Prognostic indicators of success and failure in vitrectomy for diabetic retinopathy

Photocoagulation Up to Ora Serrata in Diabetic Vitrectomy to Prevent Recurrent Vitreous Hemorrhage

PURPOSE

To evaluate the role of performing photocoagulation up to ora serrata during vitrectomy in preventing recurrent vitreous hemorrhage (VH) in patients undergoing pars plana vitrectomy (PPV) for proliferative diabetic retinopathy (PDR).

METHODS

This retrospective, nonrandomized study included 60 eyes from 60 patients who had undergone PPV for VH due to PDR. These patients were divided into two groups: group 1, those who underwent photocoagulation up to ora serrata using the scleral indentation technique during surgery; and group 2, those who did not undergo scleral indentation when photocoagulation and underwent photocoagulation up to vortex veins. Their hospital records were analyzed to investigate the recurrence rate of VH, the time until recurrence of VH after surgery, logarithm of the minimal angle of resolution (logMAR) best-corrected visual acuity (BCVA) measured before surgery and at 1, 2, and 3 years after surgery, and the occurrence of complications such as neovascular glaucoma (NVG) during follow-up.

RESULTS

Group 1 exhibited lower recurrence rate of VH (2 of 30 [6.7%] vs. 10 of 30 [33.3%], p = 0.01) and lower occurrence of postoperative NVG (2 of 30 [6.7%] vs. 8 of 30 [26.7%], p = 0.038) compared with group 2. There were no statistically significant differences in logMAR BCVA measured at 1, 2, and 3 years between the two groups (at 1 year: 0.54 ± 0.43 vs. 0.54 ± 0.44, p = 0.954; at 2 years: 0.48 ± 0.47 vs. 0.55 ± 0.64, p = 0.235; at 3 years: 0.51 ± 0.50 vs. 0.61 ± 0.77, p = 0.200). Logistic regression analysis showed that among several factors that could affect recurrence rate of VH, only range of photocoagulation performed was a statistically significant factor (odds ratio, 0.119; 95% confidence interval, 0.022-0.659; p = 0.015).

CONCLUSIONS

Photocoagulation treatment over a wider range with scleral indentation could be a beneficial adjunct procedure for preventing postoperative recurrent VH following diabetic vitrectomy.

WIDE-FIELD SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY OF DIABETIC TRACTIONAL RETINAL DETACHMENTS BEFORE AND AFTER SURGICAL REPAIR

PURPOSE

Wide-field (WF) swept-source (SS) optical coherence tomography angiography (SS-OCTA) was used to image diabetic tractional retinal detachments (TRDs) before and after pars plana vitrectomy. The clinical utility of SS-OCTA was assessed.

METHODS

Patients with diabetic TRDs were imaged prospectively with SS-OCTA. Ultrawide-field imaging was obtained when possible. Postoperative WF SS-OCTA imaging was performed.

RESULTS

From January 2018 through December 2019, 31 eyes of 21 patients with diabetic TRDs were imaged. Wide-field SS-OCTA en-face images captured all areas of TRD and fibrovascular proliferation within the posterior pole that were visualized on ultrawide-field imaging. Optical coherence tomography angiography B-scans revealed the vascularity of preretinal membranes and identified areas of vitreoretinal traction and posterior vitreous detachment. Ten eyes underwent pars plana vitrectomy. Postoperative SS-OCTA imaging demonstrated removal of fibrovascular membranes, relief of traction, and resolution of TRDs. Retinal ischemia before and after surgical repair appeared similar.

CONCLUSION

All clinically relevant features of diabetic TRDs were identified at baseline and assessed longitudinally after pars plana vitrectomy using WF SS-OCTA, which showed resolution of vitreoretinal traction and no apparent change in the status of retinal perfusion after surgery. If the media are clear and fixation is adequate, WF SS-OCTA is likely the only imaging modality needed for the diagnosis and longitudinal evaluation of diabetic TRDs.

