Spontaneous closure of small full-thickness macular holes: Presumed role of Müller cells.

PURPOSE: To document with spectral domain optical coherence tomography the formation and spontaneous closure of small full-thickness macular holes and to propose the active role of Müller cells in macular hole closure. METHODS: A retrospective case series of five patients with spontaneous closure of macular holes is reviewed. In one patient, foveal images were recorded over a period of 18 months. RESULTS: In a 66-year-old man, vitreofoveal traction caused a detachment of the inner Müller cell layer of the foveola from the outer nuclear layer (ONL) which was associated with a large pseudocyst and a horizontal gap in the central ONL. The traction caused an elongation and subsequent disruption of the stalk of the Müller cell cone in the foveola. A small full-thickness macular hole developed when a portion of the inner Müller cell layer of the foveola was pulled out. After phacoemulsification and shortly before the subsequent spontaneous closure of the hole, there were rapid increases in the number and size of the cystic cavities in the foveal walls resulting in a narrowing of the hole. The hole closed by bridging the gap in the inner part of the central ONL; a new inner Müller cell layer of the foveola was formed, and the gap of the external limiting membrane (ELM) was closed. The cystic cavities in the foveal walls rapidly disappeared within 2 weeks after the closure of the hole. One to 2.5 months after hole closure, the thickness of the central ONL increased which decreased the distance between the central ELM and retinal pigment epithelium. In three of the four other patients, the hole also closed by bridging the gap in the inner part of the ONL. CONCLUSION: It is suggested that the spontaneous closure of small macular holes and the subsequent reconstruction of the normal foveal structure are mediated by active mechanisms of Müller cells which resemble those involved in ontogenetic foveal development.

Evaluation of central corneal thickness after cataract surgery, penetrating keratoplasty and long-term soft contact lens wear.

PURPOSE: The aim of this study was to compare central corneal thickness (CCT) between corneas of normal healthy eyes (cNHE), corneas of eyes that had undergone cataract surgery by clear corneal phacoemulsification with implantation of an intracapsular intraocular lens (cIOL), corneal grafts after penetrating keratoplasty (gPK) and corneas of long-term soft contact lens wearers (cCL). METHODS: The study design was a consecutive cross-sectional trial. CCT was measured using rotating Scheimpflug camera (Pentacam, software version 1.16r04) in 80 cNHE, 79 cIOL, 46 gPK and 78 cCL. Analysis of variance (one-way ANOVA) was performed to compare differences of mean values between these four groups. Pearson's or Spearman's correlation coefficient (r) was determined between CCT value and age, follow up time after penetrating keratoplasty (timePK) or contact lens wearing time (timeCL). RESULTS: Means of CCT measurements were comparable between cNHE (mean CCT±standard deviation, 554±36µm), cIOL (551±40µm) and gPK (534±52µm) as determined by one-way ANOVA. Mean CCT values in cCL (537±37µm) were statistically significantly lower in comparison to cNHE (p=0.026, 95% CI=1.43-31.44). There was no linear correlation between age and CCT values of cNHE and cIOL (p=0.841, r=-0.031 and p=0.931, r=0.011, respectively). No linear relationship was determined between CCT values of cCL and timeCL (p=0.315, r=-0.125). CCT values of gPK did not correlate with timePK (p=0.738, r=0.054). CONCLUSIONS: The data reported here indicate that in the same statistical model among CCT values of cNHE, cIOL and gPK only long-term soft contact lenses (CL) wearer have significantly lower CCT measurements.

Surface quality of porcine corneal lenticules after Femtosecond Lenticule Extraction.

PURPOSE: To determine the surface characteristics of porcine corneal lenticules after Femtosecond Lenticule Extraction. METHODS: The Carl Zeiss Meditec AG VisuMax® femtosecond laser system was used to create refractive corneal lenticules on 10 freshly isolated porcine eyes. The surface regularity on the corneal lenticules recovered was evaluated by assessing scanning electron microscopy images using an established scoring system. RESULTS: All specimens yielded comparable score results of 5-7 points (SD = 0.59) per lenticule (score range minimum 4 to maximum 11 points). Surface irregularities were caused by tissue bridges, cavitation bubbles or scratches. CONCLUSION: The Femtosecond Lenticule Extraction procedure is capable of creating corneal lenticules of predictable surface quality. However, future studies should focus on the optimization of laser parameters as well as surgical technique to improve the regularity of the corneal stromal bed.

