelial growth factor (VEGF), stromal derived factor-1 (SDF-1), interleukin-6 (IL-6) and regulated upon activation, normal T-cell expressed and secreted (RANTES) were measured in each vitreous sample obtained at PPV. Macular thickness obtained by optical coherence tomography was also monitored during clinical course.

RESULTS

After the PRP, macular thickness in PRP-pretreated eye showed temporal increase. Vitreous levels of IL-6 and RANTES in PRP pre-treated eye were significantly higher than levels in control eyes (p = 0.013, p = 0.033). Although macular thickness in control was correlated to vitreous levels of VEGF and IL-6 (p = 0.022, p = 0.003), that in PRP-pretreated eye was closely correlated to IL-6 and RANTES (p = 0.002, p = 0.011). After the PPV, macular thickness in both eye groups improved, and there was no significant difference between both eye groups 3 months after the PPV.

CONCLUSIONS

In patients with high-risk PDR, PRP cause temporal worsening of macular edema linked with pro-inflammatory cytokines of IL-6 and RANTES, but not with VEGF and SDF-1. Thus, PRP-induced macular edema was caused by inflammation, while visual prognosis after PPV was not influenced by pretreatment of PRP.

Risk Factors for Postoperative Hemorrhage after Vitrectomy for Diabetic Retinopathy

OBJECTIVE

To identify the potential risk factors for postvitrectomy diabetic vitreous hemorrhage (PDVH).

METHODS

A matched case-control nested into a retrospective follow-up study was done to review the surgical results in 68 consecutive eyes undergoing primary pars plana vitrectomy for vitreous hemorrhage. The eyes were divided into two groups based on the presence of PDVH (19 cases and 49 controls) and were matched on surgeon and the date of surgery. Twenty-three factors related to the preoperative examination and eight factors related to the operative procedure were analyzed. Statistical analysis was based on conditional logistic regression models with PDVH as the dependent variable. The mean follow-up interval was six months.

RESULTS

The factors associated with the incidence of PDVH were iris neovascularization (OR = 9.8, P = 0.03), lower extremity amputations (OR = 8.3, P = 0.02) and the use of antihypertensive agents within three months before vitrectomy (OR = 0.2, P = 0.04). Phakic and aphakic eyes of diabetic patients with lower extremity amputations would have a 70% probability of developing PDVH. This probability would have dropped to 30-40% had they been taking antihypertensive treatment.

CONCLUSIONS

Iris neovascularization and lower extremity amputations increase the risk of PDVH. Antihypertensive treatment before vitrectomy decreases this risk.

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.

Visual outcome and risk factors for light perception and no light perception vision after vitrectomy for diabetic retinopathy

PURPOSE

To assess the visual outcome following vitrectomy for diabetic retinopathy compared with previous studies; to evaluate risk factors for light perception (LP) and no light perception (NLP) vision after diabetic vitrectomy.

DESIGN

Retrospective medical record review.

METHODS

The charts of 100 consecutive patients who underwent vitrectomy for proliferative diabetic retinopathy between November 1, 1997, and November 30, 1998, were reviewed. Surgical technique included standard pars plana vitrectomy with combination of delamination and segmentation of gliotic tractional membranes using bimanual techniques. All patients had post-operative follow-up of at least 12 months. Several factors were analyzed for their effect on poor visual outcome (LP and NLP) using Fisher's exact test.

RESULTS

Post-vitrectomy, 73% of diabetic patients had stable or improved vision; 16% had worsened but functional vision, defined as worse but still >or= 20/400; 4% had worsened but ambulatory vision, defined as worse but still count fingers (CF) or hand motion (HM); and 7% had poor visual outcome, LP or NLP. Resultant visual acuity was >or=20/40 in 38% of patients, 20/50 to 20/100 in 34%, 20/120 to CF in 18%, HM in 3%, LP in 4%, and NLP in 3%. Risk factors for eyes with LP and NLP vision included pre-operative iris neovascularization (INV), P = .05, post-operative INV, P = .02, post-operative macular ischemia, P = .0001, and post-operative vitreous hemorrhage (VH), P = .02.