Surgical management of diabetic tractional retinal detachments

Tractional retinal detachment is an end-stage form of diabetic retinopathy that occurs when contractile forces in the vitreous and neovascular tissue lead to the detachment of the neurosensory retina. We review the literature related to the management of this disease. Preoperative planning includes appropriate patient selection, diagnostic and prognostic imaging, and medical optimization with reduction of systemic risk factors. Use of antivascular endothelial growth factor for preoperative treatment has had significant benefits for tractional retinal detachment repair in improving surgical efficiency and outcomes. Advances in microsurgical instrumentation are discussed, with attention to small-gauge vitrectomy with improved flow dynamics, viewing strategies, and lighting allowing bimanual surgery. Special emphasis is placed on bimanual surgical technique, choice of tamponade, and the avoidance of iatrogenic damage. Complications and special considerations are further explored. Based on our compilation of relevant literature, we propose a surgical algorithm for the management of these complex patients.

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.

Long-term Results of Pars Plana Vitrectomy and Silicone Oil for Complications of Diabetic Retinopathy

Pars plana vitrectomy (PPV) with silicone oil implantation (SOI) was performed for advanced proliferative diabetic retinopathy (PDR) in 110 eyes of 98 diabetic patients. In, 77 eyes (70%) it was a primary SOI as part of the initial operation; in 33 eyes (30%) it was a secondary SOI in reoperations. Indications for SOI were traction retinal detachment of the posterior pole, combined traction and rhegmatogenous detachment, vitreous haemorrhage with florid vascularised fibrous proliferations, and recurrent vitreous haemorrhage after PPV. The patients were followed up for 24 to 72 months, with a mean of 53 months. At the end of follow-up, anatomical success was achieved in 63 eyes (57%), and functional success with visual acuity 0.01 and better in 35 eyes (32%). Functional failures were caused by retinal redetachment in 47 eyes (43%), by secondary glaucoma in 10 eyes (9%), retinal ischemia in 15 eyes (13%) and keratopathy in three eyes (3%). The functional success rate decreased with follow-up from 67% after six months to 50% by 60 months after SOI. Silicone oil bubble in the anterior chamber, rubeosis iridis, cataract, and glaucoma were the most frequent postoperative complications. PPV with SOI was highly effective in many serious complications of advanced PDR. Functional success was mostly lasting and markedly improved the quality of life of these patients.

Long-term results, prognostic factors and cataract surgery after diabetic vitrectomy: a 10-year follow-up study

PURPOSE

To report long-term results, prognostic factors and cataract surgery after diabetic vitrectomy.

METHODS

Retrospective review of patient files from a large diabetes centre between 1996 and 2010. Surgical history was obtained from the Danish National Patient Register. Follow-up intervals were 3 months and 1, 3, 5 and 10 years after surgery.

RESULTS

In total, 167 patients had diabetic vitrectomy indicated for non-clearing vitreous haemorrhage (47%) and tractional retinal detachment (53%). The proportion of patients with visual acuity ≥0.3 increased from 29% before surgery to 60% after 3 months (p < 0.001, chi-square test). Median visual acuity increased from 0.06 before surgery to 0.3 after 3 months (p < 0.001, paired signed-rank test) and 0.4 after 1 year (p = 0.009) before stabilizing. No significant long-term prognostic factors were identified for non-clearing vitreous haemorrhage patients. For tractional retinal detachment patients, use of silicone oil was associated with low vision (visual acuity<0.3) after 3 months and 1, 3 and 5 years (all odds ratios >4 and p-values ≤ 0.03, logistic regression). Of the 134 patients who were phakic after surgery, 43% and 29% were phakic after 5 and 10 years, respectively. Use of silicone oil increased the risk of cataract surgery (p = 0.009, log-rank test).

