Scleral Incision Research Articles

Clinical course and outcomes in patients with Mooren ulcer who had cataract surgery

To report outcomes of cataract surgery in patients with Mooren ulcer. L.V. Prasad Eye Institute, Hyderabad, India. Retrospective case series. The medical records of patients with Mooren ulcer who had cataract surgery between 2000 and 2015 were assessed. The main outcome measures were the role of preoperative immunosuppression and disease inactivity, cataract surgery safety, visual outcomes, and postoperative ulcer recurrence. Of 22 patients (26 eyes), the mean corneal ulceration was 6.8 clock hours±2.9 (SD). Corticosteroids were the most commonly used (84.6% of the 26 eyes) preoperative immunosuppression agents and 38.5% of the 26 eyes were under maintenance immunosuppression. The median disease inactivity before surgery was 7months. Cataract surgery was extracapsular in 10 patients, small incision in 3 patients, and phacoemulsification in 13 patients. Twenty-two eyes had scleral incisions. The median follow-up was 6months (interquartile range, 10months). The median corrected distance visual acuity (CDVA) improved from 1.48 logarithm of minimum angle of resolution (logMAR) before surgery to 0.30 and 0.35 logMAR at 1month and at the last follow-up after surgery, respectively (P≤.0001). Mooren ulcer recurred in 5 eyes between 3months and 7years after surgery. No disease activity was seen in the immediate postoperative period. No significant risk factors for disease recurrence were noted. With adequate immunosuppression, cataract surgery in eyes with Mooren ulcer was safe and CDVA improved significantly with no disease reactivation immediately after surgery. No proven role of maintenance immunosuppression was observed. The type of cataract surgery had no influence on ulcer reactivation. Patients with a disease-free interval of 6months or more before surgery and those who had scleral incisions had favorable outcomes.

Preliminary evaluation of the safety of the lens and the ora serrata during vitrectomy with scleral incisions at 5.0 mm behind the limbus

Objective To evaluate the safety to perform 23G vitrectomy with scleral incisions at 5.0 mm behind the limbus. Methods This is a prospective uncontrolled case study. The data of 140 consecutive primary 23G vitrectomy patients (145 eyes) were enrolled in this study. There were 56 males (59 eyes) and 84 females (86 eyes), with the mean age of (56.34±9.98) years and axial length of (23.99±2.57) mm. There were 139 phakic eye and 6 aphakic eyes. All the eyes received 23G pars plana vitrectomy with scleral incisions at 5.0 mm behind the limbus. To measure the normal Chinese adult parameters of anteroposterior axis of the eyeball, lens thickness and scleral distances from the limbus to the plane passing through the lens posterior apex, the head CT scans of 105 patients without eye diseases in our hospital were studied during the same period of time for these vitrectomy surgeries. Pearson correlation analysis was used to analyze the relationship between age, anteroposterior axis of eyeball, lens thickness and scleral distances from the limbus to the plane passing through the lens posterior apex. Results Surgical related complications included retinal tears close to the scleral incision sites (3/145 eyes, 2.1%) and lens injury (3/121 eyes, 2.5%). No other surgical complications occurred, such as retinal hemorrhage, supra-choroidal expulsive hemorrhage and iatrogenic retinal detachment. Based on CT images, the average scleral distance from limbus to the plane passing through the lens posterior apex, anteroposterior axis of eyeball and lens thickness was (6.72±0.81), (24.39±0.97), (4.22±0.47) mm, respectively. The results of Pearson correlation analysis showed that age and lens thickness had statistically significant correlation (r=0.328 9, P=0.000 6). Conclusion Primary 23G pars plana vitrectomy with incisions at 5.0 mm posterior to the limbus is safe. Key words: Lens, crystalline/injuries; Retinal perforations; Vitrectomy/adverse effects

