Nonvitrectomizing vitreous surgery: a strategy to prevent postoperative nuclear sclerosis

An objective evaluation of lens transparency after vitrectomy surgery with different intravitreal tamponades

PURPOSE

To evaluate and compare the effects of different intraocular tamponade agents on lens density after vitrectomy.

METHODS

The participating patients were divided into four groups according to the tamponade agent used: a sulfur hexafluoride (SF₆) group, a perfluoropropane (C₃F₈) group, a silicone oil group, and a no tamponade group. Lens density measurements were performed preoperatively and two weeks, one month, and three months postoperatively using a Pentacam HR device with a Scheimpflug camera. The postoperative values were compared with the preoperative baseline values, also the values were compared between the four groups.

RESULTS

The study included 82 eyes (82 patients). In the SF₆ group, lens density significantly increased in all zones two weeks and one and three months postoperatively (all P < .05). In the C₃F₈ group, lens density significantly increased in all zones three months postoperatively (all P < .01). In the silicone oil group, the zone 1, zone 2, and average lens density (ALD) value significantly increased one and three months postoperatively (all P < .05). In the no tamponade group, the zone 1, zone 2, and ALD values significantly increased three months postoperatively (all P < .05). There were no significant differences between the four groups in any zone either preoperatively or postoperatively (all P > .05).

CONCLUSIONS

Although increases in lens density were observed earlier in the tamponade groups than in the no tamponade group, between the groups over the follow-up period were no differences. We need the development of new surgical methods and materials to prevent post-vitrectomy lens damage in the future.

Comparative study of combined vitrectomy with phacoemulsification versus vitrectomy alone for primary full-thickness macular hole repair

Background

To assess the effectiveness and safety of 23-gauge pars plana vitrectomy combined with phacoemulsification versus vitrectomy alone in patients over 50 years with primary full-thickness macular holes (FTMH).

Methods

We retrospectively reviewed the medical records related to 406 consecutive vitrectomies performed for primary FTMH. Phacovitrectomy was performed in 294 phakic eyes whereas vitrectomy alone in 112 pseudophakic eyes. The cases were divided into three groups according to the stage of the FTMH: stage 2 (n = 93), stage 3 (n = 270), or stage 4 (n = 43). The primary outcome measure was the closure of the FTMH. The secondary outcome measures were the evolution of visual acuity as well as intraoperative and postoperative complications.

Results

Neither the primary nor the secondary outcomes differed between phacovitrectomy and vitrectomy alone for all three stages. The FTMH were closed in 375 eyes (92.4 %) after a first operation. The closure rate was higher for stage 2 (96.8 %) than for stages 3 (91.1 %) or 4 (90.75 %), but not significantly (P = 0.189). The mean visual acuity increased significantly from preoperatively LogMAR 0.68 (± SD 0.2) to LogMAR 0.43 (± SD 0.24) at the end of the follow-up (p < 0.001).

Conclusions

Combined 23-gauge pars plana vitrectomy with phacoemulsification for primary FTMH repair in patients over 50 years is as efficient and safe when compared with vitrectomy only.

Trial registration

The study was approved on 30^th April 2020 by the local ethics committee (Ethikkommission Ostschweiz, EKOS 20/074; BASEC Nr. 2020-01033).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-01918-2.

Epiretinal Membrane Surgery: Structural Retinal Changes Correlate with the Improvement of Visual Function

Several parameters have been studied for identifying the visual outcomes after pars plana vitrectomy (PPV) for epiretinal membrane (ERM) peeling. This retrospective study aimed to analyze structural retinal changes with spectral domain-optical coherence tomography (SD-OCT) and their correlations with visual acuity improvement in patients with ERM undergoing PPV. Twenty-one pseudophakic eyes were enrolled in the study. Ophthalmic evaluations included best corrected visual acuity (BCVA) and retinal layer thickness measurements with SD-OCT. The segmentation of the retina was divided into four parts: the inner retinal layer (IRL), composed of an internal limiting membrane, retinal nerve fiber layer, ganglion cell layer, and inner plexiform layer; inner nuclear layer (INL); outer plexiform layer (OPL); and outer nuclear layer (ONL). Correlations between changes in retinal layer thicknesses and BCVA were explored over a 6 month follow-up period. The postoperative thickness decrease of the INL was significantly correlated with thickness changes in all other measured retinal layers (p < 0.001). Non-parametric linear regression showed that postoperative improvement in BCVA was associated with a postoperatively decreased thickness in the IRL (p = 0.021), INL (p = 0.039), and OPL (p = 0.021). In eyes undergoing PPV, postoperative thickness decreases of the IRL, INL, and OPL were correlated with visual acuity improvements. Re-compaction of these retinal layers after relieving ERM-induced traction may be an important factor in postoperative visual function improvement.

