Macular function of successfully repaired macula-off retinal detachments

Microvascular changes after pars plana vitrectomy for rhegmatogenous retinal detachment repair: A comparative study based on gas tamponade agent

PURPOSE

The purpose of this study was to investigate the effect of gas tamponade on microvascular changes in patients with rhegmatogenous retinal detachment (RRD), who underwent pars plana vitrectomy (PPV), using optical coherence tomography angiography (OCTA).

METHODS

Participants in this study were 48 patients with RRD, who were treated with PPV and gas tamponade without internal limiting membrane peeling. All participants underwent slit-lamp examination, fundoscopy, spectral domain-optical coherence tomography and optical coherence tomography angiography at month 6 postoperatively. The fellow untreated eyes were also examined and served as the control data.

RESULTS

A statistically significant enlargement in the foveal avascular zone (FAZ) in both the superficial (p = 0.002) and the deep capillary plexus (p = 0.01) was noticed 6 months postoperatively in patients with RRD treated with PPV compared to the fellow eyes. The foveal avascular zone perimeter was increased in the operated eyes in the deep capillary plexus (p = 0.0003) and the foveal avascular zone circularity was decreased in both the superficial (p = 0.045) and the deep capillary plexus (p < 0.001) compared to the fellow eyes. The vessel density was not significantly different between the operated and the fellow eyes in the superficial and the deep capillary plexus. The vessel density and the foveal avascular zone parameters were comparable between the C3F8 and SF6 groups.

CONCLUSION

Specific microvascular indices as measured by OCTA were statistically different between the operated and the fellow eyes in the superficial and deep capillary plexus. C3F8 and SF6 as gas tamponades did not seem to differ in their impact on the microvascular parameters.

Injury to Cone Synapses by Retinal Detachment: Differences from Rod Synapses and Protection by ROCK Inhibition

Attachment of a detached retina does not always restore vision to pre-injury levels, even if the attachment is anatomically successful. The problem is due in part to long-term damage to photoreceptor synapses. Previously, we reported on damage to rod synapses and synaptic protection using a Rho kinase (ROCK) inhibitor (AR13503) after retinal detachment (RD). This report documents the effects of detachment, reattachment, and protection by ROCK inhibition on cone synapses. Conventional confocal and stimulated emission depletion (STED) microscopy were used for morphological assessment and electroretinograms for functional analysis of an adult pig model of RD. RDs were examined 2 and 4 h after injury or two days later when spontaneous reattachment had occurred. Cone pedicles respond differently than rod spherules. They lose their synaptic ribbons, reduce invaginations, and change their shape. ROCK inhibition protects against these structural abnormalities whether the inhibitor is applied immediately or 2 h after the RD. Functional restoration of the photopic b-wave, indicating cone-bipolar neurotransmission, is also improved with ROCK inhibition. Successful protection of both rod and cone synapses with AR13503 suggests this drug will (1) be a useful adjunct to subretinal administration of gene or stem cell therapies and (2) improve recovery of the injured retina when treatment is delayed.

RELATIONSHIP BETWEEN PREOPERATIVE FOVEAL MICROSTRUCTURE AND VISUAL ACUITY IN MACULA-OFF RHEGMATOGENOUS RETINAL DETACHMENT: Imaging Analysis by Swept Source Optical Coherence Tomography

PURPOSE

To visualize foveal microstructures in macula-off rhegmatogenous retinal detachment using swept source optical coherence tomography preoperatively and postoperatively and to investigate the relationship between foveal microstructures and postoperative visual acuity.

METHODS

We retrospectively analyzed 42 eyes of 42 consecutive patients diagnosed with macula-off rhegmatogenous retinal detachment who underwent anatomically successful repair surgery and were followed up for 6 months. We used swept source optical coherence tomography to investigate the relationship between preoperative and postoperative continuity of both the external limiting membrane (ELM) and ellipsoid zone (Ez) and preoperative and postoperative best-corrected visual acuity.

