Temporary Keratoprosthesis Research Articles

TEMPORARY KERATOPROSTHESIS COMBINED WITH VITRECTOMY FOR SEVERE GLOBE INJURY.

To describe a case of a 44-year-old man with ocular trauma after a mine explosion. From the moment of the injury, the patient reported significant visual impairment (no perception of light in the right eye and a perception of light without localization in the left eye). The patient was diagnosed with a double-sided penetrating corneal scleral wound and traumatic cataract, retinal detachment, and intraocular foreign bodies after a battlefield mine explosion. The three-stage procedure, consisting of using soft contact lens as temporary keratoprosthesis, vitrectomy, and penetrating keratoplasty, was performed in the damaged eye. A soft contact lens allowed for excellent visualization of the posterior segment during vitrectomy. At the 1-month follow-up, the eye that was operated on could sense light. The corneal transplant remained translucent, and the retina was attached. The described method, when performed by an experienced surgeon, may aid in simultaneously treating coexisting corneal opacification and vitreoretinal disorders.

Novel application of Deep Anterior Lamellar Keratoplasty for retinal detachment repair in totally opaque cornea secondary to aniridia.

We present a novel approach for managing retinal detachment in a patient with aniridia related corneal scarring precluding fundal view via a deep anterior lamellar keratoplasty. A 30-year-old female patient who had bilaterally opaque cornea, due to advanced aniridia related keratopathy presented with, experiencing flashing of light in her right eye. Examination of the retinal fundus was not possible due to the dense corneal scarring and underlying cataract. A superior bullous macula off retinal detachment was diagnosed on ultrasonography. Visual acuity at presentation was hand motions. The corneal scarring extended to the mid to deep stroma. We performed a deep anterior lamellar dissection of the opacified corneal stroma, that allowed clear visualisation of a dense cataract. The cataract was removed by phacoemulsification and IOL inserted. This allowed to proceed with repair of retinal detachment, through pars plana approach. The surgery was completed by a donor deep lamellar keratoplasty. This achieved a good fundal view to proceed with phacovitrectomy visualised through the residual corneal layers. Uneventful pars plana vitrectomy, cryotherapy and SF6 gas were performed to reattach the retina. Post-operatively the graft remains clear at 6 months with a visual acuity of 20/160 in the right eye, a level of vision the patient had not experienced for decades. Deep anterior lamellar keratoplasty offered an alternative to temporary keratoprosthesis to achieve a clear view of the retinal fundus and perform pars plana vitrectomy and repair of the retinal detachment.

Use of RGP lens as Temporary Keratoprosthesis in Open-Sky Technique for Heterotopic Autokeratoplasty

PURPOSE To present a case of a combined procedure of heterotopic autokeratoplasty and ECCE with posterior chamber intraocular lens (IOL) implantation, and to demonstrate the novel use of an RGP lens as a safe, cost-effective alternative to temporary keratoprosthesis. REPORT OF CASE A 65/F presented with blindness, OS from glaucoma but with a clear cornea, and corneal decompensation with cataract in OD with good visual potential. Heterotopic autokeratoplasty was performed due to the scarcity of corneal allografts and the high-risk nature of the case, with ECCE and IOL implantation in OD due to lens opacity. Temporary keratoprosthesis (TKP) (such as Eckardt and Landers models) was substituted with RGP due to lower cost and accessibility. Pre-placement of two polyglactin perpendicular mattress sutures in the episclera at the horizontal and vertical positions was done and left untied. Next, left corneal trephination was performed using an 8-mm vacuum trephine, followed by the instillation of oculoviscosurgical device (OVD) and placement of a 10-mm diameter RGP lens over the left open globe, secured in place by tying the pre-placed overlying cross sutures. Then, right corneal trephination using a similar-sized trephine proceeded. Cataract was extracted in open-sky technique with IOL in the bag implantation. The clear left corneal button was then transplanted to OD and vice-versa. Postoperatively, VA improved from hand motions to 10/200 (Day 1). The graft remained clear 4 weeks post-op with further improvement in VA. IOP was maintained below 15 mmHg. CONCLUSION Heterotopic autokeratoplasty is a valid option for unilateral cornea blind patients who have clear corneas in the fellow eye with no visual potential. This is useful in countries where corneal transplantation is costly, especially during time of pandemic when corneal allografts are scarce. In our experience, it can be safely performed using an RGP lens as a safe and cost-effective alternative to temporary keratoprosthesis.

