Comparison of 20, 23 and 25 Gauge Vitreoretinal Surgical Instruments

PURPOSE: To investigate the diameter, the infusion and aspiration rate of 20-, 23- and 25-gauge vitreous cutters, and compare the theoretical and practical intraocular pressure (IOP) change according to the height of the bottle. METHODS: A vitreous cutter was disassembled to measure the actual external and internal diameter. The infusion rate was measured at the height of 40, 60, 80, 100 and 120 cm and the suction rate was measured at a pressure of 100, 200, 300, 400 and 500 mm Hg for each gauge. IOP during the operation was calculated according to the bottle height and the actual IOP was measured using a mercury sphygmomanometer. RESULTS: The external diameter of the 20-, 23- and 25-gauge was 900, 596, and 500 mm, respectively, and the internal diameter was 670, 450, and 380 mm, respectively. The infusion rate increased in direct proportion to the bottle height. The aspiration rate increased as the pressure increased. However, the increment of the infusion and aspiration rate in the 20-gauge vitreous cutter was the highest and decreased in the 23- and 25-gauge, in that order. IOP was calculated as 29, 44, 59 and 74 mm Hg when the bottle height was at 40, 60, 80 and 100 cm, respectively, and was measured 34, 50, 62 and 74 mm Hg, respectively. CONCLUSIONS: The infusion and aspiration rates per outer diameter in the 23- and 25-gauge vitreous cutters and infusions using cannula were lower than in the 20-gauge vitreous cutter. The difference of the infusion and aspiration rates per diameter between the 23- and 25-gauge vitreous cutters and infusions was not significant.

Clinical Course after Intravitreal Bevacizumab Injection in Ischemic Central Retinal Vein Obstruction

PURPOSE: To determine the clinical outcome of intravitreal bevacizumab injection in patients with ischemic central retinal vein obstruction (CRVO). METHODS: The present study was conducted retrospectively on 56 eyes of 56 patients who were diagnosed with CRVO and classified according to ischemic and non-ischemic type and underwent an intravitreal bevacizumab injection. The present study measured changes in visual acuity and central macular thickness, neovascularization in the anterior segment, development of neovascular glaucoma and other clinical complications. RESULTS: The average number of bevacizumab injections in both groups was 2.07 and 1.62 in the ischemic type. No patients developed neovascular glaucoma in the non-ischemic type group, 14 of 26 eyes in the ischemic type group developed neovascular glaucoma and the mean time to diagnosis was 28.75 weeks. log MAR visual acuity of the ischemic type group prior to injection was 1.56 +/- 0.65 on average which improved to 1.44 +/- 0.97 (p = 0.45). CONCLUSIONS: Intravitreal bevacizumab injection improves the condition of cystic macular edema clinically, but does not affect the development of neovascular glaucoma and improvement of visual acuity in ischemic type CRVO.

The Short-term Effect of Intravitreal Bevacizumab for Treatment of Central Serous Chorioretinopathy

PURPOSE: To determine whether intravitreal bevacizumab is effective for the treatment of central serous chorioretinopathy. METHODS: We retrospectively examined 42 eyes after intravitreal bevacizumab (1.25 mg) injection for central serous chorioretinopathy. After 1 month, improvement of vision and change in sensory retinal detachment were evaluated with a fundus examination and optical coherence tomography. RESULTS: The mean duration of symptoms was 3.9+/-2.31 months. After intravitreal bevacizumab injection, mean best corrected visual acuity improved from 0.53+/-0.31 to 0.72+/-0.29 at 1 month. In addition, neurosensory retinal detachment disappeared in 32 patients (76.2%). Five patients among ten who did not show improvement of neurosensory retinal detachment underwent reinjection of bevaczumab, and three of those reinjected showed the resolution of neurosensory retinal detachment at another 1 month. No improvement was seen among the patients who did not undergo reinjection. CONCLUSIONS: Intravitreal bevacizumab injection appears to have a short-term benefit for the treatment of central serous chorioretinopathy.

