Byung Ro Lee

Discrepancy between fluorescein angiography and optical coherence tomography in detection of macular disease.

Purpose: To compare high-resolution optical coherence tomography (OCT) and fluorescein angiography (FA) in detection of macular edema (ME) of various etiologies. Methods: In a retrospective study over a 12-month period at one retina center, data for consecutive eyes that had undergone simultaneous conventional FA (HRA; Heidelberg Engineering, Vista, CA) and StratusOCT (Carl Zeiss Meditec, Dublin, CA) to rule out ME were reviewed. A subset of patients underwent additional examination with extremely high-resolution (6-&mgr;m)/ultrahigh-speed spectral OCT/scanning laser ophthalmoscopy (OTI, Inc., Toronto, Ontario, Canada). Results: Of 1,272 eyes, 1,208 (94.97%) had the finding of ME or subretinal fluid confirmed by both techniques. There were 49 eyes (3.86%) for which FA showed dye leakage in the macular area and OCT showed normal foveal contour. Of 10 eyes in this group that underwent imaging with ultrahigh-speed spectral OCT/scanning laser ophthalmoscopy, 8 had subtle diffuse lucencies in the retina. For 15 eyes (1.17%), OCT showed intraretinal and subretinal fluid, which was missed by FA. Conclusions: Both FA and high-resolution OCT are highly sensitive techniques and correlate well in detection of ME. However, there is a small chance that when performed alone they might miss existing subtle ME.

Overcoming segmentation errors in measurements of macular thickness made by spectral-domain optical coherence tomography.

Purpose: To assess the frequency and severity of segmentation errors in spectral-domain optical coherence tomography, and present an appropriate scan protocol for measuring macular thickness. Methods: In this study we examined 40 eyes of healthy subjects, 45 eyes with retinal pathology and 31 eyes with subretinal pathology. Patients were prospectively imaged using 12 radial scans and 3-dimensional macular cube scans by spectral-domain optical coherence tomography (3D OCT-1000; Topcon Corp., Japan) at the same sitting. Retinal segmentation errors were noted and graded using a subjective, categoric error scale to generate an error score. We compared the macular thickness measurements with and without error correction, and between the two scan protocols. Results: In this series, 63.8% of eyes (74 of 116 eyes) gave at least 1 segmentation error. Errors were more common in eyes with pathology. There was a significant difference between measurements of macular thickness with and without correcting these errors, regardless of scan protocol (P < 0.05). After error correction of both scan protocols, the macular thickness measurements obtained with the 12 radial scan protocol were equivalent to those obtained with the 3-dimensional macular cube scan protocol. Conclusion: Segmentation errors were frequent on scans obtained by spectral-domain optical coherence tomography. We recommend the 12 radial scan protocol with error correction as the standard protocol for measuring macular thickness, particularly in clinical studies.

Releasable suture technique for the prevention of incompetent wound closure in transconjunctival vitrectomy.

Releasable Suture Technique for the Prevention of Incompetent Wound Closure in Transconjunctival Vitrectomy A current major issue of transconjunctival sutureless vitrectomy is entry site leakage after surgery. Even with recent modifications of incision techniques such as two-step scleral tunnel incision to try to avoid wound leakage,1,2 it may be difficult to ensure perfect self-sealing of every entry site. In particular cases such as myopia, reoperation, or more thorough peripheral vitrectomy, the incidence of postoperative wound leakage is more frequent.3,4 Moreover, even with successful self-sealing on the operating table, delayed hypotony sometimes develops the next day and can last for days. Furthermore, the true incidence of wound leakage and associated complications is much higher in those who adopt the transconjunctival sutureless vitrectomy technique, as well as for those who are less experienced. Wound leakage or hypotony, even if transient, is not a benign condition and may develop into serious complications5 such as vitreous incarceration, endophthalmitis, suprachoroidal hemorrhage, choroidal detachment, and hypotony maculopathy. Therefore, some surgeons do suturing like as conventional vitrectomy or air-temponade to prevent leakage. Here, we describe a simple, releasable suture technique in transconjunctival vitrectomy, which helps overcome incompetent wound closure after surgery.