One-year outcomes of 27G core-pars plana vitrectomy of idiopathic epiretinal membrane

The present study aimed to assess the feasibility and safety of 27G core-pars plana vitrectomy (PPV) for idiopathic epiretinal membrane (IERM). A retrospective analysis was performed on 38 eyes from 38 patients with IERM with a mean age of 62.73±5.61 years. 27G core-PPV was combined with IERM and internal limiting membrane (ILM) peeling. Pre-operative and post-operative best-corrected visual acuity (BCVA) and lens density were measured. Optical coherence tomography (OCT) and OCT angiography were performed to determine the patients' macular area. Ultrasound biomicroscopy and B-mode ultrasound were subsequently performed to observe any complications and the follow-up period ranged from 1 week to 12 months post-operatively. A total of 36 patients achieved visual improvement of ≥2 Snellen lines, of which 33 patients exhibited improvements within 1 week and the lens density remained unchanged. The mean central macular thickness significantly decreased at 12 months post-operatively (P≤0.05); however, it was not observed to be correlated with BCVA (r=0.41; P>0.05). The foveal avascular zone of the affected eye was significantly smaller than that of the healthy fellow eye (P≤0.05) and negatively correlated with post-operative BCVA (r=-0.72; P≤0.05). Superficial retinal capillary density and deep retinal capillary density decreased post-operatively (both P≤0.05) and no complications were observed. Taken together, the results of the present study indicate that application of 27G core-PPV with ILM peeling is minimally invasive for IERM and facilitates rapid post-operative BCVA recovery.

International Board Members of the American Journal of Ophthalmology

This year marks the 100th anniversary of the "modern" American Journal of Ophthalmology (AJO). International influence has been present since the beginnings of the journal, and the AJO had boasted a number of foreign editorial board members and collaborators over the years. Within the article we present sketches of the deceased international board members of the AJO, particularly of Sir Stewart Duke-Elder, Pierre Amalric, Joaquin Barraquer, and Yasuo Tano. Although the AJO is American by name and with respect to the majority of contributions and readers, the international board members and collaborators have helped to maintain its international character and worldwide level of recognition. As the United States is a competitive society that values progress and success partially owing to foreign influence and immigrants, similarly the international contributions help to support and provoke the dynamic development of the AJO.

Modified Vitrectomy Technique for Phakic Rhegmatogenous Retinal Detachment with Intermediate Break

Purpose

To evaluate the effects of a modification of the traditional 25-gauge pars plana vitrectomy technique in the treatment of uncomplicated macula-on rhegmatogenous retinal detachment (RRD) with intermediate retinal break(s) and marked vitreous traction in the phakic eye.

Methods

Prospective, noncomparative, and interventional case series. All consecutive phakic eyes with primary uncomplicated macula-on RRD with intermediate retinal break(s) and marked vitreous traction, with at least 1 year of postoperative follow-up, were enrolled. In all eyes, "localized 25-gauge vitrectomy" under air infusion with localized removal of the vitreous surrounding the retinal break(s), in association with laser photocoagulation and air tamponade, was performed. The primary end point was the rate of primary retinal attachment. Secondary end points were cataract progression and assessed by digital Scheimpflug lens photography (mean change of nuclear density units) and the rate of complications.

Results

Thirty-two phakic eyes were included in the final analysis. At 12 months, the primary outcome of anatomical success was achieved in 94% of eyes. The mean nuclear density units did not change significantly at any time point during the follow-up. After localized vitrectomy, one eye developed an epiretinal membrane, and one eye developed cystoid macular edema; no other significant complications were reported.

Conclusions

"Localized vitrectomy" has a high anatomical success rate in phakic eyes with primary uncomplicated macula-on RRD with intermediate retinal break(s) and marked vitreous traction, without causing progression of cataract.

The quantitative assessment of alterations in lens transparency after transconjunctival 27-gauge microincision vitrectomy surgery

PurposeTo evaluate the baseline and post-vitrectomy lens densitometry values by a Scheimpflug camera in eyes with epiretinal membrane that were treated with 27-G microincision vitrectomy surgery (MIVS) without tamponade and to compare the results with those in fellow healthy eyes.Patients and methodsProspective case series. The lens densitometry measurements of 24 patients, who underwent 27-G MIVS without any tamponade for the treatment of epiretinal membrane, were taken preoperatively and on the first week, first month, and third month postoperatively with Pentacam HR-Scheimpflug imaging system.ResultsThe mean lens densitometry values at Zone 1 and average lens densitometry values significantly increased in the study eyes on the first month when compared with the preoperative values (P=0.011, P=0.033, respectively). Additionally, there were statistically significant differences regarding the mean lens densitometry values of Zone 1 and Zone 2, and also average lens densitometry values between the preoperative and third month postoperative values (P=0.003, P=0.021, P=0.009, respectively). However, the densitometry values of fellow eyes were similar at preoperatively and all the postoperative follow-up periods (P>0.05 for all).ConclusionsThis study suggests that 27-G MIVS might cause post-surgical lens density changes even in early postoperative months and vitreous may play an important role in protecting the transparency of the lens.

