Does intravitreal triamcinolone acetonide-assisted peeling of the internal limiting membrane effect the outcome of macular hole surgery?

Outcomes of 4 surgical adjuvants used for internal limiting membrane peeling in macular hole surgery: a systematic review and network Meta-analysis

AIM

To compare the outcomes of four adjuvants used for internal limiting membrane (ILM) peeling in macular hole surgery, including indocyanine green (ICG), brilliant blue G (BBG), triamcinolone (TA) and trypan blue (TB), through systematic review and random-effects Bayesian network Meta-analysis.

METHODS

PubMed, Cochrane library databases and Web of Science were searched until August 2018 for clinical trials comparing the above four adjuvants. ORs for postoperative best corrected visual acuity (BCVA) improvement and primary macular hole closure rates were compared between the different adjuvants.

RESULTS

Twenty-seven eligible articles were included. For postoperative BCVA improvement, results of BBG-assisted peeling were significantly more favorable than those of ICG (WMD 0.08, 95% credible interval 0.01-0.16) and TA ranked highest. No significant differences were found between any other two groups in postoperative BCVA improvement. For postoperative primary macular hole closure rates, BBG ranked highest. However, no significant differences were shown between any two groups.

CONCLUSION

TA and BBG are the optimum adjuvants for achieving postoperative BCVA improvement macular hole surgery with adjuvant-assisted ILM peeling. Among all adjuvants, the use of BBG is associated with the highest postoperative macular hole closure rate.

Internal limiting membrane peeling with different dyes in the surgery of idiopathic macular hole: a systematic review of literature and network Meta-analysis

AIM

To evaluate the effect of internal limiting membrane (ILM) peeling with indocyanine green (ICG), brilliant blue G (BBG), triamcinolone acetonide (TA), trypan blue (TB), or without dye for the treatment of idiopathic macular hole (IMH).

METHODS

A search was conducted using PubMed, EMBASE, and CENTRAL (Cochrane Central Register of Controlled Trials) for related studies published before October 2018.

RESULTS

A total of 29 studies and 2514 eyes were included in this network Meta-analysis. For IMH closure, the rank from the best to the worse treatment was: BBG, TB, TA, ICG, and no dye. There was a significant difference in postoperative IMH closure rate between BBG and no dye. The rank of the best to the worse treatment to improve visual acuity was: BBG, TB, no dye, TA, and ICG. The improvement rate of visual acuity after using BBG was significantly higher than ICG. The improvement rate of visual acuity was more favorable with TB than ICG, TA, and no dye.

CONCLUSION

BBG can contribute to better anatomical and functional outcomes compared to other dyes for ILM peeling in patients with IMH. The results show that the best treatment of ILM peeling with dyes is BBG.

DOUBLE ARCUATE RELAXING RETINOTOMY FOR A LARGE MACULAR HOLE

PURPOSE

To describe double arcuate relaxing retinotomy as an alternative surgical technique in a case with a secondary large macular hole.

METHODS

The management of a patient who developed a large macular hole and macular tractional rhegmatogenous retinal detachment after pars plana vitrectomy for proliferative diabetic retinopathy was retrospectively assessed. Despite surgical procedures, such as dissection of a preretinal membrane from the retina and peeling of the retinal internal limiting membrane, the macular hole could not be closed. In the absence of an alternative method, superior and inferior posterior arcuate, 120° relaxing retinotomies were performed.

RESULTS

At the follow-up, the macular hole closure was confirmed by clinical examination and optical coherence tomography imaging, and visual acuity improved. There were no intraoperative or postoperative complications.

CONCLUSION

In cases of large macular holes, double arcuate relaxing retinotomy can reduce traction, leading to hole closure.

Complications of Macular Peeling

Macular peeling refers to the surgical technique for the removal of preretinal tissue or the internal limiting membrane (ILM) in the macula for several retinal disorders, ranging from epiretinal membranes (primary or secondary to diabetic retinopathy, retinal detachment…) to full-thickness macular holes, macular edema, foveal retinoschisis, and others. The technique has evolved in the last two decades, and the different instrumentations and adjuncts have progressively advanced turning into a safer, easier, and more useful tool for the vitreoretinal surgeon. Here, we describe the main milestones of macular peeling, drawing attention to its associated complications.

