Translocation of the retina for management of subfoveal choroidal neovascularization I: experimental studies in the rabbit eye

Long-term results after limited macular translocation surgery for wet age-related macular degeneration

Purpose

To evaluate the long-term results of limited macular translocation (LMT) surgery with radial chorioscleral outfolding in patients with wet age-related macular degeneration (AMD) and subfoveal choroidal neovascularization (CNV). In addition, to identify the factors associated with the final best-corrected visual acuity (BCVA).

Methods

The medical records of 20 eyes of 20 consecutive patients (65.2±9.8 years) who had undergone LMT for the treatment of wet AMD and were followed for at least 5 years, were reviewed. The surgical outcomes including the BCVA, degree of foveal displacement, and complications were recorded.

Results

The mean foveal displacement was 1332 ± 393 μm after the LMT. The CNV was removed in 16 eyes and photocoagulated in 4 eyes. The mean preoperative VA was 0.83 ± 0.33 logMAR units which significantly improved to 0.59 ± 0.37 logMAR units at 1 year after the surgery (P = 0.015). This BCVA was maintained at 0.59 ± 0.41 logMAR units on the final examination. The final BCVA was significantly correlated with that at 1 year after the surgery (r = 0.83, P<0.001). Multiple linear regression analysis showed that the final BCVA was significantly correlated with the BCVA at 1 year after the surgery (P<0.001), a recurrence of a CNV (P = 0.001), and the age (P = 0.022).

Conclusions

LMT improves the BCVA significantly at 1 year, and the improved BCVA lasted for at least 5 years. These results indicate that the impaired function of the sensory retina at the fovea can recover on the new RPE after the displacement for at least 5 years. The ability to maintain good retinal function on the new RPE for a long period is important for future treatments of CNVs such as the transplantation of RPE cells and stem cells.

Diplopia and strabismus following ocular surgeries

Postoperative diplopia and strabismus may result from a variety of ocular surgical procedures. Common underlying mechanisms include sensory disturbance, scarring, direct extraocular muscle injury, myotoxicity from injections of local anesthesia or antibiotics, and malpositioning of extraocular muscles by implant materials. The most common patterns are vertical and horizontal motility disturbance. Treatment options include prisms, botulinum, occlusion, or surgery.

Macular translocation for neovascular age-related macular degeneration

BACKGROUND

Macular translocation has been proposed by vitreoretinal surgeons to displace the neuroretinal tissue onto healthy retinal pigment epithelium and choroid when the macula has been invaded by subretinal neovascularisation.

OBJECTIVES

This review aims at assessing the effectiveness of macular translocation for preserving or improving vision in patients with neovascular age-related macular degeneration (AMD).

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE and Caribbean Literature on Health Sciences (LILACS). There were no language or date restrictions in the search for trials.The electronic databases were last searched on 21 July 2008.

SELECTION CRITERIA

We included randomised or quasi randomised controlled trials comparing macular translocation with any other treatment or observation.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted the data. The risk ratio (RR) of visual loss and visual gain was estimated at one year after treatment.

MAIN RESULTS

Only one small unblinded study on 50 people compared full macular translocation with photodynamic therapy (PDT) in AMD patients with predominantly classic subfoveal choroidal neovascularisation (CNV). At the last examination, performed in most of the cases after one year, there was no difference in the rate of visual loss of 3 or more lines (translocation versus PDT: RR 0.56, 95% confidence interval (CI) 0.22 to 1.43), as well as in the mean change of contrast sensitivity (1 letter favouring translocation; 95% CI -3.51 to 5.51) and the rate of recurrence of CNV (translocation versus PDT: RR 1.56, 95% CI 0.83 to 2.91). Other outcomes significantly favoured translocation, such as the gain of 3 or more ETDRS lines (RR 21, 95% CI 1.30 to 340.02), the mean change of visual acuity (mean difference (MD) 14.60, 95% CI 5.39 to 23.81) and the mean change of near visual acuity score (MD 17.80, 95% CI 3.98 to 31.62) which is obtained with an algorithm. Serious complications reported after macular translocation were retinal detachment in 6/25 patients and diplopia requiring prismatic correction in 5/25 patients.

AUTHORS' CONCLUSIONS

There is insufficient evidence from randomised controlled trials on the effectiveness of macular translocation, which is also not free of important risks. Furthermore, this technique is difficult to perform and a long surgical training is required. Future studies might include patients with small neovascular lesions that failed to respond to current pharmacological therapies and are willing to accept the risks associated with surgery to try to improve visual acuity.

Étude rétrospective comparant la translocation maculaire limitée et la photothérapie dynamique dans la néovascularisation choroïdienne rétrofovéale de la myopie forte

PURPOSE

To analyze the results of limited macular translocation (MT) and photodynamic therapy (PDT) in subfoveal choroidal neovascularization due to degenerative myopia, with a minimum follow-up of 12 months.

METHODS

Retrospective review of 55 consecutive patients: 31 eyes were treated using PDT and 24 were operated on with the limited macular translocation technique with chorioscleral infolding described by de Juan. Before and after each treatment, a complete examination comprised visual acuity, fundus examination, fluorescein angiography, and optical coherence tomography. Mean follow-up was 14 months in the PDT group and 19 months in the MT group.