Primary Combined Photodynamic Therapy and Intravitreal Bevacizumab Injection for Neovascular Age-related Macular Degeneration

PURPOSE: To investigate the efficacy of the combined treatment of photodynamic therapy (PDT) with verteporfin and intravitreal bevacizumab in patients with neovascular age-related macular degeneration. METHODS: Forty-five eyes received a single session of PDT following three intravitreal bevacizumab (1.25 mg) injections at six-week intervals (IVB+PDT group). Twenty-seven eyes received three intravitreal bevacizuamb (1.25 mg) injections only at six-week intervals (IVB group). RESULTS: After the six months of follow up, the mean BCVA (LogMAR) changed significantly from 0.62+/-0.34 to 0.56+/-0.33 in the IVB group (p=0.03) and from 0.61+/-0.33 to 0.48+/-0.21 in the IVB+PDT group (p=0.001). The mean BCVA was more improved in the IVB+PDT group (p=0.049). The mean CMT changes were significant in both groups immediately after treatment, but there was no significant difference at six months between the two groups. Ten eyes (37.0%) in the IVB group and 12 eyes (26.7%) in the IVB+PDT group required retreatments during the six months of follow-up (p=0.02). CONCLUSIONS: Significant improvement in visual acuity and reduction in central macular thickness over a six-months period were observed in both groups. The mean visual acuity was significantly better and the rate of reinjections after the initial treatment schedule was lower in the IVB+PDT group.

The Relationship between the Visual Prognoses of Branch Retinal Artery Obstruction and Foveal Thickness on OCT

PURPOSE: To determine the correlation between the prognosis of branch retinal artery obstruction (BRAO) and the foveal thickness or outer nuclear layer (ONL) thickness on optical coherence tomography (OCT). METHODS: Twenty-one eyes (21 patients) in patients with resolved, non-complicated BRAO and a normal control of 10 eyes (10 volunteers) were used in this study. The average macular thickness, foveal thickness and ONL thickness at central fovea were measured in both the patients and the control group using spectral domain OCT. The thickness between the patient group and the control group were compared and correlation between the best corrected visual acuity (BCVA) and each thickness was determined. RESULTS: The average age of the patients was 52 +/- 5.8 years. The average macular thickness, foveal thickness and ONL thickness at the central fovea of the patients were significantly (p < 0.001, p = 0.023, p = 0.021, respectively) thinner than that of the control group. Both the foveal thickness (r(s) = 0.56, p = 0.008) and ONL thickness (r(s) = 0.86, p < 0.001) were significantly correlated with BCVA. There was no significant correlation between the average macular thickness and BCVA. CONCLUSIONS: The foveal thickness and ONL thickness at the fovea was positively correlated with the BCVA in patients with resolved BRAO.

Scleral Buckling and Primary Vitrectomy in Simple Rhegmatogenous Retinal Detachment

PURPOSE: To compare the outcomes of scleral buckling (SB) and primary pars plana vitrectomy (PPV) for treatment of simple rhegmatogenous retinal detachment (RD). METHODS: One hundred and fifteen Eyes undergoing SB or PPV for the treatment of simple rhegmatogenous RD were prospectively identified and followed up at least six months. Anatomic results, functional outcomes and complications were compared between eyes treated with SB and eyes treated with PPV. RESULTS: We detected no significant differences in overall success rates or final vision quality between the two treatment groups. However, the final vision quality of pseudophakic patients treated with PPV was significantly better than the final vision quality of pseudophakic patients treated with SB. Two treatment goups experienced similar rates of intraocular pressure elevation and proliferative vitreoretinopathy development. In phakic patients, the rates of cataract progression were higher in patients treated with PPV than in patients treated with SB. CONCLUSIONS: PPV can be an effective method for the treatment of simple rhegmatogenous RD, and maybe considered as a viable alternative to SB for simple cases. However, in phakic patients treated with PPV, simultaneous or follow-up cataract surgery should be considered as adjuvant treatments.