Changes in corneal astigmatism during 20 years after cataract surgery

To examine how corneal astigmatism changes with age over 20years after cataract surgery and to assess whether the changes differ from those in eyes that did not have surgery. Hayashi Eye Hospital, Fukuoka, Japan. Retrospective case study. Using an autokeratometer, corneal astigmatism was measured preoperatively, at baseline (the day the surgically induced astigmatism stabilized), and 10years and 20years after baseline. The change in corneal astigmatism between baseline and 10years, 10years and 20years, and baseline and 20years was determined using power vector analysis and compared between the time intervals and between groups. The study assessed 74 eyes that had phacoemulsification with a horizontal scleral incision more than 21years ago (surgery group) and 68 eyes that did not have surgery (no-surgery group). The mean vertical/horizontal change in corneal astigmatism (J0) between baseline and 20years was -0.64 diopter (D) in the surgery group and -0.49 D in the no-surgery group. The oblique change (J45) was -0.03 D in the surgery group and 0.07 D in the no-surgery group. Using multivariate comparison, the mean J0 and J45 values were not significantly different between baseline and 10years or between 10years and 20years in both groups (P≥.2350). The J0 and J45 values were not significantly different between the 2 groups at any time interval (P≥.1331). Corneal astigmatism continues to change toward against-the-rule astigmatism over 20years after cataract surgery. This change was similar in eyes that did not have surgery.

Modification of the wound construction to prevent dehiscence of radial keratotomy incision in cataract surgery: Wave-shaped scleral incision

We describe a modified scleral tunnel incision to provide adequate fracture resistance and maneuverability during manipulations in cataract surgery after radial keratotomy (RK) surgery. In cases without sufficient space between the RK incisions to create a corneal incision, the modified incision can be performed. A scleral groove of one-half scleral thickness is made 3.0mm posterior to the limbus. The groove circumvents the end of the preexisting RK incision at the limbus. To prevent the incisional edge from sagging, the ends of the external incision are swept up slightly, forming a wave-shaped edge. After horizontal lamellar dissection, the wound construction is completed with a steel keratome. The modified incision was performed in 3cases after RK surgery. The method prevented dehiscence of the RK incision and provided fracture resistance and maneuverability.

Clinical observation on the interlaced non-phacoemulsification cataract extraction combined with intraocular lens implantation and keratoplasty

Objective To observe the efficacy of the interlaced non-phacoemulsification catatract extraction combined with intraocular lens implantation and keratoplasty(interlaced triple procedure). Methods Twelve eyes of 12 cases with cataract and keratonosus underwent the interlaced triple procedure.Nine cases of traumatic corneal leucom, 1 case of corneal degeneration, 1 case of viral keratitis and 1 case of fungal keratitis were collected. Surgery procedure: two-thirds thickness of corneal was trephined, then the scleral tunnel incision, capsulorhexis and delivery of nuclear were done. Then the cornea was trephined through and keratoplasty was completed. Finally, lens cortex was cleared and intraocular lens was implanted. Followed-up time was 1 - 3 years. The visual acuity, transparency and complications were observed. Results The uncorrected visual acuity of 11 eyes(91.7%) were improved compared with that of the preoperative.All the corneal grafts were completely transparent after operation in 2 weeks.Corneal grafts completely transparent after operation 1 year was in 9 cases.Corneal grafts of 1 case was semitransparent and 2 cases were moderately turbid. The total transparency rate was 75.00%.The complication was glaucoma in 1 case, and IOP was normal after trabeculectomy.The posterior capsule opacification occurred in 1 case, and the treatment was YAG laser.Two cases happened rejection. The rejection was controlled after anti-rejection therapy, and the corneal was opacity. Conclusion Triple procedure compared to the traditional triple procedure and staging surgery, the interlaced triple procedure can decrease postoperative complication and is high safety. Key words: Triple procedure, interlace; Small incision cataract extraction, non-phacoemulsification; Lens intraocular; Implantation; Keratoplasty, penetrating

Modified technique for intrascleral fixation of posterior chamber intraocular lens without scleral flaps