RESULTS

The improvement in visual acuity was better in the MT group than in the PDT group and was correlated with younger age (p<0.001). At month 12, visual acuity improved by 3 ETDRS lines or more in 6 six eyes of the PDT group (19%), with no improvement over 6 lines. In the MT group, visual acuity improved by 3 lines in 14 eyes (58%) including 8 eight eyes (33%) with an improvement of 6 lines or more. Final visual acuity remain unchanged (+/-2 lines) in 16 eyes of the PDT group (66%) and 8 eight eyes of the MT group (33%), and decreased in 9 nine eyes in the PDT group (29%) versus 2 two eyes in the MT group (8%). Mean gain in visual acuity at 12 months was +3.5 ETDRS lines in the MT group and -0.1 line in the PDT group (p=0.001). The mean displacement of the fovea after translocation was 950 microm. The mMean number of PDT treatments was 2.3 during the 12-month follow-up.

CONCLUSIONS

Limited macular translocation allowed provided a significant improvement in visual acuity in some eyes with subfoveal neovascularization in myopia, especially in young patients, and resulted in a moderate rate of complications. Longer follow-up and further controlled and randomized studies are required to confirm these encouraging findings.

Two-year results of macular translocation with scleral infolding in myopic choroidal neovascularisation

PURPOSE

To assess the two year outcome following macular translocation (MT) with scleral infolding in the management of myopic subfoveal choroidal neovascularisation (CNV).

DESIGN

Prospective, clinical interventional noncomparative consecutive case series.

PARTICIPANTS

79 eyes of 79 patients with myopic subfoveal CNV and less than 6 months of duration of the symptoms.

INTERVENTION

MT with scleral infolding.

MAIN OUTCOME MEASURES

Visual Acuity (VA), reading ability of 12 point Arial letter sentences at a reading distance without magnifying systems and foveal displacement.

RESULTS

Mean preoperative VA was 20/125, after two years the mean VA was 20/80. Reading ability of 12 point Arial letter sentences at a reading distance (33 cm) was obtained in 59% of the eyes at one year, descending to 43% at two years. Mean foveal displacement after surgery was 942 microns. Intraoperative complications have been: retinal breaks (21.5%) and choroidal haemorrhage not affecting the posterior pole (3.7%). Main postoperative complications have been: Insufficient foveal displacement: 20%; Retinal detachment: 8.8%; Subfoveal recurrence: 28%; macular fold: 2.5% and macular hole: 1.2%.

CONCLUSION

MT with scleral infolding offers the opportunity to recover central vision and reading ability in patients with myopic CNV but it remains unpredictable.

Macular translocation with chorioscleral outfolding: 2-year results

PURPOSE

To evaluate the results of macular translocation with radial chorioscleral outfolding in patients with subfoveal choroidal neovascularization (CNV) and to identify factors associated with decreased postoperative visual acuity.

DESIGN

Retrospective interventional case series.

METHODS

Twenty-seven consecutive patients with surgically treated subfoveal CNV were operated on and followed for more than 2 years. Macular translocation with radial chorioscleral outfolding was performed using titanium clips. Surgical outcomes including visual acuity, foveal displacement, surgically induced astigmatism, and complications were recorded. Factors associated with decreased visual acuity postoperatively were identified by multiple logistic regression analysis.

RESULTS

Foveal displacement ranged from 349 to 3391 (median, 1576) microm. Surgically induced astigmatism ranged from 0 to 3.0 (median, 0.5) diopters. Visual acuity after surgery improved in 19 of the 27 patients (70.4%; median, 5 lines), but in 14, final vision ultimately decreased from the best postoperative level. Final visual acuity improved from the preoperative level in 11 patients (40.7%), remained unchanged in seven (25.9%), and decreased in nine (33.3%). In our series, the mean preoperative vision was 20/174, the best postoperative visual acuity was 20/74, and the mean final vision was 20/167. Factors associated with a decrease in postoperative visual acuity included the postoperative enlargement of CNV.

CONCLUSION

Macular translocation with radial chorioscleral outfolding improved or stabilized the vision in 66.7% of patients with subfoveal CNV over the course of more than 2 years. Closing the CNV or preventing its further growth is required to maintain a better postoperative visual acuity.

Retinal changes after macular translocation with 360-degree retinotomy in monkey eyes

PURPOSE

To determine the morphologic and functional changes of the fovea and retina of monkey eyes after macular translocation with 360-degree retinotomy.

DESIGN

Experimental study.

METHODS

The retinas of eight monkey eyes were surgically translocated with a 360-degree retinotomy with procedures similar to those used on human eyes. At 1, 2, and 3 months after the surgery, the six eyes that had successful surgery were studied by light and transmission electron microscopy, terminal deoxynucleotidyl transferase (TdT)-dNTP terminal nick-end labeling (TUNEL) assay, and immunohistochemistry with peanut agglutinin (PNA) lectin and glial fibrillary acidic protein (GFAP). Retinal physiology was assessed by scotopic and photopic electroretinograms (ERGs).

RESULTS

The fovea was successfully translocated approximately 30 to 40 degrees superiorly in six eyes. The translocated macula and fovea had a normal layered architecture with no TUNEL-positive cells, minimal misalignment of the outer segments, and strong immunoreactivity to GFAP. The mean amplitudes of the scotopic and photopic b-waves were significantly reduced at 1 month after the surgery, and there was only a slight recovery at 3 months. No significant changes were observed in the mean implicit times after the surgery.

CONCLUSION

These findings indicate that macular translocation surgery with 360-degree retinotomy results in minimal morphologic alterations but significant depression of electrophysiologic function.

Use of rotational sutures for limited retinal translocation: a new technique for superior limited macular translocation

PURPOSE

To report a modified surgical technique for retinal translocation in eyes with subfoveal choroidal neovascularization.