Indocyanine green-assisted internal limiting membrane peeling in macular hole surgery: a meta-analysis

Background

The opinion of application of indocyanine green (ICG) in the macular hole surgery was contradictory. Here we conducted a meta-analysis to evaluate the effect of in internal limiting membrane (ILM) peeling for macular hole surgery.

Methods and Findings

We searched electronic databases for comparative studies published before July 2012 of ILM peeling with and without ICG. Twenty-two studies including 1585 eyes were included. Visual acuity (VA) improvement, including the postoperative rate of ≥20/40 VA gained (OR, 0.65; 95% CI, 0.43 to 0.97; P = 0.033) and increased LogMAR (WMD, −0.09; 95% CI, −0.16 to −0.02; P = 0.011), was less in the ICG group. The risk of visual field defects was greater in the ICG group than in the non-ICG group. There was no significant difference in the rate of anatomical outcomes between ILM peeling procedures performed with and without ICG. RPE changes and other postoperative complications were not significantly different between the ICG and non-ICG groups. An additional analysis showed that the VA improvement of the ICG group was less than the non-ICG group only within the first year of follow up. A subgroup analysis showed that the rate of VA improvement was lower in the ICG group than in other adjuncts group. A higher rate of secondary closure and less VA improvement were observed in a high proportion (>0.1%) of the ICG group. A sensitivity analysis after the randomized-controlled trials were excluded from the meta-analysis demonstrated no differences compared with the overall results.

Conclusions

This meta-analysis demonstrated that there is no evidence of clinical superiority in outcomes for ICG-assisted ILM peeling procedure over the non-ICG one. The toxicity of ICG should be considered when choosing the various staining methods.

Deposition of triamcinolone acetonide and its effect on soft tissue topography

Bimodal imaging is utilized to characterize the topography of human tissue samples. The deposition of triamcinolone acetonide (TA) on various surfaces - including surgical human inner limiting membrane (ILM) samples and collagen fibrillar sheets - was studied. Changes in composition were well defined with bimodal imaging when TA deposition was examined on mica. TA sedimentation resulted in observable changes in ILM topography when compared to collagen fibrillar sheets. The heterogeneous chemical and topographical features of the ILM tissues promoted the TA crystallization compared to the flatter and homogeneous collagen surfaces. Higher spatial resolution was achieved by imaging ILM samples in the new bimodal imaging mode. The most apparent difference was observed in the imaging of ILM samples which had been exposed to the steroid TA. The study demonstrated the usefulness of bimodal imaging to evaluate tissue samples.

Unanticipated vision loss after pars plana vitrectomy

Although advances in vitreoretinal surgical techniques and technology have helped to minimize the risks associated with surgical manipulation of the retina, retinal pigment epithelium, and optic nerve, unanticipated or unexplained visual loss still occurs. We review causes of vision loss encountered after pars plana vitrectomy, including retinal toxicities, vascular events, and optic neuropathies, and we suggest strategies to limit or prevent them.

Outcomes of 23-gauge pars plana vitrectomy and internal limiting membrane peeling with brilliant blue in macular hole

Purpose:

The evaluation of anatomic and visual outcomes in macular hole cases treated with internal limiting membrane (ILM) peeling, brilliant blue (BB), and 23-gauge pars plana vitrectomy (PPV).

Materials and methods:

Fifty eyes of 48 patients who presented between July 2007 and December 2009 with the diagnosis of stage 2, 3, or 4 macular holes according to Gass Classification who had undergone PPV and ILM peeling were included in this study. Pre- and postoperative macular examinations were assessed with spectral-domain optical coherence tomography. 23 G sutureless PPV and ILM peeling with BB was performed on all patients.

Results:

The mean age of patients was 63.34 ± 9.6 years. Stage 2 macular hole was determined in 17 eyes (34%), stage 3 in 24 eyes (48%), and stage 4 in 9 eyes (18%). The mean follow-up time was 13.6 ± 1.09 months. Anatomic closure was detected in 46/50 eyes (92%), whereas, in four cases, macular hole persisted and a second operation was not required due to subretinal fluid drainage. At follow-up after 2 months, persistant macular hole was detected in one case and it was closed with reoperation. At 12 months, an increase in visual acuity in 41 eyes was observed, while it remained at the same level in six eyes. In three eyes visual acuity decreased. There was a postoperative statistically significant increase in visual acuity in stage 2 and 3 cases (P < 0.05), however, no increase in visual acuity in stage 4 cases was observed.

