Blood-aqueous barrier after phacoemulsification with posterior chamber lens implantation; foldable acrylate lens vs PMMA lens-- a clinical study on 46 eyes

BACKGROUND: Cataract surgery leads to a more or less pronounced postoperative inflammation due to breakdown of the blood-aqueous barrier. This alteration of the blood-aqueous barrier can be reduced by minimally invasive surgery. The purpose of this study was to quantify the early course of the postoperative alteration of the blood-aqueous barrier following phacoemulsification with implantation of conventional PMMA posterior chamber lens (IOL) in comparison with foldable acrylic lens implantation. PATIENTS AND METHODS: Forty-six eyes of 46 patients (age 63 +/- 8.8 years) without preexisting deficiences of the blood-aqueous-barrier or previous intraocular surgeries were divided into two groups: group 1 (24 patients): phacoemulsification with one-piece-PMMA-IOL implantation (6.5 mm corneoscleral tunnel incision); group 2 (22 patients): phacoemulsification with foldable acrylic-IOL implantation (3.5 mm incision, 15 patients with corneoscleral tunnel and 7 patients with clear cornea incision). All surgical procedures were performed by one surgeon. The postoperative treatment was standardized. Alteration of the blood-aqueous barrier was quantified by the laser flare-cell meter (Kowa, FC-1000) preoperatively and on the first and the second day after surgery. RESULTS: Preoperative aqueous flare values (photon counts/ms) were comparable in both groups (6.7 +/- 2.7 versus 5.6 +/- 2.7 respectively, p = 0.1). On day 1, aqueous flare in group 1 (9.7 +/- 2.9) was not statistically significantly higher than in group 2 (9.2 +/- 2.2, p = 0.2) and remained relatively constant on day 2 after surgery (9.3 +/- 3.3), whereas the aqueous flare values in group 2 decreased statistically significant (6.7 +/- 2.3, p = 0.01). Postoperatively, there was no statistically significant difference of aqueous flare values between eyes with corneoscleral tunnel incision and eyes with clear corneal incision (p = 0.7) in group 2. CONCLUSIONS: Our study shows that phacoemulsification with foldable IOL implantation leads to a mild and short-lasting alteration of the blood-aqueous barrier. Thus, implantation of foldable IOL may be useful in eyes especially with preexisting alteration of the blood-aqueous-barrier.     

Detecting disorder in spatial vision

In normal foveal vision, visual space is accurately mapped from retina to cortex. However, the normal periphery, and the central field of strabismic amblyopes have elevated position discrimination thresholds, which have often been ascribed to increased 'intrinsic' spatial disorder. In the present study we evaluated the sensitivity of the human visual system (both normal and amblyopic) to spatial disorder, and asked whether there is increased 'intrinsic' topographical disorder in the amblyopic visual system. Specifically, we measured thresholds for detecting disorder (two-dimensional Gaussian position perturbations) either in a horizontal string of N equally spaced samples (Gabor patches), or in a ring of equally spaced samples over a wide range of feature separations. We also estimated both the 'equivalent intrinsic spatial disorder' and sampling efficiency using an equivalent noise approach. Our results suggest that both thresholds for detecting disorder, and equivalent intrinsic disorder depend strongly on separation, and are modestly increased in strabismic amblyopes. Strabismic amblyopes also show markedly reduced sampling efficiency. However, neither amblyopic nor peripheral vision performs like ideal or human observers with added separation-independent positional noise. Rather, the strong separation dependence suggests that the 'equivalent intrinsic disorder' may not reflect topographic disorder at all, but rather may reflect an abnormality in the amblyopes' Weber relationship.     

