Long-term outcome of intravitreal ranibizumab treatment, compared with photodynamic therapy, in patients with polypoidal choroidal vasculopathy.

PURPOSE: To evaluate the functional outcomes of patients with polypoidal choroidal vasculopathy (PCV) who underwent intravitreal ranibizumab (IVR) treatment, compared with photodynamic therapy (PDT), after at least 2 years. METHODS: We retrospectively studied all the treatment-naïve patients with PCV who were scheduled to undergo IVR or PDT between August 2005 and June 2010. All the patients who had a 2-year or longer follow-up period were included in the study. The best-corrected visual acuity (BCVA) in the two groups was compared before treatment and at 3, 6, 12, 18 and 24 months after the initial treatment. The regression of the polyps was also assessed using indocyanine green angiography. RESULTS: A total of 77 patients were included in this study. Thirty-three eyes were treated with IVR, and 44 eyes were treated with PDT. Although no significant differences between the two groups were observed at baseline or at 3, 6, and 12 months after treatment, a significantly better BCVA was seen in the IVR group, compared with the PDT group, at 18 and 24 months after treatment (P=0.035 and P=0.021, respectively). No significant difference in the rate of polyp regression was observed between the two groups (P=0.092). CONCLUSION: IVR was well tolerated and maintained or improved the vision of patients with PCV, compared with PDT, as evaluated at 2-year follow-up examinations. PDT for the treatment of PCV might result in unfavorable outcomes, with no superiority to achieving the involution of polyps.

A2e mediated phototoxic effects of endoilluminators.

AIMS: To compare the theoretical retinal threshold time for endoilluminators and experimental phototoxic effect using A2e laden retinal pigment epithelial (RPE) cells. METHODS: The spectral irradiances of three types of 20 gauge and 25 gauge endoilluminators, currently commercially available from two manufacturers, were evaluated in conditions where the total beam spectral power was divided by the beam spot size at an estimated use distance of 5 mm from the retina. The retinal threshold time was calculated using the guidelines recommended by the International Commission on Non-Ionizing Radiation Protection. In vitro, A2e laden cells were evenly exposed to light for 30 minutes with a standard endoilluminator positioned 1 cm above the cells and the cell viability was assessed by WST-1 assay. RESULTS: The retinal threshold times were within 1 minute for all the endoilluminators tested. A significant decrease in the viability of A2e laden RPE cells was observed after they were exposed to light from two of the three 20 gauge endoilluminators. Cell viability was not affected by the exposure to 25 gauge endoilluminators under the same conditions. There was no correlation between the theoretical threshold times and experimental data. CONCLUSIONS: Light exposure during vitrectomy can induce photochemical damage to the retina. Although the A2e laden RPE model may not correctly mimic a clinical situation, this model may be useful to estimate the possible photochemical damage to RPE cells that could not be deduced by a theoretical retinal hazard model.

[Evaluation of central retinal sensitivity after vitrectomy with removal of choroidal neovascular membrane for age-related macular degeneration].

PURPOSE: To evaluate retinal sensitivity in patients with age-related macular degeneration (AMD) before and after surgery. METHODS: Seven consecutive patients with AMD underwent vitrectomy with removal of choroidal neovascular membrane(CNV). Static microperimetry using a scanning laser ophthalmoscope(SLO) was performed before and after surgery. Central dense scotoma size was measured. RESULTS: Retinal sensitivity improved in all cases. Mean size of the central dense scotoma was decreased by 42%(range 14-62%). CONCLUSION: The results suggest that vitrectomy with removal of CNV can improve the central retinal sensitivity.

Macular fold after limited macular translocation treated with scleral shortening release and intravitreal gas.

PURPOSE: To describe a case developing a macular fold as a complication of limited macular translocation, which was successfully managed without repeat vitrectomy. METHODS: Interventional case report. A 34-year-old woman who underwent limited macular translocation for subfoveal choroidal neovascularization secondary to myopic degeneration developed a postoperative macular fold. Her visual acuity deteriorated from 20/100 to 20/200 postoperatively. RESULTS: She underwent scleral shortening release and intravitreal gas injection 4 days after the initial surgery and had a resolution of macular fold with adequate foveal displacement. Her visual acuity had improved to 20/40 3 months postoperatively. CONCLUSION: Scleral shortening release and intravitreal gas injection may be considered for the management of severe macular fold caused by limited macular translocation.