Conclusion:

PPV and ILM peeling in stage 2, 3, and 4 macular hole cases provide successful anatomic outcomes, however, in delayed cases, due to photoreceptor loss, it has no effect on functional recovery. BB, used for clarity of ILM, may be beneficial due to its low retinal toxicity.

Use of triamcinolone during vitrectomy surgery to visualize membranes and vitreous

Triamcinolone is a corticosteroid that is used to treat many ophthalmic diseases. Recently, its use has been advocated to aid in visualization of transparent tissue in ophthalmic surgery. It can be used in anterior segment surgery to help manage vitreous loss during complicated cataract surgery. It has been used to visualize the posterior cortical vitreous during pars plana vitrectomy. In addition, it can be useful in the visualization and peeling of the internal limiting membrane. Triamcinolone has been advocated in surgical repair of proliferative vitreoretinopathy both for its visualizing properties and its anti-inflammatory properties. Overall, triamcinolone use in surgery is safe with low incidence of complications including elevated intraocular pressure, cataract and endophthalmitis.

In vivo safety of trypan blue use in vitreoretinal surgery

PURPOSE

The purpose of this study was to evaluate "in vivo" safety of trypan blue (TB) in patients undergoing TB-assisted internal limiting membrane or epiretinal membrane peeling.

METHODS

Prospective study including 21 patients (21 eyes) with full-thickness macular hole and/or epiretinal membrane undergoing TB-assisted internal limiting membrane/epiretinal membrane peeling. Main outcome measures included distance visual acuity, near visual acuity, amplitude of P50 and N95 of the pattern electroretinogram, and fundus autofluorescence; these were assessed preoperatively, at 6 months (n = 21) and 12 months (n = 10) postoperatively.

RESULTS

There was a statistically significant improvement in distance visual acuity, near visual acuity, P50, and N95 amplitude at 6 months and 12 months postoperatively. The mean logarithm of the minimum angle of resolution distance visual acuity and near visual acuity improved from baseline by 0.31 (SD 0.37) and 0.17 (SD 0.31) at 6 months, respectively, and by 0.4 (SD 0.25) and 0.35 (SD 0.28) at 12 months, respectively. The mean P50 and N95 component amplitudes improved by 28% compared with baseline at 6 months (P50 0.4 [SD 0.8]; N95 0.53 [SD 1.07]) and by 63% at 12 months (P50 0.9 [0.85]; N95 1.04 [1.34]). Autofluorescence did not demonstrate damage to the retinal pigment epithelium attributable to TB.

CONCLUSION

No deleterious effects of TB were observed in this study.

Retinal sensitivity and fixation changes 1 year after triamcinolone acetonide assisted internal limiting membrane peeling for macular hole surgery--a MP-1 microperimetric study

PURPOSE

To evaluate microperimetric changes 1year after macular hole surgery with triamcinolone acetonide assisted internal limiting membrane (ILM) peeling.

METHODS

Twenty-two eyes of 22 patients with stage 3 and 4 idiopathic macular holes of <6months' duration underwent vitrectomy with triamcinolone acetonide assisted ILM peeling. Best corrected visual acuity (BCVA) (logarithm of the minimum angle of resolution), and central retinal sensitivity were documented before and 1, 3, 6, and 12months after surgery. Macular sensitivity (mean sensitivity in decibels -dB), and stability and location of fixation (preferred retinal locus) were determined using MP-1 microperimetry (Nidek). The MP-1 microperimetry sensitivity map was overlaid onto infrared images recorded on a Heidelberg scanning laser ophthalmoscope using dedicated MP-1 software to evaluate the fixation location before surgery. Anatomical success was evaluated with optical coherence tomography (OCT). Optical coherence tomography scans were recorded on an OCT 3000 scanner.