Refractive changes after lens-sparing vitrectomy for macular hole and epiretinal membrane

Purpose

Cataract progression after lens-sparing vitrectomy might differ according to original posterior segment diseases. Our objective was to analyze the refractive values after lens-sparing vitrectomy for macular hole (MH) and epiretinal membrane (ERM).

Materials and methods

We reviewed the medical records of 25 MH patients (25 eyes) and 23 ERM patients (23 eyes) who underwent lens-sparing vitrectomy. Refractive changes in both groups were compared. All patients underwent 20-gauge three-port pars plana vitrectomy. Fluid–air exchange was performed during vitrectomy only in the MH group. The results were analyzed using the unpaired t-test, chi-square test, or Fisher exact probability test, and multivariate analysis.

Results

There were no significant differences in the patient’s age (P=0.45). The myopia progression rate (D/month) was higher in the MH group after surgery than that in the ERM group (P=0.035). MH group had more females (P=0.043), longer surgical time (P<0.001), and higher frequencies of surgical adjuvants use (triamcinolone acetonide, P=0.019; brilliant blue G, P<0.001). The myopia progression rate in the MH group (R=0.568, P<0.001) correlated with female gender. However, no correlation was observed between longer surgical time and the use of surgical adjuvants.

Conclusion

The rate of myopia progression was higher in the MH group. Fluid–air exchange and gender may affect the rate of myopia progression.

Change in refraction after lens-sparing vitrectomy for rhegmatogenous retinal detachment and epiretinal membrane

The aim of this study was to compare changes in refraction following lens-sparing vitrectomy between patients with rhegmatogenous retinal detachment (RRD) and epiretinal membrane (ERM) and to investigate factors associated with the change in refraction.We reviewed medical records of 49 eyes of 49 patients with RRD (53.6 ± 7.8 years, mean ± standard deviation) and 24 eyes of 24 patients with ERM (50.9 ± 15.7 years) who underwent lens-sparing vitrectomy. Spherical equivalent refractive power was evaluated before and up to 18 months after surgery. The relationship between the change in refraction and several parameters was evaluated.A significant progressive myopic shift in refractive power was observed after vitrectomy in operated RRD and ERM eyes (P < 0.001, P = 0.016, respectively), with no significant difference in fellow eyes. The refraction values observed at ≥3 and ≥12 months following vitrectomy were significantly different as compared with those observed at baseline in the RRD group (P < 0.001) and the ERM group (P < 0.05), respectively. The change in refraction between the RRD and ERM groups was significant (P = 0.030). The multiple linear regression analysis showed that only age was significantly correlated with the change in refraction in RRD (P = 0.018) and ERM (P < 0.001) groups. The change in refraction was significantly and positively correlated with age in RRD (r = -0.461, P = 0.001) and ERM (r = -0.687, P < 0.001) groups. Following lens-sparing vitrectomy, cataract surgery was performed on 30 eyes after 0.89 ± 0.26 years in the RRD group and on 10 eyes after 1.11 ± 0.14 years in the ERM group; there was a significant difference in time to cataract surgery between the groups (P = 0.007). Kaplan-Meier survival analysis demonstrated that there was a significant difference in the rate of cataract surgeries between the RRD and ERM groups (P = 0.022).Following lens-sparing vitrectomy for RRD and ERM, a progressive myopic shift in refraction owing to nuclear sclerosis was observed. Core vitrectomy itself would cause a myopic shift of refraction. The only risk factor associated with cataract progression following lens-sparing vitrectomy is age for both types of patients.

TRANSCONJUNCTIVAL NONVITRECTOMIZING VITREOUS SURGERY VERSUS 25-GAUGE VITRECTOMY IN PATIENTS WITH EPIRETINAL MEMBRANE: A Prospective Randomized Study

PURPOSE

To compare the clinical outcomes and the rate of complications of 27-gauge transconjunctival nonvitrectomizing vitreous surgery (NVS) and of 25-gauge transconjunctival sutureless vitrectomy surgery for idiopathic epiretinal membrane removal.