Clinical study of combined penetrating keratoplasty, pars plana vitrectomy with temporary keratoprosthesis, and pars plana seton implant.

PURPOSE To assess the effectiveness of a combined procedure (pars plana vitrectomy with temporary keratoprosthesis, penetrating keratoplasty, and pars plana seton implant) in preserving vision and controlling intraocular pressure (IOP). METHODS We reviewed the course of visual acuity, IOP, graft clarity, retinal status, and complications in 18 patients who underwent the above procedure during one operating sitting. RESULTS Preoperative diagnoses were varied. The majority of patients had pseudophakic bullous keratopathy and failed corneal transplants with glaucoma. Preoperative mean visual acuity was hand motions. Preoperative mean IOP was 27+/-13 mm Hg. Initially, all patients had attached retina. With a mean follow-up of 17+/-9 months, six patients had improved vision greater than 2 lines and 10 had unchanged vision. Only two patients lost vision greater than 2 lines. The final average IOP was 16+/-6 mm Hg and only one eye had a pressure above 22 mm Hg. Three eyes were classified as complete failures; two of the three became phthisical. Two patients developed rhegmatogenous detachments requiring further surgery. CONCLUSION The combined procedure offers reasonable improvement in vision, good pressure control, and a tolerable number of complications. It is a useful procedure in eyes that probably would not have been treatable otherwise.

Adjunctive use of a novel releasable suture technique in transconjunctival vitrectomy.

Purpose: The purpose of this study was to determine the merits of a transconjunctival vitrectomy with the releasable suture technique in a large series of 20-gauge, 23-gauge, and hybrid trocar vitrectomy and to assess its effectiveness in minimizing the occurrence of incompetent wound closures. Methods: One hundred and one patients, with a variety of vitreoretinal disorders, and totaling 125 eyes, were enrolled. Each entry site wound was closed, with the releasable suture technique using 8-0 nylon. Postoperatively, sutures were released under a slit lamp at the office a mean 22.9 hours after surgery. In addition to the usual intraoperative and postoperative identification of complications, preoperative and postoperative intraocular pressures were monitored. Results: The full results from all 337 sclerotomies (206, 20 gauge; and 131, 23 gauge) were assessed. It was observed that there were no significant differences between preoperative and postoperative intraocular pressure measurements (P > 0.05); no eyes required fluid or gas supplements, there was no significant wound leakage or hypotony; and no significant complications occurred, such as endophthalmitis or choroidal detachment. Conclusion: These results indicate that transconjunctival vitrectomy with releasable sutures, including those conducted with larger instrument trocar systems, offer patients excellent chances for a favorable outcome without incidences of postoperative wound leakage or hypotony.

Comparison of a novel confocal scanning laser ophthalmoscopy algorithm with optical coherence tomography in measurement of macular thickness and volume.

Purpose: To evaluate macular thickness and volume measurements using a novel Heidelberg Retinal Tomograph (HRT3) algorithm and to compare the results with optical coherence tomography (StratusOCT). Methods: This was a prospective, comparative, clinical noninterventional study. Fifty-two eyes were examined using both methods: 16 normal eyes, 12 eyes with diabetic macular edema (DME), and 24 eyes with age-related macular degeneration (AMD). The HRT3 macular thickness and volume were compared with those from the StratusOCT automated software. In addition, the distances between the retinal surface and the base of subretinal pathologic changes were measured using the StratusOCT manual-caliper technique and were compared with the HRT3 measurements in AMD eyes. Results: No statistically significant difference in macular thickness and volume measurements was observed between the two methods for normal (P = 0.89 and P = 0.33, respectively) and DME eyes (P = 0.86 and P = 0.31, respectively). However, in AMD eyes, the differences in both measurements were statistically significant between the two methods (P < 0.0001 and P < 0.0001, respectively). The HRT3 thickness measurements were in good agreement with the manual StratusOCT measurements (P = 0.4). Conclusion: In normal and DME eyes, the HRT3 measurements correlated well with the automatic StratusOCT measurements. In AMD eyes, the HRT3 measurements correlated well only with the manually corrected measurements of the retinal-subretinal pathologic changes.

