Purpose
To report the 1-year results of human amniotic membrane patch implantation for optic disc pit maculopathy.
Design
A prospective, consecutive, interventional study.
Methods
Eleven eyes of 11 patients affected by optic disc pit maculopathy associated with subretinal/intraretinal fluid were included in this single-institution study. A 25-gauge pars plana vitrectomy was performed in all cases, with an implant of a human amniotic membrane patch into the optic disc pit and air was injected as endotamponade. The primary study outcome was the subretinal and intraretinal fluid reabsorption. Secondary outcomes were visual acuity improvement and postoperative complications.
Results
Mean central retinal thickness gradually diminished from 512 ± 137 µm to 243 ± 19 µm, at the 12-month follow-up. The mean visual acuity improved from 20/80 at baseline to 20/32 at the 12-month follow-up. Complete fluid resorption occurred in 9 of 11 (81.8%) eyes and there was partial resorption in 2 eyes (18%). No subretinal fluid recurrence was observed during the 12-month follow-up. No intraoperative or postoperative complications were reported during the follow-ups. The amniotic membrane patch remained detectable inside the pit for the entire follow-up time.
Conclusion
An amniotic membrane plug may be effective for improving optic disc pit maculopathy. All cases had an anatomical improvement and encouraging visual acuity recovery.
INTRODUCTION
T he optic disc pit (ODP) is a congenital anomaly of the optic nerve head. Prevalence is estimated at 1 in 11 000 patients, , and may be bilateral in up to 15% of patients. Optic disc pit maculopathy (ODP-M) includes intraretinal fluid (IRF) and subretinal fluid (SRF) accumulation with or without retinal pigmentary changes; , it appears in 25% to 75% of patients with an ODP. , , When ODP-M is present, best corrected visual acuity (BCVA) is usually decreased to 20/70 or worse, and persistent fluid accumulation can irreversibly decrease BCVA to 20/200 or worse.
Two years ago, a pilot study including 3 patients affected by ODP-M and treated using a human amniotic membrane patch (hAM) was published with encouraging results. The hAM patch was inserted into the optic disc pit, the SRF fluid gradually diminished over the 6-month follow-up, and the BCVA improved to 20/25.
The current study included 11 eyes of 11 patients, and follow-up was extended to 12 months. This article reports the functional and anatomical outcomes.
METHODS
PATIENTS
From July 2018 to July 2020, 11 eyes of 11 patients affected by ODP-M were included in the study. All patients were treated with a human amniotic membrane implant into the optic disc pit and air as endotamponade. Two patients had previously undergone a pars plana vitrectomy (PPV) with the induction of posterior vitreous detachment and gas tamponade for ODP-M. Peeling of the internal limiting membrane (ILM) was performed in the second patient. After the first surgery, both patients were re-treated using an hAM patch, due to the SRF fluid and IRF fluid persistence after 8 and 9 months, respectively. Each patient provided informed consent to participate in this study, and the study was adherent with the Declaration of Helsinki. In addition, Institutional Review Board/Ethics Committee approval was obtained.
EXAMINATION
The patients were seen before surgery and 15 days, 1, 3, 6, and 12 months after the operation. At each visit, the patients underwent a complete ophthalmologic evaluation with a BCVA measurement, a slit lamp biomicroscopy examination to evaluate anterior and posterior eye segment, an intraocular pressure measurement, an optical coherence tomography (OCT) scan (Mirante, Nidek CO., Ltd, and Spectralis OCT, Heidelberg Engineering Inc.), and an ultra-wide field retinography (Daytona, Optos Inc.). BCVA Snellen values were converted into logMAR to carry out the statistical analysis.
STATISTICAL ANALYSIS
Statistical analysis was performed using STATA software version 15.1 (StataCorp). Wilcoxon signed-rank test was used to compare the mean values. The significance level was set at P < .05.