Combined Penetrating Keratoplasty and Vitreoretinal Surgery With Temporary Keratoprosthesis

Purpose: The aim of this study was to evaluate outcomes of vitreoretinal surgery with temporary keratoprosthesis combined with penetrating keratoplasty. Setting: The study was conducted at a university-based corneal and retinal disease referral practice, Ann Arbor, MI. Methods: This study is a retrospective analysis of 43 patients who underwent vitreoretinal surgery with a temporary keratoprosthesis combined with penetrating keratoplasty. Functional (best-corrected visual acuity and corneal transplant survival rate) and anatomical (clear corneal graft and retinal attachment) outcomes were measured. Results: Both corneal transplant and retinal attachment outcomes were evaluated. There was no difference in visual acuity, retinal attachment rates, or corneal transplant survival rates when comparing adult age, sex, and graft size. Pediatric eyes, however, were more likely to have a poor corneal transplant outcome. After an initial combined procedure with a temporary keratoprosthesis, 15 of 43 corneas (35%) remained clear and 23 (53%) retinas remained attached. With additional surgery, 19 of the corneas (44%) and 32 of the retinas (74%) had satisfactory outcomes. Best-corrected visual acuity (BCVA) initially improved in 23 patients (53%), with lasting improvement at final follow-up in 12 patients (28%). Twenty-five patients (58%) obtained equal or improved vision at last follow-up as compared to the presenting vision. The primary causes of poor visual acuity outcome were phthisis (49%) and retinal detachment (26%). Corneal decompensation and hypotony were often associated with phthisis and, therefore, resulted in a poor visual outcome. Trauma (53%) also resulted in an increased rate of phthisis. However, those eyes sustaining trauma, which did not become phthisical, had better visual outcomes. Silicone oil usage improved retinal reattachment rates and had no deleterious effects on corneal transplant survival. Conclusions: The combined procedures of vitreoretinal surgery with temporary keratoprosthesis and penetrating keratoplasty can salvage severely damaged eyes and provide functional vision in some patients. Factors predicting worse final visual outcome include preoperative total retinal detachment, severe chronic retinal pathology in the absence of trauma, and postoperative phthisis or retinal detachment.

Double-flanged knotless technique for iris prosthesis and IOL implantation associated with keratoplasty.

Anterior segment reconstruction and penetrating keratoplasty combined with iris prosthesis (IP) and intraocular lens (IOL) scleral fixation require prolonged open-sky surgery and complex suturing. Herein we present a novel double-flanged knotless surgical technique that minimizes the open sky duration and facilitates the fixation of the IP and IOL complex to the sclera. After corneal trephination and removal, a temporary keratoprosthesis is fixated. Three 5.0 polypropylene suture segments are introduced in the anterior chamber transconjunctivally and then externalized through keratoprosthesis. Each suture is threaded through the eyelets of the IP and then flanged. The temporary keratoprosthesis is removed, and the IP and IOL complex is positioned in the sulcus. A donor cornea button is sutured in place and the IP is centred on the optical axis by adjusting the polypropylene sutures. Finally, the suture ends are shortened, flanged, and buried under the conjunctiva. Surgery was performed on three eyes of three patients. No intraoperative complications occurred, while cystoid macular edema and ocular hypertension occurred in two patients during the follow-up period. The best corrected visual acuity was 6/20, 8/20, and 13/20. So far the IPs remained stable in the three eyes with a maximum follow-up of 18 months. This novel technique of penetrating keratoplasty combined with an intraocular lens (IOL) and iris prosthesis implantation makes it possible to reduce open sky surgery time, avoid complex suturing, and ensure optimal IOL visual axis alignment by adjusting suture tension.