We present a modified technique for intrascleral fixation of a posterior chamber intraocular lens (IOL) without scleral flaps and assess its long-term safety and efficacy. The haptics of the IOL are externalized with a 23-gauge forceps and fixated in a scleral tunnel. Two clockwise scleral incisions are made using a 23-gauge needle at an angle 30 degrees above the sclera. A 3-piece IOL is inserted into the anterior chamber with an injector through the cornea incision, and the trailing haptic is kept outside to prevent the IOL from falling into the vitreous cavity. The leading haptic is held wit a forceps and extracted from the eye through the scleral incisions. The trailing haptic is held with a forceps and both haptics externalized onto the sclera. The conjunctival incisions are closed with 8-0 absorbable sutures tied to fixate 1 haptic (2 o'clock) after 1 more bite on the scleral bed.

Development of cooperative robot-assistant surgery system for vitreoretinal microsurgery and its feasibility test in an animal model

Background Robotic systems are increasingly utilized in numerous disciplines including ophthalmology.Several reports showed potential benefits of robotic-assisted surgery, such as increased precision and dexterity, elimination of tremor, task automation and shortening of learning curve.However, there is still no relative report in China. Objective The present study was to develop a novel robotic-assisted vitreoretinal microsurgery system and assess its overall capacities. Methods A robotic-assisted vitreous and retinal microsurgery system was cooperatively built by Eye Hospital of Wenzhou Medical University and Beijing University of Aeronautics.This platform has two mechanical arms, end-effector of each can grip common instruments such as vitrectomy cutter, illumination probe, laser probe, 23-gauge intraocular forceps.The intraocular surgical tasks were performed assisted by surgical robot on 15 fresh in vitro porcine eyes by three interns to test the feasibility of performing pars plana vitrectomy (PPV) and posterior vitreous detachment (PVD). Vitrectomy steps consisted of preparing three 23-gauge scleral incisions, inserting vitreous cutter towards vitreous and retina via the incisions, and using vitreous cutter to induce and remove a PVD assisted with triamcinolone.The duration and the successful completion of the task with or without complications or involuntary events was assessed. Results PPV and PVD procedures were successfully finished on 15 porcine eyes, and no noted deformation of eyeballs during surgery and no iatrogenic complication such as retinal tear or retinal detachment occurred after operations, with the successful rate 100%.The mean duration of surgery was (12.76±3.44) minutes among the 15 eyeballs and the mean duration for each operator was (13.67±4.23), (10.83±2.30) and (13.77±1.91) minutes, respectively. Conclusions Robotic-assisted vitreoretinal microsurgery system is varified to have good stability and accuracy in intraocular surgery, and the robotic surgical system may be technically feasible to preform human manual PPV and PVD procedures. Key words: Robotic surgical procedures; Robotics/instrumentation; Surgery, computer-assisted/methods; Vitrectomy/methods; Feasibility studies; Swine

Minimally Invasive Surgery for the Removal of Posterior Intraocular Foreign Bodies.

This is a prospective clinical assay that included six patients who were diagnosed with penetrating corneal injury, traumatic cataract, and posterior segment intraocular foreign body (IOFB). Following anterior segment repair and extraction of traumatic cataract by clear cornea phacoemulsification, a standard 25-gauge transconjunctival pars plana vitrectomy was performed to find and release the IOFB. With active suction using a 25-gauge silicone tipped cannula, the foreign body was retrieved and safely placed in the anterior chamber. After stabilization of the anterior chamber with viscoelastic injection, IOFB extraction through the main phaco incision was easily performed, followed by placement of an intraocular lens. Of the six patients, 66.6% showed a significant improvement of visual acuity. No complications associated directly with the surgical procedure occurred. Our surgical technique is a safe alternative for handling and removing a posterior IOFB. There was no need for a scleral incision.

Minimal duration cataract surgery with oblique limbal stab incision technique.