Incidence and Characteristics of Acute Endophthalmitis Associated With Intravitreal Injection

PURPOSE: To evaluate the incidence, causative organism, clinical features, and visual outcomes of acute endophthalmitis following intravitreal injection. METHODS: For all intravitreal triamcinolone acetonide, bevacizumab, and lucentis injections performed in our outpatient clinic between January 2006 and June 2008, the number of injections, indications, type of administered drugs, and method of injection were investigated. The medical records of the patients with acute endoththalmitis were reviewed retrospectively. RESULTS: The total number of intravitreal injections was 10,153. The incidence of acute endophthalmitis for all intravitreal injections was 0.020% (2/10,153) with 0.030% (1/3,383) for the triamcinolone acetonide, 0.015% (1/6,552) for the bevacizumab, and 0.000% (0/218) for the ranibizumab drug injections. Streptococcus species were confirmed in the bacterial culture of two eyes with acute endotphthalmitis. After early vitrectomy and intravitreal antibiotics injection, one eye maintained vision but the other eye developed phthisis. CONCLUSIONS: Although the incidence of acute endophthalmitis following intravitreal injections performed in outpatient clinics is very low, due to the potentially fatal visual outcome after endophthalmitis, careful attention to aseptic injection technique is mandatory.

The Efficacy of Photodynamic Therapy With Verteporfin for Polypoidal Choroidal Vasculopathy: Retrospective Multi-Center Case Study

PURPOSE: To evaluate the efficacy of photodynamic therapy (PDT) with verteporfin for polypoidal choroidal vasculopathy (PCV) in Korean patients. METHODS: Clinical data of patients who were treated with PDT for PCV and followed up for more than 6 months were collected from 14 hospitals around the country. The changes in the best corrected visual acuity, angiographic outcome, retinal thickness measured by optical coherence tomography (OCT), and adverse effects of treatment were evaluated. RESULTS: Eighty six patients (86 eyes) were recruited (male: 75.6%, age: 65.9+/-8.3 years, mean follow-up: 14.8+/-10.2 months). The mean logMAR visual acuity at baseline was 0.55+/-0.32 and did not show any statistically significant difference from the final mean logMAR visual acuity (0.53+/-0.54) (p=0.639). The mean treatment session number of PDT was 2+/-1.2. Visual acuity stabilized or improved in 70.9% of patients. Visual acuity improved by more than 2 lines in 33 eyes (38.4%) and worsened by more than 2 lines in 21 eyes (24.4%) of patients. Vascular leakage decreased in 62.5% of patients in fluorescein angiography and polypoidal lesions disappeared or were reduced in 57.3% of patients in indocyanine green angiography. There was no systemic adverse effect of PDT, but increased subretinal hemorrhage after PDT occurred in 10 eyes (11.6%). CONCLUSIONS: In polypoidal choroidal vasculopathy, photodynamic therapy with verteporfin is safe and effective for preserving visual acuity and reducing vascular leakage and retinal thickness.

Photodynamic Therapy for Chronic Central Serous Chorioretinopathy: Multicenter Study of 65 Cases

PURPOSE: To determine the effect of photodynamic therapy (PDT) on patients with chronic central serous chorioretinopahty (CSC). METHODS: This was a retrospective multicenter study. We collected demographic and ophthalmic data for patients with chronic CSC who were treated with PDT from 16 institutions in Korea. The best corrected visual acuity (BCVA), ophthalmoscopic finding and optical coherence tomography at baseline and follow-up visits were compared longitudinally. RESULTS: Sixty-five eyes of 65 patients were recruited. Males (51 patients, 78.5%) outnumbered females (14 patients, 21.5%). The mean age was 46.4+/-10.0 years of age (28~69). By 1 month, mean BCVA improved from 0.47 to 0.37 (logarithm of the minimum angle of resolution) (P <0.01). This BCVA increased throughout 6 months. Subretinal fluid resolved partially or completely in 89.1% of the patients. Central macular thickness (CMT) decreased from 303.4 to 168.7 micrometer. The amount of change in CMT after PDT was correlated to the female sex and prePDT CMT. At 3 months after PDT, the amount of change in BCVA was significantly related to that of change of CMT (p <0.05). Adverse events were reported in 4 cases, however, most were mild. CONCLUSIONS: PDT was effective and safe for treating chronic CSC.