DESIGN

Experimental animal study.

METHODS

Nine pigmented rabbits were used consecutively to apply this technique. Placement of inferotemporal scleral imbrication sutures was followed by vitrectomy with posterior hyaloid separation. Balanced saline solution (BSS) was injected subretinally with a 30G needle or with a 39G hydrodissection cannula and viscous fluid injector to detach one retinal quadrant. Under low intraocular pressure, the imbrication sutures were tied, the sclerotomy sites were closed, and intravitreal air tamponade was injected. Rotation sutures were passed and the eye globe was rotated approximately 90 degrees counterclockwise. The rotation sutures were removed after 24 hours. Retinal photographs were taken and fundus examination was performed on postoperative days 1, 2 and 7. The animals were sacrificed after 7 to 10 days for postmortem macroscopic examination.

RESULTS

The entire procedure was performed in nine eyes of nine rabbits. In eight eyes, translocation could be seen on the first postoperative day after removal of the rotation sutures. The average amount of translocation was 667 microm (range: 500-800 microm) in a nasal to inferonasal direction. Vitreous hemorrhage occurred at the end of surgery in one eye due to hypotony. Iatrogenic small retinal breaks occurred in 2 eyes but did not prevent completion of the procedure. There was only a temporary hyperemia of the eyelids and conjunctiva.

CONCLUSION

Limited retinal translocation using rotational sutures provided a predictable amount of translocation in the planned direction. This technique is expected to be useful for superior macular translocation in humans.

EFFECTS OF INDOCYANINE GREEN INJECTION ON THE RETINAL SURFACE AND INTO THE SUBRETINAL SPACE IN RABBITS

PURPOSE

To evaluate the effects of indocyanine green (ICG) injection on the retinal surface and into the subretinal space of rabbit eyes.

METHODS

Twenty-two Dutch-belted rabbits underwent two-port vitrectomy followed by injection of ICG (5 mg/mL) on the retinal surface and into the subretinal space. Balanced salt solution (BSS) was also injected subretinally. The locations where ICG was delivered (both epiretinal and subretinal) were exposed to light from an endoilluminator for 7 minutes. The animals were examined at 1, 7, and 14 days after surgery. The eyes were studied by fluorescein angiography as well as light and electron microscopy.

RESULTS

No damage was observed after epiretinal ICG injection, but subretinal ICG injection resulted in damage to the outer nuclear layer, photoreceptor inner and outer segments, and retinal pigment epithelium. This damage was more severe with longer follow-up. Control experiments without ICG, in which balanced salt solution was injected into the subretinal space or light was delivered on the epiretinal surface, demonstrated only damage to the photoreceptor outer segments.

CONCLUSION

Subretinal delivery of ICG (5 mg/mL) in rabbits induces retinal pigment epithelium, photoreceptor inner and outer segment, and outer nuclear layer damage. These mechanisms of damage may explain the retinal pigment epithelium changes that are sometimes seen after ICG-assisted internal limiting membrane peeling in humans.

Transposition of the anterior superior oblique insertion as a treatment for excyclotorsion induced from limited macular translocation

PURPOSE

To evaluate the transposition of the anterior superior oblique insertion as a treatment for cyclovertical diplopia accompanied by an awareness of tilted image perceived with the affected eye induced from limited macular translocation (LMT).

DESIGN

Observational case series.

METHODS

Transposition of the anterior part of the superior oblique tendon combined with or without vertical muscle surgery on the affected eye was retrospectively studied in seven patients. Clinical outcome was assessed for binocular and monocular vision. A successful result was defined as restoration of single binocular vision (SBV) at distance and near examined with the Bagolini test with disappearance of a tilted image perceived in the affected eye.

RESULTS

Six of seven patients (86%) became unaware of tilted image, and three patients (43%) obtained successful results after the strabismus surgery. Of these three patients with successful results, one (33%) patient recognized metamorphopsia, whereas two (67%) of the three patients with unfavorable results reported metamorphopsia. Patients with successful results showed a visual acuity of 20/25 or better in the affected eye and a significantly smaller difference in visual acuity between the two eyes than those patients with unfavorable surgical results (0.133 logarithm of the minimal angle of resolution for SBV(+) vs 0.675 logarithm of the minimal angle of resolution for SBV(-); P =.0255).

CONCLUSIONS

The relatively low success for restoration of SBV indicates that strabismus surgery is recommended for patients whose difference in visual acuity between the two eyes is small and who have a high level visual acuity of the affected eye.

Stable rAAV-mediated transduction of rod and cone photoreceptors in the canine retina

Recombinant adeno-associated virus (rAAV) vectors are attractive candidates for the treatment of inherited and acquired retinal disease. Although rAAV vectors are well characterized in rodent models, a prerequisite to their clinical application in human patients is the thorough evaluation of their efficacy and safety in intermediate animal models. In this study, we describe rAAV-2-mediated expression of GFP reporter gene in retinal cells following local vector delivery in dogs. Subretinal delivery of rAAV.CMV.GFP was performed unilaterally in eight normal dogs from 6 weeks of age. The area of retinal transduction was maximized by the optimization of surgical techniques for subretinal vector delivery by pars-plana vitrectomy and the use of fine-gauge subretinal cannulae to create multiple retinotomies. rAAV-2 vectors mediated efficient stable reporter gene expression in photoreceptors and retinal pigment epithelial cells. We found efficient transduction of cone photoreceptors in addition to rods in both the canine retina and after subretinal vector delivery in another intermediate animal model, the feline retina. GFP expression in dogs was confined to the area of the retinal bleb and was sustained in cells at this site for at least 18 months. Electroretinography demonstrated a modest reduction in global rod-mediated retinal function following subretinal delivery of rAAV.CMV.GFP. Three of the eight animals developed delayed-onset intraocular inflammation, in two cases associated with a serum antibody response to GFP protein. We conclude that rAAV-2 vectors mediate efficient sustained transgene expression in rod and cone photoreceptors following subretinal delivery in this intermediate animal model. The possibility of adverse effects including intraocular immune responses and reduced retinal function requires further investigation prior to clinical applications in patients.