Dorzolamide and corneal recovery from edema in patients with glaucoma or ocular hypertension

PURPOSE: To investigate whether dorzolamide alters corneal hydration control in patients with glaucoma or ocular hypertension. METHODS: Pachymetry, tonometry, and endothelial cell density were measured by a masked observer in 19 subjects with bilateral glaucoma or ocular hypertension. They were treated with 2% dorzolamide in one eye, and with saline in the other, before wearing contact lenses under patched eyes. Corneal thickness, measured each 30 minutes up to 4.5 hours after contact lens removal, enabled estimation of percentage recovery per hour and time for 95% of corneal thickness recovery for both eyes. Seven patients repeated this test after 1 year of dorzolamide use, and their results were compared with those of the preceding year. RESULTS: After induction of hypoxic corneal edema, there was no significant difference between paired corneas in swelling levels (60.0+/-11.8 and 59.8+/-12.9 microm) (P = .94), time to 95% recovery (440.6+/-255.8 and 445.4+/-186.7 minutes) (P = .93), and percentage recovery per hour (38.1%+/-10.9% and 36.1%+/-9.6%) (P = .40). Subjects followed up after 1 year of dorzolamide use did not differ significantly in values of endothelial cell density, percentage recovery per hour, or time to 95% recovery from those obtained a year before. One subject developed persistent corneal edema after his stress test in the eye treated with dorzolamide. CONCLUSION: There is no significant difference in the recovery from induced corneal edema after either a short-term or 1-year use of dorzolamide in patients with glaucoma or ocular hypertension with a normal corneal endothelium. One patient had persistent corneal edema after the stress test was performed on the dorzolamide-treated eye.     

Genetic screening in a large family with juvenile onset primary open angle glaucoma

AIMS: A number of genetic loci have been implicated in the pathogenesis of primary open angle glaucoma (POAG). The aim of this study was to identify the genetic cause of POAG in a large Scottish family and, if possible, offer genetic screening and advice to family members. METHODS: Family members were examined to determine their disease status. Base excision sequence scanning was carried out in order to test for the presence of a POAG causing mutation at known genetic loci. Direct DNA sequencing was performed in order to determine the mutation sequence. RESULTS: All family members of known affected disease status and two family members of unknown disease status were found to have a mutation in the TIGR gene. The mutation resulted in the substitution of a glycine residue with an arginine residue at codon 252 (Gly252Arg). No other sequence variations were present in any members of the family. CONCLUSION: The Gly252Arg mutation in the TIGR gene results in the development of POAG in this family. It was possible to identify younger, currently unaffected, members of the family who carry the mutation and who are therefore at a very high risk of developing POAG themselves. This is the first demonstration that Gly252Arg can be a disease causing mutation rather than a benign polymorphism. The possible pathogenic mechanisms and wider implications of the mutation are considered.     

Usual interstitial pneumonia: histologic study of biopsy and explant specimens

The pathologic findings in biopsy and subsequent explant specimens from 20 patients with usual interstitial pneumonia (UIP) were reviewed to refine histologic criteria for diagnosis, to identify factors that may confound diagnosis, and to assess the relationship of UIP and nonspecific interstitial pneumonia (NSIP). One case of NSIP was also identified and included for comparison. Surgical biopsies from 15 of the 20 UIP cases were diagnosed as UIP, whereas 5 showed only nondiagnostic changes. An important new observation is that areas resembling nonspecific interstitial pneumonia (NSIP-like areas) are present in the majority of UIP cases in both biopsy and explant specimens, and they are extensive in some. Ten of the 15 UIP biopsies were considered straightforward, with typical patchy interstitial fibrosis, honeycomb change, and fibroblast foci. Five cases were considered difficult because of prominent NSIP-like areas in two, extensive honeycomb change in one, superimposed diffuse alveolar damage in one, and superimposed bronchiolitis obliterans-organizing pneumonia in one. The most helpful feature for diagnosing UIP in difficult cases was the presence of a distinct patchwork appearance to the characteristic uneven or variegated parenchymal involvement along with evidence of architectural derangement. No explant showing UIP was preceded by biopsy findings of NSIP, and the one NSIP case appeared similar at biopsy and explant. NSIP or NSIP-like areas and UIP may reflect different mechanisms of fibrosis related either to different severity of injury or to different injuries.