Vitreous Removal Research Articles

Delayed-Onset Streptococcus Pyogenes Endophthalmitis Following Ahmed Glaucoma Valve Implantation

To report a case of delayed-onset Streptococcus pyogenes endophthalmitis following implantation of an Ahmed glaucoma valve. A 10-year-old patient presented with acute endophthalmitis 1 year after Ahmed glaucoma valve implantation. The conjunctiva and Tenon's capsule over the valve plate had been penetrated by one of the polypropylene fixation sutures. The valve was removed, and pars plana vitrectomy was performed. Vitreous specimens and removal of the discharge over the plate revealed Streptococcus pyogenes. This is the first documented case of Streptococcus pyogenes endophthalmitis following Ahmed glaucoma valve implantation. We think the conjunctival buttonhole caused by the polypropylene suture provided an entry site for the infection.

Glaskörperchirurgie mit Trypanblau bei der Behandlung von PVR-Netzhautablösungen

In our clinic we used trypan blue staining routinely for removal of internal limiting membranes (ILM) and epiretinal membranes (ERM) during vitreoretinal surgery for PVR retinal detachment. We treated 27 eyes of 27 patients with severe PVR retinal detachment with vitreoretinal surgery. After complete vitrectomy and removal of epiretinal membranes we injected 0.15 % trypan blue solution and proceeded with further removal of the visualized remaining epiretinal membranes and ILM. We performed relaxing retinotomies in 14 eyes. Follow-up lasted six months. After the first surgery the retina was reattached in 24 of 27 eyes and after the second surgery in all eyes. The final visual acuity was: hand movements in 3 eyes, 1/50 or better in 24 eyes (eight of them had a visual acuity of 0.1 - 0.5). No case of macular pucker was observed during the follow-up. Trypan blue staining during vitreoretinal surgery in PVR retinal detachment therapy allows complete removal of ILM, ERM, and peripheral vitreous. It upgrades the quality of the surgery.

REMOVAL OF ADHERENT CORTICAL VITREOUS PLAQUES WITHOUT REMOVING THE INTERNAL LIMITING MEMBRANE IN THE REPAIR OF MACULAR DETACHMENTS IN HIGHLY MYOPIC EYES

To report anatomic and visual improvement after vitrectomy with removal of adherent plaques of vitreous and gas tamponade in highly myopic eyes with detachments over posterior staphylomata. Eyes with retinal detachment over staphylomata were treated with vitrectomy and vitreous cortex removal. Adherent plaques of vitreous were invariably found on the detached retina and were easier to identify with the aid of intraocular triamcinolone. Removal of the vitreous plaques and placement of long-acting gas affected surgical repair. Outcome measures included best-corrected visual acuity and retina reattachment confirmed by biomicroscopic appearance and optical coherence tomography findings. Six eyes of five consecutive patients were treated. The mean preoperative best-corrected visual acuity was 20/100, and the mean time of documented detachment was 21 months. The internal limiting membrane was not removed in any patient. After surgery, all patients' retinas remained attached during the mean follow-up period of 19.1 months. At the end of the follow-up period, the mean best-corrected visual acuity was 20/60, an improvement that was statistically significant (P = 0.027). Retinal detachment over staphylomata in highly myopic eyes appears to be tractional from unresolved forces caused by adherent plaques of vitreous. Removal of the vitreous, without removing the internal limiting membrane, can reattach the retina and lead to anatomic and visual acuity improvements.

Combined phacoemulsification and pars plana vitrectomy for macular hole treatment

To assess the outcome of simultaneous phacoemulsification, pars plana vitrectomy and intraocular lens (IOL) implantation in eyes with macular hole. A retrospective study was conducted in 38 eyes (36 patients) after combined phacoemulsification, insertion of a posterior capsule IOL and pars plana vitrectomy. The macular hole was successfully closed in 32 of the 38 eyes (84%). In six eyes (16%) the hole failed to close and one eye underwent a second operation. Vision improved by two or more Snellen lines in 29 eyes (73%), there was no change in seven eyes (18%), and visual acuity decreased in two eyes (5%). Intraoperative and postoperative complications included retinal tears in nine eyes (24%), posterior capsule rupture in two eyes (5%), transient postoperative increase of intraocular pressure in eight eyes (21%), and posterior capsule opacification in five eyes (13%). Combining phacoemulsification, IOL insertion and pars plana vitrectomy for macular hole repair can reduce the need for cataract surgery in the future, decrease costs, shorten postoperative recovery time and allow for clearer intraoperative visualization, making the procedure safer and more effective.