Limited macular translocation with scleral retraction suture

BACKGROUND/AIMS

Macular translocation with scleral imbrication is a new technique for treating subfoveal choroidal neovascular membranes (CNV). This procedure shortens the sclera but may result in a minimal decrease in the internal circumference of the globe and limits the amount of foveal displacement. The authors propose a new scleral retraction suture aimed at decreasing the internal circumference of the globe in an effort to increase foveal displacement.

METHODS

Using a cadaver model, they compared the amount of scleral shortening using a standard scleral imbrication technique and a modified three suture scleral retraction technique. Sections of the globes were digitised and specialised software was used to estimate the amount of scleral shortening. Three patients with subfoveal choroidal neovascularisation underwent limited macular translocation using pars plana vitrectomy and macular detachment with the modified scleral suture technique. The main outcome measures were visual acuity, foveal displacement, and complications.

RESULTS

In the cadaver model, the scleral retraction suture resulted in a flatter internal scleral fold compared to the standard suture technique and created approximately 890 microm of effective scleral shortening. In the patients who underwent macular translocation and laser photocoagulation of the CNV, visual acuity improved in two patients and worsened in one patient. The range of foveal displacement was 1400-2400 microm.

CONCLUSION

The foveal displacements achieved in this limited study compared to median displacement previously published using standard suture techniques demonstrates that the scleral retraction suture technique may be a useful adjunct to limited macular translocation. The advantage of this type of suture in conjunction with translocation may depend on the effective scleral shortening offered by this retraction suture.

Diplopia after limited macular translocation surgery

PURPOSE

Full macular translocation surgery relocates the fovea away from choroidal neovascularization, inducing significant postoperative torsional diplopia. In "limited macular translocation," a saline-induced retinal detachment is followed by scleral imbrication with mattress sutures and spontaneous retinal reattachment. In this study, diplopia was characterized in patients treated with limited macular translocation.

METHODS

Two surgeons performed retinal translocation surgery on 250 patients over an 18-month time span. The extent and direction of the retinal translocation, and the amount and location of scleral imbrication, were recorded. All patients complaining of diplopia were referred for ocular motility evaluation and treatment.

RESULTS

Thirteen (5.2%) patients complained of occasional or constant diplopia. Imbricating sutures were placed supero-temporally in all cases. Inferior foveal translocation ranged from 200 to 2115 microm (median, 1750 microm). Visual acuity ranged from 20/40 to 20/400 in the operated eye. Prism-and-cover testing underestimated the strabismus when compared with subjective testing. In 3 patients, there was no shift on alternate-cover testing despite binocular diplopia. Excyclotorsion ranged from 0 degrees to 16 degrees. Diplopia resolved in 10 cases with prism; 3 required an occlusive filter for distortion or aniseikonia. One patient underwent successful strabismus surgery to eliminate dependence on prism glasses.

CONCLUSIONS

Limited macular translocation only rarely produces symptomatic diplopia. Suprisingly, traditional prism-and-cover testing does not reliably quantify the misalignment. This may result from the combination of a persistent macular scotoma and a repositioned fovea relative to the peripheral retina. Prism therapy is generally satisfactory in the absence of retinal distortion or aniseikonia.

Electrophysiological changes after 360 degrees retinotomy and macular translocation for subfoveal choroidal neovascularisation in age related macular degeneration

AIM

To evaluate electrophysiological changes after 360 degrees retinotomy and macular translocation for subfoveal choroidal neovascularisation in patients with age related macular degeneration (AMD).

METHODS

A consecutive series of 32 patients suffering from subfoveal choroidal neovascularisation secondary to AMD underwent 360 degrees retinotomy and macular translocation. The ERG served as the main parameter of the study and was recorded 1 day before the translocation surgery and no earlier than 4 weeks after the silicone oil removal.

RESULTS

The scotopic ERG amplitudes were significantly reduced after translocation surgery. Depending on the applied flash luminance the mean b-wave amplitude reduction of the scotopic ERG varied between 67% (0.2 cd.s/m2) and 74% (0.03 cd.s/m2). The a-waves and b-waves of the saturating light response decreased significantly by 46% and 59%, respectively. The photopic a-wave and b-wave amplitudes were significantly lower after the translocation surgery resulting in a mean reduction of 27% and 43%, respectively.

CONCLUSIONS

Although macular translocation may provide the potential of preserving and even restoring vision in patients with subfoveal choroidal neovascular membranes secondary to AMD the present study indicates that a significant electrophysiological decrease is caused by surgical procedures associated with this technique. Further research is necessary to clarify if certain modifications of the surgical procedure are able to substantially reduce the neuroretinal trauma.

Foveal translocation with scleral imbrication in patients with myopic neovascular maculopathy

PURPOSE

To report our surgical results of foveal translocation with scleral imbrication in patients with myopic neovascular maculopathy.

