Incidence of late-onset ocular hypertension following uncomplicated pars plana vitrectomy in pseudophakic eyes

Case Report: Microincision Vitreous Surgery Induces Bleb Failure in Eyes With Functional Filtering Bleb

Purpose

To investigate the effect of microincision vitreous surgery (MIVS) on intraocular pressure (IOP) control in glaucomatous eyes with functional filtering bleb.

Methods

We enrolled 18 patients (15 males; median age, 73 years) who previously had filtering surgery and underwent MIVS with functional filtering bleb. Kaplan–Meier method was used to calculate the survival rate with defined the failure as when more number of preoperative antiglaucoma medication was started or additional glaucoma surgery including bleb revisions were performed, and IOP increase of 20% (criteria 1) and 30% (criteria 2) from preoperative levels after 2 weeks of MIVS.

Results

The median follow-up duration was 970 days. Preoperative IOP was 13.3 ± 3.8 mmHg (mean ± SD). Postoperative IOP were 14.7 ± 4.9 (P=0.365), 15.2 ± 3.5 (P=0.137), 16.4 ± 5.6 (P = 0.073), 17.6 ± 6.1(P = 0.020), and 14.5 ± 4.0 (P = 0.402) mmHg at 3, 6, 12, and 15 months and final visit, respectively (compared to preoperative IOP). The number of antiglaucoma medications was a median of 1.0 (range 0–4) preoperatively and 0 (0–4) at the final visit (P = 0.238). The survival rates were 55%/61% at 3 months, 50%/61% at 6 months, and 38%/55% at 12 months with criteria 1 and 2, respectively. Four eyes (22%) received additional glaucoma surgery during follow-up.

Conclusion

After several months of MIVS, IOP was likely to increase. We should focus on IOP control by conducting long-term follow-ups.

Oxidative Stress in Optic Neuropathies

Increasing evidence indicates that changes in the redox system may contribute to the pathogenesis of multiple optic neuropathies. Optic neuropathies are characterized by the neurodegeneration of the inner-most retinal neurons, the retinal ganglion cells (RGCs), and their axons, which form the optic nerve. Often, optic neuropathies are asymptomatic until advanced stages, when visual impairment or blindness is unavoidable despite existing treatments. In this review, we describe systemic and, whenever possible, ocular redox dysregulations observed in patients with glaucoma, ischemic optic neuropathy, optic neuritis, hereditary optic neuropathies (i.e., Leber's hereditary optic neuropathy and autosomal dominant optic atrophy), nutritional and toxic optic neuropathies, and optic disc drusen. We discuss aspects related to anti/oxidative stress biomarkers that need further investigation and features related to study design that should be optimized to generate more valuable and comparable results. Understanding the role of oxidative stress in optic neuropathies can serve to develop therapeutic strategies directed at the redox system to arrest the neurodegenerative processes in the retina and RGCs and ultimately prevent vision loss.

Long-Term Intraocular Pressure Changes after Pars Plana Vitrectomy: An 8-Year Study

Purpose:

To investigate the long-term changes of intraocular pressure (IOP) after pars plana vitrectomy (PPV).

Methods:

This was a retrospective historical cohort study. Patients with a history of vitrectomy in one eye by a single surgeon were enrolled. IOP of the operated eye was compared to the fellow eye. Previous scleral buckling, IOP rise due to surgical/anatomic complications, silicone oil (SO) emulsification, and contralateral ocular hypertension/glaucoma at recruitment were exclusion criteria. “Significant IOP rise” (>6.0 mmHg) and development of open angle glaucoma (OAG) were the main outcome measures.

Results:

Two hundred and twenty-five eyes were included. Mean and median follow-up duration were 20.6 and 9.0 months, respectively. Mean baseline IOP and mean final IOP were 13.53 ± 3.75 mmHg and 16.52 ± 6.95 mmHg, respectively (P < 0.001). Forty-three patients developed “significant IOP rise” with no statistically significant relation to the indication of vitrectomy, the postoperative lens status, and number of vitrectomies (P = 0.410, P = 0.900, and P = 0.160, respectively). SO injection raised the probability of IOP rise in the long-term (P = 0.028). OAG occurred in 17 patients (7.5%) with no association to SO tamponade (P = 0.840). “Significant IOP rise” and OAG occurred in 3 and 1 control eyes, respectively, significantly lower than the rates in study eyes (P < 0.001).