RESULTS

Both preoperative ELM and Ez were continuous in 9 eyes (21%; ELM+/Ez+ eyes), only the ELM was continuous in 25 eyes (60%; ELM+/Ez- eyes), and neither was continuous in 8 eyes (19%; ELM-/Ez- eyes). Postoperative best-corrected visual acuity in ELM+/Ez+ eyes (-0.05 ± 0.04 logarithm of the minimum angle of resolution units, Snellen equivalent 20/18) was significantly better than that in both ELM+/Ez- (0.16 ± 0.16, 20/29; P = 0.03) and ELM-/Ez- (0.86 ± 0.37, 20/145; P < 0.001) eyes. Postoperative best-corrected visual acuity was significantly better in ELM+/Ez- than in ELM-/Ez- eyes (P < 0.001).

CONCLUSION

In macula-off rhegmatogenous retinal detachment, preoperative continuity of the ELM and Ez may be a predictor of postoperative best-corrected visual acuity.

Coming of Age for the Photoreceptor Synapse

Purpose

To discuss the potential contribution of rod and cone synapses to the loss of visual function in retinal injury and disease.

Methods

The published literature and the authors' own work were reviewed.

Results

Retinal detachment is used as a case study of rod spherule and cone pedicle plasticity after injury. Both rod and cone photoreceptors terminals are damaged after detachment although the structural changes observed are only partially overlapping. For second-order neurons, only those associated with rod spherules respond consistently to injury by remodeling. Examination of signaling pathways involved in plasticity of conventional synapses and in neural development has been and may continue to be productive in discovering novel therapeutic targets. Rho kinase (ROCK) inhibition is an example of therapy that may reduce synaptic damage by preserving normal synaptic structure of rod and cone cells.

Conclusions

We hypothesize that synaptic damage contributes to poor visual restoration after otherwise successful anatomical repair of retinal detachment. A similar situation may exist for patients with degenerative retinal disease. Thus, synaptic structure and function should be routinely studied, as this information may disclose therapeutic strategies to mitigate visual loss.

Change in retinal and choroidal microvascular structures after rhegmatogenous retinal detachment surgery and effects on visual recovery

PURPOSE

To investigate changes in retinal and choroidal microvascular structures in the macular region after surgery for rhegmatogenous retinal detachment (RRD) and their relationship to visual function at 3months.

METHODS

This prospective, cross-sectional study included 37 eyes of 37 patients who underwent surgery for RRD (pneumatic retinopexy and/or pars plana vitrectomy). All patients underwent a comprehensive ophthalmologic examination, including measurement of best-corrected visual acuity (BCVA, logMAR), anterior segment and fundus examination, and optical coherence tomography angiography (OCTA) imaging 3months postoperatively. The healthy fellow eyes formed the control group. OCTA was used for the assessment of macular vessel density (VD), foveal avascular zone (FAZ), central macular thickness, and choroidal and outer retinal flow rates.

RESULTS

The findings showed that the VD of the superficial and deep capillary plexuses were lower in the RRD group compared to the control group (P=0.012; P<0.001). The FAZ was larger in the RRD group (P=0.035). The choroidal flows in the 1 and 3mm² were lower in the RRD group (P<0.001). Superficial FAZ area and choroidal flow rate (1 and 3mm² areas) were moderately negatively correlated with BCVA (P=0.008; P=0.035; P=0.008).

CONCLUSIONS

Our study demonstrated that the FAZ was larger, and the choroidal flow rate was lower, in the RRD group compared to the control group. Choroidal flow rate was negatively correlated with postoperative BCVA. Ischemic events resulting from the RRD were likely the reason for these changes.

