SUBRETINAL ENDOSCOPIC SURGERY FOR METASTATIC CHOROIDAL TUMOR.

PURPOSE: To report a case of a metastatic choroidal tumor treated with subretinal endoscopic surgery. METHODS: A single case report. RESULTS: A 68-year-old woman presented with a metastatic choroidal tumor in the right eye and an intraocular pressure of 54 mmHg. Chemotherapy and radiotherapy were ineffective in eliminating her eye pain. Subretinal endoscopic surgery was performed to remove the metastatic choroidal tumor with the complex retinal detachment attached to the posterior surface of the lens. The day after subretinal endoscopic surgery, the patient's intraocular pressure decreased to 7 mmHg and her pain subsided. The chemotherapeutic strategy was modified according to the pathological findings. Survival prognosis improved from 3 to 18 months. Twenty-one months after the surgery, the retinal detachment was reattached under silicone oil with a best-corrected visual acuity of 20/1,000 and an intraocular pressure of 15 mmHg. CONCLUSION: In this case, subretinal endoscopic surgery preserved visual function, eliminating the need for enucleation.

A case of functional visual loss diagnosed through bilateral randomized visual field testing with a trick method.

Purpose: To report a case of functional visual loss (FVL) diagnosed through bilateral randomized visual field testing using Imo vifa with a trick method. Observations: A 27-year-old man complained of visual field abnormality in his left eye after falling from a height of 4 m. The left eye had a best-corrected visual acuity (BCVA) of 20/16 and a critical flicker frequency (CFF) of 44.5 Hz at the first visit. Commotio retinae was observed in the inferior retina of the left eye, and the pupillary light reflex was normal. Computed tomography and magnetic resonance imaging of the head revealed no abnormalities. However, the Goldmann perimeter (GP) showed constriction of visual field in the left eye. Since traumatic optic neuropathy was suspected initially; therefore, two courses of methylprednisolone pulse therapy were administered. However, the BCVA and CFF gradually worsened to 20/200 and 14 Hz, respectively. Nevertheless, his pupillary light reflex was still normal, and GP showed a spiral visual field. Thus, we suspected that this was a case of FVL and performed bilateral randomized visual field testing using Imo vifa in three steps as a trick method. In the first step, we performed the normal method for bilateral randomized visual field testing. In the second and third steps, we explained to the patient that only the right or left eye would be examined on purpose; bilateral randomized visual field testing was then performed. The results of examinations revealed left homonymous hemianopsias and normal and concentric contraction of the visual field in both eyes. These results could not be explained by organic disease, and the patient was diagnosed with FVL. Conclusions and Importance: Bilateral randomized visual field testing using Imo vifa with a trick method was useful for diagnosing FVL.

Treatment of old submacular hemorrhage by subretinal endoscopic surgery and intraoperative subretinal endoscopic findings.

PURPOSE: We report a case of old submacular hemorrhage (SMH) due to polypoidal choroidal vasculopathy (PCV). Subretinal endoscopic surgery (SES) was performed, which improved visual function. In addition, we show the intraoperative findings of subretinal aberrant PCV vessels as seen under endoscopic observation, which cannot be observed by microscopic surgery. OBSERVATIONS: A 71-year-old Japanese man presented with an old dehemoglobinized SMH due to PCV in his left eye. At the time of presentation, three weeks had already passed after the onset of the patient's symptoms, and the best-corrected visual acuity (BCVA) was 20/200. SES was performed to remove the SMH and treat the subretinal PCV lesions. After creating retinal detachment using a 38-gauge cannula, three subretinal 25-gauge trocars were inserted from the sclera to the subretinal space. Then, SES was performed under ophthalmic endoscopic observation with continued subretinal irrigation for maintaining the retinal detachment. After removal of the SMH, subretinal polyp-shaped nodular vascular lesions (polyps) and a branching vascular network, which is located inside the retinal pigmented epithelium, were identified. The sites that presumably originated from the aberrant vessels of the PCV and the associated polyps were coagulated using endodiathermy. After the subretinal procedure, the retina was flattened with fluid/air exchange, and silicone oil (SO) was injected into the vitreous cavity. The SMH completely disappeared after surgery. Although at one-month follow-up BCVA (20/250) was slightly worse than that before surgery, there was an improvement in postoperative retinal sensitivity in the macula compared to that before surgery. At the three-month follow-up, the SO was removed. The BCVA was 20/200 one month after SO removal. No postoperative complications occurred. Additional treatment was not required, including anti-vascular endothelial growth factor therapy, for PCV progression or SMH recurrence in the left eye till the final visit two years after surgery. CONCLUSION AND IMPORTANCE: SES could effectively remove the old SMH, and the activity of PCV was suppressed by intraoperative subretinal coagulation. The retinal sensitivity of the macula improved after the SES. In addition, we observed subretinal polyps and a branching vascular network located internal to the retinal pigmented epithelium under intraoperative subretinal endoscopic observation. SES is a good surgical option for the removal of old SMH or treatment of subretinal lesions.