Conclusion:

Mean IOP slightly rose in the long-term after PPV. SO tamponade was associated with IOP rise in the long-term but not with the incidence of OAG. Both IOP rise and OAG were more probable after vitrectomy.

LATE-ONSET OCULAR HYPERTENSION AFTER VITRECTOMY: A Multicenter Study of 6,048 Eyes

PURPOSE

To determine the incidence and risk factors for late-onset ocular hypertension (LOH) after vitrectomy.

METHODS

From the electronic medical records of consecutive patients who underwent primary vitrectomy, from January 2010 to December 2015, at 5 tertiary vitreoretinal centers in Italy, patient demographics, systemic, ophthalmic, operative, and postoperative data were drawn. Main outcome measure was the presence of LOH, defined as intraocular pressure >21 mmHg detected more than 2 months after vitrectomy on at least 2 consecutive visits.

RESULTS

Among 6,048 patients, LOH was found in 294 (4.9%) vitrectomized eyes and in 87 (1.4%) fellow eyes, (chi square; P < 0.001). Multivariable logistic regression showed that significant risk factors for developing LOH included intraoperative triamcinolone use (odds ratio [OR], 7.62; P < 0.001), longer axial length (OR, 1.55; P = 3.023), preoperative higher intraocular pressure (OR, 1.81; P = 0.003), and postvitrectomy pseudophakic/aphakic status (OR, 2.04; P < 0.001). Decision-tree analysis showed that the stronger predictor of LOH was intraoperative triamcinolone use (P < 0.001). Secondary predictors were a preoperative intraocular pressure more than 15 mmHg (P < 0.001) in eyes that use triamcinolone, and postvitrectomy pseudophakic/aphakic status (P = 0.007) in eyes that did not use triamcinolone.

CONCLUSION

Late-onset ocular hypertension occurred in 4.9% of vitrectomized eyes. The main risk factors were intraoperative use of triamcinolone and postvitrectomy pseudophakic/aphakic status.

Influence of pars plana vitrectomy for macular surgery on the medium term intraocular pressure

Purpose

To evaluate the long-term effect of 20 and 23 gauge pars plana vitrectomy (PPV) on intraocular pressure (IOP).

Methods

Study type: Monocentric retrospective cohort study. 249 eyes of 249 patients undergoing PPV due to epiretinal membrane (EM), idiopathic macular hole (IMH) or vitreoretinal traction (VT) were included. The fellow eye served as control. Exclusion criteria were factors known to influence the IOP, such as cataract surgery during follow-up, extended use of steroids, cryotherapy and silicone oil endotamponade. The relative change of IOP (operated vs. fellow eye) at 6–12 months after surgery was defined as primary endpoint. Secondary endpoints were the relative change of IOP at 3–6 and 12–24 months. Possible influencing cofactors were analysed using ANCOVA.

Results

The primary endpoint did not show a significant IOP reduction of the operated eye relative to the fellow eye (P = 0.089, n = 84). However, the IOP of the operated eye alone was significantly reduced at 6–12 and 12–24 months after surgery (-0.75 ± 2.80 and -1.22 ± 3.29 mmHg, P = 0.008 and 0.007, respectively). The IOP of the fellow eye was also significantly reduced at the 12–24 months period (-0.75 ± 2.73 mmHg, P = 0.008). In the subgroup analysis, sclerotomy size was a significant influencing cofactor, leading to lower IOP after 20G compared to 23G vitrectomy (P = 0.04).

Conclusion

Pars plana vitrectomy did not induce a significant long-term IOP reduction relative to the contralateral eye. However, we observed a IOP lowering potential in 20G vitrectomy.