ROCK inhibition reduces morphological and functional damage to rod synapses after retinal injury

Retinal detachment (RD) causes damage, including disjunction, of the rod photoreceptor-bipolar synapse, which disrupts vision and may contribute to the poor visual recovery observed after retinal reattachment surgery. We created a model of iatrogenic RD in adult female pigs to study damage to the rod-bipolar synapse after injury and the ability of a highly specific Rho-kinase (ROCK) inhibitor to preserve synaptic structure and function. This model mimics procedures used in humans when viral vectors or cells are injected subretinally for treatment of retinal disease. Synaptic disjunction by retraction of rod spherules, quantified by image analysis of confocal sections, was present 2 h after detachment and remained 2 days later even though the retina had spontaneously reattached by then. Moreover, spherule retraction occurred in attached retina 1-2 cms from detached retina. Synaptic damage was significantly reduced by ROCK inhibition in detached retina whether injected subretinally or intravitreally. Dark-adapted full-field electroretinograms were recorded in reattached retinas to assess rod-specific function. Reduction in synaptic injury correlated with increases in rod-driven responses in drug-treated eyes. Thus, ROCK inhibition helps prevent synaptic damage and improves functional outcomes after retinal injury and may be a useful adjunctive treatment in iatrogenic RD and other retinal degenerative diseases.

Visual Acuity Inadequately Reflects Vision-Related Quality of Life in Patients After Macula-Off Retinal Detachment Surgery

Purpose

To determine the impact of postoperative visual function on the vision-related quality of life (VRQoL) in patients after anatomically successful surgery for macula-off rhegmatogenous retinal detachment (RRD) and to propose a classification to grade the extent of macular detachment using preoperative optical coherence tomography (OCT) scans.

Methods

This prospective study evaluated 48 patients. At 12 months after surgery, visual function assessments were as follows: metamorphopsia (M-CHARTS), aniseikonia (New Aniseikonia Test), best corrected visual acuity (BCVA) (Early Treatment Diabetic Retinopathy Study [ETDRS]), low contrast BCVA (10% ETDRS), color vision (Hardy Rand Rittler), and stereopsis (Titmus Fly). VRQoL was assessed by the National Eye Institute Visual Functioning Questionnaire-25 (NEIVFQ-25). Associations between visual function parameters and NEIVFQ-25 scores were evaluated. Preoperative OCT-scans were classified into six stages according to the extent of macular detachment based on an ETDRS-grid: incomplete perifoveal detachment (1), incomplete parafoveal detachment (2), incomplete foveal detachment (3), complete foveal detachment (4), complete parafoveal detachment (5), and complete perifoveal detachment (6).

Results

General vision and driving were the lowest scoring categories. General vision had the strongest correlation with low contrast BCVA (r = −0.41, P = 0.002), while driving had the strongest correlation with stereopsis (r = −0.39, P = 0.008). All macular detachments were graded stage 3 or beyond. Patients with stage 3 macular detachments had the highest visual function values compared to the other stages. The highest percentage of patients with metamorphopsia, aniseikonia and BCVA>0.1 logMAR was found in stages 5 and 6.

Conclusions

Macula-off RRD particularly affects general vision and driving. The extent of macular detachment is a potential predictor for visual function and can be graded using the proposed classification.

Fasudil, a Clinically Used ROCK Inhibitor, Stabilizes Rod Photoreceptor Synapses after Retinal Detachment

Purpose

Retinal detachment disrupts the rod-bipolar synapse in the outer plexiform layer by retraction of rod axons. We showed that breakage is due to RhoA activation whereas inhibition of Rho kinase (ROCK), using Y27632, reduces synaptic damage. We test whether the ROCK inhibitor fasudil, used for other clinical applications, can prevent synaptic injury after detachment.

Methods

Detachments were made in pigs by subretinal injection of balanced salt solution (BSS) or fasudil (1, 10 mM). In some animals, fasudil was injected intravitreally after BSS-induced detachment. After 2 to 4 hours, retinae were fixed for immunocytochemistry and confocal microscopy. Axon retraction was quantified by imaging synaptic vesicle label in the outer nuclear layer. Apoptosis was analyzed using propidium iodide staining. For biochemical analysis by Western blotting, retinal explants, detached from retinal pigmented epithelium, were cultured for 2 hours.