RESULTS

Anatomical success was achieved in all 22 eyes. All patients completed 1year follow-up. No recurrence of macular hole was seen in any patients in the follow-up period. The mean BCVA improved from 0.75±0.2 before surgery to 0.31±0.1 logMAR at the last visit (p<0.001). Mean sensitivity improved from 3.7±0.6 to 5.3±1.0dB at the last visit (p<0.001). Before surgery, the preferred retinal locus was located on the margin of the hole in all, in 18 eyes on its upper part and in four eyes to the side or on its lower part. Preoperatively, 12 eyes were stable and 10 were relatively unstable, but 12month after surgery, fixation stability had improved, and 20 eyes were stable and two were relatively unstable.

CONCLUSIONS

  MP-1 microperimetry sensitivity map overlaid onto an infrared image using dedicated MP-1 software can be used successfully to evaluate fixation location in patients with a macular hole before surgery. With microperimetry findings, we can also measure functional macular changes more precisely than using BCVA alone after macular hole surgery. Our results also showed that retinal sensitivity and fixation properties were improved after vitrectomy with triamcinolone acetonide assisted ILM peeling in patients with idiopathic macular hole.

Value of internal limiting membrane peeling in surgery for idiopathic macular hole and the correlation between function and retinal morphology

Idiopathic macular hole is characterized by a full thickness anatomic defect in the foveal retina leading to loss of central vision, metamorphopsia and a central scotoma. Classic macular hole surgery consists of vitrectomy, posterior vitreous cortex separation and intraocular gas tamponade, but during the past decade focus has especially been on internal limiting membrane (ILM) peeling as adjuvant therapy for increasing closure rates. With increasing use of ILM peeling and indocyanine green (ICG) staining, which is used for specific visualization of the ILM, concerns about the safety of the procedure have arisen. At present, it is not known whether ICG-assisted ILM peeling potentially reduces the functional outcome after macular hole surgery. The purpose of the present PhD thesis was to examine whether ICG-assisted ILM peeling offers surgical and functional benefit in macular hole surgery. We conducted a randomized clinical trial including 78 pseudophakic patients with idiopathic macular hole stages 2 and 3. Patients were randomly assigned to macular hole surgery consisting of (i) vitrectomy alone without instrumental retinal surface contact (non-peeling), (ii) vitrectomy plus 0.05% isotonic ICG-assisted ILM peeling or (iii) vitrectomy plus 0.15% trypan blue (TB)-assisted ILM peeling. Morphologic and functional outcomes were assessed 3, 6 and 12 months after surgery. The results show that surgery with ILM peeling, for both stages 2 and 3 macular holes, is associated with a significantly higher closure rate than surgery without ILM peeling (95% versus 45%). The overall functional results confirm that surgery for macular hole generally leads to favourable visual results, with two-thirds of eyes regaining reading vision (>or=20/40). Macular hole surgery can be considered a safe procedure with a low incidence of sight-threatening adverse events; the retinal detachment rate was 2.2%. Visual outcomes in eyes with primary hole closure were not significantly different between the intervention groups; however, for the stage 2 subgroup with primary macular hole closure, there was a trend towards a better mean visual acuity in the non-peeling group (78.2 letters) compared to the ICG-peeling group (70.9 letters), p = 0.06. Performing repeated macular hole surgery was associated with a significant reduction in functional outcome indicating that primary focus should be on closing the macular hole in one procedure. Morphological studies of closed macular holes with contrast-enhanced optical coherence tomography (OCT) found thinning and discontinuity of the central photoreceptor layer matrix that were highly specific for predicting the likelihood of an eye having regained reading vision 12 months after macular hole surgery. Additionally, healing after macular hole surgery appeared to begin with the contraction of the inner aspect of the retina, forming a roof over a subfoveal fluid-filled cavity, and to end with a gradual restoration of the anatomy in the outer layers of the retina at the junction of the photoreceptor inner and outer segments. We found the more intact this structure was on contrast-enhanced OCT 3 months after macular hole surgery, the better the visual acuity after 12 months, whereas late rather than early resolution of subfoveal fluid had no impact on final visual outcome. The use ILM peeling and intraoperative dyes did not have any functionally important effects on postoperative macular structure. Based on the above findings, we conclude that ILM peeling should be performed in all cases of full thickness macular hole surgery. The use of 0.05% intraoperative isotonic ICG with short exposure time appears to be a safe alternative in stage 3 macular hole surgery, whereas a slight reduction in functional potential not can be excluded when performing 0.05% isotonic ICG-assisted ILM peeling in stage 2 macular hole surgery.