Pars plana vitrectomy and therapeutic keratoplasty in endophthalmitis and infectious keratitis.

To describe the anatomical and functional outcomes of patients with infectious keratitis (IK) and secondary endophthalmitis who underwent penetrating keratoplasty (PK) after pars plana vitrectomy (PPV) assisted by temporary keratoprosthesis (TKP). An observational retrospective case series was performed. Data were collected from January 2013 to July 2020. Patients over 18 years old with a clinical and microbiological diagnosis of IK, and clinical, ultrasonographic, and or microbiological diagnosis of endophthalmitis were included. Anatomical success was defined as infection resolution with preservation of the ocular globe integrity. No change or improvement of best-corrected visual acuity (VA) at the last follow-up was considered as a functional success. A total of 32 eyes of 32 patients were analyzed. The anatomic success was obtained in 87.5% eyes in which the infection was eradicated. The 63% patients maintained or improved their best-corrected VA, 37.5% ended up with hand motion VA. Our results suggest that PPV assisted by TKP followed by PKP can be a good approach for treating patients with endophthalmitis secondary to IK while allowing further visual improvement after an optical PK. Further prospective studies need to be done to evaluate final visual rehabilitation of these patients.

A novel temporary keratoprosthesis technique for vitreoretinal surgery.

To investigate the safety of vitreoretinal surgery when using a soft contact lens as a temporary keratoprosthesis (TKP) in patients with severe corneal opacifications. Three patients with simultaneous corneal and vitreoretinal pathology were treated with a soft contact lens that was used as a TKP to facilitate vitreoretinal surgery. The soft contact lens was fixated with sutures onto the globe so that no leakage was possible. Vitreoretinal surgery with excellent fundus view was possible in all cases. The soft contact lens allowed safe central and peripheral vitrectomy. Surgery was successful in all cases. A soft contact lens properly fixated on the globe can successfully replace a TKP. This surgical procedure has several advantages like one size fits all, low costs, and easy access to the material.

TEMPORARY KERATOPROSTHESIS WITH PENETRATING KERATOPLASTY IN CONJUNCTION WITH PARS PLANA VITRECTOMY FOR REPAIR OF RETINAL DETACHMENTS IN PATIENTS WITH ANTERIOR AND POSTERIOR SEGMENT PATHOLOGY.

To review the visual and anatomical outcomes of combined anterior and posterior segment surgery for retinal detachment repair. Eight patients with combined retinal and corneal disease underwent combined temporary keratoprosthesis with penetrating keratoplasty combined with pars plana vitrectomy for retinal detachment repair with silicone oil tamponade. Visual and anatomical outcomes were reviewed retrospectively. Follow-up ranged from 12 months to 37 months. Preoperative visual acuity ranged from light perception to hand motion. All but one case had proliferative vitreoretinopathy present at the time of surgery. Postoperative visual acuity ranged from hand motion to light perception. At the most recent follow-up visit, all of the patients had attached retinas, no patients had phthisis bulbi, and all but one patient had a clear cornea. However, 3 of these cases (38%) required repeat retinal detachment repair and one of them also required repeat penetrating keratoplasty, which was performed at the time of retinal repair. Combined full-thickness penetrating keratoplasty and retinal detachment repair has good anatomical outcomes and is an efficient way to treat complex anterior and posterior segment abnormality. Although postoperative visual function is limited; almost all patients were agreeable to repeat surgery if they were presented with the choice again.

Modified deep anterior lamellar dissection for corneal opacity during vitrectomy: case reports