Surface quality of human corneal lenticules after femtosecond laser surgery for myopia comparing different laser parameters.

BACKGROUND: To determine the surface characteristics of human corneal lenticules after femtosecond laser surgery for myopia. METHODS: The Carl Zeiss Meditec AG VisuMax® femtosecond laser system was used for refractive correction called Femtosecond Lenticule Extraction on 24 myopic eyes. The surface regularity on the refractive corneal lenticules recovered was evaluated by assessing scanning electron microscopy images using an established scoring system. Three different energy levels 150, 180, and 195 nJ were compared (n = 8 in each group). RESULTS: Surface irregularities were caused by tissue bridges, cavitation bubbles, or scratches. The surface regularity index (R(2) = 0.74) decreased as pulse energy increased. The average surface regularity score obtained was 7.5 for 150 nJ, 7.25 for 180 nJ, and 6.25 for 195 nJ. CONCLUSIONS: The human corneal lenticules created with the VisuMax® femtosecond laser system are of predictable, good-quality surface. This study shows the influence of pulse energy on surface regularity in human eyes. Further studies should focus on optimization of laser parameters as well as surgical technique to improve the regularity of the corneal stromal bed and so make the advantages of the femtosecond laser technology over conventional techniques clearer in the future.

Identification of a novel mutation in the cornea specific keratin 12 gene causing Meesmann's corneal dystrophy in a German family.

PURPOSE: To report a novel missense mutation of the cornea specific keratin 12 (KRT12) gene in two generations of a German family diagnosed with Meesmann;s corneal dystrophy. METHODS: Ophthalmologic examination of the proband and sequencing of keratin 3 (KRT3) and KRT12 of the proband and three other family members were performed. Restriction enzyme analysis was used to confirm the detected mutation in affected individuals of the family. RESULTS: Slit-lamp biomicroscopy of the proband revealed multiple intraepithelial microcysts comparable to a Meesmann dystrophy phenotype. A novel heterozygous A-->G transversion at the first nucleotide position of codon 129 (ATG>GTG, M129V) in exon 1 of KRT12 was detected in the proband, her two affected sons but not in her unaffected husband or 50 control individuals. CONCLUSIONS: We have identified a novel missense mutation within the highly conserved helix-initiation motif of KRT12 causing Meesmann;s corneal dystrophy in a German family.

Surgical outcome after phototherapeutic keratectomy in patients with TGFBI-linked corneal dystrophies in relation to molecular genetic findings.

PURPOSE: To evaluate the correlation between surgical outcome after phototherapeutic keratectomy in patients with autosomal dominant transforming growth factor, beta-induced (TGFBI)-linked corneal dystrophies (CD) and molecular genetic findings regarding the TGFBI gene. METHODS: Twelve patients were examined to investigate genotype by direct sequencing of the TGFBI gene. Twenty eyes of 12 patients were treated with phototherapeutic keratektomy (PTK) to remove superficial corneal opacifications and to decrease recurrent erosions. Surgical outcome, including visual improvement, recurrence of opacifications, postoperative complications, and additional therapeutic proceedings were reported and compared with the molecular genetic results. RESULTS: Four different missense mutations were identified within the coding region of the TGFBI gene: Arg124Cys in one eye, Arg555Trp in nine eyes, Arg124His in four eyes and Gly623Arg in six eyes. In all eyes the PTK was successful without clinically significant recurrent opacifications after a mean follow-up time of 17.6 months (min 3 months, max 42 months). The best corrected visual acuity (BCVA) improved with an average increase of 3.1 lines (minimum 2 lines, maximum 5 lines). In one eye (Arg124Cys), we observed delayed wound healing and a delayed increase in BCVA, in two eyes we performed an Epilasik to correct remaining hyperopia, and in four eyes we fitted rigid gas-permeable tricurve contact lenses to correct the remaining irregular astigmatism. CONCLUSIONS: The variable genotypes in patients with TGFBI-linked corneal dystrophies lead to significantly different results after surgical treatment. The Gly623Arg mutation seems to be an optimum genotype on which to perform PTK even in older patients. It is essential to determine the genotype in order to standardize the PTK treatment and to evaluate the success in TGFBI-linked corneal dystrophies.

Macular corneal dystrophy: mutational spectrum in German patients, novel mutations and therapeutic options.