PURPOSE:Small incision cataract surgery (SICS) and phacoemulsification with oblique limbal stab incision technique were studied and compared.SETTING:The study was conducted in the Department of Ophthalmology, Indira Gandhi Medical College, Shimla, for 1 year.DESIGN:This was a prospective randomized study.METHODS:One hundred patients undergoing SICS (6–7 mm) were compared with another age- and sex-matched 100 patients undergoing phaco (2.8 mm) surgery with oblique limbal stab incision technique. These two groups were further subdivided into two groups of 50 each. Patients with traumatic cataract, corneal diseases, and preoperative astigmatism >1.5 D were excluded from the study. The patients were subjected to standard preoperative evaluation. Follow-up was done at 1, 2, 4, 6, and 12 weeks.RESULTS:Mean surgically induced astigmatism at 12 weeks was <1 D in both groups (+0.62 D ± 0.34 in Group A and +0.46 D ± 0.39 in Group B) (statistically significant P < 0.0010). Mean surgical duration was 690.09 s in SICS and 792.29 s in phacoemulsification (statistically significant, P < 0.0010). Visual outcome was between 6/6 and 6/9 in 86% of the patients in Group A and 97% of patients in Group B at 12 weeks.CONCLUSION:SICS and phacoemulsification with this technique yield lesser astigmatism than clear corneal and scleral incisions, with the advantage of extension without suturing in complicated cases of phaco and in patients with rigid intraocular lens phacoemulsification gives better BCVA in a larger proportion of patients at 12 weeks.

Анатомо-топографические особенности передних кортикальных слоев стекловидного тела

Introduction. The vitreous body (VB) is limited by anterior cortex (AC) layers, consisting of densely interconnected collagen fibers. There is no consensus regarding the structural AC organization and its relationship with the structures of the eyeball. Purpose. To study the anatomical and topographical features of the anterior cortical layers of VB. Material and methods . We developed an original method for contrasting the VB structures using an ultra-fine Vitreokontrast suspension based on a water-insoluble inorganic salt of barium sulfate in the isotonic solution. The study was performed in 20 cadaveric donor eyes. the original technology. Dissection was carried out according to a proposed original technology. The scleral incision was made at a 4mm distance from the limbus along the circumference. Then we cut the sclera between the rectus muscles, then the petals of choroid and retina were formed, and also they were cut off. Then we cut the sclera between the rectus muscles, then the petals of choroid and retina were formed, and also cut them off. We stained the vitreous structures using the Vitreokontrast suspension with a sequential removal of the anterior cortex up to the posterior lens capsule. Results. After the cortex removal in the cadaveric donor eyes several membranous structures (on an average of four) were detected with a covering the retrolental space with an ability to exfoliate, with sites of the attachment to the Wieger ligament and fibers of ciliary zonula and pars plana. After the removal of the membranous structures and their restaining a layer of vitreous fibers was contrasted on the posterior capsule of the lens in the area of Berger space projection. Conclusion . The study revealed no case of a true full anterior cortex detachment. The anterior cortex exfoliation occurred with the formation of a multilayer membranous structure, covering the posterior surface of lens and ciliary body. The presence of vitreous fibers closely associated with the posterior capsule of the lens in the projection area of Berger space, allows to suppose a possibility of retrolental bag existence, one of walls of which is associated with the posterior lens capsule.

25-Gauge Vitrectomy in Open Eye Injury with Retained Foreign Body.

Purpose. Ocular trauma with retained foreign body is an important cause of visual impairment in working-age population. Clinical status impacts on the timing and planning of surgery. In the last year small gauge vitrectomy has become safer and more efficient, extending the range of pathologies successfully treated. Aims. To evaluate the safety and outcomes in patients with open eye injury with retained foreign body that underwent early 25-gauge vitrectomy. Methods. In this retrospective, noncomparative, interventional case series, we performed 25-gauge vitrectomy on 10 patients affected by open globe injuries with retained foreign body, over 3 years. We analyzed age, wound site, foreign body characteristics, ocular lesions correlated, relative afferent pupillary defect, visual acuity, and intraocular pressure. Follow-up evaluations were performed at 1, 3, and 6 months. According to the clinical status we performed other procedures to manage ocular correlated lesions. Results. The median age of patients was 37 years. The foreign body median size was 3.5 mm (size range, 1 to 10 mm). 25-gauge vitrectomy was performed within 12 hours of trauma. Foreign body removal occurred via a clear corneal or scleral tunnel incision or linear pars plana scleral access. Visual acuity improved in all patients. Endophthalmitis was never reported. Only two cases reported postoperative ocular hypertension resolved within the follow-up. Retinal detachment recurred in one case only. Conclusions. 25-gauge vitrectomy could be considered as early approach to manage open globe injuries with a retained posterior segment foreign body in selected cases with good outcomes and low complication rate.