BackgroundTo introduce a modified deep anterior lamellar dissection technique to improve visibility during surgery for vitreoretinal diseases with coexisting corneal opacity.Case presentationTwo patients with retinal detachment and coexisting corneal blood staining or corneal decompensation underwent modified deep anterior lamellar dissections followed by vitrectomy. The modified deep anterior lamellar dissection techniques, unlike the dissection and removal of corneal lamellar in a typical deep anterior lamellar keratoplasty, included the creation and preservation of a deep lamellar corneal flap, the retroillumination to visualize and easily remove the remaining opaque stroma on the Descemet membrane, and the big air bubble technique in the eye with endothelial decompensation. The patient’s own cornea flap was sutured back after vitrectomy was done. The modified dissection techniques provided adequate fundus view during vitrectomy while removing as less corneal tissue as possible and decreasing the surgical complications and the requirement of a fresh cornea. Postoperatively, in case 1, the corneal blood staining was gradually absorbed and the vision improved from light perception to counting fingers. In case 2, even though the cornea remained cloudy and the vision was poor, the cornea endothelial decompensation was stable and asymptomatic. Both retinas were attached after silicone oil removal at 6-month follow-up.ConclusionsThis modified and limited deep anterior lamellar corneal dissection procedure appears to be a useful alternative to penetrating keratoplasty, ophthalmic endoscope and temporary keratoprosthesis during the vitrectomy with coexisting corneal opacity.

Pars plana vitrectomy and penetrating keratoplasty combined with temporary keratoprosthesis in traumatic cases

Pars plana vitrectomy and penetrating keratoplasty combined with temporary keratoprosthesis in traumatic cases

Clinical Results in Patients with Combined Penetrating Keratoplasty and Vitreoretinal Surgery Using Landers Wide-field Temporary Keratoprosthesis

Objectives:To evaluate the clinical results of combined pars plana vitrectomy (PPV) with Landers wide-field temporary keratoprosthesis and penetrating keratoplasty (PK).Materials and Methods:From January 2016, traumatic eyes with coexisting corneal and vitreoretinal diseases that underwent combined keratoprosthesis/PPV/PK surgery were retrospectively evaluated. Demographic characteristics, visual acuity (VA), intraocular pressure (IOP) and clinical findings of the cornea, lens, and retina were recorded during the follow-up. Cases with clear corneal graft, attached retina, normotonic IOP, and improved or stable VA were considered successful.Results:Eight eyes were enrolled in the study. The mean follow-up time was 21.1±8.20 months. Surgery was performed a mean of 23 (10-40) days after trauma. Preoperative VA ranged from no light perception to counting fingers from 50 cm. Postoperatively, corneal graft was clear in 5 patients (62.5%) and retina was attached in 6 eyes (75%). Chronic hypotonia developed in 3 patients (37.5%). VA was unchanged in 3 patients and improved in 5 patients. A total of 5 cases (50%) were considered successful. Shorter interval between trauma and surgery was associated with higher likelihood of success (p=0.043). No significant difference was observed between the groups in terms of type or location of trauma (p=1; p=0.143).Conclusion:Although the functional results are not very satisfactory, the combined procedure provides a final opportunity for preserving remaining vision and anatomic reconstruction in eyes that will otherwise result in phthisis due to severe anterior and posterior segment pathologies.

Combined Keratoplasty, Pars Plana Vitrectomy, and Flanged Intrascleral Intraocular Lens Fixation to Restore Vision in Complex Eyes With Coexisting Anterior and Posterior Segment Problems.

To restore vision in complex eyes with coexisting anterior and posterior segment problems, combined corneal transplantation (penetrating keratoplasty [PK] or Descemet-stripping automated endothelial keratoplasty [DSAEK]), pars plana vitrectomy (PPV), and/or flanged intrascleral intraocular lens (IOL) fixation, designated vitreocorneal surgery are performed. In this study, we evaluated the usefulness of vitreocorneal surgery for eyes with complex comorbidities. Thirteen consecutive eyes in 13 patients with coexisting corneal pathology (ie, corneal scarring, bullous keratoplasty, corneal laceration) and posterior segment pathology (ie, aphakia without capsular support, retinal detachment, intravitreal foreign body) underwent vitreocorneal surgery. Visual outcomes, intraoperative and postoperative complications, and additional surgery were retrospectively evaluated. Vitreocorneal surgery included PK + PPV + intrascleral IOL fixation (n = 5), PK + PPV (n = 3), PK + intrascleral IOL fixation (n = 1), DSAEK + intrascleral IOL fixation (n = 1), and DSAEK + PPV + intrascleral IOL fixation (n = 3). An intraoperative Eckardt temporary keratoprosthesis use enabled safe PPV. No vitreoretinal/IOL complications occurred. One eye required repeat DSAEK to repair endothelial graft detachment and inversion. In 3 eyes, secondary glaucoma was subsequently treated by glaucoma drainage device implantation through the pars plana. Mean best spectacle-corrected visual acuity (logMAR) improved from 1.8 ± 0.9 preoperatively to 1.1 ± 0.6 at 11.2 ± 14.6 months postoperatively (P = 0.002). Postoperative refraction was -0.68 ± 2.56 D (spherical equivalent). PK or DSAEK with PPV and/or flanged intrascleral IOL fixation is useful for complex eyes with coexisting anterior and posterior segment problems.

