A Comparison of Sequential Glaucoma Drainage Device Implantation Versus Cyclophotocoagulation Following Failure of a Primary Drainage Device.

PURPOSE: To compare sequential glaucoma drainage device (GDD) implantation with transscleral diode cyclophotocoagulation (CPC) following failure of a primary GDD. MATERIALS AND METHODS: A retrospective review of all patients who underwent GDD implantation at a single institution over 10 years. Patients who required an additional GDD and/or CPC were analyzed. Success was defined as absence of loss of light perception, reoperation for glaucoma, and intraocular pressure (IOP) >21 or <6 at 2 consecutive visits after an initial 3-month period. RESULTS: Thirty-two patients received sequential GDD. Twenty-one underwent CPC. Cohorts were statistically similar in regards to age, sex, race, and number of previous surgeries. Preoperatively, the GDD cohort had a lower IOP and better visual acuity. The mean length of follow-up was 37.9 months for the GDD group and 46.3 months for CPC. Both procedures significantly reduced IOP; however, CPC led to a greater reduction (P=0.0172). Survival analysis found the 5-year probability of surgical success to be 65.3% for sequential GDD and 58.0% for CPC (P=0.8678). No cases of phthisis occurred in either group. There were 2 cases of endophthalmitis (6.3%) in the GDD group, and none in the CPC group. In eyes without preexisting corneal edema, estimated corneal decompensation probability at 3 years was 31.6% for GDD and 6.7% for CPC (P=0.0828). CONCLUSIONS: Sequential GDD and CPC are both effective at reducing IOP following the failure of a primary GDD. CPC after GDD failure warrants further investigation as it led to a greater reduction in IOP with fewer serious adverse events.

Glaucoma drainage devices: risk of exposure and infection.

PURPOSE: To identify risk factors for device exposure and intraocular infection following implantation of a glaucoma drainage device. DESIGN: Retrospective case series. METHODS: The medical records of adult patients undergoing glaucoma drainage device implantation at an academic medical center between 2000 and 2010 were reviewed. Main outcome measures included device exposure and intraocular infection. RESULTS: Seven hundred and sixty-three cases were identified. These included 702 primary implants (ie, the first drainage device implanted into an eye) and 61 sequential implants. Among 702 primary implants, there were 41 cases of exposure (5.8%). None of the potential risk factors were statistically significant. Implant location was found to be a marginally significant risk factor. The exposure rates for inferior and superior implants were 12.8% (5 of 39) and 5.4% (36 of 663), respectively (P = .056). The highest rate of exposure for primary implants occurred in the inferior-nasal quadrant (17.2%, 5 of 29). The rate of exposure for sequential devices was 13.1% (8 of 61), with the highest rate also found in the inferior-nasal quadrant (20%, 5 of 25). Of 49 total exposures, 8 were associated with intraocular infection (16.3%). Exposures over inferior implants were more likely to be associated with infection than exposures over superior implants (41.7% vs 8.1%; P = .0151). CONCLUSION: Implant location approached, but did not reach, statistical significance as a risk factor for exposure. Exposures over inferior implants place patients at a higher risk of infection than superior exposures. More studies are needed to identify modifiable risk factors for device exposure.

Occult Perforating Corneal Injury from Mechanical Pencil Graphite.

An 11-year-old boy was struck in the left eye with a mechanical pencil in a projectile manner. Initial examination under the operating microscope revealed a presumed partial-thickness corneal injury with a retained 8-mm long segment of graphite lead. After removal of the graphite segment, a full-thickness hole in the cornea was revealed under the lead shaft. The proposed mechanism of injury and unique presentation was initial full-thickness penetration followed by lead shaft retraction (likely due to eye rubbing) and then corneal stromal reentry with stromal lamellar dissection and fixation. Prompt removal of the foreign body, corneal laceration repair, and early cataract extraction resulted in postoperative 20/40 uncorrected visual acuity. Mechanical lead pencil injuries represent a unique mechanism of penetrating trauma.

Gene expression in human cells with mutant insulin receptors.

Insulin initiates its action by interacting with specific receptors on the plasma membrane of target cells. Mutations in these receptors cause the inherited insulin-resistant syndrome leprechaunism. Affected patients have severe intrauterine and post-natal growth restriction coupled with severe metabolic abnormalities. Fibroblasts from patients with leprechaunism have impaired in vitro growth, reflecting the growth restriction seen it in vivo. To determine the reason for the defective growth of cells from patients with mutant insulin receptors, gene expression was compared among fibroblasts from controls and patients with leprechaunism using DNA microarrays. Of the 12,626 human genes tested, cells from patients with leprechaunism had consistently increased mRNA for 151 genes and decreased mRNA for 51 genes. The level of expression of selected genes was independently confirmed by real time RT-PCR. Leprechaun cells had increased expression of several genes involved in metabolic functions, several of which were not previously known to be regulated by the insulin receptor. The absence of insulin receptors modified the expression of genes controlling apoptosis and cellular growth. Functional analysis indicated that cells from patients with leprechaunism had a normal response to apoptotic stimuli when mitochondrial potential and caspase activity were assayed. About 20% of the genes whose RNA was decreased in leprechaun cells coded for proteins involved in cell growth and differentiation. These results suggest that the insulin receptor is a physiologic regulator of several genes involved in intermediate metabolism even in human fibroblasts. Decreased expression of growth-promoting genes may explain the growth restriction of patients with severe insulin resistance.