Combined pars plana vitrectomy and phacoemulsification to restore visual acuity in patients with chronic uveitis

To report the outcomes of combined phacoemulsification and pars plana vitrectomy (PPV) to restore visual acuity in patients with cataract and posterior segment involvement secondary to chronic uveitis. Ocular Immunology and Uveitis Service, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA. This study comprised 34 patients (20 women, 14 men; 36 eyes) with posterior segment involvement secondary to chronic uveitis who had combined phacoemulsification and PPV from 1998 to 2002. The main outcome measures were visual acuity, intraocular pressure, and cystoid macular edema. The mean patient age was 45 years +/- 16.09 (SD). The mean duration of uveitis before surgery was 56 +/- 44.17 months. In 24 eyes (66.7%), an intraocular lens (IOL) was implanted during surgery; 12 eyes (33.3%) were left aphakic. Five eyes (13.8%) received an intraocular steroid injection intraoperatively. Visual acuity improved in 26 eyes (72.2%), deteriorated in 5 (13.9%), and was unchanged in 5 (13.9%). The main reason for decreased visual acuity was refractory macular edema. During the follow-up, 2 IOLs were explanted secondary to lens intolerance. One IOL was repositioned because of iris capture by the haptics, and 1 dislocated inferiorly, causing monocular diplopia. The mean follow-up was 23.4 +/- 16.7 months. Results indicate that combined phacoemulsification and PPV is a feasible technique for the removal of cataract and pathologic vitreous in eyes with chronic uveitis. Although the exact role of vitrectomy in patients with uveitis remains to be determined, the combined surgery successfully restored useful vision in most cases.

Potent retinal arteriolar traction as a possible cause of myopic foveoschisis

To report retinal microfold formation after vitrectomy for myopic foveoschisis (MF). Prospective observational study. We observed 21 eyes of 17 patients who had undergone vitrectomy for MF with optical coherence tomography (OCT) in this institutional study. We also evaluated the three-dimensional retinal architecture using the OCT-ophthalmoscope in selected cases. Vitrectomy included core vitrectomy, vitreous cortex removal, internal limiting membrane (ILM) peeling with indocyanine green, and gas tamponade. Horizontal linear folds were commonly observed postoperatively. The folds, which were 1,000 to 2,000 microm superior, inferior, or both superior and inferior to the fovea, were detected only by OCT and not by conventional slit-lamp-based biomicroscopy. The microfolds were found in only five eyes (24%) 1 month postoperatively. The incidence increased over time, however, and a microfold was detected in nine eyes (43%) 3 months after surgery and in 13 (62%) 6 months after surgery. OCT-ophthalmoscope examination confirmed the location of the microfold coincided exactly with that of retinal arteriole. The presence of microfolds was not significantly related to the postoperative visual acuity. Retinal microfolds are common in eyes with MF after vitrectomy with ILM peeling, and they seem to be generated as the result of insufficient flexibility of the sclerotic retinal arteriole during axial length elongation in highly myopic eyes. This finding suggests that the inward tractional force on the retina along the arteriole may be closely related to the pathogenesis of vitreoretinal diseases specific to high myopia, including MF or paravascular microhole formation.

Surgical treatment of diabetic retinopathy.

Several complications of advanced diabetic retinopathy can be treated surgically. Vitrectomy can clear media opacities, relieve traction on the retina, and makes adequate laser treatment of the retina possible. Removal of premacular vitreous may also improve diabetic macular edema. Instrumentation, understanding of the pathophysiology, surgical skills as well as supplementary pharmacotherapy have improved surgical results. Indications and timing for surgery have considerable changed in the past decades threshold for surgery has been continuously lowered, as vitrectomy became safer. The primary disease of the retinal microvasculature with capillary occlusion and retinal ischemia is still the limiting factor, responsible for disappointing functional results in anatomically successfully operated eyes.