The Clinical Results of Sutureless Vitrectomy Using 23-Gauge Surgical System

PURPOSE: The purpose of this study is to evaluate the clinical results of 23-gauge sutureless vitrectomy. METHODS: We retrospectively analyzed 111 eyes that had undergone 23-gauge sutureless vitrectomy. The eyes underwent surgery from February 2006 to July 2006 and were examined for surgical outcome as well as intraoperative and postoperative complications. RESULTS: The preoperative best corrected visual acuity (BCVA) was 1.43+/-0.12 and increased to 0.88+/-0.11 (P>0.01). Thirteen (11.7%) of 111 eyes developed intraoperative complications, and 21 (18.9%) of 111 eyes developed postoperative complications. Intraoperative complications included wound.leaking (seven eyes), conjunctival suture (three eyes), and difficult insertion (two eyes). Postoperative complications included postoperative hypotony (seven eyes), vitreous hemorrhage (seven eyes), hyphema (five eyes), and infectious endophthalmitis (two eyes). CONCLUSIONS: Unlike 20-gauge vitrectomy, sutureless 23-gauge vitrectomy offers all the advantages of minimally invasive sutureless vitrectomy.

Photodynamic Therapy for Choroidal Neovascularization in Angioid Streaks

PURPOSE: To evaluate the efficacy of photodynamic therapy (PDT) with verteporfin in the management of choroidal neovascularization (CNV) associated with angioid streaks. CASE SUMMARY: Six eyes of four patients with CNV due to angioid streaks were treated with photodynamic therapy with verteporfin. Visual acuity testing, ophthalmologic examinations, photographs, and fluorescein angiograms were used to evaluate the results of PDT. Two of six eyes had subfoveal lesions, while four eyes had juxtafoveal lesions on initial examination. Conversion from a CNV to a fibrous scar lesion following PDT was observed in four eyes. Enlargement of the CNV was documented in two eyes at the final follow-up. Of a total of 6 eyes, the final best-corrected visual acuity decreased in 4 eyes and stabilized in 2 eyes. CONCLUSIONS: Photodynamic therapy can achieve short-term cessation or decrease of fluorescein leakage from chroidal neovascularization associated with angioid streaks. However, it does not alter the course of this disease, and multiple sessions are needed. Visual prognosis is poor.

Photodynamic Therapy for Choroidal Neovascularization Secondary to Age-Related Macular Degeneration

PURPOSE: To investigate the effects of repeated photodynamic therapy (PDT) for subfoveal choroidal neovascularization secondary to age-related macular degeneration (AMD) in Korean patients. METHODS: Clinical data of patients who were treated with repeated (3 times or more) PDT for subfoveal choroidal neovascularization secondary to AMD and followed up for more than 6 months were collected from 17 hospitals around the country. Visual outcomes at 12 and 24 months, follow-up were compared between subtypes of choroidal neovascularization. The factors related to final visual prognosis and PDT-related adverse effects were evaluated. RESULTS: 244 patients (244 eyes) were recruited (male: 60%, age: 67.7+/-9.1 years). The portion of patients with predominantly classic, minimally classic, and occult without classic choroidal neovascularization was 57%, 13%, and 24%, respectively and that of patients with visual improvements or less than moderate visual loss at 24 months follow-up were 28%, 38%, 30% and 47%, 56%, and 65%, respectively. Baseline visual acuity and age were significantly related to the final visual prognosis (p<0.05). PDT-related adverse events developed in 15 (6.1%) patients, but most were mild and transient. CONCLUSIONS: Repeated PDT for subfoveal choroidal neovascularization secondary to AMD has effects comparable to those of previous prospective, controlled trials without any significant safety concerns in Korea.