Simulation of air-bag impact on post-radial keratotomy eye using finite element analysis.

PURPOSE: To determine the physical and mechanical conditions of an impacting air bag that causes corneal rupture in a post-radial keratotomy (RK) eye using a simulation model of the human eye. SETTING: Numerical simulation study on a computer. METHODS: The simulations were performed by a computer using the finite element analysis program PAM-CRASH (Nihon ESI). The air bag was set to impact the surface of a post-RK eye with 4, 6, or 8 corneal incisions at various velocities. Strain on the corneal tissue including scarred incisions exceeding 9.0% was assumed to indicate the possibility of corneal rupture. RESULTS: At a medium velocity of 30 m/s, corneal rupture was likely to occur. At an air-bag impact velocity of 40 m/s, 3 of 4, 5 of 6, and 8 of 8 incisions were likely to rupture in the case of 4-, 6-, and 8-incision procedures, respectively, leading to likely globe rupture in all situations. Lacerations extended beyond the incisions and involved the intact cornea at a velocity of 40 m/s. If the corneal tissue strength reduction was increased to 90%, most incisions were likely to rupture at impact velocities greater than 35 m/s in all incision procedures. CONCLUSIONS: The results could partly reflect a reported case of globe rupture after RK and suggest that severe ocular trauma can be caused in the post-RK eye by air bags at ordinary impact velocities.

Clinical application of full-arc, depth-dependent, astigmatic keratotomy.

PURPOSE: To report a case series of the first clinical application of a new method of astigmatic keratotomy termed full-arc, depth-dependent astigmatic keratotomy (FDAK). METHODS: The type of astigmatism was analyzed by corneal topography. If the astigmatism was regular, paired arcuate incisions of 90 degrees length were used. Incision depth varied between 40% and 75% of local corneal thickness for controlling the level of astigmatic correction. RESULTS: All 13 cases had regular astigmatism, and paired arcuate incisions of 90 degrees length were used. Four cases with incisions at 40% depth, five cases at 50% depth, three cases at 60% depth, and one case at 75% depth induced vector astigmatic change of 0.93 +/- 0.33 D, 1.92 +/- 0.24 D, 3.17 +/- 0.26 D, and 4.44 D, respectively, 3 months after surgery. From 3 months to 1 year or 3 years, the postoperative astigmatism was stable, and no cases showed astigmatic regression of 0.50 D or more. Every topographic difference map indicated effective flattening and steepening occurring with a 1:1 coupling ratio. All postoperative color maps showed a marked improvement in corneal sphericity. CONCLUSIONS: In FDAK using paired 90 degrees incisions at 40-75% depth, an almost linear relationship between the incision depth and degree of astigmatic change was observed. FDAK may be an effective and safe method of astigmatic keratotomy that accurately controls the level of astigmatic correction. More clinical applications are necessary for drawing final conclusions and making a nomogram.

Differences in incision shape based on the keratome bevel.

PURPOSE: To evaluate differences in incision shape due to the bevel of the keratome. SETTING: Kushimoto Rehabilitation Center, Kushimoto, Japan. METHODS: Three types of keratomes (bibevel, bevel up, and bevel down) were inserted into soft polyvinyl chloride sheets and polyurethane sheets, and the incision shapes in the blade entrance and exit planes were evaluated. The experiments were repeated using soft polyvinyl chloride domes and silicone domes. RESULTS: In the experiments using artificial sheets, the incisions in the blade entrance and exit planes using the bibevel keratome had a linear shape, those using the bevel-up keratome had an inverse-V shape, and those using the bevel-down keratome had a V shape. In the experiments using artificial domes, the incision shapes were the same as those in the artificial sheets. CONCLUSIONS: The incision shape differed according to the direction of the keratome bevel. These experiments and results may provide useful data when new knives are developed or when incision shapes following intended specifications are stably made.

Histamine release test and measurement of antigen-specific IgE antibody in the diagnosis of allergic conjunctival diseases.

