Intraocular pressure following panretinal photocoagulation for diabetic retinopathy. Diabetic Retinopathy Report No. 11

[Neovascular Glaucomas - Pathogenesis, Diagnosis, Treatment and Prophylaxis]

Neovascular glaucoma (NVG) is a severe potentially blinding disease, which represents one of the most common types of secondary glaucomas. The majority of cases are caused by ischemic retinal conditions such as diabetic retinopathy, central retinal vein occlusion or ocular ischemic syndrome. If appropriately diagnosed and treated, ideally the development of NVG can be prevented. Since treatment gets increasingly challenging as the disease progresses, early diagnosis is of utmost importance. In this review pathogenesis, diagnosis, treatment and prophylaxis are discussed extensively. A focus is put on the consecutive stages through which the disease progresses and how to diagnose and differentiate them. Ultimately a stage adapted therapy approach is detailed, consisting of the three blocks: 1. treatment of the underlying disease/retinal ischemia, 2. adjunctive medical therapy (anti-VEGF) and 3. therapy of the elevated intraocular pressure.

Sekundärglaukome im Rahmen retinaler Erkrankungen

Zusammenfassung: Eine Vielzahl retinaler Erkrankungen kann zur Entwicklung eines Glaukoms führen. Die häufigste Form dieser Sekundärglaukome sind die Neovaskularisationsglaukome, die den Hauptteil dieser Übersicht bilden. Dabei handelt sich um ein schwerwiegendes Krankheitsbild, dass in mehreren Stadien verläuft, wobei die Prognose mit zunehmendem Stadium ungünstiger und die Therapie herausfordernder wird. Neben Pathogenese und Diagnostik wird daher ein Schwerpunkt wird auf die Früherkennung und eine an das jeweilige Krankheitsstadium angepasste Therapie gelegt. Auch seltenere Sekundärglaukome im Rahmen intraokularer Tumore sowie Glaukome assoziiert mit einer Netzhautablösung (Schwartz-Matsuo Syndrom) und Glaukome, die im Spätverlauf nach unkomplizierter Vitrektomie auftreten, werden in dieser Übersicht diskutiert. Abstract: A variety of retinal diseases can lead to the development of glaucoma. The most common type of these secondary glaucomas is neovascular glaucoma (NVG), which constitutes the main subject of this review. NVG is a severe condition with a poor prognosis. Treatment gets increasingly challenging as the disease progresses. Thus emphasis is put on early diagnosis and an stage adjusted therapy. Other less frequent secondary glaucomas, such as glaucomas due to intraocular tumors or associated with retinal detachment (Schwartz-Matsuo syndrome) and late onset open-angle glaucomas after uncomplicated vitrectomy are covered.

Management and Systemic Implications of Diabetic Neovascular Glaucoma

OBJECTIVES

To study the efficacy and safety of different treatments for diabetic neovascular glaucoma (NVG). We additionally attempt to determine if the presence of NVG could be a predictor of cardiovascular disease or death.

METHOD

This is a retrospective, observational cohort study including patients diagnosed with diabetic NVG from 2006 to 2016 at the Hospital Clínico Universitario de Valladolid (Spain). Extracted data included clinical characteristics of the patients, glycated haemoglobin levels, and ocular treatment. Visual acuity (VA), intraocular pressure (IOP), cardiovascular events, and deaths were registered.

RESULTS

30 eyes from 23 patients were followed for a mean of 4.48 years (SD = 2.82 years). The IOP-lowering intervention groups were: Ahmed implant (11 eyes), laser cyclo-photocoagulation (CPC; 6 eyes), both (4 eyes), or none (9 eyes). IOP success was achieved in 100% of the eyes with Ahmed and/or laser CPC and in 44.4% of the eyes with no IOP-lowering procedure (p= 0.002). Most eyes with Ahmed implant (with or without CPC) maintained or improved their VA (100 and 63.6%, respectively). 33.3% of the eyes with laser CPC and 25% of those with no IOP-lowering intervention maintained or improved their VA (p = 0.028). Hypotony was the only adverse effect (after laser CPC). No statistically significant difference could be established between low VA (finger count or worse), poor IOP control, or bad metabolic control and mortality or cardiovascular event (p > 0.05), however, the four patients who died had poor VA at the time of NVG diagnosis.