CONCLUSIONS

Pre-operative and post-operative INV, post-operative macular ischemia, and post-operative VH appear to be risk factors for LP and NLP vision following diabetic vitrectomy, whereas overall improvements in surgical technique and visual outcome continue to be reported.

Chirurgische Therapie der diabetischen Retinopathie und Makulopathie

Surgical therapy of diabetic retinopathy has been refined since the Early Treatment Diabetic Retinopathy Study (ETDRS). ETDRS did not perform panretinal photocoagulation at the time of surgery, which is currently considered a major part of vitrectomy, e.g., in vitreous hemorrhage. Despite improved surgical techniques, patient expectations and surgical outcome still differ considerably in severe cases of proliferative diabetic retinopathy. In this review of the literature we discuss the current surgical options and indications in diabetic retinopathy and maculopathy.

Krypton laser membranotomy in the treatment of dense premacular hemorrhage

BACKGROUND

Neodymium:YAG (Nd:YAG) laser and argon laser membranotomy have been used in patients with premacular hemorrhage to drain premacular blood into the vitreous cavity and rapidly clear the hemorrhage. However, the Nd:YAG laser appears to be difficult to use, and argon laser energy may be more likely to be absorbed by the ocular media. We performed a study to evaluate the safety and effectiveness of krypton laser membranotomy in selected cases of premacular hemorrhage.

METHODS

Sixteen patients (17 eyes) with dense premacular hemorrhage for 2 weeks or less were enrolled from April 1998 to February 2004. The causes of premacular hemorrhage were proliferative diabetic retinopathy (PDR) in 12 eyes, Valsalva retinopathy in 3 eyes, leukemia in I eye and retinal arterial macroaneurysm in I eye. Krypton laser was used to create a membranotomy on the sloping edge of the premacular hemorrhage. Five eyes with PDR were treated with inferior panretinal photocoagulation and laser membranotomy simultaneously. After intravitreal dispersion of premacular blood, fundus examination was performed in all eyes and fluorescein angiography in five eyes to evaluate retinal damage.

RESULTS

All eyes had visual improvement within 2 weeks postoperatively. No retinal damage was seen at the site of membranotomy in any eye. No eye needed vitrectomy postoperatively during a mean follow-up duration of 18.6 months.

INTERPRETATION

Krypton laser membranotomy appears to be a safe and simple alternative procedure for treating selected cases of premacular hemorrhage. Further trials are necessary to evaluate its benefit.

Krypton laser membranotomy for premacular hemorrhage

BACKGROUND

To evaluate the safety and effectiveness of krypton laser membranotomy.

METHODS

Eleven patients (12 eyes) with premacular hemorrhage were enrolled from April 1998 to November 2002. The causes of premacular hemorrhage were proliferative diabetic retinopathy (7 patients, 8 eyes), Valsalva retinopathy (3 patients) and leukemia (1 eye). Krypton laser was used to create a membranotomy on the sloping edge of the premacular hemorrhage. Five eyes with proliferative diabetic retinopathy were treated with inferior panretinal photocoagulation and laser membranotomy simultaneously. After intravitreal dispersion of premacular blood, fundus examinations were performed in all eyes and fluorescein angiography in 5 patients to evaluate the retinal damage.

RESULTS

Vision was improved within 2 weeks after surgery in all eyes with premacular hemorrhage, which received krypton laser membranotomy. No retinal damage was seen at the site of membranotomy. No eye needed vitrectomy postoperatively during the follow-up (mean, 17 months).

CONCLUSION

Krypton laser membranotomy appears to be a safe and simple alternative procedure for treating selected cases of premacular hemorrhage. Further trials are necessary to evaluate its benefit.