INTRODUCTION: The objective of this study was to investigate genotype-phenotype correlations, the consequences for surgical treatment, and the therapeutical options in patients with macular corneal dystrophy (MCD). MATERIAL AND METHODS: We investigated MCD genotype by using polymerase chain reaction followed by direct sequencing in one family and four patients with MCD. Results were confirmed by restriction analysis. Clinical phenotypes, histopathological findings, and therapeutical proceedings of each patient were reported and compared with the molecular genetic results. RESULTS: Five mutations, four missense mutations, and one frameshift mutation, from which three were novel, and one single-nucleotide polymorphism, were identified within the coding region of the CHST6 gene. In three patients, two with a homozygous mutation within the start codon (Met1Leu) and one with a heterozygous mutation (Leu200Arg) and a polymorphism (Arg162Gly), with irregular corneal surface and recurrent erosions a phototherapeutic keratectomy lead to a transient success. An additional fitting of rigid gas permeable contact lenses in one patient could further improve irregular astigmatism. In two patients, one with a frameshift mutation (1734_1735delTG; Arg211Gln) and one with two compound heterozygous mutations (Leu200Arg; Leu173Phe) and an additional polymorphism (Arg162Gly) a penetrating keratoplasty improved BCVA without any recurrence of the opacities within the follow-up time. DISCUSSION: Different genotypes imply several phenotypes, which influence therapeutical proceedings in MCD patients. Our study shows the wide range of diagnostic findings and therapeutical options in patients suffering from macular corneal dystrophy depending on the genotype.

Ptf1a is essential for the differentiation of GABAergic and glycinergic amacrine cells and horizontal cells in the mouse retina.

Basic helix-loop-helix (bHLH) transcription factors are important regulators of retinal neurogenesis. In the developing retina, proneural bHLH genes have highly defined expressions, which are influenced by pattern formation and cell-specification pathways. We report here that the tissue-specific bHLH transcription factor Ptf1a (also known as PTF1-p48) is expressed from embryonic day 12.5 of gestation (E12.5) to postnatal day 3 (P3) during retinogenesis in the mouse. Using recombination-based lineage tracing, we provide evidence that Ptf1a is expressed in precursors of amacrine and horizontal cells. Inactivation of Ptf1a in the developing retina led to differentiation arrest of amacrine and horizontal precursor cells in addition to partial transdifferentiation of Ptf1a-expressing precursor cells to ganglion cells. Analysis of late cell-type-specific markers revealed the presence of a small population of differentiated amacrine cells, whereas GABAergic and glycinergic amacrine cells, as well as horizontal cells, were completely missing in Ptf1a-knockout retinal explants. We conclude that Ptf1a contributes to the differentiation of horizontal cells and types of amacrine cells during mouse retinogenesis.

Varieties of contact lens fittings after complicated hyperopic and myopic laser in situ keratomileusis.

PURPOSE: To determine whether contact lenses with a special back surface design can improve visual acuity after complicated laser in situ keratomileusis (LASIK). METHODS: Fifteen eyes (six after myopic LASIK and nine after hyperopic LASIK) of eight patients were fitted with contact lenses with a special back surface design for optical rehabilitation. Four different types of lenses (aspheric, tricurve, keratoconus, and reverse) were used selectively, depending on the abnormal eccentricity (positive and exceeding 0.5-0.7 in all preoperatively hyperopic eyes, negative in all preoperatively myopic eyes) determined by videokeratoscope and on individual conditions. The patients were followed up retrospectively for an average period of 12.3 months. Lens tolerance and corrected visual acuity were evaluated and compared with the results obtained with spectacles. RESULTS: Visual acuity improved in nine (60%) of 15 eyes (three eyes by more than three lines and six eyes by three lines or fewer), with an absence of halos and ghost images in four (26.7%) of 15 eyes accompanied by good contact lens tolerance and a satisfactory contact lens fit. There were no noticeable complications. CONCLUSIONS: Contact lens fitting after LASIK is a safe and reliable procedure for improving visual acuity and reducing complications, such as ghost images or irregular corneal surface. Depending on the eccentricity and therefore on the preoperative refraction, contact lenses with a special back surface design can minimize problems in contact lens fitting and can improve tolerance and visual results.

Refractive error after triple and non-simultaneous procedures: is the application of a standard constant keratometry value in IOL power calculation advisable?