Outcomes of Cataract Surgery Following Treatment for Retinoblastoma.

PurposeTo evaluate the long-term visual outcomes and complications of cataract surgery in eyes previously treated for retinoblastoma.MethodsWe reviewed the medical records of patients who underwent cataract extraction and intraocular lens implantation at Seoul National University Children's Hospital for a secondary cataract that developed after retinoblastoma treatment.ResultsDuring the period between 1990 and 2014, 208 eyes of 147 patients received eye-salvaging treatment (radiotherapy, chemotherapy, and local therapy) for retinoblastoma at Seoul National University Children's Hospital. Among these eyes, a secondary cataract was detected in 17 eyes of 14 patients, and five eyes of five patients underwent cataract surgery. The median age of cataract formation was 97 months (range, 38 to 153 months). The medial interval between the diagnosis of retinoblastoma and cataract formation was 79 months (range, 29 to 140 months). All patients received posterior chamber intraocular lens insertion after irrigation and aspiration of the lens through a scleral tunnel incision. Anterior vitrectomy and posterior capsulotomy were performed in two eyes and a laser capsulotomy was subsequently performed in one eye. No intraoperative and postoperative complications occurred. The median follow-up after surgery was 36 months (range, 14 to 47 months). The final best corrected visual acuities were improved in all five eyes. No intraocular tumor recurrences or metastases occurred.ConclusionsAfter retinoblastoma regression, cataract extraction in our series was not associated with tumor recurrence or metastasis. Visual improvement was noted in every patient.

Change of Corneal Epithelial and Stromal Thickness after Cataract Surgery through Scleral Tunnel Incision

Change of Corneal Epithelial and Stromal Thickness after Cataract Surgery through Scleral Tunnel Incision

One-Year Outcome of 49-Channel Suprachoroidal-Transretinal Stimulation Prosthesis in Patients With Advanced Retinitis Pigmentosa.

To determine the feasibility of a 49-channel suprachoroidal-transretinal stimulation (STS) retinal prosthesis that was implanted for 1 year. Three patients with advanced retinitis pigmentosa (RP) and with less than or equal to hand motion (HM) vision were studied. A 49-channel STS system was implanted in a scleral pocket, and the stability of the prosthesis, adverse events, and its efficacy were investigated. The electrode array was implanted in a scleral pocket located under the parafoveal area through a scleral incision at 14 mm in patient (Pt) 1, 16 mm in Pt 2, and 18 mm in Pt 3 from the sclerocorneal limbus. No complications occurred during surgery in all cases. During the follow-up period, iridocyclitis developed in Pt 2 and Pt 3, which was successfully treated with topical medications. The implanted devices continued functioning and elicited phosphenes in all cases. The results of localization tests (P < 0.05) and table tests (P < 0.05) were significantly better with the prosthesis turned on than turned off in Pt 3. The deviations of the walking tests were smaller with the prosthesis turned on than off in Pt 2 and Pt 3 at multiple times after the implantation. The 49-channel STS retinal prosthesis was able to elicit phosphenes in all patients with advanced RP for the entire 1-year experimental period without major complications. Better results on visual tasks were found in the eyes in which the electrode array was implanted closer to the fovea centralis.

Poly-N-isopropylacrylamide (pNIPAM): a reversible bioadhesive for sclerotomy closure.

