Trabeculectomy without conjunctival incision.
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Animals↗
Biomedical subjects
C I Phillips
Publications and source records attributed to C I Phillips.
Ocular pulsation correlates with ocular tension: the choroid as piston for an aqueous pump?
In 26 random out-patients, including 13 treated glaucoma patients and ocular hypertensives, the higher the ocular tension, the greater the pulse amplitude, by Alcon pneumotonometry, at a statistically significant level. In a single untreated hypertensive, when 2-hourly pneumotonometry was done for 24 h, the correlation was similar and significant. The higher the diastolic blood pressure, the higher the ocular pulsation, also significantly. Pulsation is suggested to be a pump, the choroid being the piston, contributing (1) to an increase in the outflow of aqueous humour and (2) to a homeostatic mechanism contributing to normalization of the intra-ocular pressure, wherein pulsation increases or decreases, as the intraocular pressure increases or decreases, respectively.
Aqueous Humor↗
Rabbit diurnal ocular tension variations.
Ocular tension recorded by pneumatonography was estimated at 4-hour intervals during six consecutive 24-hour periods in 8 New Zealand rabbits. The animals had been acclimatized for more than 8 weeks to artificial light from 08.00 to 20.00 h and dark for the other 12 h. Inter- and intrarabbit consistency was enough to allow the generalization that the lowest pressure occurred at noon (mean -0.8 mm Hg from baseline average), while the highest pressures (mean + 1.2 mm Hg above baseline average) occurred at 16.00 and 20.00 h. Only three other studies have measured rabbit ocular tensions throughout 24 h, but for shorter periods: one observed a light-induced rise as in the present study, but the other two studies found a rise during darkness.
Animals↗
Erisocapsulorhexis.
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Cataract Extraction↗
Male proband with X linked retinoschisis apparently inherited from his father's family.
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Chromosome Aberrations↗
Central pulverulent (Coppock) cataracts. A sibship of two Arab females with full-cousin normal parents.
Two Arab (Saudi) sisters are described each with bilateral typical central pulverulent (powdery) or Coppock cataracts. As their unaffected parents are first cousins, the heredity is probably autosomal recessive, unlike the autosomal dominant heredity of the vast majority of previously described cases in the literature. Chromosomes were normal in all four individuals. There are no other children in the family. Both children and both parents were phenotypically Fy a - b+, reasonably common in Arab populations, so that any linkage to the Duffy blood group is neither supported nor refuted.
Cataract↗
Congenital alacrima without associated manifestations (AD). An affected father and son.
The authors report a Kuwaiti Arab family in which the father and one of his two sons have severe hypolacrimation with blotchy staining of the cornea and punctate staining of the interpalpebral bulbar conjunctiva by fluorescein and Rose Bengal. Pharmacologic testing together with biochemical analysis and systemic examinations and investigations suggest an isolated dysfunction of lacrimation. The authors' small Arab family differs from the only other recorded pedigree (Irish) in which all five affected members in four generations also had atopy.
Adult↗
Contact lenses and corneal deformation: cause, correlate or co-incidence?
Sporadic reports describing cases of corneal deformation (i.e. corneal warpage with astigmatism or keratoconus) after a minimum of about 4 years contact lens wear are condensed into Table 1. Some severe cases required corneal grafting. Eight personal cases are described in Table 2, including two who have worn only soft lenses and one who has worn soft lenses for 6 out of 7 years. It is suggested that although some cases of this corneal distortion might well have occurred without contact lenses, the trauma of years of contact lens wear is causative if the individual's cornea is predisposed, possibly by the carrier state of hereditary naturally-occurring keratoconus. A risk-averse patient and practitioner would probably add this to other possible complications, and restrict contact lenses to eyes with more severe refractive errors, and minimise the wearing time.
Adolescent↗
Effects of mifepristone on rabbit intraocular pressure in the presence and absence of dexamethasone.
Topical dexamethasone was used to elevate rabbit intraocular pressure in order to study the interaction with a steroid antagonist, mifepristone. Dexamethasone did not cause a consistently significant increase in intraocular pressure. Animals treated with mifepristone followed by dexamethasone showed no apparent increase in intraocular pressure after dexamethasone, indeed mifepristone caused a lower intraocular pressure than seen in other groups whether in the presence or absence of dexamethasone. Reductions of intraocular pressure when mifepristone was given after 14 days of dexamethasone administration were not found. No conclusion can be reached regarding any dexamethasone antagonism by mifepristone, except that intraocular pressure tended to be lower even in the presence of dexamethasone.
Administration, Topical↗
Corneal arcus: some morphology and applied pathophysiology.
The frequency and density of corneal arcus in 101 patients (101 eyes), 54 males and 47 females, were greatest in the 12 o'clock sector of the peripheral cornea. Sectors below 12, nasally and temporally, were approximately symmetrically affected. Both properties decreased progressively and significantly at the 11 and 1 o'clock sectors, then 10/2, then 9/3; 8/4 and 7/5 differed insignificantly from each other but were significantly less affected than 9/3, and more affected than 6 o'clock. Breadth and density were significantly positively correlated. The greater vascularity and higher temperature at the upper limbus might explain this pattern. The morphology of arcus is concluded to indicate the site of a peripheral corneal filter which prevents ingress of large light-scattering particles with the centripetal flow of tissue fluid. Filtration of immune complexes at the same site may initiate tissue destruction, hence some peripheral corneal ulcerations.
