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Eye Pathology
No full textThe conjunctiva is a thin and moist mucous membrane. It covers the anterior part of the eye, save for the cornea, reaches peripherally into the upper and lower fornices, and then reflects to outline the inner surface of the eyelids
Excimer laser phototherapeutic keratectomy for recurrent intraepithelial corneoconjunctival carcinoma
No full textNo abstract availabl
Topographically guided excimer laser photorefractive keratectomy to treat superficial corneal opacities
No full textOBJECTIVE:
To demonstrate the efficacy and safety of topographically guided excimer laser photorefractive keratectomy (PRK) in treating superficial corneal opacities.
DESIGN:
Prospective, noncomparative interventional case series.
METHODS:
Twenty-six eyes of 24 patients with postinfectious (n = 6), post-traumatic (n = 18), and post-PRK (n = 2) scars were treated with an excimer laser linked to a computerized videokeratography unit with a topographically supported customized ablation workstation.
MAIN OUTCOME MEASURES:
Manifest spectacle refraction, best spectacle-corrected visual acuity (BSCVA), uncorrected visual acuity (UCVA), change of corneal clarity, and topographic indexes of surface regularity.
RESULTS:
The mean follow-up period was 7.7+/-2.1 months (+/- standard deviation) (range = 6-12). Corneal clarity and corneal topography patterns improved in all eyes. Uncorrected visual acuity improved from 0.7+/-0.8 logarithm of the minimum angle of resolution (logMAR) to 0.4+/-0.5 logMAR (P = 0.008), and BSCVA improved from 0.3+/-0.6 logMAR to 0.1+/-0.6 logMAR (P/=2 lines in 76.9% of eyes and 1 line in 23.1%). The mean spherical equivalent refraction changed from -0.125+/-2.77 diopters (D) to +1.33+/-1.28 D (P = 0.019).
CONCLUSIONS:
The use of topographically guided PRK with the topographically supported customized ablation method resulted in significant increases of UCVA and BSCVA and improved corneal clarity in all patients. The technique seems to be safe and effective for treating various superficial corneal diseases, including postinfectious, post-traumatic, and post-PRK scars
Morphologic differences, according to etiology, in pigment epithelial detachments by means of en face optical coherence tomography.
No full textPURPOSE:
To assess morphologic differences in pigment epithelial detachment (PED) with en face optical coherence tomography in central serous chorioretinopathy (CSC) and age-related macular degeneration (AMD).
METHODS:
We recruited 30 eyes of 22 patients with PED. Nine eyes had a clinical diagnosis of CSC and 21 had AMD. All patients were assessed with en face optical coherence tomography. Morphologic PED aspects were estimated on C-scans and classified according to shape, inner silhouette, content, wall aspects, wall thickness, and size.
RESULTS:
Pigment epithelial detachment shape was predominantly circular (88.8%) in CSC and irregular or with multilobular features in AMD (76.2%). The PED inner silhouette had a smooth aspect (88.9%) in CSC and a slightly granular aspect or granular profile in AMD (100%). Clear PED content was the most characteristic feature of CSC (88.9%) but not of AMD. In CSC, PED morphologic wall aspect was uniform or slightly irregular (100%), while in AMD, it was slightly irregular (52.4%) or irregular (47.6%). Pigment epithelial detachment wall thickness and dimensions were larger in AMD than in CSC. Statistically significant differences were observed between CSC and AMD concerning PED inner silhouette, contents, wall aspects, and wall thickness measurements.
CONCLUSION:
En face optical coherence tomography scanning is a valuable tool for showing important morphologic differences between CSC and AMD
LACK OF HABITUATION IN THE LIGHT ADAPTED FLICKER ELECTRORETINOGRAM OF NORMAL SUBJECTS: A COMPARISON WITH PATTERN ELECTRORETINOGRAM
No full textAbstract: Objective: Sustained pattern stimulation (SPS) induces habituation in the normal pattern electroretinogram (PERG). In this study, the authors evaluated whether sustained flicker stimulation (SFS) induces habituation in the normal flicker ERG (FERG).
Methods: FERGs were elicited in normal volunteers by an 8 Hz flicker stimulus, presented continuously over 3 min after 20 min of light adaptation. One stimulus temporal period was sampled and averaged in packets (n = 20) of 60 events, each of 8 s duration. Amplitudes and phases of the response 1st and 2nd harmonics (1F and 2F, respectively) were measured. FERG results were compared with those obtained by recording PERGs with a similar SPS paradigm.
Results: During SFS, FERG 2F showed a modest increase in amplitude (about 25%, p < 0.05). No changes were observed for the 1F amplitude and for the phase of both components. In contrast, PERG amplitude showed SPS-induced habituation, described by an exponential decay with a time constant of similar to 20 s.
Conclusions: The normal FERG, unlike PERG, does not show habituation, suggesting that the adaptive changes of retinal neurons underlying FERG are different from those of PERG generators.
Significance: Our findings may have implications for diagnosis and/or pathophysiology of retinal disorders involving the inner retin
Photorefractive keratectomy and laser in situ keratomileusis in refractive accommodative esotropia
No full textPURPOSE:
To evaluate the efficacy of excimer laser refractive surgery as an alternative for optical correction in patients affected by fully refractive accommodative strabismus.
SETTING:
Eye Clinic, University of L'Aquila, L'Aquila, Italy.
METHODS:
After a simulation of the cycloplegic correction with contact lenses over a 30-day period, 18 patients (6 men, 12 women, mean age 32.4 years +/- 9.4 [SD]) affected by fully refractive accommodative esotropia had refractive surgery using an excimer laser; 8 patients had photorefractive keratectomy (PRK), and 10 patients had laser in situ keratomileusis (LASIK).