METHODS

In this prospective randomized study, 83 phakic eyes of 83 consecutive patients with an idiopathic epiretinal membrane were randomized to receive 27-gauge NVS (NVS-group) or 25-gauge vitrectomy (Standard-group). Main outcome measures were best-corrected visual acuity, central retinal thickness, nuclear density units' changes, and rate of complications.

RESULTS

Thirty-nine eyes of the Standard-group and 40 of the NVS-group were considered in final analysis. Mean best-corrected visual acuity improved significantly in both groups, with a significant better result at 12 months in NVS-group (P = 0.039; t-test). Central retinal thickness decreased significantly in both groups (P < 0.001, Tukey test), without significant difference between the two groups at any time point. At 12 months, nuclear density increased significantly in the Standard-group (analysis of variance, P < 0.001), and it did not change in the NVS-group (analysis of variance, P = 0.537). Epiretinal membrane recurred in 5.1% of eyes in the Standard-group and in 7.5% of eyes in the NVS-group (Fisher's exact test, P = 1.000).

CONCLUSION

The 27-gauge NVS is an effective surgical procedure in eyes with epiretinal membrane and it induces less progression of nuclear sclerosis than 25-gauge vitrectomy.

Cataract formation following vitreoretinal procedures

Purpose

To evaluate the incidence and prevalence of cataract formation, progression, and extraction in patients that underwent vitreoretinal procedures and to evaluate factors that can potentially predispose patients to postoperative cataracts.

Materials and methods

The medical records of consecutive patients who underwent vitreoretinal surgery at the Yale Eye Center with at least 6 months of follow-up and no prior intraocular surgery were obtained. Preoperative, intraoperative, and postoperative data were recorded and analyzed in this retrospective observational study. The main outcome measures were defined as cataract extraction, formation, and progression after vitreoretinal procedures. The lens status of the surgical eye was recorded preoperatively and at 1 month, 3 months, 6 months, 12 months, 24 months, and 36 months postoperatively.

Results

A total of 193 eyes of 180 patients fulfilled the inclusion criteria. The percentages of eyes with mild lens change were 96% after 20-gauge pars plana vitrectomy (PPV), 72% after small gauge (23- and 25-gauge) PPV, 38% after scleral buckle (SB), 38% after pneumatic retinopexy (PR), and 91% after PPV plus SB (PPV+SB). Posterior subcapsular and nuclear sclerotic cataracts were the most common with almost all developing within 24 months. There was no statistically significant difference (P=1.00) between the rate of cataract extraction after 20-gauge (41%) and small gauge PPV (42%), but there was a statistically significant difference between PPV and non-PPV (SB, 6%; PR, 7%; P<0.001) and PPV and PPV+SB groups (69%; P=0.0063).

Conclusion

Cataracts were common following PPV regardless of the gauge. SB and PR led to the lowest while PPV+SB led to the highest risk of postoperative cataracts.

Small-gauge vitrectomy does not protect against nuclear sclerotic cataract

PURPOSE

To determine whether the gauge of vitrectomy instrumentation is associated with the progression of nuclear sclerotic cataract.

METHODS

A prospective interventional and observational study of patients undergoing vitrectomy surgery for various retinal conditions. Patients had Scheimpflug lens photography in the operated and fellow eye at baseline and at 6 months and 12 months after vitrectomy surgery.

RESULTS

Of 42 eyes included in the analysis, 11 had 20-gauge surgery, 22 had 23-gauge surgery, and 9 had 25-gauge surgery. In all operated eyes, vitrectomy surgery led to the significant progression of nuclear sclerotic cataract, compared with the fellow, unoperated eye. This small study was unable to detect a difference in nuclear sclerotic progression when comparing small-gauge surgery (23 and 25 gauge) with standard 20-gauge surgery.

CONCLUSION

Removal of the vitreous gel using any-gauge vitrectomy surgery leads to significant progression of nuclear sclerotic cataract at 6 months and 12 months. The findings are consistent with the hypothesis that the vitreous gel is important in protecting the lens from increased exposure to oxygen that leads to the formation of nuclear sclerotic cataract. This increased exposure to oxygen occurs as a result of removing the vitreous gel and is independent of the gauge of vitrectomy instrumentation.

Non-vitrectomizing vitreous surgery for premacular haemorrhage

PURPOSE

We report three cases illustrating an alternative treatment option for premacular haemorrhage.

METHODS

This retrospective interventional case study included three eyes in three patients with premacular haemorrhage caused by idiopathic thrombocytopenic purpura in the first case, trauma in the second case and retinal arterial macroaneurysm in the third case. All patients underwent non-vitrectomizing vitreous surgery. Visual acuity as well as slit-lamp and indirect ophthalmoscopic examinations were performed pre- and postoperatively to evaluate the resolution of premacular haemorrhage and changes in lenticular opacity.