Results

Subretinal injection of fasudil (10 mM) reduced retraction of rod spherules by 51.3% compared to control detachments (n = 3 pigs, P = 0.002). Intravitreal injection of 10 mM fasudil, a more clinically feasible route of administration, also reduced retraction (28.7%, n = 5, P < 0.05). Controls had no photoreceptor degeneration at 2 hours, but by 4 hours apoptosis was evident. Fasudil 10 mM reduced pyknotic nuclei by 55.7% (n = 4, P < 0.001). Phosphorylation of cofilin and myosin light chain, downstream effectors of ROCK, was decreased with 30 μM fasudil (n = 8–10 explants, P < 0.05).

Conclusions

Inhibition of ROCK signaling with fasudil reduced photoreceptor degeneration and preserved the rod-bipolar synapse after retinal detachment.

Translational Relevance

These results support the possibility, previously tested with Y27632, that ROCK inhibition may attenuate synaptic damage in iatrogenic detachments.

RhoA Signaling and Synaptic Damage Occur Within Hours in a Live Pig Model of CNS Injury, Retinal Detachment

PURPOSE

The RhoA pathway is activated after retinal injury. However, the time of onset and consequences of activation are unknown in vivo. Based on in vitro studies we focused on a period 2 hours after retinal detachment, in pig, an animal whose retina is holangiotic and contains cones.

METHODS

Under anesthesia, retinal detachments were created by subretinal injection of a balanced salt solution. Two hours later, animals were sacrificed and enucleated for GTPase activity assays and quantitative Western blot and confocal microscopy analyses.

RESULTS

RhoA activity with detachment was increased 1.5-fold compared to that in normal eyes or in eyes that had undergone vitrectomy only. Increased phosphorylation of myosin light chain, a RhoA effector, also occurred. By 2 hours, rod cells had retracted their terminals toward their cell bodies, disrupting the photoreceptor-to-bipolar synapse and producing significant numbers of spherules with SV2 immunolabel in the outer nuclear layer of the retina. In eyes with detachment, distant retina that remained attached also showed significant increases in RhoA activity and synaptic disjunction. Increases in RAC1 activity and glial fibrillary acidic protein (GFAP) were not specific for detachment, and sprouting of bipolar dendrites, reported for longer detachments, was not seen. The RhoA kinase inhibitor Y27632 significantly reduced axonal retraction by rod cells.

CONCLUSIONS

Activation of the RhoA pathway occurs quickly after injury and promotes synaptic damage that can be controlled by RhoA kinase inhibition. We suggest that retinal detachment joins the list of central nervous system injuries, such as stroke and spinal cord injury, that should be considered for rapid therapeutic intervention.

Postoperative Recovery of Light Sensitivity in Eyes with Rhegmatogenous Retinal Detachment

PURPOSE

To investigate whether postoperative light sensitivity recovers completely to the level prior to the development of rhegmatogenous retinal detachment (RRD) after successful surgery.

METHODS

We retrospectively studied 44 eyes of 44 patients with RRD who were successfully operated and who underwent Humphrey central 30-2 perimetry postoperatively. The averaged total deviation in Humphrey perimetry in the reattached retina was compared with that of the horizontal or vertical counterpart in the preoperatively non-detached retina.

RESULTS

The averaged total deviation in the reattached retina was significantly lower than in its counterpart (p < 0.0001). The averaged residual loss of light sensitivity did not correlate with postoperative visual acuity (p = 0.8047) or with its change (p = 0.1242).

CONCLUSIONS

Light sensitivity in the detached retina in eyes with RRD does not completely recover after successful surgery.

Abnormal regional spontaneous neural activity in visual pathway in retinal detachment patients: a resting-state functional MRI study

OBJECTIVE

The aim of the study was to investigate changes of brain neural homogeneity in retinal detachment (RD) patients using the regional homogeneity (ReHo) method to understand their relationships with clinical features.