Intraocular Pressure Rise Linked to Silicone Oil in Retinal Surgery: A Review

Silicone oil represents the main choice for intraocular tamponade in cases of complicated retinal detachment surgery. The intraocular pressure of an eye filled with silicone oil could increase, driven by a variety of different forces, according to several mechanisms. Two main conditions have been highlighted, depending on the onset: early hypertension or late glaucoma. The different types of silicone oils and their physico-chemical properties are varied and may play a role in the determination of intraocular pressure rise. The current body of literature allows for the illustration and categorization of the incidence and risk factors, as well as the pathogenesis and the management of the early postoperative hypertension subtended by an open- and closed-angle, along with the late onset silicone oil-induced glaucoma. Understanding the leading actors on the stage of ocular pressure elevation concurrently with silicone oil application for retinal surgery could help in guiding the timely and appropriate course of treatment.

Anatomic and functional results of idiopathic macular epiretinal membrane surgery

AIM

To assess the impact of macular surgery on the functional and anatomic outcomes in patients with grade 2 epiretinal membrane (ERM), and the effect of internal limiting membrane (ILM) peeling on visual acuity and to analyze the long-term effect of pars plana vitrectomy (PPV) on intraocular pressure (IOP).

METHODS

Pseudophakic eyes (62 eyes) diagnosed as idiopathic grade 2 ERM with at least 6mo postoperative follow-up were included in this retrospective study. The fellow eye was nonvitrectomized. Patients were divided into two groups: group 1 (29 eyes) treated with ERM and ILM peeling and group 2 (33 eyes) with only ERM peeling. Preoperative and postoperative best corrected visual acuity (BCVA), slit-lamp, and a dilated fundus examination was performed. IOP was measured with Goldman applanation tonometer before, day 1 and first week and each visit after surgery. The incidence of significant IOP elevation was compared between vitrectomized eyes and nonvitrectomized fellow eyes.

RESULTS

Visual improvement was statistically significant and similar in both groups (P=0.008 in group 1, P=0.002 in group 2, P=0.09 inter-group). The amount of decrease in central macular thickness was statistically significant and similar in both groups (P=0.005 group 1, P=0.008 group 2, P=0.37 intergroup). At the final follow-up (14.1±9.6mo) the incidence of significant IOP elevation was 4% in vitrectomized eyes (three eyes) and 3% (two eyes) in the nonvitrectomized fellow eyes (P=0.12). Four eyes (12.1%) had recurrent ERM after a mean follow-up of 8.6±1.1mo in group 2, there was no recurrence in group 1 (P=0.01).

CONCLUSION

Recurrence of ERM may be decreased by ILM peeling during ERM surgery. However, it seems that ILM peeling do not affect the functional outcome and 23-gauge PPV alone do not have a significant effect on IOP.

INTRAOCULAR PRESSURE OUTCOMES AFTER SURGERY FOR RHEGMATOGENOUS RETINAL DETACHMENT IN SCHWARTZ SYNDROME

PURPOSE

To study intraocular pressure (IOP) outcomes after surgery for rhegmatogenous retinal detachment in Schwartz syndrome.

METHODS

We reviewed records of 32 eyes of 32 patients with Schwartz syndrome (patients with rhegmatogenous retinal detachment, IOP above 21 mmHg, and open angles without angle recession, chronic steroid use or other secondary causes of increased IOP) who had undergone surgical treatment consisting of scleral buckling or vitrectomy. Intraocular pressure, number of medication, best-corrected visual acuity were compared at baseline and postsurgery visits and also studied association of various factors on long-term IOP.

RESULTS

The median duration of rhegmatogenous retinal detachment was 2 months, and the inter quartile range was 1 to 12 months. Follow-up was 15 months (inter quartile range: 7-33 months). Sixteen (50%) had prior ocular trauma. Baseline IOP was 35 ± 8 mmHg, and 12% (4/32) of patients were on IOP-lowering medication at presentation. At the final visit, mean IOP was 17 ± 6 mmHg and 59% patients (19/32) required additional IOP-lowering medication or surgery for IOP control.

CONCLUSION

Surgical management of rhegmatogenous retinal detachment resulted in significant reduction in IOP. At the final visit, 41% did not require any IOP-lowering medication or surgical intervention for IOP control.

Intraocular Oxygen and Antioxidant Status: New Insights on the Effect of Vitrectomy and Glaucoma Pathogenesis

PURPOSE

The purpose of this study was to investigate correlations of partial pressure of oxygen (pO₂) in the ocular anterior segment of human eyes and aqueous humor antioxidant levels of ascorbate (AsA) and total reactive antioxidant potential (TRAP) with glaucoma and vitreous status.

