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Biomedical subjects

A G Chiou

Publications and source records attributed to A G Chiou.

25 records · Page 2Linked to original sources
PubMed1998

Correlation between anterior chamber IgG/albumin concentrations and laser flare photometry in eyes with endogenous uveitis.

PURPOSE: To assess the correlation between laser flare measurements and anterior chamber IgG/albumin concentrations in eyes with mild to severe inflammation. MATERIALS AND METHODS: Seventeen eyes of 17 patients with endogenous uveitis underwent diagnostic paracentesis. IgG and albumin concentrations were determined from the samples of aqueous humor. Laser flare measurements were performed 1 h prior to paracentesis. The relationship between flare measurements and IgG/albumin concentrations was studied be plotting the data on a logarithmic scale. RESULTS: The flare measurement was 97.5+/-150.0 photons ms (mean +/- SD; range 4.3-528.7). The IgG concentration was 41.0+/-51.4 mg/dl mean +/- SD; range 0.2-200). The albumin concentration was 184.6+/-196.2 mg/dl (mean +/- SD; range 4-535). When plotted on a logarithmic scale, there was a statistically significant linear relationship between the flare measurements and the anterior chamber IgG or albumin concentrations (y = 1.14x-0.64, r= 0.87, p<0.001 for IgG; y = 1.39x-0.1, r= 0.94, p<0.001 for albumin). CONCLUSION: Laser flare photometry is an accurate technique for assessing anterior chamber inflammation. Flare measurements strongly correlate with blood-aqueous barrier breakdown.

Adolescent↗
PubMed1996

[Malignant ciliary block glaucoma after deep sclerotomy--ultrasound biomicroscopy imaging].

BACKGROUND: We present the case report of a patient who presented with malignant glaucoma following deep sclerectomy with collagen implant in both eyes. To assess the IOP spike mechanisms in ciliary bloc glaucoma, we performed ultrasound biomicroscopy before and after the second filtration surgery (right eye). MATERIALS AND METHODS: A 60-year-old hyperopic patient with bilateral medically uncontrolled open-angle glaucoma underwent deep sclerectomy with collagen implant in the left eye and one month later in the right eye. Both eyes presented postoperatively a ciliary bloc glaucoma. Ultrasound biomicroscopy was performed pre- and postoperatively during the malignant glaucoma crisis in the right eye. RESULTS: Preoperative ultrasound imaging showed an anterior rotation of the ciliary body. That disappeared with local application of cycloplegics. During the malignant glaucoma crisis, the ciliary body came again in touch with the lens, thus blocking the aqueous humor pathway to the anterior chamber. Malignant glaucoma occurred despite the nonperforation of the eye undergoing deep sclerectomy with collagen implant. CONCLUSIONS: In our patient, the anterior rotation of the ciliary body and its subsequent malignant glaucoma might be either a consequence of a ciliary muscle spasm due to postoperative inflammation or of acute IOP drop. Finally, in hyperopic eyes, the ciliary muscle may be hypertrophied due to constant accommodation.

Aqueous Humor↗
PubMed1996

Ultrasound biomicroscopy of eyes undergoing deep sclerectomy with collagen implant.

AIMS: To assess the intraocular pressure (IOP) lowering mechanism of deep sclerectomy with collagen implant (DSCI), a non-penetrating glaucoma surgery. METHODS: Nine eyes of nine patients with medically uncontrolled open angle glaucoma underwent DSCI. Ultrasound biomicroscopy (UBM) of the sclerectomy site was performed 1 month after surgery. The following factors were assessed: length and height of collagen implant, and thickness of the residual trabeculocorneal membrane. RESULTS: Postoperative IOP decreased significantly in all nine eyes from a preoperative mean value of 25.8 (SD 4.8) mm Hg to a postoperative (1 month) mean value of 11.3 (6.3) mm Hg (p = 0.001). In all nine eyes, UBM at 1 month after surgery showed a subconjunctival filtration through the thin trabeculocorneal membrane and through the scleral flap around the collagen implant. In four cases, a hypoechoic area in the suprachoroidal space was observed and might represent ciliary body detachment or be due to suprachoroidal drainage of aqueous humour through the thin deep scleral wall. At 1 month after surgery the mean trabeculocorneal membrane thickness was 110.1 (16.8) microns, and the mean length and height of the collagen implant were 2.3 (0.1) mm and 1.1 (0.1) mm respectively. CONCLUSION: DSCI lowered IOP by allowing aqueous filtration through a thin trabeculocorneal membrane to the subconjunctival space and, eventually, to the suprachoroidal space.