Clinical Outcomes of Endoscope-Assisted Vitreous Surgery for Giant Retinal Tear Detachment.

INTRODUCTION: With the advent of perfluorocarbon liquid (PFCL), the success rate of refractory giant retinal tear (GRT) detachment has dramatically improved. PFCL is a very effective tool when used properly, but in GRT detachment, it may move under the retina through the tear, so it is necessary to devise ways to prevent PFCL from migrating under the retina. Ophthalmic endoscope-assisted vitrectomy may reduce the risk of subretinal migration of PFCL, facilitate safer use of PFCL, and increase the success rate of GRT detachment. The present study aimed to describe the clinical outcomes of endoscope-assisted vitreous surgery for giant retinal detachment. METHODS: Twenty consecutive eyes from 19 patients who had undergone endoscope-assisted vitreous surgery for treatment of a GRT detachment were enrolled. Subretinal fluid drainage, extension of the rolled GRT, and endophotocoagulation under air were performed with the aid of an endoscope, without the use of PFCL. Where necessary, extension of a fixed retinal fold and internal limiting membrane peeling was performed with PFCL. RESULTS: The initial and final retinal reattachment rates were 90 and 95%, respectively. In 3 eyes, a small amount of PFCL was used, and there were no PFCL remnants. The mean follow-up duration was 18 months (range, 3-69 months). After surgery, the mean best-correlated visual acuity significantly improved from 20/514 to 20/41 (p = 0.0008). DISCUSSION/CONCLUSION: Endoscope-assisted vitreous surgery for giant retinal detachment has favourable clinical outcomes for visual acuity and retinal detachment.

Evaluation of Axial Length Measurement Using Enhanced Retina Visualization Mode of the Swept-Source Optical Coherence Tomography Biometer in Dense Cataract.

INTRODUCTION: It has been reported that even using the swept-source (SS) optical coherence biometer, it is challenging to measure the axial length (AL) in cases with advanced cataracts. The enhanced retina visualization (ERV) mode, which is equipped with OCTB1 (ARGOS), shifts the peak of measurement sensitivity to the retinal side so that the AL can be measured even if the light energy is attenuated. The aim of the present study was to evaluate the accuracy and efficacy of the ERV mode in measuring the AL of dense cataracts. METHODS: This was a single-center retrospective observational case series conducted in Japan. We included 213 eyes of 213 consecutive patients with advanced cataracts who underwent preoperative evaluation. The AL was measured before and after surgery using two SS optical coherence tomography biometers (OCTB1 and OCTB2; IOLMaster 700). Cases in which OCTB1 the standard mode failed to measure AL, OCTB1 with the ERV mode was used instead. Primary outcome measures were the acquisition rate and the AL measurement accuracy using the ERV mode. The χ2 test, the Kruskal-Wallis test, and the Wilcoxon signed-rank test were used to compare the acquisition rate and differences between pre- and postoperative AL values, respectively. In the ERV subgroup, Bland-Altman plots were used to compare the pre- and postoperative AL values measured using OCTB1-ERV mode. A p-value of less than 5% was considered statistically significant. RESULTS: The AL acquisition rate was not significantly different between OCTB1 with the standard mode and OCTB2. The AL of 65 eyes (30.5%) could not be measured using OCTB1 with the standard mode. Conversely, the AL of 51 of these eyes (78.5%) was successfully measured using OCTB1 with the ERV mode. In these 51 eyes, a difference of ≤0.2 mm and of ≤0.1 mm between pre- and postoperative AL measurements was observed in 40 (78.4%) and 30 eyes (58.8%), respectively. The Bland-Altman plot found no systematic error between pre- and postoperative AL values measured using the ERV mode. CONCLUSION: In patients with dense cataracts, AL measurement using the standard mode of an SS-OCT biometer is challenging. Furthermore, the ERV mode could be promising for AL measurement in such cases.