The Outcomes After Indocyanine Green-assisted Peeling of the Internal Limiting Membrane in Macular Hole Surgery

PURPOSE: To investigate whether indocyanine green (ICG) staining of the internal limiting membrane (ILM) improves surgical and visual outcomes in macular hole surgery. METHODS: Three consecutive groups of patients with stage 3 and stage 4 macular hole underwent standard vitrectomy. Group I (45 eyes) underwent an adjunctive peeling of ILM stained with intravitreal application of 0.1 ml of 0.5% ICG dye, group II (23 eyes) an adjunctive ILM peeling without use of ICG dye, and group III (23 eyes) no adjunctive technique. Postoperative anatomic closure rates of the hole and the logarithm of the minimal angle of resolution (logMAR) visual acuity improvement were compared among the groups. RESULTS: The mean age was 61 years, and the mean follow-up period was 11 months. The rate of macular hole closure, as determined by optical coherence topography was 70% in group I, 61% in group II, and 61% in group III, and the difference were not statistically significant (p=0.726). The differences between preoperative and postoperative logMAR visual acuities among the three groups were not statistically significant (p=0.898). CONCLUSIONS: Intravitreal ICG-assisted ILM peeling did not improve anatomic outcomes in macular hole surgery. (Ed-confirm, something appears to be missing here)

Complications of Scleral Buckling

PURPOSE: To evaluate the nature and frequencies of the complications of scleral buckling surgery. METHODS: The medical records of 222 eyes of 218 patients who had undergone primary scleral buckling surgery using silicone exoplant from January 1993 to June 1999 by one surgeon and who had been followed up for more than 6 months after surgery were reviewed retrospectively. RESULTS: For intraoperative complications, scleral perforation occurred in 24 cases (9.9%) and subretinal hemorrhages in 17 cases (7.0%) out of 243 procedures. For postoperative complications, surgical failure of the primary surgery occurred in 49 eyes (22.1%), temporary increase of intraocular pressure in 13 eyes (6.7%), macular complications in 8 eyes (4.3%), choroidal detachment in 3 eyes (1.5%), strabismus in 2 patients (1.2%), conjunctival cyst in 2 eyes (1.0%) and extrusion of the buckling material in 1 eye (0.5%). Scleral encircling induced myopia of average 2.36 diopters in 13 eyes. The main causes of the primary failure were proliferative vitreoretinopathy in 21 eyes (42.9%) and inadequate buckling in 11 eyes (22.4%). CONCLUSIONS: The most common complication after scleral buckling surgery using silicone exoplant was scleral perforation intraoperatively and persistent or recurrent retinal detachment postoperatively. Temporary increase of intraocular pressure, refractive change, macular complications also occurred postoperatively.

Preretinal Neovascularization by Laser-induced Thrombosis in Albino Rats and Inhibition of Neovascularization by Genistein

PURPOSE: To determine the effect of genistein, an inhibitor of protein tyrosine kinase, on preretinal neovascularization through the quantification of retinal neovascularization using image analyzer in an experimental rat model. METHODS: In 36 eyes of 36 rats, retinal vein occlusion was induced by photodynamic therapy with an argon green laser and systemic injection of rose bengal (40 mg/kg). The development and progression of retinal neovascularization was followed weekly by fluorescein angiography. Seven rats were sacrificed each week, after which two eyes were prepared with H and E staining for histologic examination, and five were prepared as a control group using ADPase staining for neovascularization analysis. In the remaining fifteen eyes, retinal vein occlusion was also induced using the same method. Immediately after vein occlusion, 4.0 mg of genistein dissolved in dimethyl sulfoxide (DMSO) was injected intraperitoneally twice a day for the first 7 days. Five rats were sacrificed each week and stained with ADPase. After ADPase staining, those samples with evidence of neovascularization were quantified using an image analyzer. RESULTS: No retinal neovasularizaion was found at the end of the first week. The size of retinal neovascularization for the five eyes sacrificed at the end of week 2 and 3 were 6.53+/-2.11 mm2 and 3.77+/-3.51 mm2 in the control group, and 2.22+/-1.01 mm2 and 1.64+/-0.88 mm2 in the genistein treatment group, respectively. Retinal neovascularization was successfully suppressed until two weeks after laser treatment by genistein in this rat neovascularization model. CONCLUSIONS: Genistein may be a useful treatment modality to suppress retinal neovascularization complicated with retinal ischemic injury.