DESIGN

Noncomparative, interventional, consecutive case series.

METHODS

Ten eyes of 10 myopic patients with subfoveal neovascular membranes that had undergone foveal translocation with scleral imbrication were recruited for this retrospective study. Inclusion criteria were myopia 6.0 diopters or greater in refractive error (or axial length 26.5 mm or longer), subfoveal choroidal neovascularization, and preoperative best-corrected visual acuity of 20/100 or worse. None of these eyes had undergone prior laser photocoagulation or submacular surgery. The main outcome measures were surgical complications and postoperative visual function.

RESULTS

Postoperatively, visual acuity had improved more than 3 lines in the logarithm of minimum angle of resolution (logMAR) measurement in all eyes. The mean preoperative, postoperative best, and final visual acuity were 0.12, 0.59, and 0.51, respectively. Of the 10 eyes, six achieved a postoperative final visual acuity of 20/40 or better. The mean postoperative foveal displacement was 0.78 disk diameter (range, 0.3--1.3 disk diameter). Two patients underwent a reoperation because of insufficient foveal displacement. Furthermore, one of these two patients required a third operation to reduce an excessive retinal fold involving the fovea induced by the second surgery. Of the 10 patients, two noted transient diplopia. This complaint, however, resolved over time as suppression developed. Although unintentional iatrogenic retinal tears formed intraoperatively in two eyes, these were successfully treated without serious complications. Postoperatively, mild retinal pigment epithelial changes were observed in all cases, but none led to significant deterioration of visual acuity during the follow-up period. All patients but one were followed for a minimum of 6 months.

CONCLUSIONS

In eyes with myopic neovascular maculopathy, foveal translocation with scleral imbrication may be useful in improving visual acuity. Further refinements in surgical technique and assessment of the long-term complications will be needed to make this procedure safer and more useful.

Macular translocation with chorioscleral outfolding: an experimental study

PURPOSE

Macular translocation by chorioscleral infolding has been proposed as a surgical intervention for exudative age-related macular degeneration, but the surgery is unpredictable and can be associated with severe complications. We tested a new surgical technique, macular translocation with chorioscleral outfolding secured by neurosurgical clips.

METHODS

This was a prospective interventional study in two parts; the first in human cadaver eyes and the second in pigs. Chorioscleral infolding was performed on six human donor eyes, and chorioscleral outfolding was performed on an additional six. The inner surface of the eye wall was measured, and then the fold was unfolded and the distance was measured again. In the second half of the study, macular translocation surgery was performed on 33 pig eyes with one of three sclera shortening methods: 1) a circumferential chorioscleral infolding using 5-0 nylon sutures, 2) a circumferential chorioscleral outfolding using scleral clips, or 3) a radial chorioscleral outfolding using scleral clips. Foveal translocation was measured.

RESULTS

The inner wall of the human cadaver eye was shortened in the chorioscleral infolding group by a mean of 1.6 mm, and in the chorioscleral outfolding group by 3.0 mm. In the pig eyes, the fovea was translocated a mean 2377 microm by circumferential suturing, 2582 microm by circumferential clipping, and 3386 microm by radial clipping. Irregular deformation of the globe was more apparent in the circumferential suture group. Undesirable retinal folds often formed after circumferential infolding but not after radial clipping.

CONCLUSION

Radial chorioscleral outfolding with clips is more predictable and effective than infolding. It produces more translocation and prevents folds across the fovea, one of the most undesirable complications in macular translocation surgery.

Effective nasal limited macular translocation

PURPOSE

To describe a case of effective foveal displacement toward the optic disk (nasal limited macular translocation) in a patient with a large subfoveal choroidal neovascularization secondary to age-related macular degeneration.

METHODS

Case report.

RESULTS

A 77-year-old white man presented with decreased vision of 20/400 due to subfoveal predominantly occult CNV secondary to age-related macular degeneration in the left eye. The CNV, measuring 9 Macular Photocoagulation Study disk areas in size, was centered temporally relative to the fovea with a minimum desired translocation of 650 microm for nasal macular translocation. The patient underwent nasal LMT with punctate retinotomy and temporal chorioscleral infolding, followed by postoperative head-positioning on his right side. Effective LMT was achieved with a postoperative nasal foveal displacement of 1400 microm. The entire CNV was ablated with laser photocoagulation postoperatively. His vision improved to 20/40 6 months postoperatively.

CONCLUSION

Nasal LMT is feasible and may be considered in patients with subfoveal CNV centered temporally relative to the fovea.

Induced corneal astigmatism after macular translocation surgery with scleral infolding

OBJECTIVE

To document the corneal astigmatism that occurs with macular translocation after scleral infolding surgery.

DESIGN

Retrospective case series of a nonrandomized clinical trial.

PARTICIPANTS

Eight consecutive age-related macular degeneration patients (eight eyes) with choroidal neovascularization who underwent macular translocation with scleral infolding at the Duke University Eye Center from December 1998 through October 1999.

METHODS

We retrospectively reviewed the charts of eight consecutive patients who underwent macular translocation surgery involving scleral infolding in the superotemporal quadrant. Two patients subsequently underwent release of scleral infolding.

MAIN OUTCOME MEASURES

After surgery, these eyes were evaluated for corneal astigmatism with manifest refraction, keratometry, and computerized corneal topography.