PurposeTo determine the safety and efficacy of poly-N-isopropylacrylamide, a thermoresponsive adhesive, for sutureless sclerotomy closure in rabbits.MethodsEight rabbits were randomized into three groups: short-term acute, mid-term chronic, and long-term chronic studies. A corresponding control group in which the scleral wounds were sutured by 6–0 vicryl sutures was assigned for each study group. A 20-gauge sclerotomy was performed following a core vitrectomy and 0.1 mL of 50 % liquid poly-N-isopropylacrylamide was applied to the scleral wounds. Before the polymer application, the scleral surface was raised above 32 °C using a halogen bulb lamp. Follow-up exams included color external and fundus photography, fundus fluorescein angiography, optical coherence tomography, and electroretinography. After the last follow-up assessment, the rabbits were sacrificed and histopathological studies on the scleral incision sites were performed.ResultsScleral wound healing was observed in the long-term chronic study rabbits. Histological studies were able to identify poly-N-isopropylacrylamide polymer at the sclerotomy site in the mid-term chronic study rabbits. Besides iatrogenic cataracts due to mechanical instrument touch in 2 rabbits, no other ocular abnormalities were identified in any of the eyes in the perioperative setting or during the follow-up period. Cornea, retina, and vitreous remained unaffected, and no abnormal inflammatory reaction or endophthalmitis was noticed in the 3 study groups. Filtering blebs indicative of leakage through the sclerotomies were not observed during the follow-up period.ConclusionPoly-N-isopropylacrylamide may provide effective in vitro scleral adhesion above 32 °C. Clinical studies are required to evaluate its utility in patients undergoing pars plana vitrectomy.

An Endovascular Cannulation Needle with an Internal Wire for the Fragmentation of Thrombi in Retinal Vein Occlusion.

PurposeWe report a newly developed device to fragment thrombi in retinal vein occlusion.MethodsThe new instrument consists of a 23-gauge (G) pipe and a 37-G needle with an internal wire. A total of 40 porcine eyes were used; 20 eyes for experiments in the branch retinal vein (BRV group) and 20 eyes for experiments in the central retinal vein (CRV group). We placed 25-G 3-port trocars, and core vitrectomy was performed. Another 23-G scleral incision was performed for insertion of the needle. The needle pierced the retinal vein at a distance of three- to four- or one-disc diameters from the optic disc (BRV or CRV group, respectively), and the internal wire was advanced toward the disc. The success rates of needle piercing and cannulation of the internal wire were recorded in each group. In the CRV group, the cannulation was deemed successful when the tip reached inside the optic disc. Real-time optical coherence tomography imaging also was performed using the Zeiss Rescan 700 device in porcine eyes. Histologic examination of the retinal vessel inserted with the internal wire was performed.ResultsThe success rates of needle piercing into the BRV and CRV were 85% and 95%, respectively. The success rates of cannulation of the internal wire into the BRV and CRV were 85% and 0%, respectively. The process of cannulation was recorded successfully with the Rescan 700. Histologic examination showed no damages to the endothelial cell layer.ConclusionsThe needle and internal wire intended to be used for recanalization of BRV occlusion were successfully pierced and cannulated into the BRV.Translational RelevanceThis newly developed device could become a treatment modality for retinal vein occlusion to fragment thrombi that present treatment methods cannot reach and remove directly.

27-gauge microincision vitrectomy surgery system for clinical application

Objective To observe the preliminary clinical results and safety of 27-gauge microincision vitrectomy surgery for partial vitreoretinal diseases. Methods A total of 13 patients (13 eyes) who underwent 27-gauge microincision vitrectomy surgery were enrolled. The follow-up period was 6 to 12 months. Preoperative and postoperative visual acuity and intraocular, total operative time, cutting time for removing vitreous, wound healing status, intraoperative and postoperative complications were observed. Results Mean best corrected visual acuity improved from preoperative (1.26±0.66) logMAR (0.10±0.09) to postoperative (0.63±0.52) logMAR (0.35±0.24), and the difference was statistically significant (t=2.743, P=0.018). The difference of mean preoperative intraocular pressure (IOP), IOP of postoperative day 1, day 5, one month and final postoperative visit were not statistically significant (F=0.593, P>0.05). The mean total operative and cutting times were (36.38±14.97) min and (10.12± 3.54) min respectively. Postoperative scleral incision showed linear closure, no cases of postoperative sclerotomy-related complications such as wound dehiscence, vitreous incarceration and subconjunctival fluid were observed. No intraoperative and postoperative complications of iatrogenic retinal breaks, endophthalmitis, choroidal detachment, retinal detachment and vitrous hemorrhage were observed. Conclusions The 27-gauge microincision vitrectomy surgery can improve postoperative visual acuity for treatment of vitreoretinal diseases and induce fewer sclerotomy-related complications, which maybe a safer surgical approach. Key words: Vitrectomy; Microincision; Clinical efficacy