RESULTS

At postoperative day 1, visual acuity had improved from counting fingers (CF) to 6/12 in case 1, from CF to 6/20 in case 2 and from CF to 3/60 in case 3. Examination of the fundus showed resolution of the premacular haemorrhage with mild vitreous haemorrhage in all cases. Final best corrected visual acuities were 6/6, 6/7.5 and 6/15, respectively. The lens remained clear in two of two phakic eyes at the last follow-up visit.

CONCLUSIONS

In these selected cases, non-vitrectomizing vitreous surgery was a useful and safe alternative for the treatment of premacular haemorrhage.

One-port pars plana vitrectomy (by 25-G micro-incision)

PURPOSE

A pilot study to test a novel, minimal invasive vitrectomy, through one-port pars plana sclerotomy, by 25-G instruments, for selected vitreous, macular and vitreomacular interface disorders.

METHODS

SETTING

institutional.

DESIGN

interventional, prospective case series of 14 eyes of 14 patients. The "one-port pars plana vitrectomy" (OPPPV) by 25-G micro-instruments was performed on seven pseudophakic eyes, and the "phacoemulsification OPPPV" (phaco OPPPV) by 25-G on seven presbyopic/cataract phakics. Minimal vitrectomy on eight eyes. Subtotal vitrectomy on six eyes.

FOLLOW-UP

12 months. Main outcome endpoints: surgical feasibility/suitability, patient tolerability, post-operative recovery time. Intra- and post-operative complications were recorded.

RESULTS

All OPPPVs by 25 G were completed as planned. Anatomical surgical objectives were fulfilled on all eyes; functional ones on 13 out of 14 eyes. The whole OPPPV group and four of the phaco OPPPV subset of patients tolerated comfortably less than 30' surgical time, and three phaco OPPPV ones less than 45'. Full regimen anti-inflammatory therapy for 2 weeks kept ten eyes out of 14 stable. Post-operatively, two eyes developed a transient alteration of the intraocular pressure. At the end of the follow-up, neither retinal detachment nor endophthalmitis occurred.

CONCLUSIONS

OPPPV by 25 G techniques promise to be an effective,comfortable, possible office-based alternative "micro-incisional, minimal invasive vitreous surgery" for selected vitreous, macula and vitreomacular interface disorders. Future research on the safety of the OPPPV by 25 G techniques compared to conventional ones is encouraged.

Lower intraocular oxygen tension in diabetic patients: possible contribution to decreased incidence of nuclear sclerotic cataract

PURPOSE

To report intraocular oxygen tension in eyes of diabetic and nondiabetic patients.

DESIGN

A prospective, interventional consecutive case series.

METHODS

Oxygen was measured with an optical oxygen sensor in patients who were undergoing vitrectomy. Before turning on the infusion fluid, intraocular oxygen tension was measured in two locations: adjacent to the lens and in the mid vitreous cavity.

RESULTS

Fifty eyes from 50 patients were included in the study. Twenty-one eyes were from diabetic patients and 29 eyes were from nondiabetic patients. The mean oxygen tension adjacent to the lens was significantly lower in diabetic than in nondiabetic patients (8.4 +/- 0.7 mm Hg vs 10.7 +/- 0.8 mm Hg; P < .05). Similarly, the mean oxygen tension in the center of the vitreous cavity was lower in diabetic than in nondiabetic patients (5.7 +/- 0.7 mm Hg vs 8.5 +/- 0.6 mm Hg; P < .001). In subgroup analyses, previous panretinal photocoagulation or cataract surgery did not affect oxygen levels significantly in the vitreous of diabetic or nondiabetic patients.

CONCLUSION

Eyes from diabetic patients have significantly lower intraocular oxygen tension than in eyes from nondiabetic patients. Because oxidative damage to the lens nucleus and increased intraocular oxygen tension have been associated with nuclear sclerotic cataract, these findings may help explain recent reports of an apparent protective effect of diabetes mellitus against nuclear sclerotic cataract.

Development of Microelectromechanical Systems (MEMS) forceps for intraocular surgery

AIM

To develop silicon microforceps for intraocular surgery using Microelectromechanical Systems (MEMS) technology, the application of microchip fabrication techniques for the production of controllable three dimensional devices on the micrometre scale.

METHODS

Prototype MEMS forceps were designed and manufactured for intraocular surgery. Scanning electron microscopy was used to evaluate device tip construction. Designs using both thermal expansion actuators and conventional mechanical activation were tested in human cadaver eyes and in vivo rabbit eyes to assess functionality in standard vitreoretinal surgery.