SURGICAL TECHNIQUE
All patients underwent a 3-port 25-gauge PPV (Alcon Laboratories). Phacoemulsification with IOL implantation was performed on patient 1 due to an initial lens opacification. Triamcinolone acetonide was used for posterior vitreous detachment (PVD) induction. No ILM peeling was carried out. The cryopreserved hAM was obtained from the Eye Bank of Lucca, Italy. An hAM patch was prepared using a 1-mm or 1.5-mm dermatological punch (Disposable Biopsy Punch, Kai Medical) and inserted through the cannula ( Figure 1 ). The hAM was then inserted into the optic pit using vitreoretinal forceps. It is important to position the chorionic side of the hAM into the pit because this will firmly adhere to the pit concave surface. Perfluorocarbon was used to stabilize the hAM patch during the fluid-air exchange procedure. A fluid-air exchange with complete removal of the perfluorocarbon bubble was carried out. Air was chosen as endotamponade in all the patients. No peripapillary additional laser was performed. The patients were asked to maintain a face-down position for the first 3 days after surgery.
RESULTS
Eleven patients were included in the study. The mean age was 32 ± 19 years (range, 11-65 years). Seven patients were female and four were male. None of the reported cases was bilateral. Nine patients were phakic and two were pseudo phakic. Nine patients (82%) presented both SRF and IRF, and 2 patients (18%) presented IRF only. Two patients had had a previous vitrectomy for ODP-M with no anatomical resolution; 1 of these patients had had ILM peeling during the first PPV. The mean preoperative CRT was 512 ± 137 µm (range, 333-820 µm) and the mean postoperative CRT was 410 ± 57 µm (range, 301-478 µm) at the 1-month ( P = .004), 337 ± 37 µm (range, 298-401 µm) at the 3-month ( P = .0008), 280.8 ± 22 µm (range, 244-326 µm) at the 6-month ( P = .00008), and 243 ± 19 µm (range, 211-287 µm) at the 12-month ( P = .00002) follow-up. All 11 eyes had anatomical improvement 12 months after treatment. Complete fluid resorption occurred in 9 of 11 (81.8%) eyes and partial resorption in 2 eyes (18%). No recurrence was noticed in the SRF/IRF fluid after 12 months. The mean complete reabsorption time was 4.3 ± 1.2 months ( Figures 2-4 ).
The mean preoperative BCVA was 0.58 ± 0.2 logMAR (range, 0.3-1 logMAR) and the mean postoperative BCVA was 0.48 ± 0.13 logMAR (range, 0.3-0.7 logMAR) at 1 month ( P = .024), 0.35 ± 0.1 logMAR (range, 0.2-0.6 logMAR) at 3 months ( P = .001), 0.23 ± 0.1 logMAR (range 0.1–0.5 logMAR) at 6 months ( P = .00005), and 0.16 ± 0.08 logMAR (range, 0-0.3 logMAR) at 12 months ( P = .000005). No major complications, such as retinal or choroidal detachment or hAM patch dislocations, were reported during the follow-up period. Only one of the patients developed mild corneal edema, which resolved 1 week after the operation with topical steroidal therapy. The surgical video is available as supplementary material.
DISCUSSION
Serous retinal detachment is a common complication of optic disc pits (25% to 75%) and is related to a low visual outcome. , , Due to a not fully understood ODP-M pathogenesis, there is no consensus regarding the most effective treatment. The origin of SRF/IRF fluid in the ODP-M scenario is still debated: some authors have hypothesized cerebrospinal fluid leakage, while others have hypothesized vitreous fluid migration.
Slit lamp-delivered juxtapapillary laser photocoagulation to create a cicatricial barrier and prevent SRF/IRF fluid passage appears to be minimally effective therapy. In two case series, slit lamp laser photocoagulation was associated with gas tamponade to enhance fluid displacement, reporting an approximately 70% success rate. , In 2014, Jain and Johnson , hypothesized that vitrectomy might be beneficial in ODP-M; they argued that the vitreous gel movement exerts a negative pressure gradient that attracts the cerebrospinal fluid into the SRF/IRF space. This hypothesis has always been controversial, due to the lack of OCT documented vitreomacular traction in previously vitrectomized eyes, affected by a recurrent SRF or IRF in ODP-M. The aim of ILM peeling in ODP-M surgery is to further remove the tangential traction at the edges of the pit. This hypothesis has always been debated due to the lack of OCT tangential traction findings in eyes that previously underwent PPV and ILM peeling, affected by recurrent fluid in ODP-M. , Further, ILM peeling was associated with a full-thickness macular hole formation around 1 month after the operation. PPV combined with juxtapapillary endophotocoagulation is controversial because there are no clear benefits; moreover, damage to the papilla macular bundle with consequent visual field defects is clear.