CONCLUSIONS

Ahmed implant surgery is a safe and effective treatment option for diabetic NVG. Medical treatment alone is not the best option for most cases. Advanced NVG could be an indicator of higher mortality risk in diabetic patients.

Laser photocoagulation for proliferative diabetic retinopathy

BACKGROUND

Diabetic retinopathy is a complication of diabetes in which high blood sugar levels damage the blood vessels in the retina. Sometimes new blood vessels grow in the retina, and these can have harmful effects; this is known as proliferative diabetic retinopathy. Laser photocoagulation is an intervention that is commonly used to treat diabetic retinopathy, in which light energy is applied to the retina with the aim of stopping the growth and development of new blood vessels, and thereby preserving vision.

OBJECTIVES

To assess the effects of laser photocoagulation for diabetic retinopathy compared to no treatment or deferred treatment.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2014, Issue 5), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to June 2014), EMBASE (January 1980 to June 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and 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 3 June 2014.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) where people (or eyes) with diabetic retinopathy were randomly allocated to laser photocoagulation or no treatment or deferred treatment. We excluded trials of lasers that are no longer in routine use. Our primary outcome was the proportion of people who lost 15 or more letters (3 lines) of best-corrected visual acuity (BCVA) as measured on a logMAR chart at 12 months. We also looked at longer-term follow-up of the primary outcome at two to five years. Secondary outcomes included mean best corrected distance visual acuity, severe visual loss, mean near visual acuity, progression of diabetic retinopathy, quality of life, pain, loss of driving licence, vitreous haemorrhage and retinal detachment.

DATA COLLECTION AND ANALYSIS

We used standard methods as expected by the Cochrane Collaboration. Two review authors selected studies and extracted data.

MAIN RESULTS

We identified a large number of trials of laser photocoagulation of diabetic retinopathy (n = 83) but only five of these studies were eligible for inclusion in the review, i.e. they compared laser photocoagulation with currently available lasers to no (or deferred) treatment. Three studies were conducted in the USA, one study in the UK and one study in Japan. A total of 4786 people (9503 eyes) were included in these studies. The majority of participants in four of these trials were people with proliferative diabetic retinopathy; one trial recruited mainly people with non-proliferative retinopathy. Four of the studies evaluated panretinal photocoagulation with argon laser and one study investigated selective photocoagulation of non-perfusion areas. Three studies compared laser treatment to no treatment and two studies compared laser treatment to deferred laser treatment. All studies were at risk of performance bias because the treatment and control were different and no study attempted to produce a sham treatment. Three studies were considered to be at risk of attrition bias.At 12 months there was little difference between eyes that received laser photocoagulation and those allocated to no treatment (or deferred treatment), in terms of loss of 15 or more letters of visual acuity (risk ratio (RR) 0.99, 95% confidence interval (CI) 0.89 to 1.11; 8926 eyes; 2 RCTs, low quality evidence). Longer term follow-up did not show a consistent pattern, but one study found a 20% reduction in risk of loss of 15 or more letters of visual acuity at five years with laser treatment. Treatment with laser reduced the risk of severe visual loss by over 50% at 12 months (RR 0.46, 95% CI 0.24 to 0.86; 9276 eyes; 4 RCTs, moderate quality evidence). There was a beneficial effect on progression of diabetic retinopathy with treated eyes experiencing a 50% reduction in risk of progression of diabetic retinopathy (RR 0.49, 95% CI 0.37 to 0.64; 8331 eyes; 4 RCTs, low quality evidence) and a similar reduction in risk of vitreous haemorrhage (RR 0.56, 95% CI 0.37 to 0.85; 224 eyes; 2 RCTs, low quality evidence).None of the studies reported near visual acuity or patient-relevant outcomes such as quality of life, pain, loss of driving licence or adverse effects such as retinal detachment.We did not plan any subgroup analyses, but there was a difference in baseline risk in participants with non-proliferative retinopathy compared to those with proliferative retinopathy. With the small number of included studies we could not do a formal subgroup analysis comparing effect in proliferative and non-proliferative retinopathy.