Penetrating keratoplasty in patients with traumatic corneal scarring.

To evaluate the results of penetrating keratoplasty (PK) due to trauma-related corneal scarring. We evaluated 24 eyes of 24 patients who underwent PK due to trauma-related scarring of the cornea between May 2010 and June 2016. The postoperative visual acuity, graft transparency, and complications were evaluated. The patients were divided into two groups. In group 1, 14 eyes of patients with traumatic corneal scars and retinal detachment underwent PK, pars plana vitrectomy, and intravitreal silicone administration with the help of temporary keratoprosthesis. Group I included five females and nine males with an average age of 39.15+-13.32 (min 8-max 73) years. An intraocular foreign body was removed from five of the eyes. The mean visual acuity was 3.01+-0.013 (3.10-1.00) logMAR after the surgery, 1.36+-0.23 (3.10-0.80) at the postoperative first month, and 1.18+-0.03 (3.10-0.70) at the end of the first year after the removal of keratoplasty sutures. During the follow-up of patients, two eyes (14.2%) lost light sensation, eight eyes (57.1%) developed postoperative glaucoma, nine eyes (64.2%) had graft rejection, and one patient (7.1%) developed keratitis. In one eye (7.1%), the cornea was scraped using ethylenediaminetetraacetic acid due to silicone-related band keratopathy. In group 2, ten eyes with trauma-related corneal scars underwent PK. This group included two females and eight males with an average age of 29.23+-12.03 (11-63) years. The mean visual acuity was 2.98+-0.68 (3.10-1.00) logMAR before the surgery, 0.58+-0.22 (1.80-0.30) at the postoperative first month, and 0.50+-0.17 (1.80-0.10) at the end of the first year. One eye (10%) with iridodialysis developed glaucoma. Rejection was not seen in any of the patients. A statistically significant difference was observed in both groups with regard to visual acuity before operation, at 1 and 12 months after operation, and at 12 months for graft transparency rates (p=0.015, p=0.021, p=0.001, respectively). In cases of eye injuries due to trauma, the eyes subjected to combined vitrectomy and PK had poor visual prognosis and high graft rejection rate compared to those subjected to PK as the only treatment.

Observation on the efficacy of keratoplasty combined with cataract and vitreoretinal surgery for severe ocular injuries

Objective To observe the efficacy of keratoplasty combined with cataract and vitreoretinal surgery under temporary keratoprosthesis for the treatment of anterior and posterior segments severe ocular injuries. Methods The data of 18 eyes of 16 cases with anterior and posterior segments severe ocular injuries were collected and analyzed retrospectively. They received combined surgery under temporary keratoprosthesis.The etiology, operation indication, anterior and posterior segment functional restoration and complications were analyzed.The followed-up period was 10-48 months. Results The visual acuity after surgery were improved in 15 eyes(83.33%). Transparent grafts occurred in 8 eyes(44.44%)after operation.Corneal translucence occurred in 3 eyes(16.67%). The rejective corneal grafts of 7 eyes(38.89%) were cloudy and swelling. Among them, corneal grafts were not rejected after secondary corneal transplantation in 4 eyes.Four eyes(22.22%) with retinal detachment were followed up for retinal reposition, and they received silicone oil tamponade.Secondary glaucoma happened in 2 eyes (11.11%). Medicine conservative treatment was invalid. After trabeculectomy the normal intraocular pressure was controlled.No persistent low intraocular pressure was found. The eyeball structure integrity of 18 eyes were preserved. Conclusion Keratoplasty combined with cataract and vitreoretinal surgery under temporary keratoprosthesis for the treatment of anterior and posterior segments severe ocular injuries is effective. Key words: Ocular injury, severe; Keratoprosthesis, temporary; Keratoplasty, penetrating; Surgery, cataract; Surgery vitreoretinal