[Clinical Outcomes of Endoscope-Assisted 30-Gauge Single-Needle Technique for Intrascleral Intraocular Lens Fixation].

INTRODUCTION: We have developed an endoscope-assisted single-needle technique, which is an improvement of Yamane's double-needle technique of the intrascleral intraocular lens (IOL) fixation techniques. In this surgical procedure, the IOL is manipulated in the vitreous cavity, and the IOL haptic is externalized from the eye one by one with the aid of an ophthalmic endoscope. The purpose of this study was to report the postoperative visual function and safety of this new technique. METHODS: Overall, 19 consecutive eyes (16 patients; mean age, 75.1 ± 9.6 years; mean follow-up period, 5.7 months) that underwent intrascleral IOL fixation surgery with our new technique were included in the study. Manifest refraction, uncorrected/corrected visual acuity, and corneal endothelial cell density were measured before and after surgery. Tilt and decentration of IOL were analyzed using anterior segment optical coherence tomography. RESULTS: The mean absolute prediction error (spherical equivalent) was 0.82 ± 0.52. The mean postoperative best-corrected visual acuity had significantly improved at the final visits (p = 0.02). No significant differences in the mean corneal endothelial cell density were observed between the first (2,232 ± 751 cells/mm2) and final (2,099 ± 649 cells/mm2) visits (p = 0.35). The mean IOL tilt was 8.1 ± 3.2°. There were no vision-threatening complications, such as retinal detachment, endophthalmitis, or IOL dislocation, during or after surgery. CONCLUSIONS: The endoscope-assisted single-needle technique is a safe and effective method of intrascleral IOL fixation surgery.

Comparison of Clinical Outcomes Between Intracapsular Implantation and Intrascleral Fixation Using the Same Model of Intraocular Lens.

PURPOSE: To compare the clinical outcomes of intrascleral intraocular lens (IOL) fixation surgery with those of intracapsular IOL implantation in conventional cataract surgery. PATIENTS AND METHODS: Twenty-one eyes of 21 consecutive patients who underwent intrascleral IOL fixation (SF group) and 21 eyes of 21 patients who underwent IOL intracapsular implantation during cataract surgery (IN group) were retrospectively enrolled. For both groups, the same model of IOL was used in all cases. For all cases in the SF group, Yamane's double-needle technique was performed. RESULTS: The mean corrected visual acuity (logMAR) after surgery was significantly better in the IN than in the SF group (-0.063 ± 0.12 vs 0.05 ± 0.14; p = 0.0083). The mean anterior chamber depth after surgery was significantly smaller in the IN than in the SF group (4.65 ± 0.23 mm vs 4.98 ± 0.61 mm; p = 0.0231). The amounts of tilt and decentration were also significantly smaller in the IN group (5.21°± 1.47° and 0.22 ± 0.13 mm, respectively, vs 8.8° ± 3.9° and 0.52 ± 0.35 mm, respectively; p = 0.0003 and p = 0.0007). The mean absolute refractive prediction error was significantly smaller in the IN than in the SF group (0.22 ± 0.17 D vs 0.86 ± 0.59 D; p = 0.0002). CONCLUSION: The intrascleral IOL fixation surgery proved to be highly effective. However, its clinical outcomes were slightly inferior to those of IOL intracapsular implantation, and further improvement of this surgical technique may be needed.

