Results of Re-operation on the Deviated Eye in Patients with Sensory Heterotropia

PURPOSE: To evaluate the result of re-operation on the deviated eye of recurred, consecutive or undercorrected sensory strabismus after surgery. METHODS: The medical records of 11 patients who had received second strabismus operation on the deviated eye due to recurred, consecutive or undercorrected sensory strabismus were studied retrospectively. RESULTS: Among the 11 patients, five patients were operated for recurred exotropia after surgery of sensory exotropia (group 1), two for consecutive exotropia after surgery of sensory esotropia (group 2), and four for undercorrected esotropia after surgery of sensory esotropia (group 3). Re-operation was performed 19.2+/-12.6 years after the first operation and the mean preoperative deviation before re-operation was 30.0+/-8.66 prism diopters (PD), 32.5+/-10.6PD, and 32.5+/-8.66PD, respectively. In all cases, a small amount of recession or resection compared with the usual surgical dosage was applied in re-operation on the deviated eye. The mean follow-up period after re-operation was 12.3+/-14.2 (1-48 months). Among the 11 patients, postoperative deviations less than 10PD were achieved postoperatively in 8 (72.7%) at 1 month and of the 8 patients with follow-up data beyond 6 months, 5 (62.5%) showed orthotropia within 10PD at 6 months or later. CONCLUSIONS: The surgical result of re-operation on the deviated eye of recurred, consecutive or undercorrected sensory strabismus after the first surgery was satisfactory in spite of the reduced amount of surgical correction compared with the surgical dosage recommended for the non-operated eye.

Results of Re-operation on the Deviated Eye in Patients with Sensory Heterotropia

PURPOSE: To evaluate the result of re-operation on the deviated eye of recurred, consecutive or undercorrected sensory strabismus after surgery. METHODS: The medical records of 11 patients who had received second strabismus operation on the deviated eye due to recurred, consecutive or undercorrected sensory strabismus were studied retrospectively. RESULTS: Among the 11 patients, five patients were operated for recurred exotropia after surgery of sensory exotropia (group 1), two for consecutive exotropia after surgery of sensory esotropia (group 2), and four for undercorrected esotropia after surgery of sensory esotropia (group 3). Re-operation was performed 19.2+/-12.6 years after the first operation and the mean preoperative deviation before re-operation was 30.0+/-8.66 prism diopters (PD), 32.5+/-10.6PD, and 32.5+/-8.66PD, respectively. In all cases, a small amount of recession or resection compared with the usual surgical dosage was applied in re-operation on the deviated eye. The mean follow-up period after re-operation was 12.3+/-14.2 (1-48 months). Among the 11 patients, postoperative deviations less than 10PD were achieved postoperatively in 8 (72.7%) at 1 month and of the 8 patients with follow-up data beyond 6 months, 5 (62.5%) showed orthotropia within 10PD at 6 months or later. CONCLUSIONS: The surgical result of re-operation on the deviated eye of recurred, consecutive or undercorrected sensory strabismus after the first surgery was satisfactory in spite of the reduced amount of surgical correction compared with the surgical dosage recommended for the non-operated eye.

Clinical Results of Modified Muscle Transposition Surgery

PURPOSE: To report the clinical experience and surgical results of modified transposition surgery, in which half-width tendons are isolated and sutured into the paralyzed extraocular muscle. METHODS: We retrospectively reviewed the medical records of 6 patients (7 eyes), who had undergone modified transposition surgery to correct severe limitation of eye movement from January 1996 to December 2001. First, we divided the half-width tendons of two rectus muscles adjacent to the paralyzed rectus muscle and disinserted the halves from the sclera. The two half-width tendons were positioned underneath of the scleral insertion of the paralyzed muscle, sutured together and then sutured to the paralyzed muscle. In the case of contracture of the antagonizing extraocular muscle, recession of the antagonist was performed. RESULTS: Five of the six patients showed deviation under 15 prism diopters at primary gaze at distance, while synergistic divergence recurred in the sixth patient. CONCLUSIONS: Modified transposition surgery as described in this paper is thought to be an effective and safe method for correction of paralytic strabismus.