PURPOSE: The purpose of this investigation was to determine whether or not the use of a standard constant keratometry value in cases of preoperative abnormal keratometry values in biometry for triple procedures is advisable. METHODS: Cataract surgery and penetrating keratoplasty were performed in 82 eyes; 53 eyes underwent triple procedures and 29 eyes underwent non-simultaneous procedures. A standard constant keratometry value of 42.50 D was applied in 18 triple-procedure eyes because the preoperative measured keratometry values were outwith the normal range (41-47 D). The spherical equivalent and expected values were compared after a mean follow-up of 20.5 months. RESULTS: Cases in the triple-procedure group that achieved spherical equivalent within +/- 2.0 D of expected values included nine of 18 eyes (50%) in which a standard constant keratometry value of 42.50 D was applied, three of 17 eyes (18%) in which keratometry values outwith the normal range were applied (p = 0.044), and eight of 18 eyes (45%) in which keratometry values within the normal range were applied (p = 0.862). Cases in the non-simultaneous procedure group that achieved spherical equivalent within +/- 2.0 D of expected values included 22 of 24 eyes (92%) in which keratometry values within the normal range were applied (p = 0.0025), and five of five eyes (100%) in which a standard constant keratometry value was applied. CONCLUSIONS: The application of a standard constant keratometry value of 42.50 D for intraocular lens power calculation in triple procedures can be recommended if abnormal keratometry values were measured previously. If possible, non-simultaneous procedures should take priority.

[Lamellar keratoplasty - new concepts]. / Lamellierende Keratoplastik - neue Konzepte.

New concepts of lamellar keratoplasty techniques mainly deal with the refinement of the so-called deep lamellar endothelial keratoplasty (DLEK). The aim of the deep lamellar technique is to expose bare Descemet's membrane of the recipient and to suture in a full thickness graft. Graft rejections are not known with DLEK. We describe the preparation techniques of Anwar, Melles, and Krumeich and discuss the advantages and disadvantages. The femtosecond laser enables the surgeon to cut the cornea non-mechanically with a cutting accuracy of +/- 10 microns. Fuchs endothelial dystrophy can be treated by posterior lamellar keratoplasty (POLK). In this technique only a sheet of Descemet's and endothelium are replaced. In severe alkali burn with limbal stem cell deficiency a lamellar corneo-scleral disc can be grafted in order to restore the limbus. Routine central penetrating keratoplasty should follow at least half a year later.

[Nosocomial pseudomonas aeruginosa-associated keratitis in soft contact lens wearer]. / Nosokomiale Pseudomonas-aeruginosa-assoziierte Keratitis nach Tragen weicher Kontaktlinsen.

BACKGROUND: Pseudomonas aeruginosa is the most common cause of bacterial-associated keratitis in soft contact lens wearers, due to wrong use of soft contact lenses. Problems are often severe corneal ulcers and even corneal perforations. We report on a soft contact lens wearer with credibly correct use of soft contact lenses and nosocomial Pseudomonas aeruginosa-associated keratitis. CASE REPORT: A 33-year old woman suffered from corneal ulcer and corneal infiltration with beginning endophthalmitis 2 days after having used of new soft contact lenses. After systemic and local antibiosis and penetrating keratoplasty we could stop endophthalmitis before reaching the vitreous and retina. RESULTS: Histological and microbiological examinations showed a corneal ulcer with severe corneal infection due to Pseudomonas aeruginosa with resistance to mezlocillin and intermediale resistance to gentamicin. After therapy a stable situation with visual acuity of 20/60 was attained. CONCLUSIONS: Previous reports on Pseudomonas aeruginosa-associated keratitis in soft contact lens wearers demonstrate corneal problems due to extended or overnight wear or unsuccessful contact lens cleaning. We present a case of nosocomial corneal infection after soft contact lens wearing and nosocomial infection because of contact with a partner working in an intensive-care unit. Hygienic rules should be strictly followed by patients and staff using soft or hard contact lenses for visual correction or for therapeutic reasons.

[The "Clothesline Phenomenon" after Cerclage with Arruga's Suture - Is Cutting of the Suture Necessary?]. / Das "Wäscheleinenphänomen" nach Cerclage mit einem Arrugafaden - ist eine Durchtrennung unumgänglich?