A case of severe choroidal detachment in both eyes due to systemic lupus erythematosus.

PURPOSE: We report a case of severe choroidal detachments (CDs) in both eyes caused by systemic lupus erythematosus (SLE). OBSERVATIONS: The patient was a 50-year-old woman who presented with conjunctival edema in both eyes, visual dysfunction, and generalized fatigue. At the first visit, the best corrected visual acuity (BCVA) was 20/70 OD and 20/70 OS, and the intraocular pressure (IOP) was 22 mmHg OD and 27 mmHg OS. She had serous retinal detachments (SRDs), CDs, ciliary dissections, and a shallow anterior chamber with partial angle closure in both eyes. Systemic findings included hypoalbuminemia, pleural fluid, generalized fatigue, and brown papules on the back and both legs. First, we suspected Vogt-Koyanagi-Harada disease and administered two courses of methylprednisolone pulse therapy, but the CDs in both eyes gradually deteriorated and worsened to the extent that the optic nerve in both eyes could not be observed, and the BCVA deteriorated to 20/200 OD and 6/200 OS. Further multidisciplinary evaluations for diagnosing collagen diseases revealed vasculitis in the skin histopathology examination, positive results for anti-double stranded DNA antibody and anti-SS-A antibody, and hypocomplementemia in the blood examination, and she was diagnosed with severe SLE in the dermatology department. After administration of high dose intravenous γ-globulin therapy, albumin infusion, and intravenous cyclophosphamide pulse therapy, the SRDs and severe CDs improved along with improvement in hypoalbuminemia, pleural fluid, and generalized fatigue. Moreover, the shallow anterior chamber and high IOP improved to normal in both eyes. The CDs and SRDs completely disappeared, and the BCVA improved to 20/13 OU 6 months after the SLE therapy. CONCLUSION AND IMPORTANCE: In patients with observed SRDs and CDs accompanying hypoalbuminemia, it is necessary to consider collagen diseases such as SLE.

Prediction of Effective Lens Position Using Multiobjective Evolutionary Algorithm.

PURPOSE: The purpose of this study was to evaluate the prediction accuracy of effective lens position (ELP) after cataract surgery using a multiobjective evolutionary algorithm (MOEA). METHODS: Ninety-six eyes of 96 consecutive patients (aged 73.9 ± 8.6 years) who underwent cataract surgery were retrospectively studied; the eyes were randomly distributed to a prediction group (55 eyes) and a verification group (41 eyes). The procedure was repeated randomly 30 times to create 30 data sets for both groups. In the prediction group, based on the parameters of preoperative optical coherence tomography (OCT), biometry, and anterior segment (AS)-OCT, the prediction equation of ELP was created using MOEA and stepwise multiple regression analysis (SMR). Subsequently, the prediction accuracy of ELPs was evaluated and compared with conventional formulas, including SRK/T and the Haigis formula. RESULTS: The rate of mean absolute prediction error of 0.3 mm or higher was significantly lower in MOEA (mean 4.9% ± 3.2%, maximum 9.8%) than SMR (mean 7.3% ± 4.8%, maximum 24.4%) (P = 0.0323). The median of the correlation coefficient (R 2 = 0.771) between the MOEA predicted and measured ELP was higher than the SRK/T (R 2 = 0.412) and Haigis (R 2 = 0.438) formulas. CONCLUSIONS: The study demonstrated that ELP prediction by MOEA was more accurate and was a method of less fluctuation than that of SMR and conventional formulas. TRANSLATIONAL RELEVANCE: MOEA is a promising method for solving clinical problems such as prediction of ocular biometry values by simultaneously optimizing several conditions for subjects affected by various complex factors.

Clinical Evaluation of a New Swept-Source Optical Coherence Biometer That Uses Individual Refractive Indices to Measure Axial Length in Cataract Patients.