RESULTS

All eight eyes of eight patients revealed marked degrees of corneal astigmatism. Measurement of astigmatism via manifest refraction, keratometry, and corneal topography confirmed postoperative astigmatism corresponding to the axis of the scleral infolding. The amount of corneal astigmatism ranged from 1.75 to 7.37 diopters (D; mean, 4.60 D), with steepening along the axis of scleral infolding in the superotemporal quadrant of each eye (mean, 42.50 degrees from vertical; range, 24 degrees -66 degrees from vertical). Release of scleral infolding in two patients resulted in significant reduction of corneal astigmatism.

CONCLUSIONS

Scleral shortening procedures used in macular translocation surgery may induce large amounts of corneal astigmatism. These patients should be assessed with keratometry and corneal topography to determine the accurate amount and axis. Thereafter, contact lens fitting or scleral infolding release may be considered as therapeutic options for large amounts of astigmatism persisting after surgery.

Macular translocation: unifying concepts, terminology, and classification

PURPOSE

To describe some unifying concepts, terminology, and classification of macular translocation so as to facilitate communication within the scientific community.

METHODS

A panel of ophthalmologists with expertise in macular translocation reviewed available data and developed some unifying concepts, terminology, and classification of macular translocation.

RESULTS

Macular translocation may be defined as any surgery that has a primary goal of relocating the central neurosensory retina or fovea intraoperatively or postoperatively specifically for the management of macular disease. It may be classified according to the size of the retinotomy and, where applicable, the technique of chorioscleral shortening used. The direction of macular translocation is denoted by the movement of the neurosensory macula relative to the underlying tissues. Effective macular translocation may be defined as successful intraoperative or postoperative relocation of the fovea overlying a subfoveal lesion to an area outside the border of the lesion. The concepts of minimum desired translocation and median postoperative foveal displacement can give some useful idea of the likelihood of effective macular translocation before surgery.

CONCLUSIONS

Use of a common standardized terminology for macular translocation will facilitate communication within the scientific community and enhance further research in this area. However, the definitions, terms, classification, and concepts concerning macular translocation are likely to continue to evolve as macular translocation undergoes further modifications and refinements.

Initial experience of inferior limited macular translocation for subfoveal choroidal neovascularization resulting from causes other than age-related macular degeneration

PURPOSE

To report our initial experience of inferior limited macular translocation in patients with subfoveal choroidal neovascularization resulting from causes other than age-related macular degeneration.

METHODS

We conducted a retrospective study of 23 eyes of 22 patients with choroidal neovascularization involving the foveal center secondary to pathologic myopia (11 eyes), ocular histoplasmosis syndrome (four eyes), angioid streaks (four eyes), idiopathic neovascularization (three eyes), and multifocal choroiditis (one eye), in which the fovea was moved inferiorly by means of limited macular translocation surgery. The mean preoperative best-corrected visual acuity was 20/150, and in five of 23 eyes (21.7%) the visual acuity was 20/80 or better. The major outcome measures were preoperative and postoperative visual acuity, postoperative foveal displacement, and complications related to the surgery.

RESULTS

The mean postoperative follow-up was 10.82 months (range, 6 to 18 months). Postoperative best-corrected visual acuity improved by 2 or more Snellen lines of visual acuity in 11 of 23 eyes (47.82%), remained within 1 line in seven of 23 eyes (30.43%), and worsened 2 or more lines of vision in five of 23 eyes (21.74%). The mean postoperative best-corrected visual acuity was 20/100, and in 12 of the 23 eyes (52.17%) the visual acuity achieved was 20/80 or better. Retinal detachment was the most frequent complication and occurred in six eyes (26%).

CONCLUSIONS

Our initial experience with limited macular translocation shows that this treatment modality offers the potential to improve visual function in some eyes with subfoveal choroidal neovascularization secondary to myopia, ocular histoplasmosis syndrome, angioid streaks, idiopathic neovascularization, and multifocal choroiditis. Although longer and more complete follow-up is needed, the results of this initial series warrant further studies to define the precise role of macular translocation in the management of these conditions.

Complications associated with limited macular translocation

PURPOSE

To report the ocular complications associated with the limited macular translocation procedure.

METHODS

Retrospective review of 153 consecutive eyes of 151 patients that had the limited macular translocation procedure for subfoveal choroidal neovascularization between April 1996 and February 1999. The major study variables investigated included the incidence of specific ocular complications and their impact on visual acuity at 3 months after the surgery. In addition, baseline patient characteristics and operative factors were evaluated to determine whether they were significant risk factors for the development of an ocular complication. The existence of a surgical procedure learning process was investigated.

RESULTS

One hundred forty-one (92.15%) of 153 eyes achieved at least 3-month follow-up. At least one complication occurred in 53 of 153 eyes (34.6%) and in 51 of these 53 eyes (96. 22%) the complications occurred before 3 months of postoperative follow-up. The intraoperative and postoperative complications included retinal detachment (17.4%), retinal breaks (13.4%), macular holes (7.8%), macular fold (4.6%), and intraocular hemorrhage (vitreous, subretinal, or choroidal; 9.2%). Eyes that developed retinal detachment, subretinal hemorrhage, and macular fold had significantly more loss of visual acuity than eyes without each of these complications (P =.0001, P =.038, and P =.027, respectively). The presence of predominantly classic choroidal neovascularization, the occurrence of an intraoperative retinal break, any intraocular hemorrhage, or macular fold formation were significantly associated with retinal detachment (P =.021, P =.025, P =.013, and P =.014, respectively). The incidence of any complication, retinal detachment, and hemorrhage significantly decreased during the study period, suggesting a learning process (P =.03, P =.006, P =.027, respectively).