RESULTS

MEMS forceps were constructed with various tip designs ranging from 100 mum to 2 mm in length. Scanning electron microscopy confirmed accurate construction of micro features such as forceps teeth as small as tens of micrometres. In surgical testing, the silicon forceps tips were effective in surgical manoeuvres, including grasping retinal membranes and excising tissue. The mechanical actuator design on a 20 gauge handle was more operational in the intraocular environment than the thermal expansion actuator design. While handheld operation was possible, the precision of the forceps was best exploited when mounted on a three axis micromanipulator.

CONCLUSION

MEMS microforceps are feasible for conventional vitreoretinal surgery, and offer advances in terms of small scale, operating precision, and construction tolerance.

25-gauge, sutureless vitrectomy and standard 20-gauge pars plana vitrectomy in idiopathic epiretinal membrane surgery: a comparative pilot study

BACKGROUND

The aim of the study was to evaluate the safety and functional outcome of a small incision, sutureless vitrectomy in the treatment of idiopathic epiretinal membranes (ERM) compared with a standard 20-gauge vitrectomy system.

METHODS

Forty-six consecutive patients with idiopathic ERM were recruited for this study and prospectively evaluated. In group 1 (n=26) we used a transconjunctival sutureless 25-gauge vitrectomy system (TSV), patients in group 2 (n=20) were operated on using a standard 20-gauge vitrectomy system. The ERM was removed and the internal limiting membrane (ILM) was peeled in all eyes. Surgery-related complications, operating time, intraoperative balanced salt solution (BSS) consumption, postoperative discomfort, postoperative intraocular inflammation, lens opacification, and long-term visual outcome are reported and compared.

RESULTS

No surgery-related complications were observed in either group. Operating time was shorter in group 1 compared with group 2 (mean 15.6 and 29.6 min respectively). Intraoperative amount of BSS consumption was less in group 1 (mean 28 ml in group 1 and 42 ml in group 2). Postoperative discomfort and intraocular inflammation were significantly reduced in the 25-gauge group. In the 20-gauge group cataract formation requiring surgery was observed in two eyes. Visual acuity improved significantly in both groups. The 25-gauge group improved on average by more lines of vision and the improvement in vision was more rapid.

CONCLUSION

The TSV system is a safe and efficient surgical technique for ERM surgery. Operating time is significantly reduced, minimizing surgery-induced trauma, and reducing postoperative intraocular inflammation and the patients' discomfort. The incidence of cataract formation may be less using TSV. Postoperative recovery is accelerated.

Nonvitrectomizing vitreous surgery for epiretinal membrane long-term follow-up

PURPOSE

To report the long-term follow-up results of nonvitrectomizing vitreous surgery for idiopathic epiretinal membrane (ERM).

DESIGN

Nonrandomized comparative case series.

PARTICIPANTS

Thirty patients were followed up for at least 5 years after nonvitrectomizing vitreous surgery.

INTERVENTION

Epiretinal membranes were peeled without infusion of balanced salt solution and removal of the vitreous. The data from the fellow eye was the control data.

MAIN OUTCOME MEASURES

We examined the visual acuities (VAs), objective refractions, and slit-lamp and Scheimpflug photographs from the preoperative and the final examinations of both eyes. Quantitative assessment of the progression of nuclear sclerosis was performed by densitometry analysis using Scheimpflug photography. The recurrence rate of ERM was determined.

RESULTS

The follow-up periods ranged from 60 to 102 months (mean+/-standard deviation, 72.2+/-11.0 months). The patient ages ranged from 52 to 76 years (68.8+/-6.3 years). The final VA improved or stabilized within 2 lines in 29 of 30 eyes (96.7%). No unilateral progression of nuclear sclerosis occurred in any cases. The mean preoperative and postoperative refractions without additional surgery were -0.4+/-2.9 diopters (D) and -0.2+/-3.0 D in the operated eyes, respectively, and -0.2+/-2.5 D and 0.1+/-2.4 D, respectively, in the unoperated fellow eyes. The mean differences in the refractive error between both eyes (operated eye data minus fellow eye data) were -0.2+/-0.7 D before surgery and -0.3+/-0.8 D after surgery (P = 0.319, paired t test). The mean preoperative and postoperative nuclear densities in 16 patients were 69+/-14 nuclear density units (NDUs) and 76+/-12 NDUs in the operated eyes and 71+/-14 NDUs and 78+/-14 NDUs in the fellow eyes, respectively. The mean preoperative and postoperative differences in nuclear densities in both eyes were -2+/-2 NDUs and -2+/-5 NDUs, respectively (P = 0.836, paired t test). The ERM recurred in 10 eyes (33%), and 3 eyes underwent conventional vitrectomy combined with cataract surgery.

