Expression of Neurofilament Protein in the Nerve of Human Cornea

This study was performed to identify the expression of neurofilament in sensory nerve of human cornea. The three normal corneal tissues were dissected. Monoclonal antibody to neurofilament protein were used to visualize the corneal nerve. The one normal cornea was examined to observe the corneal nerve with electron rnicroscope. Transmission electron rnicroscope showed that the corneal nerve contained the neurofilament within the axon. The indirect iinmunofluorescent techniques revealed the expression of neurofilament in corneal stroma. The results of this study show that immunofluorescent technique may useful method in identification of sensory nerve of human cornea, and make it easy for us to visualize corneal innervation pattern in flat section by using of antibody to neurofilament protein.

Excimer Laser Photorefractive Keratectomy for the Correction of Compound Myopic Astigmatism: One Year Follow-Up

To prospectively examine the predictability of excimer laser photorefractive keratectomy for compound myopic astigmatism, we treated 107 eyes of 70 patients with a VisX Twenty/Twenty excimer laser and followed them up for 12 months. Patients were divided into three groups with preoperative myopia: group 1 with diopters of -6.00 or less, group 2 with diopters between -6.01 and -10.00, and group 3 with diopters greater than -10.00. Also, two groups of patients were evaluated with preoperative astigmatism: group I with -2.00 diopters or less and group II with greater than -2.00 diopters. At 12 months group1, with amean preoperative refractive error of -4.332D, changed to -0.19D, group 2 changed from -7.35D to -0.66D, and group 3 changed from -11.72D to -1.23D. Group I with a mean preoperative refractive error of -1.22D changed to -0.55D, while group II changed from -2.63D to -0.77D. Finally, 85% of eyes with preoperative spherical equivalent diopters of -6.00 or less, 65% of eyes between -6.01 and -10.00D, and 42% of eyes greater than -10.00D were corrected within 1D of intended refraction, respectively.

Pattern of Glaucomatous Optic Disc Damage in Primary Open-Angle Glaucoma

To identify the pattern of glaucomatous changes of the optic disc, the rim area to disc area ratio (RA/DA ratio) of 149 eyes (149 cases) with primary open-angle glaucoma (POAG) were measured and compared with that of 88 eyes (88 cases) of normal individuals. At all stages of the disease, glaucomatous rim loss was present in all sectors of the optic disc. The location of the most pronounced rim loss changed depending on the severity of the disease. In the early (RA/DA ratio > 61%; mean deviation(MD): -6.43+/-3.32dB) and medium (RA/DA ratio=41~60%; MD: -7.54+/-5.65dB) glaucoma subgroups, rim loss was found predominantly at the inferior temporal and superior temporal disc region. In the advanced glaucoma subgroup (RA/DA ratio=40~21%; MD: -18.27+/-8.40dB), the temporal horizontal disc region showed relatively marked rim loss. In the far advanced glaucoma subgroup (RA/DA ratio=20~0%; MD: -25.91+/-5.40dB), the rim remnants were located mainly in the nasal disc sector, with a larger rim portion in the upper nasal region than in the lower nasal region. These results indicate that generally in POAG, the loss of neuroretinal rim was found to start predominantly in the inferior temporal and superior temporal disc region, and then the temporal horizontal, the inferior nasal, and the superior nasal disc sectors followed.

Sensitivity, Specificity, and Predictive Value of Optic Disc Parameters in Primary Open-Angle Glaucoma

Attempts to quantify the parameters of optic nerve head structure have been made to recognize the earliest structural abnormalities in glaucoma, and to efficiently monitor the structural changes of the optic nerve head with advancing disease. Optic disc parameters were measured in 88 normal subjects and 149 primary open-angle glaucoma patients using a computer graphic program (Adobe photoshopTM) and the photographic magnification was corrected according to Littmanns method. The sensitivity, specificity, and predictive value of optic disc parameters were calculated to discriminate between normal and glaucomatous eyes at different stages of glaucoma. Receiver operating characteristics curves were used for comparisons of different disc parameters. In the group with mild glaucomatous visual field (VF) defects (mean deviation (MD); better than -5dB, group 1), optic disc parameters did not provide greater sensitivity and specificity enough to detect early glaucomatous optic nerve head damage. In the group with moderate VF defects (MD; -6~-10dB, group 2) and advanced VF defects (MD; worse than -11dB, group 3), the minimum rim width within the 60 sector across the vertical meridian (predictive value; 84.4%, 95.9%, respectively), vertical cup to disc ratio (83.7%, 95.2%, respectively), and rim area to disc area ratio (83.7%, 95.1%, respectively) were helpful to identify the glaucomatous eyes, whereas horizontal cup to disc ratio (77.3%, 90.3%, respectively) and cup area (75.2%, 89.0%, respectively) were less helpful in this regard.

Effects of Subconjunctival Mitomycin C on Glaucoma Triple Procedure, as Compared with Trabeculectomy alone

Mitomycin C (MMC) trabeculectomy combined with extracapsular cataract extraction and posteor chamber intraocular lens implantation (glaucoma triple procedure, 30 eyes) was clinically compared with MMC trabeculectomy alone (30 eyes). The age, type of glaucoma, and preoperative number of medications were matched with the previous group (P>0.05). The mean preoperative intraocular pressures (IOPs) were 30.2+/-8.3mmHg (range, 22~56mmHg) in the glaucoma triple procedure group and 31.6+/-8.9mmHg (range, 22~57mmHg) in the trabeculectomy alone group (p=0.55). The mean postoperative IOPs were significantly higher in the glaucoma triple procedure group compared with the trabeculectomy alone group at all postoperative vistis (one month to nine months) (p0.05). Although hypotensive effect of MMC on the glaucoma triple procedure was less than on the trabeculectomy alone, glaucoma triple procedure using MMC could be recommended to be safe and effective on controlling the high IOP for treating glaucoma patients with coexisting cataract.

Two Cases of Cortical Blindness after Gas Exposure

Cortical blindness is defined as the partial or complete loss of vision from bilateral lesions to the occipital cortex, with intact pupillary reflexes, normal fundi and extraocular movements. Although cerebrovascular disease is the most common cause of cortical blindness, cardiac surgery, cerebral angiography, eclampsia, head trauma, drug and carbon monoxide poisoning are causes too. Two patients with cortical blindness, following exposure to LNG (Liquefied Natural Gas) and argon gas are presented. Cortical blindness was thought to result from hypoxic or anoxic-ischemic change in the visual cortex, which is due to respiratory arrest from LNG intoxication and asphyxiating atmospheres from inhalation exposure to argon gas. Diagnosis was made with MRI scan showing bilateral occipital infarctions, which are the most valuable in diagnosing cortical blindness.