ABSTRACT
PURPOSE: The outer nuclear layer (ONL) contains photoreceptor nuclei, and its thickness is an important biomarker for retinal degenerations. Accurate ONL thickness measurements are obscured in standard optical coherence tomography (OCT) images because of Henle fiber layer (HFL). Improved differentiation of the ONL and HFL boundary is made possible by using directional OCT, a method that purposefully varies the pupil entrance position of the OCT beam. METHODS: Fifty-seven normal eyes were imaged using multiple pupil entry positions with a commercial spectral domain OCT system. Cross-sectional image sets were registered to each other and segmented at the top of HFL, the border of HFL and the ONL and at the external limiting membrane. Thicknesses of the ONL and HFL were measured and analyzed. RESULTS: The true ONL and HFL thicknesses varied substantially by eccentricity and between individuals. The true macular ONL thickness comprised an average of 54.6% of measurements that also included HFL. The ONL and HFL thicknesses at specific retinal eccentricities were poorly correlated. CONCLUSION: Accurate ONL and HFL thickness measurements are made possible by the optical contrast of directional OCT. Distinguishing these individual layers can improve clinical trial endpoints and assessment of disease progression.
Subject(s)
Ependymoglial Cells/cytology , Nerve Fibers , Retinal Neurons/cytology , Tomography, Optical Coherence/methods , Adolescent , Adult , Cell Nucleus , Female , Fourier Analysis , Healthy Volunteers , Humans , Male , Prospective Studies , Young AdultSubject(s)
Epiretinal Membrane/etiology , Intraoperative Complications , Postoperative Complications , Retinal Detachment/etiology , Retinal Perforations/etiology , Vitrectomy/adverse effects , Epiretinal Membrane/diagnosis , Epiretinal Membrane/surgery , Follow-Up Studies , Humans , Recurrence , Retinal Detachment/diagnosis , Retinal Detachment/surgery , Retinal Perforations/diagnosis , Retinal Perforations/surgery , Retrospective Studies , Risk Factors , Scleral BucklingABSTRACT
PURPOSE: To evaluate the rates of adverse reactions to suture materials and compare the rates for plain gut, polyglycolic acid, and polyglactin 910. METHODS: Postoperative adverse suture reaction rates were compared using Fisher exact test. One hundred and forty-six patients who underwent pars plana vitrectomy were included in this study. RESULTS: Adverse suture reaction rates were 2% (1/48) for plain gut, 30% (6/20) for polyglycolic acid, and 12% (11/78) for polyglactin 910. CONCLUSION: Plain gut suture was associated with fewer adverse suture reactions when compared with polyglycolic acid and polyglactin 910 and seems to be suitable for sclerotomy closure.
ABSTRACT
OBJECTIVE: To compare 20-gauge standard pars plana vitrectomy (PPV) with transconjunctival cannulated PPV in the development of intraoperative retinal breaks and postoperative rhegmatogenous retinal detachments (RRDs) in a large series of patients undergoing PPV for macular pucker or macular hole. METHODS: This study was conducted at an academic tertiary care vitreoretinal practice in Milwaukee, Wisconsin. Patients undergoing 3-port PPV with standard 20-gauge instrumentation were compared with patients undergoing 3-port PPV with transconjunctival cannulated systems, including 20 gauge, 23 gauge, and 25 gauge, from January 1, 2003, through December 31, 2009. The main outcome measures were rates of intraoperative retinal breaks and postoperative RRD. RESULTS: Four hundred twenty-six unique eyes met inclusion criteria. Fifty-four of 426 eyes (12.7%) were diagnosed as having new retinal tears intraoperatively as follows: 47 of 204 patients (23.0%) undergoing the standard 20-gauge procedure developed intraoperative retinal tears compared with 7 of 211 patients (3.3%) undergoing the transconjunctival cannulated procedure (risk ratio [RR], 0.12; 95% CI, 0.05-0.26; P < .001). Patients experiencing intraoperative retinal tears were not at increased risk of developing postoperative RRD (RR, 1.4; 95% CI, 0.39-5.0; P = .61). Although a trend was present, transconjunctival cannulated vitrectomy was not significantly protective against the development of postoperative RRD (RR, 0.60; 95% CI, 0.17-1.3; P = .14). CONCLUSION: Transconjunctival cannulated PPV, including 20-gauge, 23-gauge, and 25-gauge systems, is associated with significantly reduced rates of intraoperative retinal tear formation compared with standard 20-gauge PPV.