CONCLUSIONS

Unilateral nuclear sclerosis did not progress for at least 5 years after nonvitrectomizing vitreous surgery. The recurrence rate of ERM appeared to be higher than that after conventional vitreous surgery.

Visual outcomes following vitrectomy and peeling of epiretinal membrane

BACKGROUND

Visual outcomes of patients following vitrectomy and peeling of visually significant epiretinal membranes were assessed to determine the influence of specific perioperative factors and surgical complications on final visual acuity and functional vision.

METHODS

In an unmatched, consecutive surgical series, vitrectomy and membrane peeling were performed on 125 eyes of 123 patients with visually significant macular epiretinal membranes. Patients were followed for 6-36 months. Visual outcome measures included postoperative logMAR visual acuity, change in visual acuity and functional vision tasks evaluated by questionnaire. Perioperative factors including duration of symptoms, preoperative visual acuity, aetiology, membrane type and leakage on fundal fluorescein angiogram were correlated with final visual outcomes.

RESULTS

Visual acuity improved by a mean of 0.31 A+/- 0.21 units (three lines of vision). In 104 cases (83%), visual acuity improved in patients by two lines or more, with 20 cases (16%) having unchanged acuity and one case (1%) having worse acuity. Ninety-three per cent of interviewed cases reported improvement in functional vision, especially reduction of distortion. Cataract was observed in 52 cases (52% of phakic eyes) postoperatively compared with 19 cases (19%) preoperatively. Postoperative visual acuity correlated with preoperative visual acuity. Patients with worse preoperative vision recorded greater visual improvement following surgery. No other perioperative factors were found to have a prognostic value in this study.

CONCLUSION

Epiretinal membrane peeling improves vision in the majority of patients with significant symptoms, even if preoperative visual acuity is not substantially reduced. Surgery improves functional vision including metamorphopsia not measurable by visual acuity, and thus assessment of functional vision should be included in surgical case planning.

Vitrectomy surgery increases oxygen exposure to the lens: a possible mechanism for nuclear cataract formation

PURPOSE

To report vitreous oxygen tension before, immediately after, and at longer times after vitrectomy.

DESIGN

A prospective, interventional consecutive case series.

METHODS

Oxygen was measured using an optical oxygen sensor in patients undergoing vitrectomy. Intraoperatively, oxygen measurements were taken before and after vitrectomy in two intraocular locations: adjacent to the lens and in the mid-vitreous.

RESULTS

Sixty-nine eyes underwent oxygen tension measurements at the time of vitrectomy. In baseline eyes, oxygen tension in the vitreous was low, measuring 8.7 +/- 0.6 mm Hg adjacent to the lens and 7.1 +/- 0.5 mm Hg in the mid-vitreous. The difference between the two locations was statistically significant (P < .003), indicating that vitreous gel maintains an intraocular oxygen gradient. Immediately after vitrectomy, oxygen tension in the fluid-filled eye was higher, measuring 69.6 +/-4.8 mm Hg adjacent to the lens and 75.6 +/- 4.1 mm Hg in the mid-vitreous. There was no statistically significant oxygen gradient between the two locations. The difference in oxygen tension pre- and postvitrectomy is highly statistically significant (P < .0001 lens, P < .0001 mid-vitreous). In eyes with a history of vitrectomy and previous removal of the vitreous gel, the intraocular oxygen tension was significantly higher than in eyes with a formed vitreous gel undergoing a first vitrectomy (P < .02 lens, P < .003 mid-vitreous).

CONCLUSION

Vitrectomy surgery significantly increases intraocular oxygen tension during and for prolonged periods after surgery. This exposes the crystalline lens to abnormally high oxygen and may lead to nuclear cataract formation.

The role of patient age and intraocular gas use in cataract progression after vitrectomy for macular holes and epiretinal membranes

PURPOSE

To evaluate the rate of increase in nuclear sclerosis and posterior subcapsular cataracts in eyes as a function of patient age and use of intravitreal gas at the time of vitrectomy.

DESIGN

Observational case series.

METHODS

Nuclear sclerosis and posterior subcapsular cataracts were evaluated as a function of patient age and use of intravitreal gas at vitrectomy.

SETTING

A clinical practice.

STUDY POPULATION

The study population consisted of 301 consecutive eyes.

OBSERVATIONAL PROCEDURE

Nuclear sclerotic cataracts and posterior subcapsular cataracts were graded on a scale from 0 to 4.0 before and after vitrectomy.

MAIN OUTCOME MEASURE

Linear regression analysis was performed to measure and compare the rate of change in cataract score over time based on patient age and use of intraocular gas.