METHODS

This prospective, cross-sectional study stratified patients (n = 288 eyes) by lens and vitreous status and the presence of primary open-angle glaucoma for statistical analyses. Intraocular pO₂ concentrations were measured using a fiberoptic probe in patients at the beginning of planned glaucoma and/or cataract surgery. Aqueous humor specimens were obtained for antioxidant analysis of AsA and TRAP.

RESULTS

Following prior pars plana vitrectomy, pO₂ levels were significantly higher than in the reference group of cataract surgery in the anterior chamber angle (16.2 ± 5.0 vs. 13.0 ± 3.9 mm Hg; P = .0171) and in the posterior chamber (7.6 ± 3.1 vs. 3.9 ± 2.7 mm Hg; P < .0001). AsA and TRAP levels were significantly lower (1.1 ± 0.4 vs. 1.4 ± 0.5 mM, respectively; 403.3 ±116.5 vs. 479.0 ± 146.7 Trolox units, respectively; P = .004 and P = .024, respectively) in patients after vitrectomy. In patients with an intact vitreous, neither pO₂ nor antioxidant status correlated with lens status or glaucoma.

CONCLUSIONS

Increased pO₂ and antioxidant depletion following vitrectomy suggests an alteration of the intraocular oxidant-antioxidant balance. Our study links physiologic factors such as increased pO₂ in the anterior chamber angle and the posterior chamber to decreased antioxidant levels in aqueous humor following vitrectomy. Oxidative stress/damage to the trabecular meshwork in such post-vitrectomy cases may contribute to intraocular pressure elevation and increased risk of glaucoma. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Chandelier-assisted scleral buckling using wide angle viewing contact lens for pseudophakic retinal detachment repair

AIM

To evaluate a modified technique for scleral buckling (SB) in pseudophakic retinal detachment (RD).

METHODS

A retrospective non-comparative study included 21 consecutive eyes with uncomplicated pseudophakic RD that was repaired by chandelier assisted SB using wide angle viewing (WAV) contact lens. Segmental tire alone was used in 5 eyes (23.81%), and combined with encircling band in 7 eyes (33.33%). Radial sponge alone was used in 3 eyes (14.29%) and combined with encircling band in 6 eyes (28.57%).

RESULTS

Primary success rate was (90.48%). External drainage of subretinal fluid was performed in 8 eyes (38.1%). Intraoperative complications included vitreous prolapse at chandelier sclerotomy site in 4 eyes (19.05%) and localized subretinal hemorrhage at drainage site in one eye (4.76%). No case of intraocular lens (IOL) displacement, retinal incarceration or iatrogenic retinal tear was detected. Postoperative complications included choroidal detachment in one eye (4.76%), elevated intraocular pressure in 2 eyes (9.52%), epiretinal membrane formation in one eye (4.76%) and proliferative vitreoretinopathy in 3 eyes (14.29%). Mean postoperative corrected distance visual acuity was 0.7±0.3 logMAR units.

CONCLUSION

Chandelier-assisted SB using WAV contact lens is a reliable technique for repairing selected cases of simple pseudophakic RD.

Changes in the anterior segment of the eye following uncomplicated pars plana vitrectomy. A review

Pars plana vitrectomy is currently the most common technique used in retinal surgery. Although primarily involving the posterior segment of the eye it also affects the anterior segment. As this is a less published topic, the aim of this paper was to review the literature on changes in the anterior segment after uncomplicated pars plana vitrectomy using data based literature search. The conclusions are that even in otherwise ophthalmologically healthy patients, complications may occur in the anterior segment. Surgeons need to pay utmost attention in glaucoma patients and in those with endothelial insufficiency who are at highest risk of complications. He/she must also correctly plan a potential cataract surgery if not already done earlier. From the literature, most of the changes in the anterior segment after uncomplicated PPV are found to be temporary.