Single-field fundus photography for diabetic retinopathy screening: a report by the American Academy of Ophthalmology

OBJECTIVE

To evaluate whether single-field fundus photography can be used as a screening tool to identify diabetic retinopathy for referral for further ophthalmic care.

METHODS

A MEDLINE search of the peer-reviewed literature was conducted in June 2001 for the years 1968 to 2001 and updated in September 2003, yielding 145 articles. The search was limited to articles published in English. The Cochrane Library of clinical trials was also investigated. The authors reviewed the abstracts of these articles and selected 63 of possible clinical relevance for review by the panel. Of these 63 articles, the panel selected 32 for the panel methodologist to review and rate according to the strength of evidence.

RESULTS

Three of the 32 articles reviewed were classified as level I evidence, and 4 were classified as level II evidence. Evidence from level I studies demonstrates that as a tool to detect vision-threatening retinopathy, single-field fundus photography interpreted by trained readers has sensitivity ranging from 61% to 90% and specificity ranging from 85% to 97% when compared with the gold standard reference of stereophotographs of 7 standard fields. When compared with dilated ophthalmoscopy by an ophthalmologist, single-field fundus photography has sensitivity ranging from 38% to 100% and specificity ranging from 75% to 100%.

CONCLUSIONS

Single-field fundus photography is not a substitute for a comprehensive ophthalmic examination, but there is level I evidence that it can serve as a screening tool for diabetic retinopathy to identify patients with retinopathy for referral for ophthalmic evaluation and management. The advantages of single-field fundus photography interpreted by trained readers are ease of use (only one photograph is required), convenience, and ability to detect retinopathy. Further studies will be required to assess the implementation of single-field photography-based programs to confirm the clinical and cost-effectiveness of these techniques in improving population visual outcomes. Future research also should include establishing standardized protocols and satisfactory performance standards for diabetic retinopathy screening programs.

Tele-screening for diabetic retinopathy with the retinal thickness analyzer

OBJECTIVE

To compare the effectiveness of tele-screening using a novel enhanced retinal thickness analyzer (RTA) with onsite routine ophthalmologic examination for diabetic retinopathy.

RESEARCH DESIGN AND METHODS

A consecutive series of 31 eyes from diabetic patients were included. All underwent ophthalmologic examination, including stereoscopic dilated funduscopy and scanning with the RTA. The RTA reports consisted of a wide-angle, red-free fundus photograph and a macular-region retinal thickness map. Reports were graded by three independent graders in a masked manner. The diagnoses of proliferative retinopathy, macular edema, and treatment decisions made by the RTA graders and the clinical examiner were compared.

RESULTS

On clinical examination 5 of 31 eyes were diagnosed with proliferative diabetic retinopathy (PDR). All five were referred for treatment by two graders and four eyes by one grader. All eyes with PDR and 12 of the 26 eyes with nonproliferative diabetic retinopathy showed severe macular edema. Seven of the 12 eyes with macular edema were clinically eligible for focal laser treatment, and all of them were detected by all RTA graders. Macular thickening was detected in eight eyes by RTA where no treatment was necessary, as judged by clinical examination. Thus, sensitivity was 93% (mean) for detecting PDR and 100% for detecting macular edema, with a specificity of 58-96% depending on the grader. The RTA did not allow valid assessment due to poor image quality in only one case.

CONCLUSIONS

Screening for diabetic retinopathy with a combination of wide-angle fundus photography and macular thickness mapping by an objective method, such as optical coherence tomography or the RTA, offers the prerequisites for establishing a successful tele-screening program.