RESULTS

Nuclear sclerotic cataracts showed minimal increase in patients younger than 50 years of age after vitrectomy (0.13 grades/year). Nuclear sclerotic cataracts increased at a rate of 0.7 to 0.9 grades/year (mean, 0.812) in patients aged 50 to 60 years, 60 to 70 years, 70 to 80 years, and 80+ years, even though the baseline nuclear sclerosis scores were progressively greater for each decade. The increase in nuclear sclerotic cataracts in patients younger than 50 years of age was significantly less (P <.001) than in patients aged 50 years or older. Eyes with intraocular gas use had a higher rate of nuclear sclerosis progression (0.8 grades/year) compared with eyes without intraocular gas bubbles (0.5 grades/year; P <.001). Posterior subcapsular cataract scores showed minimal or no increases in all groups.

CONCLUSIONS

Patients older than 50 years of age have a similar rate of increase in nuclear sclerotic cataracts, independent of age. The rate is approximately sixfold greater than in patients younger than 50 years of age. Intravitreal gas bubbles are associated with a nuclear sclerosis increase of approximately 60% compared with eyes without use of a gas bubble.

Assessment of nuclear sclerosis after nonvitrectomizing vitreous surgery

PURPOSE

Nuclear sclerosis develops frequently after successful pars plana vitrectomy. We evaluated changes in the degree of nuclear sclerosis after nonvitrectomizing vitreous surgery for idiopathic epimacular proliferation.

METHODS

Forty-one consecutive patients (41 eyes) underwent removal of idiopathic epimacular proliferation by nonvitrectomizing vitreous surgery and were followed postoperatively for at least 12 months. Visual acuity, refractive error, slit-lamp biomicroscopy, and Scheimpflug photographs were assessed preoperatively and postoperatively to evaluate changes in the degree of lenticular opacification. Quantitative analysis of the nuclear sclerosis was performed by densitometry with Scheimpflug photographs performed on only the last 21 patients. We evaluated these measurements by comparing statistically the preoperative and postoperative difference between both eyes (operative eye minus nonoperative ocular data).

RESULTS

There was no significant difference in the progression of nuclear sclerosis or degree of myopic shift between the operated and fellow eyes during postoperative follow-up (mean +/- SD, 22 +/- 8 months; median, 22 months; range, 12 to 48 months). The average preoperative and postoperative refractive errors in operated eyes were 0.0 +/- 2.4 diopters and 0.1 +/- 2.5 diopters, respectively; the average difference in the refractive errors between both eyes was -0.2 +/- 0.7 diopter preoperatively and -0.2 +/- 0.9 diopter postoperatively (P =.961, paired t test). The average preoperative and postoperative nuclear density values by Scheimpflug photography in 21 operated eyes were, respectively, 72 +/- 18 nuclear density units and 75 +/- 17 nuclear density units; the average difference in nuclear density values between both eyes was -1 +/- 4 nuclear density units preoperatively and 0 +/- 6 nuclear density units postoperatively (P =.631, paired t test).

CONCLUSION

Progression of nuclear sclerotic cataract based on changes in refractive error and Scheimpflug photography was not observed after nonvitrectomizing vitreous surgery.

Epiretinal membrane with macular pucker

BACKGROUND: Epiretinal membranes are a common finding in people over the age of 50 years. Clinically, they usually cause minor visual distortion. However, in some patients, there may be a significant visual loss and/or metamorphopsia and surgery may be required in more severe cases. CASE HISTORY: In this report, we document the findings of a patient having an epiretinal membrane with macular pucker. The patient underwent surgery consisting of posterior vitrectomy and peeling away of the membrane. DISCUSSION: The classification and terminology commonly used to describe epiretinal membranes are reviewed. In addition, the aetiology, prevalence, symptoms, differential diagnosis, treatment and complications of epiretinal membranes are discussed.

Macular epiretinal membranes

Epiretinal membranes (ERM) are a common finding in older patients. Although they may be associated with numerous clinical conditions, most epiretinal membranes occur in the absence of ocular pathology. Patients symptoms range from asymptotic to complaints of severe vision loss and metamorphopsia. Epiretinal membranes are commonly classified according to their density, to the severity of retinal distortion and to associated biomicroscopic changes. Pars plana vitrectomy has been found to be effective in removing ERM from the macula, improving the visual acuity and decreasing metamorphopsia. Both idiopathic and secondary ERMs do well after surgery, although secondary ERMs showed a greater amount of improvement than idiopathic ones. Complications are frequent including accelerated postoperative nuclear sclerosis, retinal breaks and RD, macular edema, RPE and, occasionally, macular hole and hypotony. However only RD involving the macula have a worsening prognosis on final outcome.