Choroidal change in acute anterior uveitis associated with human leukocyte antigen-B27

Purpose To evaluate choroidal changes in eyes with acute anterior uveitis associated with human leukocyte antigen (HLA)-B27 Methods In 44 patients with first-onset, unilateral, acute-onset (<1 week) anterior uveitis for which diagnostic work-ups revealed positivity only for HLA-B27, wide-field three-dimensional volumetric raster scan using swept-source optical coherence tomography was performed for both eyes. Choroidal thickness was measured by automated segmentation and thickness mapping and compared between eyes with uveitis and the fellow eyes at baseline. Choroidal thickness was compared before and after topical and/or systemic corticosteroid therapy. Relative choroidal thickening was defined as the choroidal thickness of the uveitic eye minus that of the corresponding eye and correlated with the degree of intraocular inflammation. Results Compared to the fellow eyes, eyes with acute anterior uveitis showed significant choroidal thickening on the subfoveal and parafoveal areas at baseline (all P <0.05). En face choroidal imaging showed dilation of large choroidal vessels on the macula. Relative choroidal thickening significantly correlated with the degree of anterior chamber inflammation at baseline (correlation coefficient = 0.341, P = 0.023). After treating inflammation, the choroid on the macula thinned significantly (from 262.1 ± 66.5 to 239.5 ± 61.0 μm in the subfoveal choroid, P<0.001). Conclusions Eyes with HLA-B27-associated anterior uveitis showed significant choroidal thickening at acute phase that subsequently decreased after treatment, indicating subclinical choroidal inflammation in the eyes. Choroidal thickness might indicate disease activity in acute anterior uveitis associated with HLA-B27.

Retinal Nerve Fiber and Optic Disc Morphology in Patients with Human Immunodeficiency Virus Using the Heidelberg Retina Tomography 3

Purpose To use novel confocal scanning ophthalmoscopy technology to test hypothesis that HIV-seropositive patients without history of retinitis with a history of a low CD4 count are more likely to have damage to their retinal nerve fiber layer (RNFL) when compared to patients with high CD4 count. In addition, we compared optic disc morphologic changes with glaucoma. Design Cross-sectional study. Participants and Controls 171 patients were divided into four groups. The control group consisted of 40 eyes of 20 HIV-seronegative patients. The second group consisted of 80 eyes of 41 HIV-positive patients whose CD4 cell count never dropped below 100 (1.0 x 109/L). The third group consisted of 44 eyes of 26 HIV-positive patients with a history of low CD4 counts <100. Fourth group consisted of 79 eyes of 79 patients with confirmed glaucoma who served as positive controls. Testing Confocal scanning laser ophthalmoscopy was performed with the Heidelberg Retina Tomograph (HRT3) and data were analyzed with HRT3, software (Heyex version 1.5.10.0). Main Outcome Measures Disc area, cup area, cup volume, rim volume, mean cup depth, maximum cup depth, cup-to-disc ration, mean RNFL thickness, and RNFL cross-sectional area. Results Analysis of the global optic nerve and cup parameters showed no difference in disk area among the four groups. There was also no difference in cup, rim volume, mean cup depth, or maximum cup depth among the first three groups but they were all different from glaucoma group. The RNFL was thinner in glaucoma and both HIV-positive groups compared to HIV-seronegative subjects. The cross sectional RNFL area was thinner in both high and low CD4 HIV-positive groups compared to HIV-seronegative group in the nasal and temporal/inferior sectors, respectively. Glaucoma group showed thinning in all sectors. Conclusions HIV retinopathy results in retinal nerve fiber layer loss without structural optic nerve supportive tissue change. RNFL damage may occur early in HIV disease by mechanism different than in glaucoma.