Comparison of the influence on tear film between scleral tunnel incision and clear corneal tunnel incision in phacoemulsification

Comparison of the influence on tear film between scleral tunnel incision and clear corneal tunnel incision in phacoemulsification

Value of posterior keratometry in the assessment of surgically induced astigmatic change in cataract surgery.

To investigate the value of posterior keratometry in the assessment of surgically induced astigmatic change (AC) in cataract surgery, with particular emphasis on the influence of test-retest variability. Seventy-seven eyes of 77 cataract patients scheduled for routine cataract surgery were enrolled. All patients received a 2.2-mm self-sealing scleral incision (n=24), single-plane clear corneal incision (SPCCI; n=29) or biplanar clear corneal incision (BPCCI; n=24). Measurements of anterior and posterior corneal astigmatism were performed with a rotating Scheimpflug camera (Pentacam HR) preoperatively and postoperatively. Two repeated readings were taken preoperatively to assess the role of the test-retest effect. Astigmatic change (AC) was analysed according to the polar value method. On the anterior corneal surface, SPCCIs and BPCCIs caused a statistically significant mean flattening of the incisional meridian of 0.37 and 0.27dioptres (D), respectively. Scleral incisions on average did not cause AC, although steepening, flattening or torque beyond the test-retest effect was observed in individual cases. On the posterior surface, mean power changes in the incisional meridian were below 0.1D for all incisions, and these changes were of the same order of magnitude as the test-retest effect. Surgically induced AC of the posterior corneal surface after cataract surgery is of negligible clinical relevance. Moreover, it is of the same order of magnitude as the test-retest variability of the measurement device and therefore cannot (yet) be reliably assessed.

Four‐port bimanual 23‐gauge vitrectomy for diabetic tractional retinal detachment

Four-port bimanual vitrectomy is a surgical technique that facilitates removal of epiretinal membranes in severe proliferative diabetic retinopathy (PDR). As the illumination is held by the assistant through the fourth scleral incision, fibrovascular membranes are removed by bimanual manipulation techniques. The objective of this study was to evaluate the safety and efficacy of four-port bimanual 23-gauge vitrectomy for patients with tractional retinal detachment (TRD) in severe PDR. Retrospective, comparative, consecutive, interventional case series. Sixty-six eyes of 58 consecutive patients who underwent primary vitrectomy for severe diabetic TRD. Thirty-six eyes of 31 cases that were treated with four-port 23-gauge vitrectomy were compared with 30 eyes of 27 cases that were treated with 23-gauge pars plana vitrectomy (PPV). Main outcome measures were best-corrected visual acuity (BCVA), retinal status, intraocular pressure, and incidence of intraoperative and postoperative complications with at least 6months of follow-up. The primary and ultimate anatomic success rates (94.4% versus 93.3%, and 100% in both groups, respectively) and the mean BCVA changes did not differ significantly between groups. The whole surgical time and the membrane removal time were significantly (p<0.001, respectively) shorter in the four-port 23-gauge group than in the 23-gauge group. There was no difference in the incidence of intraoperative and postoperative complications in both groups. Four-port bimanual 23-gauge vitrectomy offers comparable anatomic success and shortens the surgical time compared with conventional 23-gauge PPV in patients with TRD resulting from severe PDR.