Clinical evaluation of the safety and efficacy of preservative-free triamcinolone (triesence [triamcinolone acetonide injectable suspension] 40 mg/ml) for visualization during pars plana vitrectomy

PURPOSE

To evaluate the safety and efficacy of preservative-free triamcinolone (TRIESENCE(R) suspension) for visualization during pars plana vitrectomy.

METHODS

This phase III, observer-masked study was conducted in 6 centers by 10 surgeons and enrolled 60 patients undergoing pars plana vitrectomy. Preservative-free triamcinolone (up to 4 mg) was administered to all patients to enhance visualization of vitreous and membranes. During each surgery, video recordings captured visualization pre- and postinstillation of preservative-free triamcinolone. An independent, masked reader evaluated the videos for the degree of visualization using a five-point scale ranging from 0 (not visible) to 4 (clearly delineated). Surgeons used a five-point scale ranging from "strongly disagree" to "strongly agree" to assess whether preservative-free triamcinolone improved visualization.

RESULTS

In 59 of 60 cases, the masked reader's scores for visualization of posterior segment structures were higher (i.e., structures were more clearly visible) after instillation of preservative-free triamcinolone. The preinstillation mean visualization score was 0.5 compared to 3.7 postinstillation (P < 0.0001). Greater than 90% of surgeon evaluations agreed or strongly agreed that preservative-free triamcinolone enhanced visualization of posterior segment structures. No safety issues were identified.

CONCLUSIONS

Preservative-free triamcinolone (TRIESENCE(R) suspension) was well tolerated and effectively enhanced visualization of posterior segment structures during pars plana vitrectomy.

Combined pars plana lensectomy/vitrectomy for idiopathic macular hole repair without postoperative prone positioning

Purpose

The aim of this study is to determine the anatomic and visual outcomes following combined pars plana lensectomy/vitrectomy (CPPLV) as a primary procedure for idiopathic macular hole (MH) without post-operative prone positioning (PPP).

Materials and Methods

A retrospective chart review of 42 patients (47 eyes) with MH who underwent CPPLV was performed. No PPP was performed; however, patients were instructed to avoid the supine position during the first postoperative week. The main outcome measures included MH closure rate, best corrected post-operative Snellen visual acuity (BCVA), and procedure complications.

Results

Anatomical closure was achieved in 44 eyes (93.6%). The average BCVA in these eyes improved from 20/203 at baseline to 20/91 post-operatively, with 28 (63.6%) having 20/40 or better. Twenty-eight (59.6%) of the 47 eyes had a BCVA of 20/40 or better post-operatively and 35 (74.5%) eyes improved by at least 2 Snellen lines. Post-operative retinal detachment (RD) was observed in 4 eyes (8.5%) and late reopening of the hole in 4 (9.1%).

Discussion

The anatomical and visual outcomes and the RD rate of CPPLV with sulcus intraocular lens implantation without PPP are comparable to those of traditional MH surgery techniques. The main advantages include sparing the patient the inconvenience of PPP and eliminating the need for additional post-vitrectomy cataract extraction procedure.

Macular hole surgery with triamcinolone acetonide-assisted internal limiting membrane peeling: one-year results

PURPOSE

To report the 1-year results of macular hole surgery with triamcinolone acetonide (TA)-assisted internal limiting membrane (ILM) peeling and to compare those with results of indocyanine green (ICG)-assisted ILM peeling.

METHODS

In a nonrandomized, retrospective, interventional case series, 40 eyes of 39 consecutive patients with idiopathic full-thickness macular holes underwent macular hole surgery with TA-assisted ILM peeling. Surgical results 1 year after surgery, including changes in best-corrected visual acuity (BCVA) and macular hole closure, were evaluated. Moreover, we compared the results for these 40 eyes (TA group) with those for 27 eyes of 27 consecutive patients who had undergone macular hole surgery with 0.25% ICG-assisted ILM peeling (ICG group).