MATERIALS AND METHODS

A total of 30 patients with RD (16 men and 14 women), and 30 healthy controls (HCs) (16 men and 14 women) closely matched in age and sex were recruited. Resting-state functional magnetic resonance imaging scans were performed for all subjects. The ReHo method was used to investigate the brain regional neural homogeneity. Patients with RD were distinguished from HCs by receiver operating characteristic curve. The relationships between the mean ReHo signal values in many brain regions and clinical features in RD patients were calculated by Pearson correlation analysis.

RESULTS

Compared with HCs, RD patients had significantly decreased ReHo values in the right occipital lobe, right superior temporal gyrus, bilateral cuneus and left middle frontal gyrus. Moreover, we found that the mean ReHo signal of the bilateral cuneus showed positive relationships with the duration of the RD (r=0.392, P=0.032).

CONCLUSION

The RD patients showed brain neural homogeneity dysfunction in the visual pathway, which may underline the pathological mechanism of RD patients with acute vision loss. Besides, the ReHo values can reflect the progress of the RD disease.

Contrast Sensitivity after Pars Plana Vitrectomy: Comparison between Macula-On and Macula-Off Rhegmatogenous Retinal Detachment

PURPOSE

To evaluate the contrast sensitivity (CS) of eyes successfully repaired by vitrectomy for rhegmatogenous retinal detachment (RRD) with or without preoperative macular involvement.

METHODS

In this retrospective, consecutive, interventional case series, 109 eyes received primary vitrectomy for RRD, of which 36 with at least 12 months of follow-up and a best-corrected visual acuity (BCVA) ≥1 at 12 months postoperatively were investigated. The main outcome measurements were BCVA and CS at 12 months postoperatively. Patients with macula-on RRD preoperatively were included in the macula-on group, and patients with macula-off RRD preoperatively were included in the macula-off group. The between-group difference in CS under evening vision conditions was measured with a Takagi glare tester CGT-2000 at 6 visual angles and 13 contrast levels with and without glare.

RESULTS

CS was significantly lower in the macula-off group for targets with visual angles of 1.6, 1.0, and 0.64° with glare (p < 0.05) and for the target with a visual angle of 0.64° without glare (p < 0.05).

CONCLUSIONS

CS in the higher spatial frequency range (especially with glare) is reduced in macula-off RRD patients with good postoperative BCVA compared to macula-on RRD patients with good postoperative BCVA.

Vision-related quality of life, metamorphopsia, and stereopsis after successful surgery for rhegmatogenous retinal detachment

PurposeTo determine the relationship between vision-related quality of life, metamorphopsia, and stereopsis after successful surgery to correct rhegmatogenous retinal detachment (RRD).Patients and methodsData were obtained from 30 patients with RRD who had scleral buckle surgery or vitrectomy. Age, gender, duration of blurred vision, the best-corrected visual acuity (BCVA), extent of detachment, and the location of retinal tears were measured before surgery. Approximately 1 year after surgery, stereopsis was measured with the Randot stereo test, visual acuity (VA) was measured using a Snell VA acuity measurement at a distance of 5 m and was presented as a linear LogMAR value, metamorphopsia was examined using an M-chart, and vision-related quality of life was determined using the 25-Item National Eye Institute Visual Function Questionnaire (VFQ-25).ResultsAll of the patients achieved anatomical retinal reattachment. There was a significant difference between preoperative BCVA (0.78±0.72) and BCVA 1 year postoperatively (0.25±0.25) (P<0.05). Twenty-three patients had visual distortion postoperatively, including vertical metamorphopsia (0.53±0.52°), and horizontal metamorphopsia (0.48±0.53°). Twenty patients had no stereopsis. The composite score of VFQ-25 was 76.60 postoperatively. Significant differences in postoperative BCVA, metamorphopsia, and VFQ-25 were found between macula-on and macula-off groups (all P<0.05). There was a negative correlation between VFQ-25 composite score and metamorphopsia (P<0.005); there was no significant correlation between VFQ-25 composite score and BCVA or stereopsis.ConclusionVision-related quality of life correlated with metamorphopsia, but did not correlate with VA or stereopsis.