Vitrectomy and internal limiting membrane peeling for myopic foveoschisis

Purpose Myopic foveoschisis is common in high myopia. We report results of a pilot study of vitrectomy for patients with myopic foveoschisis. Design Interventional case series. Methods In an institutional setting five patients with high myopia (six eyes), and who had progressive visual impairment presumably due to myopic foveoschisis were studied. No eyes had a macular hole preoperatively based on optical coherence tomography (OCT). We performed vitrectomy including vitreous cortex removal, internal limiting membrane (ILM) peeling, and gas tamponade. Patients were followed for at least 6 months. Best-corrected visual acuity (BCVA), OCT. Scanning laser ophthalmoscope (SLO) microperimetry was examined in three eyes. Results The foveal detachment resolved completely in five eyes and partially in one eye. No serious complications developed including macular hole formation or retinal detachment; BCVA improved more than two lines in all eyes (100%) 6 months postoperatively ( P < .01); SLO microperimetry showed smaller scotoma compared with preoperatively and stabilized fixation. Conclusions Vitrectomy with vitreous cortex removal, ILM peeling, and gas tamponade could be useful to treat myopic foveoschisis in highly myopic eyes. Because the natural course of the disease is not well-understood, further study should establish indications for this surgery.

Perfluorocarbon perfused vitrectomy: animal studies

PurposeTo investigate the feasibility and advantages of using perfluorocarbon liquid (PCL) perfusion to remove vitreous during suction-cutting vitrectomy in rabbit and pig eyes. DesignExperimental study. MethodsBalanced salt solution (BSS) was replaced by PCL perfusion during experimental vitrectomy. Oxygenated or nonoxygenated PCL was used in a recycling or a nonrecycling system. Recycling was achieved by two systems: a manual recycling system or a closed-loop system. The experiments in this study consisted of: an in vitro solubility observation, safety and feasibility of vitrectomy in rabbit eyes, effectiveness of vitrectomy with equal vitrectomy time in rabbit eyes, and retinal stability and pigment and blood dispersion in porcine eyes. Toxicity was assessed by a complete ophthalmic examination, endothelial cell count, electroretinography, and histopathology. ResultsVitreous, blood, and pigments were immiscible in PCL. Manual recycling required less amounts of PCL than nonrecycling (15 vs 25 cc). Oxygenated and nonoxygenated PCL were not toxic. Perfluorocarbon liquid infusion removed more vitreous than balanced salt solution in a 3-minute vitrectomy time using the same settings on the vitrectomy machine. The PCL infusion in porcine eyes stabilized the retina and isolated vitreous cavity from pigment and blood and maintained a clear vitreous cavity. ConclusionsThese data indicate that perfusion of PCL can be used to remove vitreous with a suction-cutting probe in rabbit and pig eyes. Retinal stability and isolation of the vitreous cavity at the time of vitreous removal along with PCL immiscibility and its specific gravity suggest that PCL has a potential clinical use as an irrigating solution to remove vitreous.

Retinal detachment rate after vitrectomy for retained lens material after phacoemulsification

Purpose To report the rate of retinal detachment after vitrectomy for retained intravitreal lens material after phacoemulsification using specific vitrectomy techniques designed to minimize retinal detachment. Design Consecutive, interventional case series. Methods Retrospective chart review of 100 consecutive eyes (one surgeon) of 100 patients undergoing vitrectomy for retained lens material after phacoemulsification and followed up for 3 months or longer unless an outcome event had occurred. Vitrectomy techniques employed to minimize the frequency of retinal detachment included inducing posterior vitreous detachment with maximal vitreous removal before phacofragmentation to avoid vitreous trauma, lens fragment debulking before fragmentation, use of low energy with high aspiration during removal of retained lens material, and intraoperative indirect ophthalmoscopic evaluation of the retinal periphery with scleral indentation to diagnose and treat intraoperative retinal breaks. The main outcome measures included prevalence of coexisting retinal detachment in eyes with retained lens material, incidence of retinal detachment or retinal breaks after vitrectomy for removal of retained lens material, and final visual acuity. Results The prevalence of previtrectomy retinal detachment was 4%; the incidence of postvitrectomy retinal detachment was 4%; the final visual acuity was 20/40 or better in 53%. One patient had a retinal break recognized during vitrectomy and was treated with retinocryopexy, but postoperative retinal detachment developed from a separate break. Three others were treated during vitrectomy for retinal breaks (including two with known preexisting breaks) and did not have any retinal detachment. Poor previtrectomy visual acuity (hand motions) was a risk factor for postvitrectomy retinal detachment. Conclusions The rate of retinal detachment reported after vitrectomy for retained lens material after phacoemulsification can be minimized to approximately the rate expected with cataract extraction complicated by vitreous loss by employing standard surgical techniques. Higher risk eyes may benefit from more frequent postvitrectomy examinations.