CONCLUSIONS

Most diabetic vitrectomy patients stand to gain visual acuity ≥0.3 after surgery and a stable long-term visual acuity after 1 year. The only consistent long-term predictor of low vision after surgery is use of silicone oil for endotamponade. About 2/3 of phakic patients will subsequently have cataract surgery the first 10 years after diabetic vitrectomy.

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.

Association of preoperative vitreous IL-8 and VEGF levels with visual acuity after vitrectomy in proliferative diabetic retinopathy

PURPOSE

To determine whether the vitreous levels of interleukin 8 (IL-8) and vascular endothelial growth factor (VEGF) of patients with proliferative diabetic retinopathy (PDR) were associated with poor visual acuity after vitrectomy.

METHODS

Observational cross-sectional study. Patient clinical characteristics and preoperative eye characteristics (63 eyes): visual acuity, iris neovascularization, vitreous haemorrhage, macular detachment, macular oedema, active retinal neovascularization, neovascularization of the disc, burned out PDR (defined as natural end stage of PDR with inactive membranes without previously performed laser photocoagulation) and panretinal photocoagulation were registered prior to vitrectomy for each patient. Vitreous VEGF and IL-8 levels were measured using the cytometric bead array method. Poor postoperative visual acuity was defined as visual acuity of <20/200 and was checked 2 years after vitrectomy.

RESULTS

Twenty-one of the 63 eyes (33.3%) had poor visual acuity after vitrectomy. Univariate analysis showed that vitreous levels of IL-8, the absence of panretinal photocoagulation, preoperative macular detachment and poor preoperative visual acuity were significantly associated with poor final visual acuity after vitrectomy. A stepwise multiple logistic regression analysis showed that elevated vitreous levels of IL-8 (p < 0.0001), macular detachment (p = 0.011) and the absence of panretinal photocoagulation (p = 0.03) were independent predictors for poor visual outcome.

CONCLUSIONS

Elevated vitreous IL-8 level could either be a marker of ischaemic inflammatory reaction, or it could play a role in deteriorating visual acuity by DR progression or both. Further studies are needed to provide better understanding of IL-8 and inflammation involvement in visual prognosis in PDR.

Cryotherapy of sclerotomy sites for prevention of late post-vitrectomy diabetic hemorrhage: a randomized clinical trial

BACKGROUND

To evaluate the role of cryotherapy of sclerotomy sites in prevention of late (after 4 weeks) post-vitrectomy diabetic hemorrhage.

METHODS

In a prospective randomized double-masked clinical trial, a total of 124 eyes of 119 patients underwent pars plana vitrectomy for complications of proliferative diabetic retinopathy. At the end of vitrectomy, the eyes were randomly assigned to two groups. The case group received two cryotherapy spots at each sclerotomy site, whereas the eyes in the control group received no further intervention. Evaluations were repeated at months 1, 2, 4, and 6. The primary outcome measure was occurrence of vitreous hemorrhage after the first month and up to the sixth month. Ultrasound biomicroscopy (UBM) examination of the sclerotomy sites was performed concurrent with the occurrence of vitreous hemorrhage or at the last follow-up.

RESULTS

Thirty-six eyes were excluded mostly because of early postoperative vitreous hemorrhage. Finally, the data of 42 eyes of the cases and 46 eyes of the controls were used for analysis. Late vitreous hemorrhage occurred in 17 out of 88 eyes (19.3%). This rate was significantly higher in the cases compared to the controls, 28.6% (12 eyes) versus 10.9% (five eyes) within 6 months (P = 0.036). There was no statistically significant difference in the UBM findings of the sclerotomy sites between the two groups. No relationship was noticed between morphologic patterns detected by UBM and occurrence of late vitreous hemorrhage.

CONCLUSIONS

Cryotherapy of the sclerotomy sites at the end of the operation is not helpful for prevention of late post-vitrectomy diabetic hemorrhage, and it may even increase this risk.

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.

Outcome of diabetic vitrectomy in Latino population

PURPOSE

Evaluation of visual acuity and anatomic outcome in Latino patients undergoing vitrectomy for proliferative diabetic retinopathy, using silicone oil or gas tamponade.