Postoperative vision-related quality of life in macula-off rhegmatogenous retinal detachment patients and its relation to visual function

Objective

To determine the vision-related quality of life (VR-QOL) after surgery for macula-off rhegmatogenous retinal detachment (RRD) in relation to visual acuity, contrast acuity, and color vision.

Methods

In a prospective observational study, we included 55 patients with a macula-off RRD. Best corrected visual acuity (BCVA), color vision (saturated and desaturated color confusion indices (CCI)) and contrast acuity were measured at 12 months postoperatively in both the RRD eye and the fellow control eye, and the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25) was filled out.

Results

Operated and fellow control eyes differed significantly in mean LogMAR BCVA (P<0.0001), median Log contrast acuity (P<0.0001), saturated CCI (P = 0.009), and desaturated CCI (P = 0.016). Significant correlations were observed between the NEI VFQ-25 overall composite score and postoperative LogMAR BCVA (R = −0.551, P<0.0001), contrast acuity (R = 0.472, P<0.0001), saturated CCI (R = −0.315, P = 0.023), and desaturated CCI (R = −0.283, P = 0.044).

Conclusions

A lower VR-QOL was highly correlated to a worse postoperative BCVA and contrast acuity and to a lesser extent to color vision disturbances.

Postoperative recovery of visual function after macula-off rhegmatogenous retinal detachment

PURPOSE

To determine which factors affect the recovery of visual function in macula off rhegmatogenous retinal detachment (RRD).

METHODS

In a prospective study of forty-five patients with a primary macula-off RRD of 24 hours to 6 weeks duration, the height of the macular detachment was determined by ultrasonography. At 12 months postoperatively, best corrected visual acuity (BCVA), contrast acuity, and color confusion indexes (CCI) were obtained.

RESULTS

Macular detachment was present for 2-32 (median 7) days before repair. A shorter duration of macular detachment was correlated with a better CCI saturé (p = 0.0026) and lower LogMAR BCVA (better Snellen visual acuity) (p = 0.012). Also, a smaller height of macular detachment was correlated with a lower LogMAR BCVA (p = 0.0034). A younger age and lower pre-operative LogMAR BCVA at presentation were both correlated with better postoperative contrast acuity in the total group (age: p = 1.7×10(-4) and pre-operative LogMAR BCVA: p = 0.0034).

CONCLUSION

Functional recovery after macula-off RRD is affected by the duration and the height of the macular detachment. Recovery of contrast acuity is also affected by age and BCVA at presentation.

MEETING PRESENTATION

ARVO annual meeting 2013, May 7, Seattle, Washington, United States of America.

TRIAL REGISTRATION

trialregister.nl NTR839.

Metamorphopsia and optical coherence tomography findings after rhegmatogenous retinal detachment surgery

PURPOSE

To investigate the relationship between metamorphopsia and macular morphologic changes after successful repair of rhegmatogenous retinal detachment (RD).

DESIGN

Prospective, interventional, consecutive study.

METHODS

The study included 129 eyes of 129 patients who had undergone successful retinal reattachment surgery. The severity of metamorphopsia was recorded using M-CHARTS and foveal microstructure was assessed with spectral-domain optical coherence tomography (OCT) at 6-12 months postoperatively.