OCULAR HYPERTENSION AND GLAUCOMA FOLLOWING VITRECTOMY: A Systematic Review

PURPOSE

Pars plana vitrectomy has been reported to increase the risk of ocular hypertension and open-angle glaucoma. The authors conducted a systematic review of randomized and nonrandomized studies to compare the incidence of open-angle glaucoma and ocular hypertension in vitrectomized versus nonvitrectomized eyes.

METHODS

A literature search was performed using MEDLINE and EMBASE until August 2016. Data on ocular hypertension and open-angle glaucoma incidence and mean intraocular pressure after at least 1 year were pooled using random-effects metaanalysis models. Because only nonrandomized studies were retrieved, ROBINS-I tool was used to assess risk of bias in the review.

RESULTS

Seven included studies had a paired design to compare the outcomes of vitrectomized versus fellow eyes, with mean follow-up of least 12 months. Four studies (851 patients) provided data on open-angle glaucoma: incidence in vitrectomized versus non-vitrectomized eyes was 7.8% and 4.8%, respectively, yielding a metaanalytic odds ratio of 1.67 (95% CI: 1.08-2.57). Six studies (1,060 patients) reported on the occurrence of ocular hypertension, which was 5.8% in vitrectomized eyes versus 3.1% in fellow eyes (odds ratio: 2.03, 95% CI: 0.97-4.22), without significant differences in the mean postoperative intraocular pressure (mean difference 0.31 mmHg, 95% CI: -0.26 to 0.89).

CONCLUSION

Although the review found increased risk of open-angle glaucoma with pars plana vitrectomy, the studies were heterogenous or inconsistent regarding ocular hypertension and intraocular pressure increase. Larger studies should be conducted in homogenous cohorts of patients undergoing macular surgery, excluding complex conditions such as retinal detachment or diabetic retinopathy.

Effect of the Notch signaling pathway on retinal ganglion cells and its neuroprotection in rats with acute ocular hypertension

AIM

To explore the effect of the Notch signaling pathway on retinal ganglion cells (RGCs) and optic nerve in rats with acute ocular hypertension (OH).

METHODS

Totally 48 Sprague-Dawley (SD) rats were included, among which 36 rats were selected to establish acute OH models. OH rats received a single intravitreal injection of 2 µL phosphate buffered solution (PBS) and another group of OH rats received a single intravitreal injection of 10 µmol/L γ-secretase inhibitor (DAPT). Quantitative real-time polymerase chain reaction (qPCR) and Western blot assay were adopted to determine the mRNA level of Notch and the protein levels of Notch, Bcl-2, Bax, caspase-3, and growth-associated protein 43 (GAP-43). The RGC apoptosis conditions were assessed by TUNEL staining.

RESULTS

The OH rats and PBS-injected rats had increased expression levels of Notch1, Bax, caspase-3, and GAP-43, decreased expression levels of Bcl-2, and increased RGC apoptosis, with severer macular edema and RGCs more loosely aligned, when compared with the normal rats. The DAPT-treated rats displayed increased expression levels of Notch1, Bax, caspase-3, and GAP-43, decreased expression levels of Bcl-2, and increased RGC apoptosis, in comparison with the OH rats and PBS-injected rats. RGCs were hardly observed and macular edema became severe in the DAPT-treated rat.

CONCLUSION

The Notch signaling pathway may suppress the apoptosis of retinal ganglion cells and enhances the regeneration of the damaged optic nerves in rats with acute OH.

LONG-TERM INTRAOCULAR PRESSURE AFTER UNCOMPLICATED PARS PLANA VITRECTOMY FOR IDIOPATHIC EPIRETINAL MEMBRANE

PURPOSE

To investigate long-term intraocular pressure trends after uncomplicated pars plana vitrectomy for idiopathic epiretinal membrane.

METHODS

Three hundred and sixty-eight eyes of 368 consecutive patients were enrolled. Changes in intraocular pressure 1, 3, 6, and 12 months after surgery and during the final follow-up visit were evaluated in vitrectomized eyes and nonvitrectomized fellow eyes.