Nowadays, the predominant approach for the treatment of ODP-M seems to be PPV with induction of PVD, and gas tamponade, , with approximately 75% anatomical success (dry fovea). Internal limiting membrane (ILM) peeling or juxtapapillary laser photocoagulation was not significant in improving visual outcomes. However, in the absence of a gold standard technique to treat ODP-M, other authors have proposed alternative bio-materials to physically close the pit, such as fibrin glue, autologous ILM flaps or autologous scleral flaps.
The use of ILM flaps was first introduced for the treatment of macular holes. Mohammed reported cases of ODP-M resolution after sealing the pit using an ILM flap. Pastor-Idoate reported good anatomical and functional results using a nasal, fovea-sparing, ILM pedunculated flap, flipped and folded onto the ODP; they reported complete fluid resolution in 56% of cases (5 of 9 eyes). In contrast, Nawrocki reported better results when the ILM flap was inserted into the pit, with complete fluid resolution in all three cases and final BCVA of 20/85. Babu and colleagues reported an 85.7% anatomical resolution in patients treated using an ILM plug inserted into the pit, with a final BCVA of 20/56. However, ILM peeling has been associated with post-surgical full-thickness macular hole formation between 9.2% to 50% of the cases. ,
The use of an autologous scleral patch was first proposed by Travassos and associates, who reported a complete resolution of the SRF in all three patients, with a final BCVA ranging from 20/200 to 20/25. Shah and associates reported complete SRF fluid resorption after 1 year, with a final BCVA of 20/30 in the eyes treated using this technique. Babu and associates treated 8 patients with an autologous scleral patch, with an 87.5% anatomical resolution and a final mean BCVA of 20/60 after 1-year follow-up, without SRF recurrence. Nadal and associates reported a 100% anatomical success, between 2 and 8 months postoperatively, in 19 eyes treated with autologous platelet concentrate, with a visual acuity improvement in 36.8% patients. Soni and associates described the use of fibrin glue for the treatment of ODP-M; they reported a 60% anatomical success rate after an average follow-up of 7 months, without complications, in 5 patients.
The application of hAM for retinal pathologies was introduced in 2018. In 2020, hAM was proposed in ODPs treatment, with encouraging results. Because of its deformability, hAM can be better inserted into the optic nerve head pit than rigid tissue such as the sclera, or very thin and fragile tissue such as the ILM. Moreover, harvesting a scleral flap could be considered time-consuming and peeling the ILM has been associated with postoperative complications such as macular hole formation. On the other hand, cutting an hAM patch using a dermatological punch is straightforward, and several techniques to insert hAM into the vitreous cavity through a trocar have already been described.
It may be hypothesized that the progressive resolution of the macular fluid in the current cases was due to the hAM patch’s ability to close the ODP. A gradual and slow anatomical resolution was observed during the follow-ups. Complete resolution was achieved in all but 2 cases; these 2 cases had partial resolution, although the fluid reduction was considerable, and the visual acuity improved.
Two eyes had previously been treated using a lens-sparing PPV with PVD and gas tamponade. ILM peeling was performed in 1 of these patients. Both had anatomical and functional improvement after the hAM plug implantation. Due to the small number of eyes, it is difficult to conclude if secondary interventions may improve both anatomical and functional results. In the literature, the outcomes of secondary operations for ODP-M are not homogeneous and vary on the time of re-operation and technique.
The current study had faster or similar reabsorption (<9 months) compared to most of the studies regarding the fluid resolution time. , The mean fluid complete reabsorption time was 4.3 ± 1.2 months. Visual acuity showed an overall progressive improvement over the 12-month follow-up in all patients. These results are comparable with postoperative VA results described in the literature.
The hAM has not shown any immunogenicity in vitro, and has not triggered any form of intraocular inflammation when inserted inside the human eye. One patient in the current series developed mild corneal edema, which resolved with topical steroidal therapy 1 week after the operation. In all cases, the hAM presented thinning and partial resorption, but was still detectable in all the eyes at the end of the follow-ups. Moreover, no form of severe complication was observed, such as retinal detachments or endophthalmitis, and the hAM remained inside the optic disc pit for all the 12-month follow-ups ( Table 1 ) .