CONCLUSIONS

A variety of ocular complications can occur during or after limited macular translocation, and some are associated with reduced postoperative visual acuity. Improved surgical techniques and experience may significantly reduce the incidence of these complications.

Macular translocation: histopathologic findings in swine eyes

PURPOSE

Macular translocation has been proposed as an alternative technique in the treatment of some cases of choroidal neovascularization. The purpose of the paper is to report the histopathologic findings in the retina of swine eyes undergone macular translocation.

METHODS

Ten eyes of ten Yucatan pigs underwent posterior pars plana vitrectomy and scleral imbrication to achieve macular translocation. Mattress sutures were preplaced at the equator of the eyes. After a pars plana vitrectomy, balanced saline solution was injected under the temporal retina to produce a retinal detachment. Scleral imbrication was achieved by tightening the mattress sutures. An air-fluid exchange was performed and the eye was filled with sulfur hexafluoride 18%. The eyes were enucleated 2, 4, 8 and 12 weeks after surgery and analyzed under light and electron microscopy.

RESULTS

Macular translocation was achieved in all cases. The major findings consist of a minimal decrease in the number of photoreceptors outer segments; also a change in the morphology was noted. This included some degree of loss of vertical alignment and an increase in the interphotoreceptor space. There was a recovery in the morphology of the photoreceptors over time.

CONCLUSIONS

Minimal changes in the photoreceptors and retinal pigment epithelium are observed when macular translocation is performed with recovery of these changes over time. Scleral imbrication is an effective technique to achieve translocation of the fovea.

Limited inferior macular translocation for the treatment of subfoveal choroidal neovascularization secondary to age-related macular degeneration

PURPOSE

To review a series of patients with age-related macular degeneration undergoing limited macular translocation for the treatment of subfoveal choroidal neovascularization, to determine short-term visual acuity outcomes, to measure amounts of attainable retinal movement, and to identify prognostic factors.

METHODS

A retrospective review was conducted on a consecutive series of patients undergoing inferior limited macular translocation with scleral imbrication for the treatment of subfoveal choroidal neovascularization secondary to age-related macular degeneration. The main outcome measures investigated were distance of macular translocation, visual acuity at 3 and 6 months after surgery, change in visual acuity from baseline, and the development of intraoperative and postoperative complications. Univariate and multivariate analyses of a number of potential prognostic factors were undertaken.

RESULTS

Macular translocation was achieved in all 102 eyes (101 patients) included in this study. The range of movement varied from 200 to 2,800 microm with a median movement of 1, 200 microm. Nearly 33% of the study group achieved a visual acuity better than 20/100 at 3 months, and 49% achieved this vision at 6 months. At 3 and 6 months, 37% and 48% of the study group, respectively, experienced 2 or more lines of improvement on visual acuity testing, and by 6 months 16% experienced greater than 6 lines of visual improvement. Good baseline vision, achieving the desired amount of macular translocation, a greater amount of macular translocation, and recurrent choroidal neovascularization at baseline were associated with better visual acuities at 3 and 6 months. Poor preoperative vision and the development of complications were associated with worse vision at 3 and 6 months.

CONCLUSIONS

Limited macular translocation is a technically feasible procedure that can lead to significant visual improvement and good visual acuity in some patients presenting with subfoveal choroidal neovascularization associated with age-related macular degeneration. A randomized prospective clinical trial of this surgical technique is warranted.

Macular translocation

Macular translocation is a term used to describe any surgical procedure that involves the deliberate detachment of the retina with subsequent repositioning of the macula to a new location relative to the underlying retinal pigment epithelium. By moving the fovea away from abnormal pigment epithelium and/or choroid and repositioning it over more normal tissue, macular function can be stabilized or improved. Various techniques have been developed to accomplish this movement. Although this approach holds great promise for selected conditions (in particular, subfoveal choroidal neovascularization), the optimal technique to be used and the long-term prognosis are uncertain.

Limited macular translocation for neovascular maculopathy

Subfoveal choroidal neovascularization presents one of the most difficult challenges to vision. No treatment option has yet solved the problem of subretinal hemorrhage and fibrovascular scarring causing permanent photoreceptor degeneration and loss. Limited macular translocation provides a surgical approach to this challenge by moving the fovea onto an adjacent area of relatively normal subretinal space and pigment epithelium in a selected group of patients. The choroidal neovascularization, thus, becomes extrafoveal or juxtafoveal and can be treated with focal laser photocoagulation. This article describes the current technique of limited macular translocation and reviews early results. The procedure offers selected patients a chance to retain useful central vision. About 40% of patients at 6 months are able to read and drive (visual acuity >20/100). Complications including retinal detachment, hemorrhage, and macular folds have decreased with experience. Limited macular translocation is a promising approach to neovascular maculopathy, but needs ongoing careful evaluation.

Biomaterials used in the posterior segment of the eye

The treatment of posterior segment eye disease and related conditions has improved greatly in recent years with the advent of new therapies, materials and devices. Vitreoretinal conditions, however, remain significant causes of blindness in the developed world. Biomaterials play a major role in the treatment of many of these disorders and the success rate of vitreoretinal surgery, especially in the repair of retinal detachment and related conditions, would increase with the introduction of new and improved materials. This review, which focuses on disorders that feature retinal detachment, briefly describes the anatomy of the eye and the nature and treatment of posterior segment eye disorders. The roles, required properties and suitability of the materials used in vitreoretinal surgery as scleral buckles, tamponade agents or drug delivery devices, are reviewed. Experimental approaches are discussed, along with the methods used for their evaluation, and future directions for biomaterial research in the posterior segment of the eye are considered.

