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H Quiroz-Mercado

Publications and source records attributed to H Quiroz-Mercado.

At least 19 recordsLinked to original sources
PubMed2006

[Macular hole surgery without postoperatory < > down positioning. Pilot study].

PURPOSE: To evaluate the visual and anatomical outcomes of macular hole surgery using phacoemulsification, vitrectomy and intraocular gas tamponade without the use of postoperative face down positioning. METHODS: Phacoemulsification with an intraocular lens implant, followed by vitrectomy with internal limiting membrane peeling and perfluoropropane (C3F8), was performed in patients with stage 3 or 4 macular holes. After surgery, patients had to avoid the supine position for 15 days. Patients with a gas level <50% during the first week had a fluid-gas exchange. Visual acuity and closure of the macular hole were evaluated after 1 year of follow-up. RESULTS: 20 eyes of 20 patients, aged 60 to 75 years (median age 68 years), were included in this study. The best initial visual acuity ranged from 0.05 to 0.13 (ETDRS), with the median being 0.06. The final visual acuity was 0.05 to 0.30 with a median of 0.10. A statistically significant improvement (p=0.001, Wilcoxon) was found. The anatomic postoperative results revealed 90% (n=18) of the macular holes were closed while 10% (n=2) were not. CONCLUSIONS: Macular hole surgery has, in general, good results and patients can achieve improvement in their visual acuity without the need for uncomfortable and unbearable post operative posture positions.

Aged↗
PubMed2006

[Sub-tenon steroid treatment in choroidal neovascularization caused by serpiginous choroiditis. A case report].

CASE REPORT: We present a report of a patient suffering from serpiginous choroiditis complicated by choroidal neovascularization (CNV). Sub-tenon steroid treatment, added to the usual immunosuppressive therapy, resolved the CNV, improving visual acuity in one eye. DISCUSSION: Choroidal neovascularization is a sight-threatening complication of posterior uveitis. Our case suggests that sub-tenon steroid treatment, added to systemic immunosuppressive therapy, may accelerate the CNV resolution in posterior uveitis.

Azathioprine↗
PubMed2005

Radial optic neurotomy for ischaemic central vein occlusion.

BACKGROUND/AIMS: Ischaemic central retinal vein occlusion (CRVO) accounts for 20-50% of all CRVO. No treatment has been proved to be effective. The efficacy of radial optic neurotomy (RON) was evaluated in eyes with ischaemic CRVO. METHODS: 10 patients with ischaemic CRVO underwent RON. After pars plana vitrectomy, a microvitreoretinal blade was used to incise the scleral ring, cribriform plate, and adjacent sclera at the nasal edge of the optic disc. Best corrected visual acuity (BCVA), intraocular pressure (IOP), fluorescein angiography (FA), multifocal electroretinography (mfERG), and optical coherence tomography (OCT) were measured preoperatively and at 1, 3, and 6 months postoperatively. RESULTS: No visual improvement was noted in the eyes that underwent RON. FA and mfERG showed no increase in retinal perfusion or retinal function postoperatively. Mean macular central thickness changed from 841 (SD 170) mum preoperatively to 162 (SD 34) microm at the sixth postoperative month. One patient had retinal central artery perforation intraoperatively. One patient developed neovascular glaucoma. CONCLUSION: RON in ischaemic CRVO did not improve visual function (by mfERG) or visual acuity although macular thickness did improve. This technique may be associated with potential risks. Randomised studies are needed to corroborate these results.

Aged↗
PubMed2005

[Retained intraocular foreign body. an unusual presentation].

CLINICAL CASE: A 25-year-old man presented with a unilateral retinal detachment, and an ipsilateral preretinal mass; ultrasonographic findings included a high-reflective peripheral mass and a retinal fold. A presumptive diagnosis of a peripheral toxocara granuloma was entertained. We performed a 360 degree circumferential scleral buckle and a conventional vitrectomy via the pars plana. Histologic examination of the mass defined a central non-metallic foreign body surrounded by fibrous tissue. DISCUSSION: An intraocular non-metallic foreign body, surrounded by a fibrous capsule and feeding and draining blood vessels, can mimic the characteristics of a peripheral toxocara granuloma, and the differential diagnosis has to be kept in mind.