RESULTS

The median follow-up period was 36 months (range 12-92 months). Longitudinal data analysis evidenced a 2.5-mmHg (2.2 mmHg; 2.7 mmHg, 95% confidence interval) statistically significant difference in intraocular pressure 30 days after surgery between treated and fellow untreated eyes, gradually recovering to a not significant 0.2-mmHg (-0.1 mmHg; 0.4 mmHg, 95% confidence interval) difference within 26 months. The incidence of late-onset ocular hypertension was 5.7% (21 over 347, 2%; 12%, 95% confidence interval) without difference between the treated eyes and the group control. No significant difference in the incidence of late-onset ocular hypertension and sex, lens status, or gauge of vitrectomy instruments was detected. Only patient's age was significantly higher (mean difference 4.2 years; 0.1-8.0 years, Monte Carlo, 95% confidence interval) in those who developed late-onset ocular hypertension in the vitrectomized eye.

CONCLUSION

Uncomplicated pars plana vitrectomy for idiopathic epiretinal membrane seems not to increase the risk of late-onset ocular hypertension or open-angle glaucoma development.

SUPRACHOROIDAL BUCKLING FOR THE MANAGEMENT OF RHEGMATOGENOUS RETINAL DETACHMENTS SECONDARY TO PERIPHERAL RETINAL BREAKS

PURPOSE

To evaluate functional and anatomical outcomes of eyes undergoing suprachoroidal buckling for the management of peripheral retinal breaks in rhegmatogenous retinal detachment.

METHODS

Retrospective cohort study of 41 eyes of 41 patients undergoing suprachoroidal buckling for the management of rhegmatogenous retinal detachment secondary to single or multiple retinal breaks. Suprachoroidal indentation was achieved through the introduction of filler material using a 23-gauge (23-G) olive-tipped, suprachoroidal cannula. This allowed for the creation of a suprachoroidal dome and chorio-retinal apposition. Healon5 (Abbott Medical Optics) was used as filler material in all eyes. Combined 25-G vitrectomy was performed in 5 eyes. Cryopexy and laserpexy were used in 37 and 4 eyes, respectively.

RESULTS

Mean visual acuity gain was the primary outcome measure. Final retinal reattachment rate, single-surgery reattachment rate, and complications were secondary outcome measures. Mean best-corrected distance visual acuity improved from 20/1,100 to 20/42. Single surgery reattachment rate was 92.7% (38/41 eyes). Final retinal reattachment was achieved in all 41 eyes (100%). There was no statistically significant difference in visual acuity gain or anatomical reattachment in terms of retinal break quadrant or extent. No major complications were observed. Two localized suprachoroidal hemorrhages occurred at the entry site for the cannula. These resolved without further intervention.

CONCLUSION

Suprachoroidal buckling using a specially designed cannula is a safe and effective procedure for the management of rhegmatogenous retinal detachment secondary to peripheral retinal breaks.

Effects of Vitrectomy and Lensectomy on Older Rhesus Macaques: Oxygen Distribution, Antioxidant Status, and Aqueous Humor Dynamics

Purpose

The purpose of this study is to evaluate effects of vitrectomy (PPV) and lens extraction with intraocular lens implantation (PE/IOL) on molecular oxygen (pO₂) distribution, aqueous humor antioxidant–oxidant balance, aqueous humor dynamics, and histopathologic changes in the trabecular meshwork (TM) in the older macaque monkey.

Methods

Six rhesus monkeys underwent PPV followed by PE/IOL. pO₂, outflow facility, and intraocular pressure (IOP) were measured. Aqueous and vitreous humor specimens were analyzed for antioxidant status and 8-hydroxy-2′-deoxyguanosine (8-OHdG), a marker of oxidative damage. TM specimens were obtained for immunohistochemical and quantitative PCR analysis.

Results

pO₂ at baseline revealed steep gradients in the anterior chamber and low levels in the posterior chamber (PC) and around the lens. Following PPV and PE/IOL, pO₂ significantly increased in the PC, around the IOL, and angle. IOP increased following both surgical interventions, with no change in outflow facility. Histopathologic analysis did not show changes in TM cell quantification, but there was an increase in 8-OHdG. Quantitative PCR did not reveal significant differences in glaucoma-related gene expression. Aqueous and vitreous humor analysis revealed decreased ascorbate and total reactive antioxidant potential and increased 8-OHdG in the aqueous humor only in the surgical eyes.