METHODS

Retrospective review of 57 vitrectomies, 42 in Latino patients, performed by a single surgeon over a 3-year period.

RESULTS

Seventy-four percent of vitrectomies were on patients of Latino descent. Sixty-three percent of eyes had traction retinal detachments involving the macula. Overall, 29% in the Latino group received silicone oil tamponade, while the remainder received gas tamponade. In the gas treatment group, 16% developed rhegmatogenous detachments, while no rhegmatogenous detachments occurred in oil-treated eyes. This difference was not statistically significant. Follow-up ranged from 1 to 4 years (median, 1 year). The change from pre- to postsurgery visual acuity was calculated for both gas and oil treated groups, showing no statistically significant difference. Pre- and postsurgery visual acuity median was hand motions for both.

CONCLUSION

There was no statistically significant difference in final anatomic outcome or visual outcome in Latino eyes undergoing surgery for severe proliferative diabetic retinopathy. Silicone oil and gas tamponade appeared to work equally well in this population.

Diabetic vitrectomy: risks, prognosis, future trends

PURPOSE OF REVIEW

We review the current standards, risks, prognosis, and indications for diabetic pars plana vitrectomy and consider recent developments in surgical techniques. We also examine surgery's role as a treatment modality for diabetic eye disease among the other accepted and developing treatment options, such as systemic and intravitreal pharmacotherapy.

RECENT FINDINGS

Pars plana vitrectomy for diabetic macular edema and for traction retinal detachment is addressed. Techniques to decrease retinal swelling and ischemia are showing promising results. The use of the smaller 25-gauge and 23-gauge vitrectors is gaining acceptance and offers advantages such as less trauma, less postoperative discomfort, and quicker healing. Techniques are being developed and refined to help prevent postoperative vitreous hemorrhage using cryotherapy around sclerotomy sites and/or endolaser in a near-confluent pattern in an effort to quell fibrovascular ingrowth and subsequent hemorrhage. Finally, pharmacological advances include targeting three levels of intervention: achieving the best glycemic control, correcting altered retinal metabolism secondary to increased glucose availability, and employing neuroprotective and vasoprotective agents.

SUMMARY

The combination of therapies and interventions as they improve and evolve offers the potential to revolutionize the approach to the complications of diabetic eye disease and may soon render many current interventions obsolete. Diabetic pars plana vitrectomy continues to advance with better anatomic and visual success.

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.

Auckland Proliferative Diabetic Vitrectomy Fellow Eye Study

BACKGROUND

To review medical and ophthalmic findings of primary diabetic vitrectomy patients to examine indices important in progression to fellow eye surgery.

METHODS

A retrospective analysis was undertaken of all diabetic patients undergoing vitreoretinal surgery at Auckland Public Hospital between January 1992 and July 1996. Kaplan-Meier survival analysis was performed along with univariate and multivariate (Cox Proportional Hazards) data analysis.

RESULTS

One hundred and fourteen primary diabetic vitrectomy cases were reviewed with mean follow-up duration of 4 years. Thirty-eight per cent (n = 43) of the study group underwent fellow eye surgery at a mean time of 1.6 years after first eye surgery. Fourteen patients were already blind in the fellow eye at baseline, and five patients refused second eye surgery on intention to treat. Thus there were 62 (54%) patients with severe (surgical threshold) fellow eye disease diagnosed within the follow-up period. The presence of either tractional retinal detachment or combined rhegmatogenous/tractional retinal detachment but without vitreous haemorrhage in the presenting eye was, in this series, a risk factor for fellow eye surgery (OR 5.56; 95% CI 1.96-15.8). Maori and Pacific Islander ethnicity was significantly associated with traction retinal detachment (OR 2.23; 95% CI 1.05-4.7). At data analysis 57% (n = 60) of the study patients had died. The mean time to death was 4.3 years, with 84% of these patients having evidence of renal disease at the time of their first eye surgery. Good visual function in at least one eye was maintained in many patients.