Adult↗
PubMed2004

[Bilateral macular cysts secondary to electric current strike. A case report].

OBJECTIVE: To report the clinical and tomographic findings in a case of maculopathy secondary to high-tension electric current strike. CASE REPORT: A 27-year-old male refers a reduction in his visual acuity after electric strike. Visual acuity was 0.05 in both eyes. Circular reddish macular lesions measuring 400 micro m in RE and 200 micro m in LE were evident. Optical coherence tomography (OCT) showed intraretinal foveal cysts. At the third month follow-up visit, visual acuity had improved to 0.4 in RE and 0.5 in LE. Clinical and tomographic evaluation showed a reduction of the foveal cysts. DISCUSSION: Electricity affects retinal pigment epithelium and retina by thermal denaturation. OCT provides a conclusive diagnosis.

Adult↗
PubMed2004

Complete achromatopsia associated with skeletal anomalies: a new autosomal recessive syndrome.

Complete achromatopsia associated with skeletal anomalies: a new autosomal recessive syndrome: Achromatopsia or rod monochromatism is the complete absence of color discrimination, with an estimated frequency of 1 in 100,000. To date the McKusick Catalogue includes more than 10 entities related to Achromatopsia. This paper describes four Mexican sibs with a stationary rod monochromatism, associated with long fingers and toes, hypothenar and thenar hypoplasia and pes planus, suggesting a new genetic entity probably inherited in an autosomal recessive mode.

Adolescent↗
PubMed2001

Successful erbium: YAG laser-induced chorioretinal venous anastomosis for the management of ischemic central retinal vein occlusion. A report of two cases.

BACKGROUND: Central retinal vein occlusion (CRVO) is a disorder with potentially blinding complications, particularly when associated with retinal ischemia. There is no reliable treatment for ischemic CRVO. METHODS: We developed a new approach for ischemic cases of CRVO consisting of vitrectomy, posterior hyaloid detachment, and four erbium:YAG laser-induced chorioretinal anastomoses, one in each quadrant. RESULTS: We report two cases of ischemic CRVO treated with this approach, with initial visual acuity of count fingers at 30 cm and hand movements respectively. After the surgery, there was resolution of hemorrhages and macular edema and visual improvement to 20/400 in the first case and to 20/180 in the second case. In both cases, there was successful creation of chorioretinal anastomoses, and there was no anterior segment neovascularization or other complications related to the surgery. CONCLUSION: This treatment shows promise in the management of the ischemic cases of CRVO, and further evaluation is justified.

Adult↗
PubMed2000

Induced posterior vitreous detachment by intravitreal sulfur hexafluoride (SF6) injection in patients with nonproliferative diabetic retinopathy.

PURPOSE: To induce posterior vitreous detachment (PVD) in patients with nonproliferative diabetic retinopathy (NPDR) by injecting an intravitreal gas bubble of SF6 and to compare the evolution of the diabetic retinopathy between eyes with gas induced PVD and non-injected eyes without PVD. METHODS: An intravitreal gas bubble of SF6 was injected via the pars plana in twelve eyes of twelve patients with NPDR and no previous PVD. Subsequent clinical, ultrasonographic and angiographic controls were performed to evaluate the development of PVD and progression of the disease. RESULTS: All gas-injected eyes developed PVD. All eyes with induced PVD (treatment group) remained stable without progression of the retinopathy after 2 years of follow up. In the control group (contralateral eyes without PVD), two eyes (16.6%) progressed to proliferative diabetic retinopathy (PDR) (p= 0.23); five (41.6%) showed progression to more severe stages of NPDR (p= 0.01) and another 41.6% of such eyes remained stable. CONCLUSIONS: Intravitreal SF6 injection induced PVD in all eyes of our study without undesirable side effects. Further studies are necessary to make conclusions regarding the correlation between the presence of induced PVD and the progression of diabetic retinopathy.

Adult↗
PubMed1999

Effect of chloroquine on experimental melanin-protein-induced uveitis in Lewis rats.