RESULTS

In the TA group, macular holes were closed in 39 (98%) of 40 eyes. Mean BCVA +/- SD significantly improved from 0.78 +/- 0.31 logarithm of the minimal angle of resolution (logMAR) preoperatively to 0.20 +/- 0.30 logMAR (P < 0.001). BCVA improved by > or =0.2 logMAR in 37 eyes (93%). BCVA was 20/40 or better in 33 (83%) of 30 eyes. In the ICG group, macular holes were closed in all 27 eyes (100%), and mean BCVA +/- SD significantly improved from 0.81 +/- 0.4 logMAR preoperatively to 0.34 +/- 0.2 logMAR 1 year postoperatively (P < 0.001). BCVA improved by > or =0.2 logMAR in 22 eyes (81%). BCVA was 20/40 or better in 16 (59%) of 27 eyes. Significant differences between groups were seen in mean BCVA 1 year after surgery (P = 0.049) but not in BCVA of 20/40 or better (P = 0.17) or change in BCVA by > or =0.2 logMAR (P = 0.05).

CONCLUSION

TA is useful as an adjuvant for ILM peeling in macular hole surgery, and BCVA 1 year after surgery might be more favorable when compared with ICG-assisted ILM peeling.

Improvement of visual acuity one-year after vitreous surgery in eyes with residual triamcinolone acetonide at the macular hole

PURPOSE

To investigate whether triamcinolone acetonide in the macular hole after surgery interferes with anatomic macular hole repair or visual acuity improvement.

DESIGN

Prospective, interventional case series with historical comparison.

METHODS

Pars plana vitrectomy and triamcinolone acetonide-assisted internal limiting membrane peeling were performed in 26 eyes (24 patients) with stage 3 or 4 idiopathic macular hole. The visual acuities one-year after surgery were compared between eyes with and without residual triamcinolone acetonide after surgery.

RESULTS

The macular holes were closed successfully in all 26 eyes. Nine eyes (35%) had residual triamcinolone acetonide in the macular hole at the end of the surgery and in the fovea on day 3 after surgery. The mean preoperative logarithm of the minimum angle of resolution (logMAR) visual acuity +/- standard deviation was 0.73 +/- 0.36 and improved significantly to 0.20 +/- 0.29 one-year after surgery (P = .010). In the nine eyes with residual triamcinolone acetonide, the preoperative mean logMAR triamcinolone acetonide was 0.81 +/- 0.33, which improved to 0.20 +/- 0.19 one-year after surgery (P = .013). In the remaining 17 eyes, the mean visual acuity also improved from 0.71 +/- 0.38 before surgery to 0.21 +/- 0.28 after surgery (P = .001). No significant difference was found between the groups in preoperative and postoperative logMAR visual acuities.

CONCLUSIONS

Residual triamcinolone acetonide in the macular hole does not interfere with anatomic or visual improvement.

PREVENTING THE DEPOSITION OF TRIAMCINOLONE IN MACULAR HOLE BY USE OF WHOLE BLOOD IN TRIAMCINOLONE-ASSISTED MEMBRANE PEELING

PURPOSE

To prevent triamcinolone acetonide (TA) deposition in the macular hole by use of whole blood during TA-assisted internal limiting membrane (ILM) peeling.

METHODS

The prospective, interventional case series study included 18 consecutive idiopathic macular holes (18 patients) that underwent TA-assisted internal limiting membrane (ILM) peeling for macular hole treatment. After core vitrectomy, autologous whole blood was applied to cover the macular hole. Pre-prepared TA solution was gently injected onto the macular area. Residual TA particles were removed after ILM peeling. Closure rate of macular hole, preoperative and postoperative median visual acuity, and retinal changes were evaluated.

RESULTS

Autologous whole blood prevented the deposition of TA particles in the macular hole. The ILM could be recognized after TA-assisted visualization for removal. Average follow-up time was 8.6 months. The hole was closed with one surgery in 17 eyes (94%); visual acuity improved in 15 eyes (83%). Preoperative median best-corrected visual acuity was 20/100 (range = 20/400-20/50). Postoperative median best-corrected visual acuity was 20/40 (range = counting fingers-20/20).

CONCLUSIONS

Whole blood can prevent TA particle deposition in the macular hole. Potential toxicity of TA on retinal pigment epithelium and retina also may be reduced.