Diabetic retinopathy and diabetic macular edema: pathophysiology, screening, and novel therapies

Diabetic retinopathy (DR) and diabetic macular edema (DME) are leading causes of blindness in the working-age population of most developed countries. The increasing number of individuals with diabetes worldwide suggests that DR and DME will continue to be major contributors to vision loss and associated functional impairment for years to come. Early detection of retinopathy in individuals with diabetes is critical in preventing visual loss, but current methods of screening fail to identify a sizable number of high-risk patients. The control of diabetes-associated metabolic abnormalities (i.e., hyperglycemia, hyperlipidemia, and hypertension) is also important in preserving visual function because these conditions have been identified as risk factors for both the development and progression of DR/DME. The currently available interventions for DR/DME, laser photocoagulation and vitrectomy, only target advanced stages of disease. Several biochemical mechanisms, including protein kinase C-beta activation, increased vascular endothelial growth factor production, oxidative stress, and accumulation of intracellular sorbitol and advanced glycosylation end products, may contribute to the vascular disruptions that characterize DR/DME. The inhibition of these pathways holds the promise of intervention for DR at earlier non-sight-threatening stages. To implement new therapies effectively, more individuals will need to be screened for DR/DME at earlier stages-a process requiring both improved technology and interdisciplinary cooperation among physicians caring for patients with diabetes.

Retinopathy in juvenile diabetes: a 10-year (1990-2000) review

Diabetic retinopathy (DR) is the most frequent complication of diabetes and a leading cause of impaired vision in the Western world. There is general agreement that early diagnosis and treatment of DR can slow its progression and help to prevent blindness. However, as a result of its asymptomatic nature and its etiopathogenesis, which is still unclear due to its multifactorial complexity, DR-related blindness has a growing social impact in industrialized countries. Therefore, in order to gain a better understanding of this serious disease, the author performed an updated 10-year review of risk factors and management of DR in type 1 diabetes.

Biomaterials used in the posterior segment of the eye

The treatment of posterior segment eye disease and related conditions has improved greatly in recent years with the advent of new therapies, materials and devices. Vitreoretinal conditions, however, remain significant causes of blindness in the developed world. Biomaterials play a major role in the treatment of many of these disorders and the success rate of vitreoretinal surgery, especially in the repair of retinal detachment and related conditions, would increase with the introduction of new and improved materials. This review, which focuses on disorders that feature retinal detachment, briefly describes the anatomy of the eye and the nature and treatment of posterior segment eye disorders. The roles, required properties and suitability of the materials used in vitreoretinal surgery as scleral buckles, tamponade agents or drug delivery devices, are reviewed. Experimental approaches are discussed, along with the methods used for their evaluation, and future directions for biomaterial research in the posterior segment of the eye are considered.

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.

Vitreous Hemorrhage

The incidence of spontaneous vitreous hemorrhage is approximately 7 cases per 100,000 population. Proliferative diabetic retinopathy (32%), retinal tear (30%), proliferative retinopathy after retinal vein occlusion (11%) and posterior vitreous detachment without retinal tear (8%) are the most common causes of spontaneous vitreous hemorrhage. Vitreous hemorrhage can be caused by the pathologic mechanisms of disruption of normal retinal vessels, bleeding from diseased retinal vessels or abnormal new vessels, and extension of hemorrhage through the retina from other sources. Hemorrhage into the vitreous gel results in rapid clot formation and is followed by slow clearance of approximately 1% per day. The cellular response to vitreous hemorrhage is unusual with regard to hemorrhage in any tissue outside the vitreous cavity and has been compared to a "low-turnover" granuloma. Unique clinicopathologic features of long-standing vitreous hemorrhage include cholesterolosis bulbi (synchysis scintillans), hemoglobin spherulosis, and vitreous cylinders. Complications of nonclearing vitreous hemorrhage are hemosiderosis bulbi and glaucoma. Ghost cell glaucoma, hemolytic glaucoma, and hemosiderotic glaucoma may result from vitreous hemorrhage. The established treatment option for nonclearing vitreous hemorrhage is pars plana vitrectomy. Experimental nonsurgical treatment options involve improvement of physiologic clearance mechanisms in order to accelerate fibrinolysis, liquefaction, hemolysis and phagocytosis.