AUTHORS' CONCLUSIONS

This review provides evidence that laser photocoagulation is beneficial in treating proliferative diabetic retinopathy. We judged the evidence to be moderate or low, depending on the outcome. This is partly related to reporting of trials conducted many years ago, after which panretinal photocoagulation has become the mainstay of treatment of proliferative diabetic retinopathy.Future Cochrane Reviews on variations in the laser treatment protocol are planned. Future research on laser photocoagulation should investigate the combination of laser photocoagulation with newer treatments such as anti-vascular endothelial growth factors (anti-VEGFs).

Diabetic retinopathy - An update

Management of diabetes should involve both systemic and ocular aspects. Control of hyperglycemia, hypertension and dyslipidemia are of major role in the management of diabetic retinopathy. In the ocular part; laser treatment remains the cornerstone of treatment of diabetic macular edema (focal/grid), severe non-proliferative and proliferative diabetic retinopathy (panretinal photocoagulation). There is a strong support to combination therapy. Using one or two intravitreal injections such as anti-VEGF and or steroid to reduce central macular thickness followed by focal or grid laser to give a sustained response may offer an alternative to treatment in diabetic macular edema. Anti-VEGF were found to be effective as an adjunct therapy in proliferative diabetic retinopathy patient who is going to have vitrectomy for vitreous hemorrhage with neovascularization, panretinal photocoagulation, and other ocular surgery such as cases with neovascular glaucoma and cataract with refractory macular edema.

Retinectomy for treatment of intractable glaucoma: long term results

AIM

To report long term efficacy and complications of retinectomy as an intraocular pressure lowering procedure for intractable glaucoma.

METHODS

This was a consecutive interventional case series. In 44 consecutive eyes (39 patients, 22 men and 17 women) retinectomy was performed to lower the intraocular pressure (IOP) in patients with uncontrolled IOP (>35 mm Hg for more than 4 months) despite conventional filtering surgery and drug treatment. Pars plana vitrectomy was performed and the peripheral retina was surgically excised to various degrees. The procedure was concluded by an intraocular gas tamponade of 20% C(3)F(8). Included were patients with neovascular glaucoma (12 eyes), infantile and juvenile glaucoma (three eyes), secondary glaucoma due to aphakia (13 eyes), severe ocular trauma (seven eyes), uveitis (seven eyes), and glaucoma in Ehlers-Danlos syndrome (two).

RESULTS

All patients underwent successful surgical retinectomy. All patients were followed for 5 years. Mean postoperative IOP after 4 years was 15.7 (SD 9.4) mm Hg, representing a decrease of IOP by 61% compared to the preoperative level (41.2 (9.4) mm Hg). In 52.3% of eyes long term regulation of IOP could be achieved without complications. Retinectomy was least effective in neovascular glaucoma because of central retinal vein occlusion (CRVO). Eyes with glaucoma secondary to uveitis showed a tendency towards low IOP levels with subsequent phthisis bulbi. The initial visual acuity of all patients was lower than 20/50 (mean 1.8 (0.8) logMAR) in the treated eye. Final visual acuity was 2.3 (0.6) logMAR. 21 out of 44 cases developed retinal complications (retinal detachment or proliferative vitreoretinopathy (PVR)) after surgery, requiring silicone tamponade in 11 eyes (52%) either for persistent low IOP or for PVR. Nine eyes developed phthisis, seven of which were enucleated during the follow up.

CONCLUSIONS

Long term results after retinectomy demonstrate its efficacy in otherwise intractable glaucoma. Efficacy and safety of retinectomy are dependent on the underlying disease.