RESULTS

The mean metamorphopsia score was 0.30 ± 0.46, and 50 of 129 patients (39%) had metamorphopsia. Metamorphopsia was more severe in eyes with macula-off rhegmatogenous RD than those with macula-on (P < .001). Eighteen of 50 eyes with metamorphopsia exhibited abnormal structures in the macular region (epiretinal membrane, disruption of the photoreceptor inner and outer segment junction, cystoid macular edema, macular hole, or subretinal fluid), whereas the other 32 eyes showed no morphologic changes with OCT. In these 32 eyes, the horizontal metamorphopsia score (0.86 ± 0.50) was significantly higher than the vertical metamorphopsia score (0.62 ± 0.39, P < .05). Nine of 69 eyes with preoperative macula-on rhegmatogenous RD developed postoperative metamorphopsia. Of the 9 eyes, 6 showed abnormal macular structures and the other 3 had normal-appearing OCT. The macula briefly detached during vitrectomy in these 3 cases.

CONCLUSIONS

In eyes that remained macula-on throughout surgery and had normal-appearing OCT, metamorphopsia did not develop. In some cases, the reason for metamorphopsia was anatomically obvious. In other cases that were preoperative and intraoperative macula-off, postoperative retinal vertical displacement could cause predominantly horizontal metamorphopsia.

Changes in contrast sensitivity after surgery for macula-on rhegmatogenous retinal detachment

PURPOSE

To evaluate changes in contrast sensitivity after surgery for macula-on rhegmatogenous retinal detachment (RRD).

DESIGN

Prospective, interventional, consecutive, case-control study.

METHODS

This study included 84 eyes of 84 patients with unilateral macula-on RRD undergoing primary scleral buckling or vitrectomy without postoperative macular complication. We examined the logarithm of the minimal angle of resolution best-corrected visual acuity (logMAR BCVA) and contrast sensitivity at 4 spatial frequencies (3, 6, 12, and 18 cycles/degree) using the CSV-1000E (Vector Vision) before and after surgery. From the data obtained with the CSV-1000E, the area under the log contrast sensitivity function was calculated. The logMAR BCVA and contrast sensitivity in the contralateral normal eyes also were measured and were used as normal controls. Clinical data were collected, including age, gender, surgical procedures, the number of retinal tears, circumferential dimension of retinal tears, and area of retinal detachment, to determine the clinical factors related to visual function.

RESULTS

Preoperative contrast sensitivity was significantly worse in eyes with RRD than in normal controls, but the preoperative logMAR BCVA was not different from that of normal controls. Contrast sensitivity decreased significantly after surgery, but logMAR BCVA did not change by surgery. Multiple regression analysis revealed that postoperative contrast sensitivity had a significant correlation with the circumferential dimension of retinal tears, whereas no clinical parameters were associated significantly with postoperative BCVA.

CONCLUSIONS

Surgery for macula-on RRD did not change visual acuity, whereas contrast sensitivity was affected significantly in association with the extent of retinal tears.

RhoA inactivation prevents photoreceptor axon retraction in an in vitro model of acute retinal detachment

PURPOSE

An early injury response to retinal detachment is disruption of synaptic connectivity between photoreceptors and second-order neurons. Most dramatic is the retraction of rod cell axons and their terminals away from the outer synaptic layer and toward their cell bodies. This study tested whether axonal retraction in detached retina was due to the activation of the small GTPase RhoA and was preventable using RhoA antagonists.

METHODS

Retinal detachments were created in in vitro preparations of porcine eyecups. RhoA activation was determined with a Rhotekin binding assay. To block axon retraction, drugs were applied to neural retinal explants either before or after detachment from the retinal pigment epithelium. Presynaptic movement was quantified by image analysis of double-labeled retinas examined with confocal microscopy.

RESULTS

Active RhoA increases transiently after detachment followed by morphologic evidence of axonal retraction over the next 24 hours. Pretreating the retina with a RhoA antagonist, CT-04, or a Rho kinase inhibitor, Y27632, at multiple concentrations significantly inhibited axonal retraction. Reducing calcium influx through L-type calcium channels with nicardipine also blocked retraction. To create a more plausible therapeutic scenario, drug treatments were delayed and applied after retinal detachment. The Rho kinase inhibitor, but not nicardipine, significantly blocked rod axonal retraction when applied up to 6 hours after detachment.

