The Inoveon Diabetic Retinopathy (DR-3DT) system provides highly accurate referral decisions for patients with diabetic retinopathy when compared with the existing Early Treatment Diabetic Retinopathy Study film “gold standard,” indicates an independent, masked, cross-sectional, U.S. clinical validation study.

The DR-3DT system (Inoveon Corp., Oklahoma City) is a scalable evaluation method for the management of diabetic retinopathy that uses high-quality digital retinal imaging.

Investigators recruited 290 adult patients with diabetes. All participants underwent DRS7 imaging using a Zeiss FF450 fundus camera (Carl Zeiss Instruments, Jena, Germany) with images recorded on 35-mm film and a

Investigators say high-resolution digital images of diabetic retinopathy from Inoveon’s Diabetic Retinopathy system provide highly accurate referral decisions.

Tim Booher

Kodak DCS520 digital camera. Masked double grading with independent third reader adjudication yielded an ETDRS Final Retinopathy Severity Scale Level and macular edema stage for each eye.

Threshold events requiring referral were the presence of ETDRS Level 53, questionable or definite clinically significant macular edema in either eye, or ungradeable images. The main outcome measures were accuracy (sensitivity, specificity, predictive values) of the digital system relative to the film “gold standard” on the patient’s threshold referral criteria.

Investigators included all patients with gradeable 35-mm slides from at least one eye. The prevalence of threshold events was 19.3 percent. They say the digital system correctly identified 55 of 56 patients, or 98.2 percent (95 percent confidence interval), and specificity was 89.7 percent. The positive predictive value was 69.5 percent, and the negative predictive value was 99.5 percent.

The authors emphasize that, given their inherent advantages, high-quality digital imaging systems could replace the film “gold standard” as the basis for scalable, accessible, diabetic retinopathy evaluation.
(Ophthalmology 2002;109:3:595-601)
Fransen S, Leonard-Martin T, Feuer W, Hildebrand P, and the Inoveon Health Research Group

MMC Effective for Probing
Probing with adjunctive, topical mitomycin C for cases of adult epiphora caused by obstruction of the nasolacrimal duct is safe and effective, according to a prospective, noncomparative, interventional Taiwanese case series.

Researchers treated and evaluated 32 adult patients (36 eyes) with epiphora caused by primary nasolacrimal duct obstruction. Follow-up exams were conducted at two weeks, then at one, three, six and nine months. Investigators confirmed patency with irrigation and evaluated patient satisfaction from subjective evaluation of epiphora improvement.

Investigators say 32 (89 percent) of the treated eyes remained free of obstruction and open on irrigation at nine months. Patients with patency loss during follow-up underwent repeat probing, increasing the overall patency rate to 94 percent.

Patient satisfaction indicated that the epiphora was at least mildly improved for 30 (83 percent) of the treated eyes. Watering was completely absent for nine eyes (25 percent), rated as moderately improved for 17 (47 percent), and mildly improved for four (11 percent).

Researchers say no complications were found over the follow-up period. They recommend this technique as simple, effective and minimally invasive.
(Ophthalmology 2002;109:2:172-74)
Tsai C, Kau H, Kao S, Hsu W, Liu J

Scleral Tunnel Incision Induces Less Trauma
Using Specular microscopy, scleral tunnel incisions showed less postoperative endothelial damage than two clear corneal incision techniques, suggests a prospective, randomized Italian study.

Researchers assigned 81 eyes having phacoemulsification to one of three groups of 27 eyes each: 3.5-mm unsutured clear CCI with silicone foldable intraocular lens implantation; 5.5-mm sutured CCI with polymethylmethacrylate IOL implantation; and 5.5-mm unsutured sclero-corneal tunnel with PMMA IOL implantation. They centered all incisions at the 120-degree semimeridian—superotemporal in right eyes and superonasal in left eyes.

Investigators performed noncontact specular microscopy in the center and at the 12 o’clock position preoperatively, as well as one week and one, three and 12 months postop.

Investigators considered for measurement the endothelial cell density, mean cell area, cell size variation coefficient, percentage of hexagonality and corneal thickness. Cell loss percentages relative to the endothelial center appeared similar among the groups and slightly, although not significantly, lower in the scleral tunnel group.

Researchers say progressive endothelial cell loss and an increase in mean cell area occurred in all groups during the follow-up, with a statistically significant difference between one week and one month at the 12 o’clock position. They note that the scleral tunnel group had a significantly lower cell loss percentage at the 12 o’clock position than the two CCI groups. Investigators theorize that this was probably because the scleral tunnel incision is placed more posteriorly and, therefore, induces less direct and indirect endothelial trauma.
(J Cataract Refract Surg 2002; 28:1:118-25)
Beltrame G, Salvetat M, Driussi G, Chizzolini M

Oxygenation Effective for Sleep Apnea and IIH
Sleep apnea may be an associated finding in men with idiopathic intracranial hypertension (IIH), and treatment with nocturnal oxygenation may improve the signs and symptoms of IIH. So indicates a multicenter, retrospective, noncomparative interventional U.S. case series.

Researchers reviewed 32 cases of men with the diagnosis of IIH seen within five years at three tertiary referral centers. They identified and reviewed cases with sleep apnea and IIH. Six cases with sleep apnea met the modified Dandy criteria for the diagnosis of IIH. Of these six patients, one received acetazolamide alone, one was treated with continuous positive airway pressure (CPAP) alone, and four received treatment with both acetazolamide and CPAP.

Researchers say all patients had preserved central acuity (20/20 or better in both eyes) and enlarged blind spots caused by optic disc edema in both eyes at presentation.

Investigators say that four patients had normal visual fields after treatment, and one patient had residual visual field loss. Three patients had normal optic discs at last follow-up and are continuing CPAP treatment alone. One patient had persistent but improved papilledema and is under continued treatment with acetazolamide and CPAP. One patient had optic disc pallor in both eyes and is stable.

Researchers say sleep apnea should be considered in association with optic disc edema in men. They say further work is necessary to establish the role of sleep apnea in the pathogenesis of IIH in men.
(Ophthalmology 2002;109:3:482-85)
Lee A, Golnik K, Kardon R, Wall M, Eggenberger E, Yedavally S


Frequency Doubling Perimetry for Glaucoma
Frequency doubling perimetry has a high sensitivity and specificity for detecting glaucomatous field defects, states an Indian study.

Investigators included 85 eyes of 85 patients with established field defects, as documented on the Swedish Interactive Testing Algorithm standard 30-2 program of the Humphrey Field Analyzer (Humphrey Instruments, San Diego). Group I was classified by severity of defect. Group II consisted of 48 eyes of 48 control subjects. Both groups underwent SITA standard tests, as well as FDP screening strategies (C20-1 and C20-5 and full threshold test).

Researchers calculated sensitivity and specificity measures for the FDP tests using one new and two previously published algorithms.

The authors say the C20-1 scoring system, based on location, as well as severity, provided the best sensitivity (85.9 percent) and specificity (95.1 percent). The sensitivity improved to 91 percent for moderate and severe cases.

Researchers suggest that media opacities (for example, mild cataract) may affect the interpretation of FDP, and the exclusion of these eyes increased the specificity markedly. 
(Journal of Glaucoma 2002;11:1:46-50)
Thomas R, Bhat S, Muliyil J, Parikh R, George R