Phacoemulsification and intraocular lens implantation following pars plana vitrectomy: a prospective study.

To examine the intraoperative characteristics of phacoemulsification in eyes that had undergone pars plana vitrectomy and to determine complication rates and visual outcomes. A prospective study of 45 consecutive cataract operations on vitrectomised eyes performed over a 9-month period by a single surgeon. Data were collected on preoperative characteristics, intraoperative observations and complications, postoperative complications, and visual acuities. Zonular laxity with abnormal deepening of the anterior chamber and mydriasis was noted in six eyes that had undergone extensive vitreous removal for the treatment of retinal detachment or proliferative diabetic retinopathy, but not in eyes that had had limited 'core vitrectomy' such as for macular hole or epiretinal membrane. In two eyes, the initial deepening of the anterior chamber was accompanied by paradoxical shallowing with miosis (the 'infusion deviation syndrome'). Sight-threatening complications were rare. Snellen visual acuity improved in 84.6% of eyes previously treated for 'macular hole, 85.7% of eyes treated for 'macula-on' retinal detachment, 66.7% of eyes treated for 'macula-off' retinal detachment, and 57.1% of eyes treated for diabetic retinopathy. Surgeons need to be aware of additional challenges arising from zonular instability in eyes that have had extensive vitreous removal. A lower infusion bottle height may guard against sudden changes in anterior chamber depth. The use of a corneal tunnel avoids difficulties associated with an unusually deep anterior chamber. Visual acuity is less likely to improve in patients previously treated for diabetic retinopathy or for macula-off retinal detachment.

Transcriptional Up-regulation of the Protooncogenes c-fos and c-jun Following Vitreous Removal and Short-term in vitro Culture of Bovine Lenses

Chemical (mainly oxidative) and mechanical (anterior capsule injury) stresses have been reported to up-regulate the expression of the protooncogenes c-fos and c-jun in the lens. Another potentially stressful, yet largely unexplored condition, inherent to all experiments requiring the in vitro culturing of isolated lenses, is vitreous removal. Based on the results of an extensive RNA gel blot analysis conducted on epithelial/capsule preparations isolated from calf lenses dissected and cultured under different conditions, we show, here, that lens isolation and short-term culture (1–2.5hr, without any significant GSH depletion) result in a strong and time-dependent up-regulation of the c-jun and c-fos mRNAs. This response, which relies on transcriptional protooncogene activation and is more intense for c-fos than for c-jun, is in part prevented by the preservation of the lens-vitreous contact, but not by the culture of vitreous-stripped lenses on a vitreous bed. Supplementation of the culture medium with the antioxidant N -acetyl-cysteine slightly reduced the c-jun, but not the c-fos response. Protooncogene up-regulation thus appears to be mainly determined by the disruption of critical lens–vitreous interactions. Since this response takes place in the epithelial cells, these data also point to the existence of a communication mechanism whereby a posteriorly applied mechanical stress is transmitted to, and perceived by, the anterior lens surface.

Advantage of combined procedure in vitreous surgery

Lens preservation facilitates the progression of nuclear cataracts after vitreous surgery among patients over 45 years old, and postoperative nuclear cataracts frequently necessitate intraocular lens surgery. Once the lens is removed, the fundus from the posterior pole to the ciliary process becomes recognizable and surgically reachable, thus making total vitreous removal possible. The complete removal of the incarcerated vitreous to the scleral wound prevents postoperative vitreous base tears, and anterior hyaloidal fibrovascular proliferation. Simultaneous vitreous surgery plus intraocular lens surgery (triple surgery) will prevent these complications before they arise. Triple surgery for patients over 45 years of age is reasonable even if they have amplitude of accommodation, and is an effective surgical strategy in that it improves both the result of the vitreous surgery and the patient’s quality of life.