PURPOSE: To evaluate the effect of chloroquine on experimental recurrent autoimmune melanin-protein-induced uveitis in Lewis rats. METHODS: Five Lewis rats were immunized with melanin to induce uveitis (group I); another six were immunized and treated with 5 mg/kg/day of chloroquine (group II). To reinduce uveitis, they received two booster injections of melanin. They were killed when uveitis was present after the last booster injection; every eye was evaluated by means of clinical and histopathological examination. A control group of four rats received the same chloroquine dose to evaluate retinal toxicity (group III). RESULTS: Rats in group I showed more severe uveitis episodes than rats in group II. The second uveitis episode was more severe in group I than in group I. Rats in group III showed no clinical or histopathological abnormalities. CONCLUSIONS: Chloroquine decreased the severity and duration of uveitis, and in two rats it prevented recurrences. Thus, chloroquine can be considered an effective treatment for chronic, recurrent experimental uveitis.

Animals↗
PubMed1998

The use of dextran after keratoplasty for visualizing the vitreous cavity.

BACKGROUND AND OBJECTIVE: Corneal edema during penetrating keratoplasty (PK) precludes the visualization of the fundus required to perform vitreoretinal surgery. In this study, the clearing of the cornea and fundus visualization with dextran 40 following PK was evaluated. PATIENTS AND METHODS: Topical dextran 40 was used in 12 eyes that underwent uncomplicated PK (phase 1) and in 5 eyes that underwent combined PK with vitreoretinal surgery (phase 2). RESULTS: Clearing of the cornea and visualization of the fundus were observed in all eyes after dextran had been instilled for a mean of 4 and 5 minutes in eyes for phase 1 and 2, respectively. Vitreoretinal surgery could successfully be performed after PK in all eyes of phase 2. CONCLUSION: Topical use of dextran 40 following PK produces enough clearing of the cornea to enable visualization of the fundus for further vitreoretinal procedures after the graft has been sutured.

Administration, Topical↗
PubMed1996

Experimental intravitreous cysticercosis.

BACKGROUND: Cysticercosis is one of the parasitic diseases that most frequently affects the eye. The most common and severe manifestations of ocular infection are secondary to posterior segment involvement, which often leads to blindness and atrophy of the eye. The pathogenesis of ocular injury in this disease is poorly understood. The authors have developed an experimental animal model for intravitreous cysticercosis using New Zealand rabbits and Taenia crassiceps cysticerci. METHODS: Twelve rabbits were divided into two groups. Rabbits in group I were inoculated with one living cysticercus in the vitreous cavity. Rabbits in group II received an intramuscular dose of steroids prior to inoculation of parasites. RESULTS: An intense inflammatory reaction, which lead to a severe ocular injury, was observed in rabbits of group I, while rabbits in group II had minimal inflammatory changes. Histopathological studies showed a severe histiocytic infiltrate with generalized retinal damage in group I, and a mild inflammatory infiltrate, limited to the area of direct contact with the parasite in group II. The ocular lesions found in rabbits which did not receive steroids (group I) resembled those found in human ocular cysticercosis. CONCLUSION: These observations indicate that ocular damage in this parasitic disease might be directly related to inflammatory changes produced by the presence of cysticerci. This model appears to be useful for future investigations.

Animals↗
PubMed1996

Multicenter clinical experience using an erbium:YAG laser for vitreoretinal surgery.

PURPOSE: To evaluate the advantages, disadvantages, safety, complications, and surgical applicability of an erbium:YAG laser system for maneuvers in vitreoretinal surgery. METHODS: A prospective, consecutive trial of 68 eyes in 66 patients undergoing vitreoretinal surgery in which an erbium:YAG laser with graduated output from 0.2 to 5.0 mJ per pulse, repetition rate of 2 to 30 Hz, and equipped with a flexible fiber optic and interchangeable 20-gauge intraocular fiber optic endoprobes was used to perform specific maneuvers, including transection, incision, and ablation of membranes, retinotomy, vessel coagulation, iridectomy, and lens tissue ablation. The patients were treated in five centers in contemporary vitreoretinal surgical settings for surgical indications, including proliferative diabetic retinopathy, proliferative vitreoretinopathy, epiretinal membrane, and retinopathy of prematurity. RESULTS: One hundred seventy-four maneuvers were performed with an overall surgical efficacy rating of excellent or good in 84% of maneuvers, ranging from a high of 100% for subretinal membrane transection to a low of 25% for coagulation of blood vessels. Complications included retinal break or photocoagulative injury in 5% of epiretinal membrane incisions, minor bleeding from transected retinal vessels during 29% of retinotomies, and intraocular lens damage during two posterior capsulotomies. The most significant limitation was the cautious pace used during maneuvers near the retinal surface. CONCLUSION: The erbium:YAG laser is capable of versatile new approaches offering precise tissue cutting and ablation in vitreoretinal surgical maneuvers with a high degree of safety. The main limitation encountered was the slow speed of certain critical maneuvers near the retina.

