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Backside damage of the polyethylene in TKA is a potential source of debris. The location of the tibial post in posterior-stabilized implants may influence micromotion, and thus affect backside damage, as may surface roughness.We used implant retrieval analysis to (1) examine if there were differences in backside damage among three modern posterior-stabilized implants attributable to variable surface roughness; (2) determine if the location of damage on the tibial post affected the pattern of backside damage; and (3) determine if demographics influenced backside damage.We identified 403 posterior-stabilized tibial retrieved inserts (147 NexGen(®), 152 Optetrak(®), 104 Genesis(®) II). The damage on the surfaces of the tibial posts was previously graded. The backside of the inserts (divided into quadrants) were scored for evidence of damage. The total quadrant damage was compared for each implant group, the relationship between post face damage and location of damage on the backside was determined for each implant group, and total backside damage was compared among the three implant groups.No correlation was found between the location of damage on the post and location of damage on the backside of the implant for any of the three groups. The Genesis(®) II polyethylene implants, which articulate with a highly polished tibial tray, showed a significantly lower total backside damage score (p0.01) when compared with the other two implant groups. The Genesis(®) II and Optetrak(®) showed significantly more damage in the posterior quadrants of the implants (p0.01) when compared with the anterior quadrants. A linear regression analysis revealed that lower tibial tray surface roughness was correlated with decreased damage.An implant design with a highly polished tibial tray was associated with decreased backside damage. However, tibial post design and location did not influence the location of backside damage.Our study showed that a highly polished tibial tray was associated with decreased damage to the backside of polyethylene inserts independent of post design and location. These findings should be taken into consideration when new generations of implants are designed.

We examined the role of DNA copy number variants (CNVs) of known glaucoma genes in relation to primary open angle glaucoma (POAG).

Purpose: Compare clinical characteristics, patient outcome with herpes simplex virus (HSV), and varicella-zoster virus (VZV) uveitis. Methods: Retrospective study; HSV 40 patients, VZV 24; median follow-up 46 months. Diagnosis by clinical, serological findings. Clinical characteristics, treatment, complications, final visual acuity were compared. Results: HSV patients had recurrent disease, VZV had chronic disease (p=0.046). Most frequent ocular complication was glaucoma (54% HSV, 38% VZV). VZV patients had more posterior pole complications (25%.vs 8%). Steroids were required more in HSV patients (60% vs. 25%). Visual outcome was similar in both populations (p=0.99). Conclusions: VZV patients developed more posterior pole complications, HSV prients needed more steroid treatment.

The current study adapted the Garner paradigm for diagnosing separable versus integral perceptual dimensions to the eye-blink classical conditioning paradigm using rabbits. Specifically, this study examined the ability of rabbits to categorize stimuli based on one auditory dimension while ignoring a second, irrelevant dimension by displaying an appropriate eye-blink for bilaterally conditioned discriminative responses. Tones used in training varied along two dimensions, starting frequency and magnitude of frequency sweep upwards from the start. Rabbits first learned to categorize along a single dimension (blinking one eye for one category response and the other eye for the other response) and then continued to categorize tones in a second phase in which the irrelevant dimension was varied. The variation of the irrelevant dimension did not disrupt performance, indicating that rabbits perceive these dimensions as separable.

Objective: To evaluate the safety and efficacy of Ahmed glaucoma valve implantation for the management of glaucoma associated with chronic uveitis. Design: Retrospective, noncomparative case series. Participants: Nineteen patients (21 eyes) with chronic uveitis underwent Ahmed glaucoma valve implantation for uncontrolled glaucoma between 1995 and 1998. Intervention: All patients had their uveitis controlled before surgery via immunomodulatory therapy. Ahmed glaucoma valve implantation was performed, Immunosuppression was continued in the early postoperative period for strict control of inflammation. Main Outcome Measures: Control of intraocular pressure (IOP). A secondary outcome measure was the number of antiglaucoma medications required to achieve the desired IOP. Visual acuity and complications associated with the surgery were monitored. Results: The postoperative follow-up averaged 24.5 months. At the most recent visit, all 21 eyes had IOPs between 5 and 18 mmHg. The average pressure reduction after Ahmed glaucoma valve implantation was 23.7 mmHg, The average number of antiglaucoma medicines required to achieve the desired IOP was reduced from 3.5 before surgery to 0.6 after surgery. No eye lost even a single line of Snellen acuity at the most recent postoperative visit. Two eyes developed hypotony in the course of follow-up. One resolved without specific intervention, and the other eye required two autologous blood injections and tube ligature to correct the hypotony. One eye underwent Ahmed glaucoma valve replacement for abrupt valve failure, Two eyes underwent penetrating keratoplasty for reasons believed to be unrelated to the glaucoma surgery, Kaplan-Meier life-table analysis showed a cumulative probability of success after Ahmed glaucoma valve implantation of 94% at 1 year. Conclusions: Ahmed glaucoma valve implantation can be an effective and safe method in the management of uveitic glaucoma. The authors hypothesize that control of the patients’ uveitis, through preoperative and long-term postoperative immunomodulatory therapy, may have contributed to the success rate reported herein.