CONCLUSIONS

A substantial proportion of diabetic vitrectomy patients require fellow eye surgery. Absence of vitreous haemorrhage in the presenting eye (i.e. tractional or combined rhegmatogenous/tractional retinal detachments but without vitreous haemorrhage) was predictive of need for fellow eye surgery. The need for diabetic vitrectomy correlates with poor survival in this study population.

Hemostatic effects of SF6 after diabetic vitrectomy for vitreous hemorrhage

PURPOSE

To investigate the hemostatic effects of SF6 gas in preventing postoperative vitreous hemorrhage in diabetic vitrectomy.

METHODS

A prospective, randomized study of 33 diabetic eyes with vitreous hemorrhage, treated by vitrectomy. In 17 of our cases SF6 20% was injected into the eye at the end of the operation, while in 16 cases BSS remained in the vitreous cavity.

RESULTS

The incidence of vitreous hemorrhage recurrence was 17.6% for the SF6 group and 12.5% for the BSS group (statistically not significant). Progression of lens opacities was observed in 23.5% of the SF6 group, and in 18.8% of the BSS group (statistically not significant, with a higher incidence in the SF6 group).

CONCLUSIONS

SF6 gas did not show hemostatic effects in the cases studied. Furthermore, it may have contributed to cataract progression. Therefore we suggest that the use of SF6 is not recommended as a treatment modality in preventing new vitreous hemorrhage after diabetic vitrectomy.

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.

Nd:YAG laser removal of pupillary membranes developed after ECCE with PC-IOL implantation

PURPOSE

To define the frequency of development of pupillary membranes after ECCE with PC-IOL implantation, and to remove the pupillary membranes using the Nd:YAG laser.

METHODS

From 400 patients who had undergone ECCE and were free from local or systemic illness affecting the blood-ocular barrier, 20 eyes developed pupillary membranes Nd:YAG laser was used to remove these pupillary membranes.

RESULTS

The frequency of pupillary membranes was found to be 5% (9.8% in pex eyes and 3.3% to the non-pex eyes). Visual acuity improved in 17 eyes by 2 to 5 Snellen lines. No serious complications were observed, endothelium inclusive.

CONCLUSION

Pseudoexfoliation might play a significant role in the development of postoperative pupillary membranes which could be successfully treated with the use of Nd:YAG laser. The safety of the procedure has to be evaluated in relation to the corneal endothelium damage in long-term.

Neodymium: YAG membranectomy for pupillary membranes on posterior chamber intraocular lenses

PURPOSE

To evaluate the effectiveness of neodymium: YAG laser for the removal of membranes from the anterior surface of intraocular lenses.

METHODS

Seven patients had reduced vision due to a membrane on the anterior surface of a posterior chamber intraocular lens (PC IOL). Six of the membranes developed after extracapsular cataract surgery and PC IOL combined with trabeculectomy and one after pars plana vitrectomy. Six of the membranes developed in the early postoperative period in association with a fibrinous reaction of the anterior chamber. One formed 7 months after surgery in an eye with iris capture behind the IOL. The membranes persisted despite intensive topical steroid therapy. A neodymium: YAG (Nd:YAG) laser was used to remove the membranes from the anterior of the IOL in all the seven cases.

RESULTS

The Nd:YAG laser effectively severed the peripheral connections of the membranes to the iris and lens, creating a clear central zone within the visual axis. The settings were fundamental mode, 1.2-to 3.1-mJ energy per shot and 48.3 +/- 20.1 single pulses. Vision improved significantly in six patients, whereas elevated intraocular pressure was observed in one patient.

CONCLUSION

Postoperative pupillary membranes may be successfully lysed with use of the Nd:YAG laser.

Vitrectomy for complications of proliferative diabetic retinopathy. Functional outcomes

PURPOSE

To quantitate the effect of diabetic vitrectomy on each patient's visual system and function.