Electrophysiological Analysis of Deafferentation Effect on Visual Cortex in Rats

PURPOSE: Temporary deafferentation (TD) by local anesthesia in small parts of the body induces an immediate and reVersible reorganization of the receptive field (RF). It is thought that an adaptation for deafferentation would occur in the visual system. Therefore, in this study, simultaneous multi-single unit recording (SMSUR) from visual cortex (VI cortex) of rats have been carried out to characterize; 1) the TD-induced changes in the populational activities of single neurons, 2) the alteration of the neural network among neurons in each area during TD and 3) the synaptic mechanism underlying the neuronal plasticity of the visual system. METHODS: Using four channels of a multi-electrode made from tungsten microwire, the neuronal activities (evoked responses and spontaneous activities) and networks in the VI cortex of anesthetized rats have been investigated. In this study, TD was induced by a retrobulbar injection of lidocaine (2%, 0.1 ml). RESULTS: After the induction of TD, the cortical neurons showed reversed changes in their evoked reoponses. The induction of TD suppressed the activities of the target cells in the VI cortex. However, TD also caused facilitation of the activities of the neighboring neurons. The spontaneous activities of the neighboring neurons were also gradually facilitated after the induction of TD and then gradually recovered to their initial control period values. CONCLUSIONS: The results from the present study suggest that; 1) TD-induced plasticity of the central visual system involving the VI cortex may be due to disinhibition of the lateral inhibition and 2) the spontaneous activities of the VI cortical neurons, as well as evoking responses, may be involved in the TD-induced visual plasticity of anesthetized rats.

The Clinical Outcome of the Consecutive Esotropia after Surgical Correction

PURPOSE: To investigate the clinical outcome in patient underwent surgical correction of consecutive esotropia. METHODS: The medical records of 20 patients with at least 1 year follow-up who underwent surgical correction of consecutive esotropia from 1986 to 2001 were reviewed retrospectively. The authors investigated the deviation angle, amblyopia, diplopia before and after exotropia surgery, efficacy of occlusion on the angle of consecutive esotropia, and clinical course after consecutive esotropia surgery. RESULTS: Incidence of the consecutive esotropia was 0.9% (20 out of 2260 exotropia patients who were required surgery to correct consecutive esotropia), average age at exotropia surgery was 5 year-old, and average deviation of exotropia was 33 prism diopters (PD). There were lateral incomittancy in 4 patients, convergence insufficiency in 3 patients, amblyopia in 1 patients and no had diplopia. Monocular lateral rectus recession and medial rectus recession (R and R) was performed in 13 patients and bilateral recession in 7 patients. In most patients, even though esotropic angle was reduced by occlusion therapy, they were still esotropic. Postoperative cyclic esotropia in 3 patients, diplopia in 7 patients and amblyopia in 7 patients were developed. Surgery for esotropia was performed average 13months after surgery for exotropia, angle of esodeviation at surgery was average 31PD and amblyopia improved after surgery and occlusion in 3 eyes. There were exotropia in 15 patients, esotropia in 3 patients and orthotropia in 2 patients after surgery for consecutive esotropia. The second surgery for exotropia in 2 patients and esotropia in 1 patient were performed. CONCLUSIONS: The clinical results in surgical correction of consecutive esotropia were variable. We could not anticipate the surgical result. Careful observation and treatment for development of amblyopia is needed.