CONCLUSIONS

Thus, RhoA and downstream Rho kinase activity constitute part of the mechanism that produces rod axonal retraction in retinal explants. Treatments that manipulate RhoA signaling may promote synaptic stability after retinal detachment.

Study of macular function by multifocal electroretinography in patients with Vogt-Koyanagi-Harada syndrome

PURPOSE

We longitudinally investigated macular function by multifocal electroretinography (mfERG) in a cohort of patients with Vogt-Koyanagi-Harada (VKH) syndrome.

DESIGN

Prospective study.

METHODS

VKH syndrome was diagnosed in 11 patients (22 eyes) according to history and ocular examinations. They were treated with immunosuppressive agents and the macular function was evaluated using best-corrected visual acuity (BCVA) and mfERG before treatment and one, three, six, and 12 months after treatment.

RESULTS

All investigated patients with VKH syndrome showed active intraocular inflammation at their first visit. A decreased visual acuity (VA) and abnormalities of mfERG were observed in all these patients. VA rapidly improved at one and three months and gradually improved thereafter. All but one eye achieved a BCVA of > or =20/25 at 12 months following treatment. The N1 amplitude and latency were significantly improved at three and six months and continuously improved thereafter. The P1 amplitude and latency were significantly improved at one and three months and progressively improved thereafter. However, the amplitude of N1 and P1 waves was still significantly decreased at 12 months.

CONCLUSION

Macular function revealed by Snellen chart and mfERG is severely impaired in VKH patients with active uveitis. Treatment with immunosuppressive agents leads to an earlier, faster, and better recovery of VA, and a delayed but limited recovery of macular function as indicated by mfERG at 12 months. MfERG could be an ancillary test that may be useful in guiding therapy of patients with VKH syndrome.

High-resolution Fourier-domain optical coherence tomography and microperimetric findings after macula-off retinal detachment repair

OBJECTIVE

To evaluate the morphologic changes in the macula of subjects with repaired macula-off retinal detachment (RD) using high-resolution Fourier-domain optical coherence tomography (FD OCT) and to perform functional correlation in a subset of patients using microperimetry (MP-1).

DESIGN

Prospective observational case series.

PARTICIPANTS

Seventeen eyes from 17 subjects who had undergone anatomically successful repair for macula-off, rhegmatogenous RD at least 3 months earlier and without visually significant maculopathy on funduscopy.

METHODS

FD OCT with axial and transverse resolution of 4.5 mum and 10 to 15 mum, respectively, was used to obtain rapid serial B-scans of the macula, which were compared with that from Stratus OCT. The FD OCT B-scans were used to create a 3-dimensional volume, from which en face C-scans were created. Among 11 patients, MP-1 was performed to correlate morphologic changes with visual function.

MAIN OUTCOME MEASURES

Stratus OCT scans, FD OCT scans, and MP-1 data.

RESULTS

Stratus OCT and FD OCT images of the macula were obtained 3 to 30 months (mean 7 months) postoperatively in all eyes. Although Stratus OCT revealed photoreceptor disruption in 2 eyes (12%), FD OCT showed photoreceptor disruption in 13 eyes (76%). This difference was statistically significant (P<0.001, chi(2)). Both imaging modalities revealed persistent subretinal fluid in 2 eyes (12%) and lamellar hole in 1 eye. Among 7 subjects who had reliable MP-1 data, areas of abnormal function corresponded to areas of photoreceptor layer disruptions or persistent subretinal fluid in 5 subjects (71%); one subject had normal FD OCT and MP-1.

CONCLUSIONS

Photoreceptor disruption after macula-off RD repair is a common abnormality in the macula that is detected better with FD OCT than Stratus OCT. A good correlation between MP-1 abnormality and presence of photoreceptor disruption or subretinal fluid on FD OCT demonstrates that these anatomic abnormalities contribute to decreased visual function after successful repair.