Adult↗
PubMed1994

The syndrome of presumed ocular histoplasmosis in Mexico: a preliminary study.

A study to screen for the syndrome of presumed ocular histoplasmosis (SPOH) among native populations from three Mexican states was performed. Two of these states, Guerrero and Querétaro, were selected as histoplasmosis is endemic there, whereas Tlaxcala was considered a control, due to the absence of reported cases. A total of 253 individuals were submitted to ocular fundus examination to obtain evidence of SPOH. A high percentage of positive reactors to histoplasmin skin test (ST) was observed in Guerrero (83%) and Querétaro (53%), whereas in Tlaxcala positive ST were almost absent (2.04%). Only five individuals had retinal lesions, although these lesions were not characteristic of the syndrome. Stimulation of these individual's cells showed different patterns in the histoplasmin-induced lymphocyte transformation response, and two out of five individuals with retinal lesions presented a stimulated response, as well as three controls without lesions. Histocompatibility antigens (HLA) were determined in a sample of each population and no particular allele, including HLA-B7, was found to be related to SPOH as reported in the USA; however, HLA-B22 was found in three individuals who developed pulmonary histoplasmosis. Results do not provide clinical evidence or data on specific HLA risk factors, for the presence of SPOH in the population studied.

Alleles↗
PubMed1991

Defects of the retinal pigment epithelium in scleroderma.

We completed ocular examination, including retinal fluoroangiography, in 19 unselected patients with diffuse systemic sclerosis (scleroderma) and compared the findings with those made in 50 consecutive patients with systemic lupus erythematosus, 18 with primary Sjögren's syndrome, 20 with mixed connective tissue disease, and 20 healthy women. Five of 19 scleroderma patients had atrophy of the retinal pigment epithelium (26.3%) while none of the controls and only four of the 88 (4.5%) patients with other connective tissue diseases (P less than 0.01) had this anomaly. Atrophy of the pigmented epithelium of the retina may occur in scleroderma as a result of damage of the choroidal plexus.

Adult↗
PubMed1990

Techniques for the preservation of enucleated animal eyes in surgical training.

The main problem with using enucleated animal eyes in surgical training is that they remain fresh for such a short time. We describe a simple technique to preserve them by replacing the aqueous humor and part of the vitreous with another substance. We used 18 eyes of nine dogs (nine for the study and nine as controls), and three substances (2% methylcellulose, silicone oil, and gelatin). The methylcellulose group had the best results (including long-lasting mydriasis), preserving the eyes in which it was used in optimal surgical condition for up to 8 days, twice as long as the eyes in the control group (P less than .005).

Animals↗
PubMedDate not supplied

Vitrectomy for ocular trauma: a question of timing?

PURPOSE: A long-standing controversy exists regarding the proper timing for vitrectomy in a traumatized eye. The present study was conducted to assess the influence of timing on the final visual acuity. MATERIALS AND METHODS: A retrospective review was made of 45 consecutive patients who underwent a pars plana vitrectomy procedure for repair of ocular trauma. The patients were divided into two groups according to the timing of the surgery post-trauma: those operated before or after 14 days. Type of trauma and pre- and postoperative visual acuities were compared. RESULTS: A contusion type of trauma was more frequent in the late surgery group. Sharp, penetrating injuries were more common in the early vitrectomy group. No significant difference was found though visual acuity was worse in the patients with a contusion component to their injury. Timing of surgery seems to have very little effect on the final outcome. CONCLUSIONS: Final visual acuity is determined by the type and extent of trauma rather than the timing of surgery.

Adult↗