BACKGROUNDS: Although the OCT biometer using individual refractive index is available, comparisons of measurement value and intraocular lens (IOL) power calculation error with other SS-OCT biometers are not known. OBJECTIVES: To compare the new SS-OCT biometer ARGOS (OCTB1), which uses individual refractive indices to measure axial length, with the IOLMaster 700 (OCTB2) and OA-2000 (OLCR), which use equivalent refractive index. METHOD: Six hundred and twenty-two eyes of 622 patients who had been diagnosed with cataract were enrolled in the study. Among the 158 eyes that had undergone cataract surgery, the postoperative refractive error was evaluated using the Haigis formula. RESULTS: The axial length measured by the OCTB1 showed a proportional bias in comparison with the other two biometers and a fixed bias in eyes with an axial length ≥26 mm. No significant difference was found in the median absolute refractive prediction error (p = 0.3278). However, in eyes with an axial length ≥26 mm, the OCTB1 showed myopic error compared with the other two biometers (p < 0.0001). CONCLUSIONS: In eyes with long axial length, when the conventional IOL calculation was optimized with the equivalent refractive index-based instrument, we need to consider that IOL calculation using OCTB1 tends to cause slightly myopic refractive prediction error.

SUBRETINAL ENDOSCOPIC SURGERY TO TREAT LARGE SUBRETINAL HEMORRHAGES SECONDARY TO AGE-RELATED MACULAR DEGENERATION.

PURPOSE: To evaluate the potential of subretinal endoscopic surgery as a novel treatment for large subretinal hemorrhage secondary to age-related macular degeneration. METHODS: Five patients with large subretinal hemorrhage secondary to age-related macular degeneration underwent subretinal endoscopic surgery, with a minimum follow-up of 12 months. RESULTS: The large subretinal hemorrhage was completely removed by subretinal endoscopic surgery without a large retinotomy in all cases. The fibrovascular pigment epithelial detachment including choroidal neovascularization was completely removed in four cases. In three of these cases, the bleeding was confirmed to be originating from one point of rupture in the Bruch membrane, which was treated by coagulation using intraocular diathermy. Although visual acuity improved in three cases, it deteriorated and remained stable in one case each. Fibrovascular pigment epithelial detachment persisted in one patient after surgery; he needed anti-vascular endothelial growth factor therapy, whereas the other four did not because their fibrovascular pigment epithelial detachment was removed. At the final follow-up, no severe postoperative complications, such as retinal detachment or proliferative vitreoretinopathy, were noted. CONCLUSION: Subretinal endoscopic surgery can completely remove subretinal hemorrhage and fibrovascular pigment epithelial detachment including choroidal neovascularization without a large retinotomy. It also aids in the direct and detailed confirmation of subretinal lesions by ophthalmic endoscope.

NOVEL ENDOSCOPE-ASSISTED VITREOUS SURGERY COMBINED WITH ATMOSPHERIC ENDOSCOPIC TECHNIQUE AND/OR SUBRETINAL ENDOSCOPIC TECHNIQUE FOR RHEGMATOGENOUS RETINAL DETACHMENT WITH GRADE C PROLIFERATIVE VITREORETINOPATHY.

PURPOSE: The purpose of this study was to investigate the clinical outcomes of novel endoscope-assisted vitreous surgery techniques in patients with rhegmatogenous retinal detachment complicated by Grade C proliferative vitreoretinopathy. METHODS: Eight consecutive patients who had undergone endoscope-assisted vitreous surgery for rhegmatogenous retinal detachment complicated by Grade C proliferative vitreoretinopathy were investigated. The peripheral vitreous was cut under air with the aid of endoscopic view (atmospheric endoscopic technique), and the subretinal proliferation was removed under subretinal endoscopic observation (subretinal endoscopic technique). RESULTS: Retinal reattachment was achieved after the primary surgery without a large retinotomy and scleral buckling in each case. The mean follow-up was 16.8 months (range, 8-28 months). Atmospheric endoscopic technique was performed in all cases, and subretinal endoscopic technique was performed in three cases. After surgery, the mean best-corrected visual acuity significantly improved from 20/778 to 20/111 (P = 0.014). Although microretinal breaks occurred during the removal of vitreous using atmospheric endoscopic technique in all cases, there were no severe postoperative complications, such as retinal detachment or proliferative vitreoretinopathy. CONCLUSION: Endoscope-assisted vitreous surgery with atmospheric endoscopic technique and/or subretinal endoscopic technique is safe and effective in the treatment of rhegmatogenous retinal detachment with Grade C proliferative vitreoretinopathy.