Conclusions

Oxygen distribution in the older rhesus monkey is similar to humans at baseline and following surgical interventions. Our findings of histopathologic changes of TM oxidative damage and alterations in the oxidant-antioxidant balance suggest a potential correlation of increased oxygen exposure with oxidative stress/damage and the development of open angle glaucoma.

Long-Term Changes in Intraocular Pressure after Vitrectomy for Rhegmatogenous Retinal Detachment, Epi-Retinal Membrane, or Macular Hole

Purpose

To determine the long-term changes in the intraocular pressure (IOP) following vitrectomy for rhegmatogenous retinal detachment (RRD), epiretinal membrane (ERM), and macular hole (MH), and to investigate the relationship between the retinal disease and the incidence of late-onset IOP elevation.

Methods

This was a retrospective, observational, comparative study. We reviewed the medical records of 54 eyes of 54 RRD patients, 117 eyes of 117 ERM patients, and 75 eyes of 75 MH patients who underwent 20-, 23- or 25-gauge vitrectomy. The IOPs before surgery and 1, 3, 6, and 12 months following vitrectomy, and also at the final visit (average, 23.95 months) were evaluated. We defined a significant increase in the IOP as an increase of ≥4 mmHg from the preoperative IOP, and this increase was taken to be a ‘death’ event for the Kaplan-Meier survival analyses.

Results

The mean follow-up period was not significantly different among the groups. The mean IOP at 3 (P = 0.001) and 12 (P = 0.011) months following the vitrectomy and at the final visit (P = 0.002) were significantly higher than that before the vitrectomy in the RRD group. The mean IOP in the RRD group was significant higher than that in the ERM group at 1 (P = 0.005), 3 (P = 0.009), and 12 (P = 0.013) months following vitrectomy, and at the final visit (P = 0.032). Kaplan-Meier survival analyses showed that the RRD group had a significantly higher risk of an IOP increase following vitrectomy than the other groups (P<0.001 by log-rank test). Multivariate logistic regression analyses showed that a preoperative diagnosis of RRD was the only risk factor that was significantly associated with a postoperative IOP elevation after excluding eyes with a low preoperative IOP (odds ratio, 3.208; P = 0.003).

Conclusions

A late-onset IOP elevation following vitrectomy was observed only in eyes that underwent RRD surgery. The elevation was probably caused by the specific characteristics and surgical procedures of RRD. Clinicians should pay more attention to the IOP elevation for long times after vitrectomy especially in eyes with RRD.

Advantages of diabetic tractional retinal detachment repair

Purpose

To evaluate the outcomes and complications of patients with diabetic tractional retinal detachment (TRD) treated with pars plana vitrectomy (PPV).

Patients and methods

We retrospectively studied a case series of 24 eyes of 21 patients at a single tertiary, university-affiliated medical center. A review was carried out on patients who underwent PPV for the management of TRD due to proliferative diabetic retinopathy from October 2011 to November 2013. Preoperative and final visual outcomes, intraoperative and postoperative complications, and medical background were evaluated.

Results

A 23 G instrumentation was used in 23 eyes (95.8%), and a 25 G instrumentation in one (4.2%). Mean postoperative follow-up time was 13.3 months (4–30 months). Visual acuity significantly improved from logarithm of the minimum angle of resolution (LogMAR) 1.48 to LogMAR 1.05 (P<0.05). Visual acuity improved by ≥3 lines in 75% of patients. Intraoperative complications included iatrogenic retinal breaks in seven eyes (22.9%) and vitreal hemorrhage in nine eyes (37.5%). In two eyes, one sclerotomy was enlarged to 20 G (8.3%). Postoperative complications included reoperation in five eyes (20.8%) due to persistent subretinal fluid (n=3), vitreous hemorrhage (n=1), and dislocated intraocular lens (n=1). Thirteen patients (54.2%) had postoperative vitreous hemorrhage that cleared spontaneously, five patients (20.8%) required antiglaucoma medications for increased intraocular pressure, seven patients (29.2%) developed an epiretinal membrane, and two patients (8.3%) developed a macular hole.

Conclusion

Patients with diabetic TRD can benefit from PPV surgery. Intraoperative and postoperative complications can be attributed to the complexity of this disease.