Prevention of age-related macular degeneration

Age-related macular degeneration (AMD) is one of the leading causes of blindness in the developed world. Although effective treatment modalities such as anti-VEGF treatment have been developed for neovascular AMD, there is still no effective treatment for geographical atrophy, and therefore the most cost-effective management of AMD is to start with prevention. This review looks at current evidence on preventive measures targeted at AMD. Modalities reviewed include (1) nutritional supplements such as the Age-Related Eye Disease Study (AREDS) formula, lutein and zeaxanthin, omega-3 fatty acid, and berry extracts, (2) lifestyle modifications, including smoking and body-mass-index, and (3) filtering sunlight, i.e. sunglasses and blue-blocking intraocular lenses. In summary, the only proven effective preventive measures are stopping smoking and the AREDS formula

Controversies in the Use of MIGS

Abstract Minimally invasive glaucoma surgery (MIGS) has fulfilled an unmet need in the management of glaucoma. This chapter highlights some controversial issues regarding the use of MIGS in clinical practice, including (1) whether there is sufficient evidence to advocate combining MIGS with cataract surgery over cataract surgery alone, (2) the merits and drawbacks of different approaches to trabecular bypass and canal-based MIGS procedures, (3) the effect of MIGS on endothelial cell loss, (4) suprachoroidal MIGS devices and whether there is still a role for these procedures, and (5) a comparison between subconjunctival MIGS and trabeculectomy. Several questions are still left unanswered and hopefully, further research and more clinical experience with these new technologies will help improve surgical outcomes for patients

Trans-stromal epithelial cyst after multiple lamellar keratoplasties - Case report and review of literature.

DesignSingle Observational Case Report.SettingA 67-year-old male of Persian descent had a complex systemic and ocular history prior to a right penetrating keratoplasty (PK) reported here. The clinical diagnoses leading to the PK included Cogan's syndrome, chronic uveitis, secondary glaucoma, and corneal stromal scarring, presumed secondary to a corneal ulcer diagnosed on the second visit to our clinic. The specimen described here had been in place for 11 months and 17 days after the third failed Descemet stripping endothelial keratoplasty (DSEK). Visual acuities had ranged from 20/100 to 20/400 in both eyes. Visual acuity in the right eye just before surgery was 20/400. Intraocular pressures were 22 mmHg in both eyes with functioning Ahmed glaucoma shunts. The stromal cyst was not suspected preoperatively and no clinical imaging was performed.Study methodsHistopathology including serial sections and immunohistochemistry.ResultsHistologic study demonstrated a trans-stromal corneal epithelial cyst without goblet cells that extended through a 500 μm gap in the donor tissue surface and edge.ConclusionsThis large stromal cyst was an unusual complication of serial posterior lamellar keratoplasties and we postulate that multiple prior posterior lamellar grafts may have been a risk factor for this complication. Anterior segment imaging with either anterior segment optical coherence tomography or high-resolution ultrasound would likely have detected this stromal cyst

Circadian rhythm of intraocular pressure: a rat model

The purpose of this study was to examine whether there is a circadian rhythm of intraocular pressure (IOP) in the Lewis rat. Therefore, 20 Lewis rats (40 eyes) were subjected to an alternating 12-hour-light and 12-hour-dark cycle. Using a Tono-Pen 1, IOP was measured every 2 h between 6 a.m. and 12 midnight and every 3 h between 12 midnight and 6 a.m. for 2 consecutive days. These measurements in the Lewis rat revealed a reproducible circadian rhythm with a peak at 8 p.m. and a trough at 6 a.m. In conclusion, when using the Lewis rat as an animal model in longitudinal studies that involve the IOP, the IOP should be measured at the same time each day to correct for diurnal variations. Additionally, Lewis rats may be a useful model to study the causes of circadian rhythms of IOP and for pharmacologic studies of new glaucoma medications

Prostaglandines E2 et F2-alpha au cours du glaucome uveitique chez le rat Lewis. [Prostaglandins E2 and F2-alpha in uveitic glaucoma in the Lewis rat]

PURPOSE: In the preinflammatory phase of S-antigen (S-ag) induced uveitis, an ocular hypotension occurs between day 2 and day 6 after S-ag injection. To better understand this phenomenon, we studied the levels of prostaglandin E2 (PGE2) and prostaglandin F2-alpha (PGF2-alpha) in the aqueous humor of S-ag injected rats at various time points after induction of disease. METHODS: Twenty-five female Lewis rats weighting 150 to 175 gm were injected in the hind foot-pad with 50 micrograms of S-antigen. IOP was measured each day at 9 am with a Tono-Pen tonometer. Aqueous humor was collected at days 0, 2, 4, 6, 9, 14 and 18 after S-ag injection. PGE2 and PGF2-alpha were assayed in the aqueous humor using an enzyme immunoassay method. RESULTS: The concentration of PGE2 increased after day 6 and peaked at day 14 after S-ag injection (45.6 +/- 9.0 mu/ml vs 1.1 +/- 0.1 mu/ml in controls, P = 0.04). The peak of PGE2 corresponded to the maximum inflammation and ocular hypertension. PGF2-alpha was increased from day 2 to day 6, with a peak at day 6 after S-ag injection (128.0 +/- 51 pg/ml vs 56 +/- 2.0 pg/ml in controls, P = 0.047), which corresponded to the preinflammatory ocular hypotension. A second peak was observed at day 18 after S-ag injection (3643 +/- 824 pg/ml, P = 0.049), which corresponded to the cessation of intraocular inflammation and ocular hypertension. CONCLUSIONS: The early increased concentration of PGF2-alpha in the aqueous humor of rats with S-ag induced uveitis may explain the ocular hypotension observed from day 2 to day 6 after S-ag injection