Late pigmented-membrane formation on silicone intraocular lenses after phacoemulsification with or without trabeculectomy.

PURPOSE: To determine the incidence of late inflammatory membrane formation with pigment precipitates on foldable silicone or poly(methyl methacrylate) (PMMA) intraocular lenses (IOLs) after phacoemulsification with or without simultaneous trabeculectomy and to identify probable causative factors. SETTING: Eye Department, Bnai-Zion Medical Center, and the Faculty of Medicine, the Technion, Haifa, Israel. METHODS: In this retrospective study, 155 eyes (140 patients) were divided into 4 groups by the surgery performed: Group 1, phacoemulsification combined with trabeculectomy and foldable silicone IOL implantation (12 eyes); Group 2, phacoemulsification combined with trabeculectomy and PMMA IOL implantation (15 eyes); Group 3, phacoemulsification alone with foldable silicone IOL implantation (66 eyes); Group 4, phacoemulsification alone with PMMA IOL implantation (62 eyes). Preoperative, intraoperative, and postoperative data were compared. RESULTS: Late inflammatory membranes were found on the anterior surface of 33% of the IOLs in Group 1, 3% in Group 3, and none in Groups 2 and 4. Membranes developed 3 to 4 months after surgery, were resistant to topical corticosteroid treatment and required repeated neodymium:YAG laser treatments. No correlation with preoperative, intraoperative, or postoperative factors was found. CONCLUSION: Foldable silicone IOLs may induce late postoperative inflammatory membranes with pigment precipitates, especially after combined phacoemulsification and trabeculectomy.

[Progression of diabetic retinopathy after cataract extraction].

A prospective study of the effect of cataract extraction with intraocular lens implantation on the course of diabetic retinopathy (DR) in 44 patients (59 eyes) was carried out. It showed that in the 1-3 years following surgery, there was progression of DR (including development of newly formed retinopathy) in 35% of the patients (28.8% of eyes). Progression was more marked in patients with pre-operative bilateral DR compared to those without bilateral DR (77% and 16% respectively). Insulin dependence did not play a role in progression. Final visual acuity was better in patients without pre-operative DR, as well as in eyes without progressive retinopathy.

The course of nonproliferative diabetic retinopathy following ECCE with posterior chamber IOL implantation.

A prospective study on the effect of ECCE + IOL implantation on the course of diabetic retinopathy (DR) in 59 eyes showed that in one to three years following surgery, progression of DR, including the development of newly formed one, occurred in 28.8% of the eyes. This was more marked in patient with IDDM (IDDM-46%, NIDDM-24%) as well as in eyes with pre-operative BDR (pre-operative BDR-62.5%, no pre-operative BDR-16.3%). Final visual acuity was better in eyes without pre-operative DR as well as in eyes that did not show progression of the retinopathy.

Miniature fiber-optic pattern-reversal stimulator for determination of the visual evoked potential threshold; comparison with Snellen acuity.

In this report we recommend the estimation of visual acuity by detection of the visual evoked potential (VEP) threshold, defined by the smallest visual angle of a constant check size that evokes potentials. This approach was implemented using a fiber-optic pattern-reversal stimulator placed at measured, increasing distances from the examined eye. Snellen visual acuity as determined in 113 subjects was correlated with the VEP detection threshold. A highly significant correlation was found between visual acuity and the threshold visual angle of check size in subjects whose vision was impaired due to opacity in ocular media. For any given visual acuity a somewhat wide range of threshold check sizes, typically 5-10 min of arc was observed. Technical difficulties that need to be overcome to improve these results are discussed.