Rigid Gas Permeable Lens Intraocular Foreign Body following Blunt Trauma

A 76-year-old man with a history of penetrating keratoplasty (PK) for advanced keratoconus was struck in the eye by a fist, resulting in partial dehiscence of the graft and extrusion of the crystalline lens. Globe repair was performed with the existing graft (Fig 1A). Initial cornea clearing revealed the rigid gas permeable (RGP) lens the patient was wearing at the time of trauma, which was retained in the vitreous cavity with no sign of infection (Fig 1B). The graft eventually opacified and the patient underwent successful surgery with temporary keratoprosthesis, pars plana vitrectomy, removal of the RGP, and cornea graft placement (Magnified version of Fig 1A-B is available online at www.aaojournal.org).

Feasibility study on robot-assisted retinal vascular bypass surgery in an exvivo porcine model.

To describe a new robot-assisted surgical system for retinal vascular bypass surgery (RVBS) and to compare the success rate with freehand RVBS. A robot-assisted system for retinal microsurgery was constructed to include two independent robotic arms. A 23-gauge light probe and an intraocular forceps were affixed to the arm end effectors to perform the intraocular manipulation. Harvested porcine eyes were introduced to be established animal models of closed-sky eyeballs after that pars plana vitrectomy using temporary keratoprosthesis was performed by a skilful surgeon. Retinal vascular bypass surgery (RVBS) was performed by an inexperienced ophthalmologist to test the ease of use. A stainless steel wire (45-μm pipe diameter) was used as an artificial vessel. Before RVBS, the wires were prepositioned at the retinal surface of the eyes. The Control group (n=20) underwent freehand RVBS, and the Experimental group (n=20) underwent robot-assisted RVBS. To create the simulated bypass, the distal end of the wire was inserted into the selected vessel and advanced ~4mm away from the optic disc. If successful, then the proximal wire end was inserted and advanced ~2mm towards the optic disc. The difference in the success rate for the freehand and robot-assisted procedures was analysed by the chi-square test. The success rate for the freehand RVBS was 5% (1/20 eyes). In contrast, the robot-assisted success rate was 35% (7/20) of eyes (p<0.05). This study demonstrated the feasibility of robot-assisted RVBS in exvivo porcine eyes. The robotic system increased the accuracy and stability of manipulation by eliminating freehand tremor, leading to a higher surgical success rate.

Posttraumatic endophthalmitis due to tobacco drying wire treated with vitrectomy, temporary keratoprosthesis, and keratoplasty

AIM. To report a case of posttraumatic endophthalmitis with corneal opacity that was treated by combined penetrating keratoplasty using temporary keratoprosthesis and pars plana vitrectomy (PPV) with silicon oil tamponade. CASE PRESENTATION. A 35-year-old woman was admitted to our clinic after open globe injury due to wire used for tobacco drying. At the time of her first visit, her best-corrected visual acuity was light perception. On the day of admission a 20-G PPV with phacoemulsification and vancomycin administration in tapping was performed. The operation was aborted due to visualisation constraints. Four days later 20-G PPV in combination with penetrating keratoplasty with use of temporary keratoprosthesis and silicon oil tamponade was performed. General and topical antibiotics and topical antifungal drugs were administered. Five months after hospitalisation visual acuity was light perception, and the corneal graft remained clear, but proliferative vitreoretinopathy was observed. CONCLUSIONS. Combined penetrating keratoplasty using temporary keratoprosthesis and PPV could be advantageous in managing visualisation constraints due to posttraumatic endophthalmitis; however, functional results are not satisfactory.