Clinical outcomes of endoscope-assisted vitrectomy for treatment of rhegmatogenous retinal detachment.

SUMMARY: We evaluated the clinical outcomes for ophthalmic endoscope-assisted vitrectomy in consecutive patients with uncomplicated rhegmatogenous retinal detachment (RRD). The primary success rate was 98.4% (125/127) without performing a posterior drainage retinotomy or using perfluorocarbon liquids (PFCL) for subretinal fluid drainage. PURPOSE: To investigate the clinical outcomes of endoscope-assisted vitrectomy in patients with uncomplicated RRD. METHODS: We examined 127 eyes from consecutive patients who underwent repair of RRD by 23- or 25-gauge endoscope-assisted vitrectomy, with a minimum follow-up of 3 months. Eyes with the following criteria were excluded: Giant retinal tears, grade C proliferative vitreoretinopathy, dense vitreous hemorrhage, retinal detachment secondary to other ocular diseases, and prior retinal or vitreous surgery. All cases underwent subretinal fluid drainage, endolaser photocoagulation and fundus inspection were performed under ophthalmic endoscopic observation. Success rate, visual acuity, surgery time and complications were evaluated. RESULTS: Primary and final success rate was 98.4% (125/127) and 100% (127/127), respectively, Surgery time was 59.6±26.3 minutes. The best-corrected visual acuity significantly improved from 20/100 to 20/20 (P<0.0001). There were 2 cases (1.6%) of creation of a peripheral drainage retinotomy and 4 cases (3.1%) of using PFCL to suppress movement of the detached retina, but there were no cases of creation of a posterior drainage retinotomy or using PFCL for subretinal fluid drainage. There was 1 case of presumed endophthalmitis after surgery. There were 12 hypotonous cases at postoperative day 1 and one of them needed additional scleral sutures at postoperative day 4 for prolonged hypotony. CONCLUSION: The present study demonstrated the efficacy of endoscope-assisted vitrectomy for patients with uncomplicated RRD. To perform endoscope-assisted vitrectomy safely, sufficient closure of sclerotomies is necessary at the end of surgery.

Increased internal higher-order aberrations as a useful parameter for indication of vitrectomy in three asteroid hyalosis cases.

We report three asteroid hyalosis cases in which internal higher-order aberrations (HOAs) were improved concomitant with improved visual symptoms after vitrectomy. Cases 1 and 2 reported severe floaters and glare disability, although their visual acuities were fairly good. Case 3 showed poor visual acuity since this patient also suffered from mild macular degeneration. For these three asteroid hyalosis cases, we were unsure if treatment with vitrectomy could improve visual symptoms. Therefore, we measured internal HOAs with an aberrometer, and found that the internal HOA values in these cases were high. We suspected that internal high HOAs values were associated with visual disturbance, and performed vitrectomy. After the vitrectomy, the internal HOA values in these three asteroid hyalosis cases markedly decreased, and visual symptoms improved. These observations suggested that measurement of internal HOAs may be useful to determine the indication for vitrectomy.

[Comparison of central visual field visualization while using a combination of spherical intraocular lenses with vitreous contact lenses].