Foveal relocation by redistribution of the neurosensory retina

AIM

To describe a new surgical technique for foveal relocation, and to report the outcome in nine patients treated with this procedure.

METHODS

Nine consecutive patients with subfoveal choroidal neovascular membranes (CNVMs) secondary to age related macular degeneration underwent foveal relocation surgery by redistribution of the neurosensory retina (RNR). The technique involved induction of a retinal detachment via a single retinotomy, relocation of the fovea by "sweeping" the retinal tissue with a retinal brush, and stabilisation of the retina in its new location using perfluorocarbon liquid peroperatively and silicone oil postoperatively.

RESULTS

In eight of nine eyes successful relocation of the fovea was achieved; in one eye the CNVM remained in a subfoveal location postoperatively. Visual acuity improved in two eyes, remained unchanged in three, and decreased in four eyes after a median follow up of 4 months (range 2.5-6 months). Complications included rupture of a foveal cyst with the development of a macular hole in one eye and epimacular membrane formation in another eye. In two eyes, macular retinal vessel closure occurred at the time of laser photocoagulation; one of these eyes later developed cystoid macular oedema and the other an epiretinal membrane. Recurrence of the CNVM was observed in one eye, but was controlled with further laser treatment.

CONCLUSIONS

Foveal relocation by RNR appears to be feasible, obviating the need for extensive retinotomies or scleral shortening.

Effective macular translocation without scleral imbrication

PURPOSE

To describe a case of effective macular translocation accomplished without scleral imbrication or extensive retinotomy.

METHODS

A case report of a 59-year-old woman with subfoveal choroidal neovascularization in her left eye who underwent vitrectomy with macular detachment and fluid-air exchange.

RESULTS

The macula was translocated approximately 500 microm inferiorly, allowing for photocoagulation of extrafoveal neovascularization.

CONCLUSION

Limited macular translocation may be attained without scleral imbrication or significant retinotomy.

Macular translocation for subfoveal choroidal neovascularization in age-related macular degeneration: a prospective study

PURPOSE

To conduct a prospective study of macular translocation in patients with subfoveal choroidal neovascularization secondary to age-related macular degeneration.

METHODS

In 10 eyes of 10 patients with subfoveal choroidal neovascularization and best-corrected visual acuity ranging from 20/50 to 20/800 (median, 20/111), the fovea was relocated by means of scleral imbrication, intentional retinal detachment with small posterior retinotomies, and partial fluid-air exchange. In two eyes, the choroidal neovascular membranes were removed at the time of macular translocation; in seven eyes they were photocoagulated in the postoperative period; and in one eye the membrane was removed during reoperation to unfold a macular fold.

RESULTS

All 10 eyes were followed up for 6 months. The median postoperative foveal displacement was 1286 microm (range, 114 to 1,919 microm). In three eyes (30%), a foveal fold formed postoperatively requiring reoperation, with one of these eyes requiring a second reoperation for a rhegmatogenous retinal detachment. Best-corrected visual acuity improved in four eyes (median, 10.5 letters) and decreased in six eyes (median, 14.5 letters). The median change in visual acuity was a decrease of 5 letters. The final best-corrected visual acuity was 20/80 in two eyes, 20/126 in one eye, 20/160 in four eyes, 20/200 in one eye, 20/250 in one eye, and 20/640 in one eye.

CONCLUSIONS

Our initial experience with limited macular translocation suggests that this surgical technique is unpredictable. However, in patients with subfoveal choroidal neovascularization from age-related macular degeneration, it offers the potential for improving visual function and may be associated with less loss of vision than the disease itself, if allowed to progress. Further refinements in surgical indications and technique are needed to make this procedure safer, more predictable, and more beneficial.

Translocation of the retina for management of subfoveal choroidal neovascularization II: a preliminary report in humans

PURPOSE

To report a surgical method for translocation of the foveal retina in eyes with subfoveal choroidal neovascularization.

METHODS

In three eyes of three patients, a crescent-shaped, partial-thickness scleral resection was performed near the equator at either the superotemporal or the inferotemporal quadrant. A near-total retinal detachment was created; then the edges of the resected sclera were sutured, causing shortening of the sclera with subsequent reattachment of the retina, resulting in translocation of the fovea to an area overlying nonfoveal retinal pigment epithelium and choroid.

RESULTS

In three eyes of three patients, the fovea was surgically translocated to overlie retinal pigment epithelium that preoperatively was not underlying the fovea. In two patients, laser photocoagulation was applied to the choroidal neovascularization that, after translocation of the fovea, was no longer subfoveal, so that the photocoagulation was not associated with immediate visual loss. After a follow-up of 4 to 6 months, the visual acuity had improved in all patients (from 20/126 preoperatively to 20/70 in one patient, from 20/200 preoperatively to 20/70 in the second, and from 20/160 to 20/30 in the third). The patients noted distortion or tilting of the images, which improved over time.

CONCLUSIONS

Limited foveal translocation may offer a therapeutic modality to preserve or improve vision in cases of subfoveal choroidal neovascularization. Additional follow-up is needed to assess the impact of potential complications associated with the surgical procedure, such as retinal detachment, proliferative vitreoretinopathy, and cataract, as well as the possibility of recurrent choroidal neovascularization.