Adult↗
Topical dexamethasone lowers rabbit ocular tension, as does topical mifepristone (RU 486), a peripheral blocker of dexamethasone and progesterone.
The variability of the response of the rabbit eye to topical 1% dexamethasone has been shown in two groups of 20 young albino rabbits each (total 40) tested in succession. The pressure anomalously fell significantly (but by only 1 mm Hg) in both groups in the first 4 weeks of administration, but not in subsequent weeks. Mifepristone (RU 486), a peripheral antagonist of dexamethasone and progesterone, reduced the pressure significantly, again by only 1 mm Hg, in the first group of 20 rabbits, not the second. Accordingly, no conclusion was possible on the originating question: does pre-treatment with mifepristone prevent the dexamethasone-induced rise in rabbit intra-ocular pressure?
Administration, Topical↗
Interaction between progesterone and mifepristone on intraocular pressure in rabbits.
The interaction between a topically administered progesterone, medrysone, and a steroid antagonist, mifepristone, on rabbit intraocular pressure (IOP) has been determined. Medrysone alone increased IOP significantly above parallel controls over the first three weeks; this increase was not sustained. When medrysone and mifepristone were given simultaneously the IOP increased initially, but then fell after two weeks to control levels. When mifepristone was added 14 days after medrysone, the IOP was again reduced to, or below, control levels by mifepristone. The use of mifepristone alone reduced IOP relative to controls and the further addition of medrysone at 14 days had no effect on IOP. It appears that mifepristone is an effective antagonist against progesterone effects on IOP.
Animals↗
Aqueous humor flow rate and intraocular pressure during and after pregnancy.
Intraocular pressure and aqueous humor formation rate have been determined from the first trimester of pregnancy through term, with further determinations 3 months postpartum, in 7 patients. The intraocular pressure showed a consistent, statistically significant fall during pregnancy, returning to values seen in early pregnancy after delivery. Aqueous humor formation rate showed no change during pregnancy. The data indicate that the sustained elevated hormonal levels during pregnancy, either directly or indirectly, cause an increase in fluid outflow conductance from the eye without altering the rate of fluid entry.
Adult↗
Aniridia, ectopia lentis, abnormal upper incisors and mental retardation--an autosomal recessive syndrome.
A 13-year-old boy presented with bilateral aniridia, ectopia lentis, two palatally placed upper incisors which may be supernumerary teeth or may be malpositioned lateral incisors, and mental retardation. The cause is very probably a single autosomal recessive gene defect although the mental state may have a separate, genetic cause. Since his parents, who are normal, are second cousins and his father's and his mother's parents are also full cousins, the coefficient of inbreeding is 1/64 which is only 25% of the coefficient for full cousinhood of parents alone (1/16). No biochemical correlate has been identified.
Adolescent↗
Centripetal movement of fluorescein dextrans in the cornea: relevance to arcus.
The centripetal movement of fluorescein and fluorescein-labelled dextrans (4 to 150 kD) from sclera or cut edge of the cornea was determined in isolated rabbit corneas at 4 and 24 h. Corneas were divided into 5.5 mm diameter central core, inner 5.5 to 8 mm donut, 8 to 12 mm peripheral donut and, where applicable, scleral rim. For all molecules greater than sodium fluorescein (376 D) tracer concentrations in the 5.5 mm core and the 5.5 to 8 mm donut were equal. Without sclera rim, the more central portions of the cornea (5.5 mm core and 5.5 to 8 mm donut) had tracer concentrations equal to those of corneas-with-sclera for all tracers greater than 10 kD. The tracer concentrations in the central cornea were the same in the presence or absence of sclera. The data indicate a physiological barrier to the lateral diffusion of molecules greater than 10 kD between the peripheral and more central cornea.
Animals↗
Posterior synechiae after glaucoma operations: aggravation by shallow anterior chamber and pilocarpine.
Posterior pupillary synechiae affect a proportion of eyes subjected to iridectomy with or without drainage operation because (1) aqueous humour bypasses the pupil; (2) traumatic iridocyclitis occurs; (3) there is immobility of the iris in the iridectomy sector; (4) in eyes with angle closure glaucoma closer apposition of the iris to the anterior lens capsule increases the tendency; (5) pilocarpine aggravates (4) both in angle closure glaucoma and open angle glaucoma and produces a small immobile pupil facilitating pupillary membrane formation (occlusio pupillae). Pilocarpine should be avoided if possible as medical treatment at any time after a drainage operation. A beta blocker is the drug of choice. To eliminate posterior synechiae over a fair number of degrees of pupil (say 30 degrees) sector iridectomy can be done.
Aged↗