METHODS

The anatomic and visual acuity outcomes of diabetic vitrectomy among three surgeons at one institution over a 4-year time interval were studied. Outcome parameters describing the visual system function were defined and applied to quantitate the effect on visual system disability.

RESULTS

The anatomic and visual success rates and prognostic factors in the cohort of 213 patients by standard statistical analysis were similar to previous studies. The study eye was the eye with better vision in 68 (32%) patients at the conclusion of the study, and vision was equal to the fellow eye in 35 (16%) patients. The mean impairment of the visual system by the American Medical Association Guidelines for Disability was reduced from 61% preoperatively to 50% postoperatively. The factor associated with greatest degree of reduction of impairment of the visual system was a previtrectomy diagnosis of vitreous hemorrhage. There was at least a one-step improvement of visual system function in 65 (31%) patients.

CONCLUSIONS

Vitrectomy for complications of severe proliferative diabetic retinopathy is especially valuable in improving the patient's overall visual function.

Vitrectomy in the management of diabetic eye disease

Vitrectomy techniques including endolaser photocoagulation allow visual rehabilitation in many eyes that are otherwise untreatable. Discerning the indications and timing for diabetic vitrectomy is increasingly important as the treatment of complications of diabetic retinopathy continues to undergo modification and redefinition. The most common indications for diabetic vitrectomy include: 1) severe nonclearing vitreous hemorrhage; 2) traction retinal detachment recently involving the macula; 3) combined traction and rhegmatogenous detachment; 4) progressive fibrovascular proliferation; and 5) rubeosis iridis and vitreous hemorrhage for eyes in which the media opacity has prevented adequate laser photocoagulation. Other less common indications in selected cases include dense premacular hemorrhage, ghost cell glaucoma, macular edema with premacular traction, cataract preventing treatment of severe, proliferative diabetic retinopathy, anterior hyaloidal fibrovascular proliferation, and fibrinoid syndrome with retinal detachment. The rationale and surgical objectives are discussed and results are summarized.

A light pipe guard to prevent iatrogenic retinal injury during vitrectomy

Images

Hemostatic effects of air versus fluid in diabetic vitrectomy

The potential hemostatic effect of an intravitreal air bubble after diabetic vitrectomy was studied in an animal model and in a randomized clinical trial. One day after vitrectomy with induced intraoperative hemorrhage, vitreous cavity hemorrhage was present in 60% of air-filled rabbit eyes compared with 27% of fluid-filled eyes. The prevalence and extent of hemorrhage was equal in the two groups on postoperative days 3 and 7. In a clinical trial of 51 eyes undergoing diabetic vitrectomy, 70% of eyes randomized to air-filled vitreous cavity after vitrectomy had vitreous cavity hemorrhage on postoperative day 1 compared with 50% of fluid-filled eyes. At 1 week, the incidence of hemorrhage was 78% for air and 61% for fluid. The 6-month visual and anatomic results were similar in both groups. These findings suggest that an intravitreal air bubble neither improves hemostasis nor reduces the visual outcome after diabetic vitrectomy.

Vitreous hemorrhage after closed vitrectomy for proliferative diabetic retinopathy

The authors reviewed the medical records of 191 patients (232 eyes) who underwent closed vitrectomy for complications of diabetic retinopathy to evaluate the clinical picture of postvitrectomy hemorrhage (PVH). One hundred thirty-nine eyes (59.9%) had at least one episode of PVH (average, 1.5 per eye) that was variable in onset, not associated with a known cause in four fifths, with no noted source in two thirds, and severe in three fourths of the cases. Using logistic regression statistical analyses, the factors significantly associated with decreased incidence of PVH include older age of patient (P = 0.0004), long duration of surgery (P = 0.0002), and poor preoperative vision (P = 0.05). Of the 139 eyes with PVH, 65 (47%) had spontaneous clearing in an average of 11.3 weeks, 53 (38%) required repeat surgery, and 21 (15%) were inoperable, lost to follow-up, or refused reoperation. Postvitrectomy hemorrhage did not significantly influence the final visual outcome.