Aged↗
PubMed1995

[Surgery of ectopia lentis in Marfan disease in children and young adults].

INTRODUCTION: To determine the visual outcome of surgical therapy and conservative management, we retrospectively reviewed all our patients with ectopia lentis and Marfan's disease. MATERIAL AND METHOD: Thirty-five eyes of 18 patients (age 8 to 47, average 25.3) were studied. Eight eyes were followed conservatively, the remaining 27 eyes underwent a lensectomy either with the Klöti vitreous stripper (18) or using other techniques (9). RESULTS: Over follow-up periods ranging from 0.5 to 13 years (average 6.2 years) low visual acuity was found in non-operated eyes. Retinal detachment occurred in 2 out of 8 eyes. Eyes undergoing other surgical techniques had a mean final visual acuity of 0.2. Retinal detachment occurred with high frequency (6 out of 9 eyes). Lensectomy-vitrectomy was a safe and effective procedure with a mean final visual acuity of 0.6. No retinal detachment or secondary glaucoma were found. COMMENT: Our study suggests that performing lensectomy-vitrectomy with the Klöti vitreous stripper is the best surgical approach in ectopia lentis with Marfan's disease. This technique allows the vitreous to be handled more effectively and has led to improve results.

Adolescent↗
PubMedDate not supplied

Deep sclerectomy: results with and without collagen implant.

PURPOSE: To study the need, the safety and the success rate of collagen implant in eyes that underwent deep sclerectomy, a new non penetrating filtration procedure, we compared the results of deep sclerectomy with (DSCI) and without (DS) collagen implant. METHODS: Of 168 patients (168 eyes) with various types of medically uncontrolled open angle glaucoma, 86 (86 eyes) underwent DSCI, and 82 (82 eyes) underwent DS. Visual acuity, slit lamp examination, intraocular pressure (IOP) measurements were performed before surgery and prospectively at days 1 and 7 and months, 1, 2, 3, 6, 9, 12, 15, 18, and 24 after surgery. Deep sclerectomy was performed according to Kozlov's original technique. The collagen implant drainage device was radially secured in the center of the deep sclerectomy dissection. RESULTS: The mean follow-up period was 9.7 +/- 6.5 months for DSCI, and 9.0 +/- 4.8 months for DS. The mean preoperative IOP was 26.9 +/- 8.8 mmHg for DSCI and 25.8 +/- 8.5 mmHg for DS. The mean postoperative IOP and visual acuity were similar between the two groups. Complete and qualified success rates were better when the collagen implant was used (Log-Rank test: p = 0.0002 and 0.033 for complete and qualified success respectively). The need for postoperative glaucoma medications was significantly lower when the collagen implant was used (0.2 +/- 0.5 versus 0.5 +/- 0.7 medication per patient in the DSCI and DS respectively, Student's t test: p = 0.0038). There was significantly less bleb fibrosis when the collagen implant was used (2% and 11% in DSCI and DS respectively, p = 0.029). CONCLUSION: The collagen implant device is safe, increases the success rate of deep sclerectomy, and lowers the need for postoperative glaucoma medications.

Aged↗
PubMedDate not supplied

Management of conjunctival cicatrizing diseases and severe ocular surface dysfunction.

Physical or chemical injuries, infections, immunologic oculocutaneous disorders, drugs, and various systemic disorders may cause scarring of the conjunctiva and disturbances of the ocular surface. Trichiasis, lid margin malposition, and dry eye may result in persistent ocular irritation. The cornea may be primarily or secondarily involved. If severe, disturbances of the ocular surface may lead to significant visual impairment. Thorough evaluation of patients and of the underlying disease process is required for optimal management. Treatment may be challenging and should be comprehensive, combining medical measures and surgical correction of structural changes. Suppression of exogenous irritants, treatment of dry eye, antiinflammatory therapy, and immunosuppressants are paramount to control the underlying disease and allow optimal surgical results. Surgical correction of trichiasis and lid margin malposition, conjunctival grafting, mucous membrane transplantation, limbal stem cell transplantation, amniotic membrane transplantation, and penetrating keratoplasty help reestablish a physiologic ocular surface. Severe cases may require keratoprosthetics for visual rehabilitation. Corneal ulceration or perforation requires prompt attention to maintain ocular integrity. Special measures should be considered for patients who require cataract or glaucoma surgery.

Cicatrix↗