Although systemic allergic laboratory tests for the quantification of allergen-specific serum IgE antibody have been widely used, in these tests a high titer of serum specific IgE does not necessarily indicate evidence of allergy. We evaluated the diagnostic value of the glass microfiber-based histamine release test (HRT) using small amounts of whole blood, in 36 cases of allergic conjunctival diseases: 17 cases of allergic conjunctivitis and 19 of atopic keratoconjunctivitis. The patients were evaluated by HRT, capsulated hydrolic carrier polymer (CAP)-RAST, and conjunctival provocation test (CPT) against ten allergens. The positive rates for all allergens were higher in CAP-RAST than in HRT. The mean concordance of HRT with CAP-RAST results was 0.789. The mean concordance of HRT with CPT was 0.892 and that of CAP-RAST with CPT was 0.693. A significantly higher concordance was observed in HRT than CAP-RAST for Japanese cedar and mite antigen. The mean sensitivity, specificity, and efficiency of HRT were higher than those of CAP-RAST. These results indicate that CAP-RAST is good for the screening of allergens and that HRT has an advantage in the confirmation of clinical allergens in allergic conjunctival diseases because of its high sensitivity, specificity, efficiency, and higher concordance with CPT.

Treatment of retinal detachment resulting from myopic macular hole with internal limiting membrane removal.

PURPOSE: To examine the efficacy of vitrectomy with internal limiting membrane removal for retinal detachment resulting from a macular hole in highly myopic eyes. METHODS: Eleven consecutive highly myopic eyes (11 patients) with retinal detachment resulting from a macular hole were treated by vitrectomy with removal of the internal limiting membrane, which was stained with indocyanine green and sulfur hexafluoride gas injection. Postoperatively, the patients were instructed to remain prone for 2 weeks. The excised specimens were evaluated with transmission electron microscopy. RESULTS: The mean postoperative follow-up was 9.2 +/- 2.3 months (range, 7 to 13 months). In 10 of the 11 eyes (91%) the retina was reattached during the initial surgery. Redetachment occurred in one eye, which was successfully treated during the second surgery. Best-corrected visual acuity improved in all eyes and ranged from 20/400 to 20/50. Pathologic examination showed that the internal limiting membrane and epiretinal tissues were present in all specimens. CONCLUSIONS: The use of indocyanine green staining can facilitate removal of a macular internal limiting membrane and overlying epiretinal membrane, resulting in complete relief of the macular traction. Primary removal of the internal limiting membrane may contribute to a high initial success rate for retinal reattachment and be an important adjuvant to the treatment of retinal detachment resulting from a macular hole in highly myopic eyes.

Guided knives.

A new type of knife that enables a surgeon to easily create tunnel-shaped incisions with a prescribed depth has been developed. The knife features an incision guide, the arm of which extends just beyond the tip of the blade. The space between the blade and the arm can be set at the desired width. By moving the knife as if sliding the arm across the corneal or scleral surface, the blade can move to a certain depth from the surface. The guided knife enables even novice surgeons to easily make a self-sealing incision during cataract surgery. In addition, the innovative nature of this device seems to be applicable to many other surgeries that require a partial-thickness incision.

Iris neovascularization after vitrectomy combined with phacoemulsification and intraocular lens implantation for proliferative diabetic retinopathy.

PURPOSE: To analyze the incidence of iris neovascularization after vitrectomy combined with phacoemulsification and intraocular lens (IOL) implantation using a small incision in the treatment of proliferative diabetic retinopathy (PDR). PATIENTS AND METHODS: We studied a consecutive series of 46 eyes in which vitrectomy combined with phacoemulsification and IOL implantation had been performed, and compared the surgical results with a prior series of 40 eyes in which vitrectomy alone had been performed. RESULTS: Postoperative iris and angle neovascularization was found in 6 eyes (15%) treated by vitrectomy alone, but in only 1 eye (2%) treated by combined vitrectomy (P<0.05). Final visual acuity improved by two or more lines in 23 eyes (57%) in the vitrectomy alone group, and in 35 eyes (76%) in the combined vitrectomy group. CONCLUSIONS: The incidence of postoperative rubeosis iridis was significantly lower, and the visual results were satisfactory with vitrectomy combined with phacoemulsification and IOL implantation for PDR. These findings suggest that combined vitrectomy for PDR is a useful surgical procedure.

Perifoveal microcirculation before and after vitrectomy for diabetic cystoid macular edema.