Identifying maculopathy after neodymium: YAG membranotomy for dense diabetic premacular hemorrhage

PURPOSE

To assess the value of neodymium:YAG membranotomy in achieving rapid intravitreal dispersion of dense diabetic premacular hemorrhage and allowing the identification and treatment of maculopathy before panretinal photocoagulation (PRP).

METHODS

A pilot study, in which nine eyes with dense diabetic premacular hemorrhages were treated with neodymium:YAG membranotomy, is described. After intravitreal dispersion of premacular blood, fundus examination and fluorescein angiography were performed to identify neovascularization and macular edema. Macular photocoagulation was performed before PRP in eyes with co-existing maculopathy and neovascularization.

RESULTS

Complete intravitreal dispersion was achieved in all eyes within 1 week. Clinically significant macular edema was identified and treated, before PRP, in three eyes. No exacerbation of macular edema occurred after PRP, and visual acuity was stabilized at pre-hemorrhage levels in seven eyes and to within one line in the remaining two eyes. No traction retinal detachments or rebleeding occurred, and vitrectomy was not required in any eye.

CONCLUSIONS

Early neodymium:YAG membranotomy may obviate the need for early vitrectomy for dense diabetic premacular hemorrhage, and allows early identification and treatment of maculopathy, before PRP, thus reducing the risk of exacerbation after PRP. Further studies to evaluate this treatment modality, particularly with respect to long-term visual prognosis, appear warranted.

Life expectancy of diabetic patients undergoing vitreous surgery

BACKGROUND

Patients with advanced diabetic eye disease are commonly in poor general health. In addition to the ocular status, life expectancy is an important factor in the decision whether and how to perform vitreous surgery. The present study investigates mortality and risk factors for survival in diabetic patients following vitrectomy.

METHODS

The follow up of 332 consecutive patients who underwent vitrectomy for complications of diabetic retinopathy between 1990 and 1994 was studied retrospectively. Survival and risk factors for survival were analysed using the Kaplan-Meier life table method and for multivariate analysis the Cox proportional hazard model.

RESULTS

The 5 year survival rate was 68%. Absence of heart disease was the most important predicting factor for survival. Fifty per cent of the patients with heart disease had died within 3.5 years. Patients without heart disease had a 5 year survival rate of 90%. Other significant, independent risk factors were age and presence of nephropathy.

CONCLUSION

In diabetic patients undergoing vitrectomy the presence of heart disease indicates a poor prognosis for survival. This should be taken into consideration for indications and strategies in cases of vitrectomy.

Postoperative endophthalmitis in association with diabetes mellitus

BACKGROUND

Endophthalmitis continues to be a potentially devasting complication of ocular surgery, despite advances in microsurgical technique and infection-preventing measures. Patients with diabetes have altered immunity at various levels and may be more susceptible to infection after ocular surgery. The authors evaluate the associations between diabetes mellitus and postoperative endophthalmitis.

METHODS

The records of 162 consecutive patients treated over a 5-year period for endophthalmitis occurring within 2 weeks of ocular surgery were retrospectively reviewed.

RESULTS

Twenty-one percent of this consecutive series of patients with endophthalmitis after surgery had diabetes mellitus. Both the diabetic and nondiabetic groups were similar with respect to age, type of primary surgery, duration from surgery to onset of symptoms, presenting visual acuity, and management of endophthalmitis. Seventy-nine percent of the patients with diabetes and 68% of those without diabetes had culture-proven endophthalmitis. Staphylococcus was responsible for 74% and 71% of the culture-positive cases, respectively. The patients with diabetes were more likely to have endophthalmitis secondary to a gram-negative organism (P < 0.001) than those without diabetes (18.5% versus 5.7%). Visual outcome was worse in the diabetic group, although this may be related to preoperative visual status.

CONCLUSIONS

Twenty-one percent of this consecutive series of patients with endophthalmitis after surgery had diabetes mellitus. The patients with diabetes mellitus were more likely to have endophthalmitis caused by gram-negative organisms and appear to have a poorer visual prognosis after treatment for endophthalmitis.