Indocyanine green–assisted peeling of the retinal internal limiting membrane

Objective To determine whether indocyanine green (ICG) stains and facilitates peeling of the retinal internal limiting membrane (ILM). To investigate the different staining properties of the posterior cortical hyaloid, retinal ILM, and the retina after ILM removal. Design Autopsy eye study. Materials Eleven human cadaveric eyes. Methods Open sky vitrectomy including removal of the posterior cortical vitreous was performed. A 0.5% ICG solution was then injected into the posterior vitreous cavity over the macula. The dye was allowed to settle on the macula for 5 minutes and was then removed by mechanical aspiration. Peeling of the ILM was initiated with a bent needle and completed with intraocular forceps. Specimens were submitted for light and electron microscopy. Main outcome measures Staining properties and ease of peeling of retinal ILM were evaluated. Retinal ILM removal was confirmed by histopathologic and electron microscopic examination. Results ICG contact with the retinal surface resulted in bright green staining of the ILM. This stain greatly facilitated ILM peeling by improving direct visualization of the membrane. The underlying retina did not stain, thus providing a clear distinction between the stained ILM and the unstained retina. Continuous circular peeling of the ILM was easily completed with this technique. Light microscopic and ultrastructural studies confirmed removal of the ILM. Conclusions ICG solution distinctly stains the nearly invisible retinal ILM in human cadaveric eyes. ICG staining greatly facilitates ILM peeling by providing a stark contrast between the stained ILM and the unstained retina.

Use of the Multifocal Electroretinogram to Evaluate Retinal Function After Pars Plana Vitrectomy for Diabetic Macular Edema

Purpose: Multifocal electroretinograms (multifocal ERGs) were performed to evaluate retinal function in patients with diabetic macular edema. Materials and Methods: Eight eyes of 5 patients underwent pars plana vitrectomy for diabetic macular edema. Multifocal ERGs, fundus examinations, and fluorescent angiographies were done both before and after the operation. Results: Post-operative visual acuity was improved by two or more lines in 3 eyes. In multifocal ERGs, the amplitude of the positive wave (P1) from the macular area decreased transiently after surgery ( P < 0.05), but it improved with the passage of time. The P1 amplitude from the peripheral area was decreased throughout the observation period of six months ( P < 0.05). For both areas, the P1 latency was increased significantly ( P < 0.05) at one month post-operatively, and then decreased. Conclusion: These findings are consistent with the possibility that the surgical method, especially removal of the posterior cortical vitreous, can cause retinal damage. (J Jpn Ophthalmol Soc 103:464–469, 1999)

Anterior hyaloid face opacification after pediatric Nd:YAG laser capsulotomy

Purpose: The purpose of this study was to examine the clarity of the visual axis after Nd:YAG laser capsulotomy following cataract extraction and primary intraocular lens implantation in a pediatric population. Methods: A retrospective review was performed of all cases of cataract extraction and primary intraocular lens implantation over a period of 5 years. A group of children who had been treated by primary surgical posterior capsulotomy and anterior vitrectomy (Group 1) was used as the “gold standard,” with whom the children treated with Nd:YAG laser capsulotomy (Group 2) were compared. The groups were studied for the incidence of opacification of the visual axis after the primary procedure. Results: Data on 78 eyes were reviewed, and 56 eyes met inclusion criteria. Of these, 33 eyes were treated with primary posterior capsulotomy and anterior vitrectomy (Group 1) and 23 eyes were treated with Nd:YAG laser capsulotomy (Group 2). One eye (3%) of Group 1 experienced postoperative visual axis reopacification. Thirteen (57%) of 23 eyes in Group 2 experienced reopacification, requiring retreatment. Four eyes (17%) treated with Nd:YAG laser required a third treatment. Conclusions: In our series, 57% of patients treated with Nd:YAG laser capsulotomy experienced reopacification across the anterior hyaloid face. With the removal of the anterior vitreous at the time of cataract extraction, the scaffolding for cell migration is removed and reopacification of the visual axis is rarely seen. For patients in whom slit-lamp capsulotomy is not possible, especially if there is no Nd:YAG laser available for use in the operating room or when loss to follow-up may be an issue, primary posterior capsulotomy and anterior vitrectomy should be strongly considered. (J AAPOS 1999;3:303-7)