Clinical Features of Anterior Ischemic Optic Neuropathy

PURPOSE: To analyze the clinical features of anterior ischemic optic neuropathy (AION) and to evaluate the visual prognosis METHODS: Medical records of 52 eyes in 47 patients who were diagnosed with AION from January 1991 to December 2000 were retrospectively reviewed. The clinical features, associated systemic disease, visual fields findings, and fundus findings in the patients were analyzed. RESULTS: The mean age of the patients was 55.9 years (20~81 years). Twenty-six were men (55.3%) and 21 were women (44.7%). The initial visual acuity of less than 0.1 was 24 eyes (46.2%), that of 0.1 to 0.5 was 23 eyes (44.2%), and more than 0.5 was 5 eyes (9.6%). In seasonal onset, frequency of AION during the winter was 18 eyes (37.5%). As the associated systemic diseases, 15 had diabetes mellitus (31.9%), and 27 had hypertension (57.4%). In laboratory examination, erythrocyte sedimentation rate (ESR) was elevated in 4 patients (8.5%). In fundus examination, the optic disc swelling was found in 16 eyes (30.8%), and optic disc atrophy was found in 36 eyes (69.2%). In Goldmann perimetry, the altitudinal field defect was found in 23 eyes (44.2%), most commonly. The mean follow-up period was 1.7 years (2 months ~ 9 years), and the visual acuity improved in 13 eyes (25.0%), worsened in 6 eyes (11.5%), and did not change in 33 eyes (63.5%) at the final follow-up. CONCLUSIONS: In conclusion, patients with AION showed various clinical features and overall visual prognosis is poor. Because AION is frequentely associated with systemic diseases, careful evaluation on the systemic disease is mandatory.

Cortical Responses Evoked by the Light and Electricity in the Rabbit Retina

PURPOSE: By recording the electrically evoked potential (EEP) we tried to verify that focal electrical stimulation of retina sends a signal to the cortex that is similar to that elicited by light and also to investigate optimal stimulus parameters. METHODS: Five New Zealand white rabbits were placed under anesthesia. A tungsten bipolar stimulating electrode (diameter: 250 um) was placed on the vitreal surface of the retina. Cutaneous Ag/AgCl patch electrodes of VEP were used to record EEP. EEP was recorded at each stimulation. Focal visual evoked potentials (VEPs) were also recorded and compared to the focal EEP to ascertain cortical origin of the EEP, and similarities of the EEP to the VEP were determined. RESULTS: EEP recordings were elicited in 8 eyes. Current amplitudes which produced detectable responses ranged from 100 to 5000 micro A. In our best series, EEP amplitudes increased by 8 to 119 micro V in response to the current increasing from 100 to 1000 micro A. In comparing latencies of the EEP and focal VEP, the EEP latencies were 12~16 ms faster, which supports our EEP recording was done properly. CONCLUSIONS: EEPs obtained using VEP setting with adequate parameters of current duration and threshold level for the retinal implant showed that use of the EEP response is a good way to monitor the proper functioning of the retinal implant.

The Changes of Myosin Heavy Chain Isoforms after Tenotomy on Extraocular Muscle Layers of Rabbits

PURPOSE: Extraocular muscle (EOM) consists of two layers, the global and the orbital layer, which are readily distinguished by their histopathology. This study was conducted to investigate the changes of myosin heavy chain (MHC) and MHC isoforms of the global and the orbital layers of EOM after tenotomy. METHODS: Twenty four New Zealand white rabbits were used. The rectus muscles were harvested on day 3, week 1, week 2, week 3, week 4, and week 8 after EOM tenotomy. The change of MHC amount was measured using an electrophoresis. The changes of MHC isoforms were also measured quantitatively using western blot immunostaining. RESULTS: The amount of total MHC, fast MHC isoform, and slow MHC isoform decreased maximally at 1-week after EOM tenotomy and recovered at 4-week and 8-week after tenotomy. There was no significant change in the amount of the neonatal and developmental MHC isoform. CONCLUSIONS: Fast and slow MHC isoform changed mainly due to the changes in the global layer rather than in the orbital layer after EOM tenotomy.