A vitreoretinal service

Many serious disorders that threaten eyesight can now be treated with vitreoretinal surgery. As there was no regional facility for this treatment a service was developed to provide it. Among the first 100 patients treated over half had diabetic vitreoretinal disease. The remainder had ocular trauma (15), non-diabetic vasculopathy (10), rhegmatogenous retinal detachment (10), and miscellaneous disorders including diagnostic procedures (14). Sight was improved in most cases, 27 diabetic and 21 non-diabetic patients regaining navigating vision. Few patients were made worse: one only of the 49 non-diabetic patients and 12 of the 51 diabetic patients, and none whose vision was better than the ability to count fingers before operation. The many indications for this procedure, the size of the population that could benefit (an estimated minimum of 3800 operations per year in the United Kingdom in patients with diabetes alone), and the great potential benefit of the procedure all suggest the need for regional services. These would be cost effective in preventing blindness.

Posterior chamber intraocular lens insertion during pars plana lensectomy and vitrectomy for complications of proliferative diabetic retinopathy

We inserted posterior chamber lenses into 21 eyes with complications of diabetic retinopathy upon completion of pars plana lensectomy and vitrectomy in a single session. After the original surgery, two eyes developed retinal detachments and underwent vitrectomy revisions with scleral buckling, one eye had a fluid-gas exchange for residual vitreous cavity blood, one eye had supplemental laser treatment, and one eye had intraocular antibiotics for endophthalmitis. Six months later, postoperative vision was better in 16 of the 21 eyes (76%), the same in four eyes (19%), and worse in one eye (5%). In 16 eyes visual acuity was 20/200 or better, and in six eyes it was 20/40 or better postoperatively. Decreased vision was caused by preexisting macular disease; two eyes had corneal edema with iris neovascularization associated with residual retinal detachment. The procedure and lenses were well tolerated and provided good pseudophakic vision.

Posterior chamber intraocular lens implantation during diabetic pars plana vitrectomy

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

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

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

Factors influencing the results of vitreous surgery in diabetic retinopathy. I. Iris rubeosis and/or active neovascularization at the fundus

A consecutive series of 100 vitrectomies for tractional retinal detachment involving the macula in proliferative diabetic retinopathy was analyzed to determine the influence of preoperative iris rubeosis (NVI) and active neovascularization at the fundus (NVF) on surgical results. The minimum follow-up was 12 months. Preoperatively, iris rubeosis was present in 52% and active neovascularization at the fundus in 85%. Surgery was performed under Spitznas wide-angle observation, using a stereoscopic diagonal inverter, either with the panfundoscope or binocular ophthalmoscopy through the operating microscope. Most of the eyes were phakic (94%). No lensectomy was performed. Anatomical success was achieved in 81%, ambulatory vision in 77%. Anatomical success was reduced to 63% in cases with preoperative NVI and to 78% in cases with preoperative NVF. Including 5 cases of re-vitrectomy, silicone oil was used for internal tamponade in 9%, SF 6/air 50:50 in 39% and air in 26%. In 26%, no internal tamponade was applied. Postoperative complications consisted of vitreous hemorrhage (25%), increased rubeosis (22%), neovascular glaucoma (2%), and redetachment (7%). The final causes of failure in 19% of eyes were: neovascular glaucoma (1%), rubeosis/hypotony/cataract (14%), and phthisis bulbi (4%).

Vitrectomy for diabetic eye disease

Thirty four eyes which underwent vitrectomy because of diabetic proliferative retinopathy were reviewed. The overall success rate of the operation was 62%. Excluding table top retinal detachments, which all did badly, the success rate was 72%. Grading by ultrasound was found to be helpful in; (a) planning surgical approach, (b) assessing visual outcome. The most common late complication was cataract. Extracapsular cataract extraction with implantation was found to be successful in these cases.