RESULTS:
The correction of the refractive error with excimer laser allowed a reduction of the angle of deviation in all but 1 patient, who presented with a regression of refractive error and of the angle of deviation 2 years posttreatment. The 2-year follow-up showed that the mean angle of deviation in PRK was 2(Delta) esophoria at near and 0.4(Delta) esophoria at distance (P<.06); in LASIK, it was 1.7(Delta) esophoria at near and 0.2(Delta) esophoria at distance (P<.06). The difference between the 2 groups was not statistically significant at near (P = .56), at distance (P = .74), or for spherical equivalent (P = .16).
CONCLUSION:
Excimer laser refractive surgery seems to be useful in the correction of fully refractive accommodative esotropia
Iatrogenic keratectasia following laser in situ keratomileusis
No full textPURPOSE:
To evaluate keratectasia after laser in situ keratomileusis (LASIK) for high myopia.
METHODS:
A 49-year-old male patient with myopia of -23.50 D in both eyes underwent LASIK with a Summit Technology Apex Plus excimer laser. A Moria manually-guided MDSC microkeratome was used. Preoperative corneal topography in both eyes did not reveal underlying or fruste form of keratoconus. Four months after LASIK, a progressive keratectasia occurred in right eye and after 12 months, in left eye. Corneal transplantation was performed in both eyes.
RESULTS:
Histological and ultrastructural examinations were performed on one corneal button. The analysis showed regular stromal morphology and cellularity, with no sign of inflammation. The morphometric analysis showed an overall thickness of 334 microm, with a flap of 262 microm and a stromal residual bed of 72 microm, in the center of the button.
CONCLUSION:
A LASIK corneal flap made with a planned 120-microm plate turned out histologically to be approximately 260 microm thick, in an eye with a refractive correction of -23.50 D. The excessive flap thickness and excessive ablation produced progressive keratectasia requiring a penetrating keratoplasty
Flap measurements with the Hansatome microkeratome
No full textTo evaluate flap thickness, flap diameter, and hinge length during laser in situ keratomileusis (LASIK) and to correlate these measurements with preoperative keratometric power, central corneal thickness, and patient refraction, gender, and age
Pre-excimer laser and post-excimer laser refractive surgery measurements of scotopic pupil diameter using 2 pupillometers
No full textPURPOSE:
To compare a digital infrared pupillometer with a handheld light amplification pupillometer for measuring scotopic pupil size and to evaluate if the postoperative refractive changes of the cornea can influence pupil measurements.
DESIGN:
Prospective noncomparative interventional case series.
PARTICIPANTS:
One hundred eyes, 50 myopic (mean spherical equivalent [SE] refraction [+/- standard deviation], -4.32+/-2.44 diopters [D]) and 50 hyperopic (mean SE refraction, +2.95+/-0.99 D), of 50 otherwise healthy subjects underwent photorefractive keratectomy or LASIK.
INTERVENTION:
The preoperative and postoperative scotopic pupil sizes were measured by 2 examiners (E1, E2) with both a handheld light amplification pupillometer (Colvard, Oasis Medical, Glendora, CA) and a digital infrared pupillometer (Eye World Pupillometer [EWP], Oculus Keratograph, Oculus Opikgerate GmbH, Wetzlar, Germany). The agreement and interrater repeatability were determined using the comparison method described by Bland and Altman. The paired Student's t test was used to evaluate the difference between the preoperative and postoperative measurements.
MAIN OUTCOME MEASURES:
Scotopic pupil diameter, topographic corneal refractive power, uncorrected visual acuity (VA), best spectacle-corrected VA, and manifest spectacle refraction.
RESULTS:
The preoperative mean scotopic pupil diameter was 6.12+/-0.90 mm with the EWP and 6.18+/-0.91 mm with the Colvard. After the surgery, mean SE refractions were -0.22+/-0.98 D (myopic patients) and +0.19+/-0.40 D (hyperopic patients). Postoperative mean scotopic pupil diameters were 6.12+/-0.89 mm (EWP) and 6.17+/-0.90 mm (Colvard). There was no statistically significant difference between preoperative and postoperative mean scotopic pupil sizes in either patient group. The limits of agreement between the 2 devices ranged from 2.24 mm (E1) to 2.12 mm (E2) preoperatively and from 2.27 mm (E1) to 2.08 mm (E2) postoperatively. The coefficient of interrater repeatability ranged from 0.56 mm (EWP) to 1.12 mm (Colvard) preoperatively and from 0.62 mm (EWP) to 1.14 mm (Colvard) postoperatively.
CONCLUSIONS:
The digital infrared pupillometer showed better preoperative and postoperative repeatability than the handheld light amplification pupillometer. In the present study, a mean correction of <3 D of the corneal refractive power did not seem to modify the preoperative scotopic pupil size measurements
Surgical treatment of obstruction of the nasolacrimal ducts in patients with anatomical endonasal variants.
No full textThe presence of anatomical endonasal variants (concha bullosa, nasal septal deviation, or hypertrophic turbinates) may cause more complications in patients with epiphora who have external dacryocystorhinostomy (DCR). The purpose of this study was to assess the results of surgical placement of a stent in 28 patients. They were randomised into two groups and had either DCR or placement of a Song's polyurethane stent. They were followed up for 18 months. Twenty-six patients had a good result. The success rate was 13/14 for those who had DCR and 13/14 for those who had a stent. Operating time was significantly less for placing a stent (mean (SD) 15 (2) minutes) compared with 40 (3) minutes for DCR (p <0.01). Placement of a polyurethane stent is an effective and short procedure for nasolacrimal obstruction, which is suitable for patients with unusual intranasal conditions
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