Macular hole surgery in conjunction with endolaser photocoagulation

PURPOSE: To determine whether endolaser photocoagulation to the retinal pigment epithelium at the base of a macular hole increases the anatomic success rate of surgery. METHODS: In a prospective consecutive clinical trial, eight eyes of seven patients with idiopathic macular hole underwent vitrectomy with posterior cortical vitreous removal and peeling of visible epiretinal membrane when present. A single shot of argon endolaser photocoagulation was applied to the retinal pigment epithelium at the center of the macular hole with a duration of 0.05 to 0.2 seconds and an intensity of 50 to 200 mW. After fluid-gas exchange was performed with 14% perfluoropropane gas, patients maintained face-down positioning for 2 weeks. RESULTS: One eye with stage 2 macular hole, six eyes with stage 3 macular hole, and one eye with stage 4 macular hole were included. All eight eyes had a closed macular hole (100% anatomic success rate) at final examination 6 to 12 months after surgery. Best-corrected visual acuity improved 3 or more lines on the Early Treatment Diabetic Retinopathy Study visual acuity chart in all eyes. Four (50%) of the eight eyes had a final visual acuity of 20/40 or better. CONCLUSIONS: Endolaser photocoagulation may be a useful adjunct to macular hole surgery but requires further investigation and long-term evaluation.

Idiopathic Macular Hole Following Vitrectomy: Implications for Pathogenesis

Attention to the pathogenesis and clinical features of macular hole formation has increased with the advent of therapy. The purpose of this study is to present three cases that occurred in atypical settings that may have important pathogenic implications. The authors conducted a retrospective study of three patients who presented with macular holes that developed 10 months to 5.5 years after previous vitrectomy. In each case, the cortical vitreous layer was absent in the region of the macula at the time of operation for the macular hole. The macular hole was successfully sealed and the visual acuity improved in all patients. All three cases in this report lacked an operculum, occurred long after vitreous removal, and had no evidence of any residual cortical vitreous. Macular hole formation in the absence of cortical vitreous suggests the possibility that the etiology of macular holes may involve a spontaneous umbo dehiscence rather than vitreous-induced surface traction. A mechanism involving a cystic degenerative process is proposed as the cause of atypical and typical macular hole formation.

Vitreous Substitutes

The removal of vitreous by surgical techniques was a great revolution in ophthalmic surgery. More recently, the development of vitreous substitutes has resulted in further advances. The publication of Drs Peyman and Schulman's small, though somewhat expensive, volume is particularly timely now that silicone oil, long-acting gases, and heavier-than-water perfluorocarbon liquids have been approved for clinical use by the Food and Drug Administration. There are but 3 chapters, each devoted to 1 of the vitreous substitute materials and each summarizing a wealth of basic science and clinical trial information as well as the techniques used for their surgical applications. In the opening pages of the book, credit is appropriately given to Paul A. Cibus, MD, and Leland C. Clark, Jr, PhD, for their pioneering work in silicone oil use in the development of fluorocarbon liquids. The silicone oil chapter devotes adequate attention to the complications of its use, ie, emulsification,

The role of retinotomy in an experimental rabbit model of proliferative vitreoretinopathy

PURPOSE. To create a model of proliferative vitreoretinopathy (PVR) using retinotomy with vitrectomy, cryotherapy, and platelet-rich plasma (PRP) injection, which more closely resembles the human pathophysiologic condition. METHODS. One hundred and twenty albino rabbits were divided into 10 groups of 12 rabbits each and underwent the following procedures: group 1, vitrectomy; group 2, cryotherapy; group 3, PRP intravitreous injection; group 4, retinotomy; group 5, retinotomy and vitrectomy; group 6, retinotomy and cryotherapy; group 7, retinotomy and PRP injection; group 8, retinotomy, vitrectomy, and cryotherapy; group 9, vitrectomy, cryotherapy, and PRP injection and group 10, retinotomy, vitrectomy, cryotherapy, and PRP injection. All animals underwent follow-up examinations with indirect ophthalmoscopy and fundus photography on days 1, 3, 7, 10, 14, 21, and 28 after the procedure(s). Retinal changes were categorized according to the classification of Fastenberg et al. At the end of the experiments, the eyes were enucleated, and examined under light and electron microscopy. RESULTS. No retinal detachments (RDs) were observed in groups 1, 2, 4, 5, 6, and 8. RDs of varying severity were observed in group 3 (n = 1), group 7 (n = 2), group 9 (n = 6), and group 10 (n = 12). Light and transmission electron microscopy confirmed the findings. CONCLUSIONS. Combining retinotomy with vitreous removal, cryotherapy, and PRP injection creates an efficient and different model of PVR that produced RD in 100% of rabbit eyes.