OBJECTIVE: To investigate intraocular lens (IOL) and vitreous contact lens (VCL) combinations that provide good central visual field visualization in vitreous surgery. METHOD: ZEMAX optical design software was used to perform optical simulations using the ray tracing method on a Gullstrand eye model. The implanted IOL was assumed to consist of material with a refractive index of 1.550 (high refractive index acrylic IOL), 1.470 (low refractive index acrylic IOL) and 1.413 (silicon IOL), and was set as a biconvex spherical lens (optical diameter 6 mm, 23.5 D). The VCL was assumed to have a refractive index of 1.900 (HEMA VCL), 1.490 (PMMA VCL) and 1.413 (silicon VCL), and was set as a concave lens (optical diameter 10 mm) with a flat anterior surface and a posterior surface with a radius of curvature of 7.70 mm. The spherical aberration of the overall optical system, including the IOL-implanted eyeball and the VCL, was calculated. RESULTS: Spherical aberration was lowest with the silicon VCL for the high refractive index acrylic IOL and with the PMMA VCL for the low refractive index acrylic and silicon IOLs. CONCLUSION: The combinations providing the best central visual field visualization in vitreous surgery are a silicon VCL for implantation of a high refractive index acrylic IOL and a PMMA VCL for implantation of a low refractive index acrylic or silicon IOL.

Evaluation of axial length measurement of the eye using partial coherence interferometry and ultrasound in cases of macular disease.

PURPOSE: The present study evaluated the accuracy of using partial coherence interferometry (PCI) and ultrasound (US) to measure axial length in eyes with macular disease, the nature of the double peak (DP) in PCI measurements, and the applicability of intraocular lens (IOL) power calculation. DESIGN: Retrospective noncomparative case series. PARTICIPANTS: We studied 132 eyes with macular edema, epiretinal membrane, and macular hole in 132 patients who underwent combined cataract and vitrectomy surgery. METHODS: Axial length was measured using PCI and US. If a DP was observed in the PCI measurement, the posterior peak was used for the IOL calculation. The central retinal thickness (CRT) was measured using optical coherence tomography. MAIN OUTCOME MEASURES: Measurements were made of the frequency of DP observation in PCI measurement and the postoperative refractive errors when either PCI or US measurements were applied. RESULTS: A DP was observed in 25 (18.7%) of 132 eyes in the axial length measurement using PCI. There was a significant correlation between the interpeak distance and the CRT (P<0.001, r(2)=0.3869). The 6-month postoperative refractive errors in the DP and single peak (SP) groups were predicted correctly within +/-0.5 diopters in 56.0% (DP) and 61.7% (SP) of the cases and within +/-1.0 diopters in 92.0% (DP) and 92.2% (SP) of the cases. The accuracy of the axial length measurement was similar between PCI and US. CONCLUSIONS: Our results suggest that the longer axial length of the DP observed in PCI represents retinal pigment epithelium. If a DP was observed in PCI measurement, application of the longer peak for the IOL calculation resulted in a refractive error similar to that in the SP group.

Clinical evaluation of the arched blade for cataract surgery.

PURPOSE: To evaluate the efficacy of the arched blade for making clear corneal incisions in cataract surgery. METHODS: This prospective study comprised 112 eyes of 74 patients scheduled for cataract surgery. Temporal clear corneal incisions were made with either a 3.2-mm conventional flat blade or the arched blade. The choice of knife was randomly assigned. Two surgeons, one with substantial cataract surgery experience and the other with less experience, performed the surgery. Corneal topography and aberration were examined pre- and postoperatively. The degree of surgically induced astigmatism (SIA) and high order aberration was analysed. The self-sealing ability of the wound was also compared between both blades. RESULTS: For the less experienced surgeon, the degree of SIA was significantly higher with the 3.2-mm flat blade than with the 3.2-mm arched blade as measured at any time during postoperative follow-up. For the more experienced surgeon, the degree of high order aberration increased significantly with the 3.2-mm flat blade. The incision's self-sealing ability was significantly better when the wound was made with the arched blade rather than with the flat blade. CONCLUSION: The arched blade proved to be effective in reducing surgically induced astigmatism and high order aberration in cataract surgery, particularly when used by the less experienced surgeon. Using the arched blade should lead to better wound self-sealing and, therefore, safer surgical results.