BACKGROUND: Several early and late complications have been described since the introduction of cerclage surgery using a supramid suture. Due to cutting of the supramid suture through scleral tissue the supramid suture may appear at the fundus. Long-term results of scleral penetration and crossing the bulbus by the supramid suture, which is then only covered by the retina ("clothesline phenomenon"), could not be described so far. We report on a patient 20 years after cerclage surgery with Arruga's suture. CASE REPORT: A now 63-year old female patient with high myopia (D - 14.0 OU) suffering from complete retinal detachment had had ophthalmic surgery using Arruga's encircling suture with additional horizontal buckling at her left eye in 1983. Postoperative visual acuity was 10/20. The retina was attached. In 2002 phakoemulsification with posterior chamber lens implantation due to cataracta corticalis was done externally. In 2003 a complete scleral and chorioidal penetration and appearance of the Arruga's suture behind the retina occurred extending from 4 over 6 to 8 o'clock position with a visual acuity of 20/25. The patient did not agree with the cutting of the suture at any time. CONCLUSIONS: The "clothesline phenomenon" is a very rare late complication after encircling surgery using an Arruga suture by retinal detachment. Suture cutting is suggested because of a possible risk of retinal detachment. As shown in our case report, stable retinal attachment after Arruga's suturing is possible.

[Hydrophobic AcrySof lenses or heparin-modified PMMA lenses in combined vitrectomy surgery -- results of a four-year study]. / Hydrophobe Acryllinsen (AcrySof) oder heparinmodifizierte PMMA-Linsen bei kombinierten Vitrektomieeingriffen -- Ergebnisse einer 4-Jahres-Studie.

BACKGROUND: Combining pars plana vitrectomy with phacoemulsification and implantation of an intracapsular IOL provides many advantages and is performed as a routine operation. MATERIALS AND METHODS: Over a period of 3 years we compared foldable acrylic lenses AcrySof (Alcon) to heparin-modified PMMA lenses (Pharmacia) in a prospective study. The last implanted lenses had a follow-up period of at least 1 year. Out of 396 eyes from 329 patients we implanted 182 AcrySof lenses and 214 heparin-modified lenses. RESULTS: Both a smaller scleral tunnel incision and a lower rate of secondary cataract are advantages of foldable AcrySof lenses. Higher vulnerability of an AcrySof lens and a less stable lens-iris-diaphragm are of disadvantage. Heparin-modified PMMA lenses do not show these disadvantages, however, in consequence of using them you have to accept the wider scleral tunnel incision and a higher adhesion to cells. Furthermore, we found slightly more posterior synechiae with these lenses. CONCLUSIONS: In all, both types of intraocular lenses are suitable for combined surgery. We recommend using heparin-modified PMMA lenses in case of pre-existent instability of the lens-iris diaphragm or of patients' inability to maintain the prone position.

[Aberrometry due dilated pupils--Which mydriatic should be used?]. / Aberrometrie in Mydriasis - welche Art der Mydriasis ist zu bevorzugen?

BACKGROUND: For a wavefront-based LASIK procedure aberrometric measurements are necessary via a dilated pupil. The more dilated the pupil is the more aberrations can be identified. There are different mydriatic eyedrops used to dilate the pupil. It is unclear so far which mydriatic is best for measuring aberrations before LASIK. METHODS: We performed aberrometry measurements on 50 eyes under the following different conditions: physiological mydriasis under mesopic environment, tropicamide-induced dilation, phenylephrine-induced dilation, and cyclopentolate-induced dilation. The wavefront measurements were compared with the respective subjective refraction (sr). RESULTS: The refractive myopic error measured by aberrometry was less than after subjective refraction depending on the mydriatic used. Phenylephrine-induced mydriasis resulted in 0.19 D less myopia, tropicamide induced 0.35 D less myopia, and cyclopentolate 0.42 D less on the average. The aberrometry measurements under mesopic conditions led to 0.24 D less myopia than measured subjectively. CONCLUSION: Using cyclopentolate eyedrops wavefront analysis results in a considerable difference in the preoperative refractive error compared to the standard subjective refraction. Regarding the average differences in refraction the aberrometry measurements after neosynephrine-induced dilation of the pupil usually resemble the subjective refractive error. For practical reasons we would like to recommend aberrometry measurements under mesopic conditions without applying mydriatics provided the pupillary diameter is at least 6 mm.