Dilute triamcinolone-assisted peeling of the internal limiting membrane in cases of diffuse diabetic macular oedema

PURPOSE

In this study we evaluated the efficiency of diluted triamcinolone particles in peeling of the internal limiting membrane (ILM) in cases of diffuse diabetic macular oedema.

METHODS

A prospective observational study of thirteen consecutive patients with diffuse diabetic macular oedema who had undergone ILM peeling aided by use of a diluted (1 mg mL(-1)) suspension of triamcinolone particles (0.05 mg). The results were assessed by measurement of visual acuity and intraocular pressure, by ophthalmoscopy, and by fluorescein angiography.

RESULTS

ILM peeling in all eyes could be performed easily and completely with the aid of triamcinolone particles homogeneously dispersed over the macular ILM. During the peeling procedure, triamcinolone particles resulted in clear contrast between the peeled and unpeeled ILM thus enabling us to easily find the edge of the ILM and to be able to continue peeling at further attempts. In twelve of the thirteen eyes the macular oedema was completely resolved or reduced. Visual acuity improved by at least two lines in nine eyes (70%). The intraocular pressure increase did not exceed 21 mmHg in any of the patients.

CONCLUSIONS

The diluted triamcinolone suspension enables good visualisation of the ILM during the ILM peeling procedure in cases of diffuse diabetic macular oedema. Use of a diluted suspension may reduce the risk of intraocular pressure increase and the potential toxicity of triamcinolone.

Intravitreal triamcinolone acetonide: a change in a paradigm

BACKGROUND

Based on experimental studies and clinical observations by Robert Machemer, Gholam Peyman and others, the vitreous cavity has increasingly been used as a reservoir of drugs for the direct treatment of intraocular diseases.

METHODS AND RESULTS

The most widely injected drug so far has been triamcinolone acetonide for various intraocular neovascular and edematous diseases. Comparing the various diseases with respect to effect and side effects of the treatment, the best response in terms of gain in visual acuity has been achieved for intraretinal edematous diseases such as diffuse diabetic macular edema, branch retinal vein occlusion, central retinal vein occlusion, and pseudophakic cystoid macular edema. In eyes with various types of noninfectious uveitis including acute or chronic sympathetic ophthalmia and Adamantiadis-Behçet's disease, visual acuity increased and the degree of intraocular inflammation decreased. Some studies have suggested that intra- vitreal triamcinolone may be useful as an angiostatic agent in eyes with iris neovascularization and proliferative ischemic retinopathies. Intravitreal triamcinolone may possibly be helpful as adjunct therapy for exudative age-related macular degeneration, particularly in combination with photodynamic therapy. In eyes with chronic, therapy-resistant ocular hypotony, intravitreal triamcinolone can induce an increase in intraocular pressure and may stabilize the eye. The complications of intravitreal triamcinolone therapy include secondary ocular hypertension in about 40% of the eyes injected; medically uncontrollable high intraocular pressure leading to antiglaucomatous surgery in about 1-2% of the eyes; posterior subcapsular cataract and nuclear cataract leading to cataract surgery in about 15-20% in elderly patients within 1 year after injection; postoperative infectious endophthalmitis with a rate of about 1:1,000; noninfectious endophthalmitis, perhaps due to a reaction to the solvent agent, and pseudoendophthalmitis with triamcinolone acetonide crystals appearing in the anterior chamber. Intravitreal triamcinolone injection can be combined with other types of intraocular surgery including cataract surgery, particularly in eyes with iris neovascularization. Cataract surgery performed some months after the injection does not show a markedly elevated complication rate. The injection may be repeated, if vision redecreases. In nonvitrectomized eyes, the duration of the effect and side effects of a single intravitreal injection of triamcinolone is about 6-9 months for a dosage of about 20 mg, and about 2-4 months for a dosage of 4 mg. It has remained unclear so far, whether and how to remove the solvent agent. In the future, intravitreal triamcinolone may be combined with other antiangiogenic drugs for the treatment of exudative age-related macular degeneration or with neuroprotective drugs for treatment of diabetic retinopathy.

CONCLUSIONS

Despite an exponentially increasing number of mostly case-series studies, the intravitreal injection of triamcinolone may still be considered an experimental procedure until randomized studies have been presented.