PURPOSE: To quantify the perifoveal microcirculation in diabetic eyes before and after successful vitreous surgery for cystoid macular edema without posterior vitreous detachment, and to determine whether improvement in perifoveal microcirculation is associated with improvement in postoperative visual acuity. METHODS: In a prospective study, vitreous surgery was performed on 11 eyes of nine consecutive diabetic patients with cystoid macular edema, and their mean perifoveal capillary blood flow velocity was measured by fluorescein angiography with a scanning laser ophthalmoscope. Visual acuity was measured preoperatively and postoperatively, and the results were converted to the logarithm of the minimum angle of resolution (logMAR). The correlation between changes in logMAR visual acuity and capillary blood flow velocity was evaluated. RESULTS: In all nine eyes of seven patients with successful vitreous surgery, the cystoid macular edema resolved within 6 months after surgery, and the mean capillary blood flow velocity was significantly increased compared with that before surgery (2.19 mm per second versus 2.68 mm per second, P =.021); the changes in capillary blood flow velocity were significantly correlated with the changes in the logMAR visual acuity (P =.024). CONCLUSIONS: Vitreous surgery may improve perifoveal microcirculation in the eyes of diabetic patients with cystoid macular edema and resolve the macular edema. Improvement of perifoveal microcirculation may be an important factor affecting visual outcome.

The Effect of Intraocular Lidocaine in White Rabbit Eyes.

Purpose: Recently, intraocular lidocaine anesthesia has been used in cataract surgery. We studied the toxicity of intraocular unpreserved lidocaine for corneal endothelial cell and retina using Japanese white rabbits.Methods: The rabbits were divided into two groups. One group was injected intracamerally and the other was injected intravitreally with 0.2 ml of unpreserved lidocaine of 0%, 0.02%, 0.2%, or 2% concentration. The number of corneal endothelial cells was measured 1 week after the injection. After measurements, the rabbit corneas were studied histologically. The retina was examined by electroretinogram prior to initial injection through 1 week after the injection.Results: There was no significant change in number of corneal endothelial cells after injection of 0.2% lidocaine. However, histological abnormality was seen in corneal endothelial cells after 2% lidocaine injection. There was also significant change in electroretinogram with 2% lidocaine injection. No histological abnormality was seen in the retina 1 week after the injection.Conclusion: The rabbit cornea and retina manifested no serious changes after the injection of lidocaine at less than 0.2% concentration functionally and histologically.

Staining of internal limiting membrane in macular hole surgery.

Removal of internal limiting membranes (ILMs) is a potentially useful surgical approach to close an idiopathic macular hole. However, the removal of ILMs is difficult to perform because of poor visibility of the ILMs. We have developed a technique for staining the ILM with a solution of indocyanine green to facilitate the removal of ILMs in eyes with an idiopathic macular hole. Thirteen eyes of 13 patients (8 women and 5 men, aged from 54 to 68 years) with idiopathical macular hole stage 3 or stage 4 that underwent removal of ILMs using this technique had an anatomical closure rate of 92% and an improvement of visual acuity of 89% (>/=2 Snellen letter chart lines). The excised specimens were evaluated using transmission electron microscopy. Our results show that this technique is safe and useful in visualizing the ILM, leading to the performance of successful removal of an ILM with least damage to the retina. Arch Ophthalmol. 2000;118:1116-1118

[The effect of intraocular lidocaine in white rabbit eyes].

PURPOSE: Recently, intraocular lidocaine anesthesia has been used in cataract surgery. We studied the toxicity of intraocular unpreserved lidocaine for corneal endothelial cell and retina using Japanese white rabbits. METHOD: They were divided into two groups. One group was injected intracamerally and the other group was injected intravitreally with 0.2 ml of unpreserved lidocaine of 0%, 0.02%, 0.2%, or 2% concentration. The number of corneal endothelial cells was measured 1 week after the injection. The rabbits were killed after measurements, and their corneas were studied histologically. The retina was examined by electroretinogram from before the injection through 1 week after the injection. RESULTS: There was no significant change in number of corneal endothelial cells after injection of 0.2% lidocaine. However, histological abnormality was seen in corneal endothelial cells after 2% lidocaine injection. There was also significant change in electroretinogram with 2% lidocaine injection. No histological abnormality was seen in the retina 1 week after the injection. CONCLUSION: The rabbit cornea and retina manifested no serious changes after the injection of lidocaine at less than 0.2% concentration functionally and histologically.