The Effect of Growth Factors and Surgical Precedures on Fibrovascular Ingrowth into anophthalmic Socket Implant of Porous Polyethylene

No Abstract Available.

The Effects of Pars Plana Vitrectomy on the Corneal Endothelium

The objective of this study was to examine the effects of pars plana vitrectomy on the corneal endothelium. Thirty-one patients scheduled for pars plana vitrectomy were enrolled in this prospective study. Specular microscopic examination to check central corneal thickness (CCT) and central corneal endothelial density (CCED) was underwent at preoperatively and 1 week, 1 month, 2 months postoperatively. The duration of intravitreal irrigation and the volume of solution were checked also. Transient corneal edema and decrease in endothelial cell density with statistical significance was observed at 1 week postoperatively. We found that neither duration of intraocular irrigation nor the volume of solution used is related with corneal changes. The eyes with combined lensectomy showed more severe corneal edema and significant greater reduction of endothelial cell density at 1 month and 2 months postoperatively compared to phakic eyes. Diabetic eyes also showed a significant greater reduction of endothelial cell density at 2 months postoperatively compared to nondiabetic eyes.

Evaluation of Retinal Circulation Times in Rhegmatogeneous Retinal Detachment with SLO

This study was designed to evaluate the association between rhegmatogenous retinal detachment and retinal circulation times. We observed retinal circulation times in 30 patients with rhegmatogeneous retinal detachment before and after operation using the scanning laser ophthalmoscope. We measured arm to retina time(ART) and arteriovenous passage time(AVT) before the operations and after(average 2.5 weeks) successful reattachment of detached retina. Preoperative ART and AVP were 13.83 +/- 3.08 see and 2.91 +/- 0.69 see respectively, whereas postoperative ART and AVP were 13.60 +/- 2.99 see and 2.90 +/- 0.63 see in detached areas. There was no statistically significant difference between pre- and post-operative ART and AVP in detached retina(P>0.05). Preoperative ART and AVP in flat retinal area were 13.82 +/- 3.08 and 2.91 +/- 0.69 see respectively. There was no statistically significant difference between flat and detached area preoperatively (P>0.05). No significant correlation was noted between retinal circulation times and rhegmatogeneous retinal detachments by scanning laser ophthalmoscope.

Measurement of Blood Retina Barrier in Branch Retinal Vein Occlusion (BRVO)

Vitreous fluorophotometry was used to measure blood retinal barrier permeability to fluorescein in 15 patients with branch retinal vein occlusion(BRVO). Mean posterior vitreous fluorescein concentration(3mm) was 20.0 +/- 11.3(ng/ml) in affected eyes, and 2.99 +/- 1.22(ng/ml) in unaffected eyes. There was a statistically significant difference between the affected eye and unaffected eye(p<0.05). Also there was a correlation between the hemorrhage area and the posterior vitreous fluorescein concentration(r2=0.819). This study revealed that the permeability of blood retinal barrier was increased in BRVO as compared to the contralateral eye, and the higher permeability values were associated with the extent of area involved.

Evaluation of Retinal Circulation Times in Branch Retinal Vein Occlusions with Scanning Laser Ophthalmoscope

To investigate retinal hemodynamics in branch retinal vein occlusion(BRVO), we measured retinal circulation times using scanning laser ophthalmoscope(SLO) and studied the relationships with clinical findings. Arm-retina time(ART) and arteriovenous passage time(AVP) were measured in 35 eyes of 35 patients. Mean ART was 13.05 sec. ART showed no difference with sex and systemic diseases, but increased withage. AVP of occluded branch was much longer than those of other branches. AVP was delayed according to the size of capillary nonperfusion area, but showed no difference according to the duration of disease and macular edema. These results suggest that SLO is an useful method for studying retinal hemodynamics in BRVO.