Penetrating Ocular Trauma with Retained Intraocular Foreign Body: Management, Follow-up and Medico-legal Evaluation.

Ocular trauma is the leading cause of acquired monocular blindness, accounting for 1.97-6% of such cases. Particularly, penetrating ocular injuries are among the most common eye injuries with this kind of outcome. Early diagnosis and prompt management are crucial to avoid complications, and the especially dreaded enucleation. In this article, the authors describe the clinical management, and evaluate the visual and anatomical results obtained in a case of ocular injury with retained intraocular foreign body (IOFB) in a 20-year old female patient. The course of treatment involved a combination of penetrating keratoplasty with a temporary keratoprosthesis, phacoemulsification with intraocular lens implantation and pars plana vitrectomy. At three years from the initial injury, the patient was able to count fingers at 30 centimetres and anatomical restitutio ad integrum of the globe had been achieved.

Wide-Field Landers Temporary Keratoprosthesis in Severe Ocular Trauma: Functional and Anatomical Results after One Year.

Purpose. To evaluate longitudinal functional and anatomical results after combined pars plana vitrectomy (PPV) and penetrating keratoplasty (PKP) using a wide-field Landers intraoperative temporary keratoprosthesis (TKP) in patients with vitreoretinal pathology and corneal opacity due to severe ocular trauma. Material and Methods. Medical records of 12 patients who had undergone PPV/PKP/KP due to severe eye trauma were analyzed. Functional (best-corrected visual acuity) and anatomic outcomes (clarity of the corneal graft, retinal attachment, and intraocular pressure) were assessed during the follow-up (mean 16 months). Results. Final visual acuities varied from NLP to CF to 2 m. Visual acuity improved in 7 cases, was unchanged in 4 eyes, and worsened in 1 eye. The corneal graft was transparent during the follow-up in 3 cases and graft failure was observed in 9 eyes. Silicone oil was used as a tamponade in all cases and retina was reattached in 92% of cases. Conclusions. Combined PPV and PKP with the use of wide-field Landers TKP allowed for surgical intervention in patients with vitreoretinal pathology coexisting with corneal wound. Although retina was attached in most of the cases, corneal graft survived only in one-fourth of patients and final visual acuities were poor.

In Vivo Retinal Vein Bypass Surgery in a Porcine Model

Purpose: To evaluate the feasibility of retinal vein bypass surgery for induced branch retinal-vein occlusion (BRVO) in the living porcine eye.Methods: Fifteen minipigs were used in the study. Seven days before vascular surgery, hyaluronidase and plasmin were intravitreally injected for induction of posterior vitreous detachment. Aspirin and warfarin were oral administered daily starting 5 d prior to vascular surgery for anti-coagulation. The minipigs were anethetized with an intraperitoneal injection of 300 mg/kg chloral hydrate for intravitreal injection procedure and vascular surgery. Temporary keratoprosthesis vitrectomy was performed, and intraoperative video fluorescein angiography (VFA) was possible. The central and posterior vitreous was removed together with the posterior hyaloid membrane to facilitate vascular maneuvers. BRVO was induced by bipolar diathermy on the vein at the main vein’s first branching. Polyimide tubes (50.8-μm internal diameter and 7.6-μm wall thickness) were used as artificial vessels. Vascular manipulation was performed in a bimanual manner. Both end of a prepared tubing was inserted into venous lumen by puncturing and catheterization, and the vein bypass bridging the occlusion was created. Then, the patency of the bypass graft was assessed by intraoperative VFA.Results: The retinal vein bypass surgery was surgically accomplished in 33% (5/15) of the eyes, and the immediate graft patency was confirmed by intraoperative VFA only in one eye. We observed and recorded fluorescein flow from the branch vein to the main vein through the bypass graft which bridging the occlusive vein segment.Conclusions: We demonstrated the feasibility of retinal vein bypass for induced BRVO in the living porcine eye, and the immediate graft patency was successfully evaluated by intraoperative VFA. Despite the potential, there are still some significant hurdles in vivo retinal vein bypass surgery, and modification of both surgical instruments and maneuvers is needed for further study.