Capillary blood flow velocity in patients with idiopathic epiretinal membranes.

PURPOSE: Eyes with idiopathic epiretinal membranes (ERM) often have tortuous vessels and macular edema, suggesting that eyes with ERM may have a disturbance of the macular microcirculation. The authors studied perifoveal microcirculation in eyes with ERM by means of scanning laser ophthalmoscope (SLO) fluorescein angiography. METHODS: Mean capillary blood flow velocity (CFV) was measured by SLO fluorescein angiography in 19 eyes with ERM before and 6 months after vitreous surgery and in 19 healthy control eyes. RESULTS: Mean CFV was significantly reduced in the eyes with ERM compared with the healthy control eyes (2.98 +/- 0.32 mm/sec versus 3.34 +/- 0.12 mm/sec, P < 0.05), and postoperative mean CFV was significantly increased compared with preoperative mean CFV (3.14 +/- 0.32 mm/sec versus 2.98 +/- 0.32 mm/sec, P < 0.05). CONCLUSIONS: Eyes with ERM show abnormal hemodynamics in the perifoveal capillaries. Surgical treatment of eyes with ERM results in improvement of the abnormal blood flow.

Perifoveal microcirculation in eyes with epiretinal membranes.

BACKGROUND/AIMS: Eyes with epiretinal membranes (ERMs) often have alterations of retinal vessels. The authors studied perifoveal microcirculation in eyes with epiretinal membranes (ERMs) using scanning laser ophthalmoscope (SLO) fluorescein angiography. METHODS: Mean capillary blood flow velocity (CFV) was measured as an index of perifoveal microcirculation by SLO fluorescein angiography in 26 eyes with ERMs (19 eyes with idiopathic epiretinal membranes, seven eyes with epiretinal membranes after retinal detachment surgery) before and 6 months after vitreous surgery, and in 23 healthy control subjects. RESULTS: The mean CFV was significantly reduced in eyes with ERMs compared with healthy controls (p=0.012), and the postoperative mean CFV was significantly increased compared with the preoperative mean CFV (p=0.041). CONCLUSION: Significant changes of capillary blood flow velocity in the perifoveal areas were observed between normal subjects and eyes with epiretinal membranes. This indicates that eyes with ERMs show abnormal haemodynamics in the perifoveal capillaries.

Expression of matrix metalloproteinase-7 in choroidal neovascular membranes in age-related macular degeneration.

PURPOSE: Matrix metalloproteinases are a family of extracellular matrix-degrading enzymes associated with neovascularization. We evaluated the expression and localization of matrix metalloproteinase-7 in choroidal neovascular membranes in age-related macular degeneration. METHODS: Immunofluorescence and transmission electron microscopic examinations were performed on subfoveal neovascular membranes that had been surgically removed from seven eyes of seven patients with age-related macular degeneration. RESULTS: Matrix metalloproteinase-7 was expressed in all specimens and distinctly expressed in the thickened layer of Bruch membrane and basement membrane-like structure around retinal pigment epithelial cells. CONCLUSIONS: Matrix metalloproteinase-7 was expressed in Bruch membrane of choroidal neovascular membranes in age-related macular degeneration. Matrix metalloproteinase-7 may be an important factor for the development of the submacular neovascular membrane in age-related macular degeneration.

New iris retractor for pupil dilatation during anterior vitrectomy: double-hook iris retractor.

To report a new iris retractor as a tool for pupillary dilatation in eyes with a small pupil. This instrument was designed to prevent the retractor from dropping out of corneal incision, especially during anterior peripheral vitrectomy requiring a scleral indentation. A new iris retractor was designed with the top in the form of a double-hook, based on the conventional flexible iris retractor. The new instrument was used in 16 eyes, and the conventional flexible iris retractor was used in 14 eyes, with proliferative retinopathy or proliferative diabetic retinopathy in cases in which anterior vitrectomy was performed. The number of times that the instrument has been replaced were recorded. The conventional flexible iris retractor was replaced at mean number of 4.2 times, while the new iris retractor was replaced a mean number of 0.3 times during vitreous surgery. The difference was statistically significant (P = 0.009, Mann-Whitney test). The new iris retractor can easily hook onto the iris and is useful in anterior vitrectomy.