Molecular Genetic Study on Primary and Secondary Mitochondrial DNA Mutations of Leber's Hereditary Optic Neuropathy in Koreans

PURPOSE: In order to evaluate the spectrum of mitochondrial DNA (mtDNA) mutations in the patients with suspected Leber's hereditary optic neuropathy (LHON). METHODS: We investigated 14 primary mtDNA mutations at nucleotide positions (nps 3460A, 4160C, 5244A, 9101C, 9804A, 10663C, 11778A, 13730A, 14459A, 14482G, 14484C, 14495G, 14498T, and 14568T) and one common secondary mutation (np15257A) in 82 Korean patients with suspected LHON. RESULTS: Among them, only three kinds of LHON mutations were identified in 60 (73%) of 82 probands, which were comprised of 46 (56%) cases with the 11778A, 13 (16%) with the 14484C, and 1 (1%) with the 3460A. None of the other mtDNA mutations was detected. Of the 60 probands with LHON positive mutations, 19 (32%) had relevant family histories. Heteroplasmy was determined in 2 (4%) of the 46 probands with the 11778A and 1 (8%) of 13 probands with the 14484C. CONCLUSIONS: In conclusion, the 11778A was the most common cause (56%), and higher prevalence of the 14484C and the lower prevalence of the 3460A were characteristic in Korean patients with LHON. Especially, the 3460A had a remarkable racial difference compared with Caucasians. Except 3460A, 11778A, and 14484C, the other mutations screened may not be involved in pathogenesis and not have a synergistic effect on the clinical expression of LHON in Koreans.

The Change of Extraocular Muscle Layers After Tenotomy: Histologic and Immunohistochemical study

PURPOSE: Extraocular muscle (EOM) consists of two layers, orbital and global layers which are readily distinguished by their histology. This study was conducted to investigate the changes of histology, myosin heavy chain (MHC), and MHC isoforms of the global and orbital layers of EOM after tenotomy. METHODS: Forty-two New Zealand white rabbits were used. The rectus muscles were harvested at day 3, week 1, week 2, week 4, and week 8 after EOM tenotomy. EOM mass change was measured. The EOM were serially sectioned in coronal plane and stained with Masson's trichrome. The diameters of muscle fibers and cross sectional areas of two layers were measured in the middle of the muscles. Changes of MHC isoforms were also measured using immunohistochemistry. RESULTS: The EOM mass was decreased at all periods of surgery especially at day 3 and week 1, increased maximally at week 8. The diameters of EOM fibers in global layer were decreased at day 3, week 1, and week 2 after EOM tenotomy and increased maximally at week 8. The immunohistochemical stains of fast and slow MHC were weakened in the global layer at week 1 after tenotomy. CONCLUSIONS: EOM changes due to atrophy appeared at day 3, week 1, and week 2 after EOM tenotomy while EOM atrophy was recovered at week 4 and week 8 after the surgery. These changes did not appear on the EOM orbital layer but was shown in EOM global layer. These results were due to the histological and functional differences between the EOM global and orbital layers.

Clinical Features of Ischemic Ophthalmoplegia caused by Diabetes Mellitus or Hypertension

PURPOSE: This study is to evaluate the clinical features of ischemic ophthalmoplegia including the frequency of the paralyzed cranial nerve, the difference in frequency according to the causative disease, the clinical feature of the iridoplegia in cases of the third cranial nerve involvement, and the feature and time of recovery. METHODS: We retrospectively reviewed the medical records of 26 eyes of 26 patients who had been diagnosed with ischemic ophthalmoplegia caused by diabetes mellitus (DM) or hypertension (HT). RESULTS: Twelve patients had DM, 5 patients had HT, and 9 patients had both diseases. Three patients were revealed to have DM or HT during the work-up for searching the cause of ophthalmoplegia. The third cranial nerve was most frequently paralyzed, followed by the 6th and 4th cranial nerves. The opthalmoplegia was preceded or accompanied by ocular pain or headache in 10 patients. In patients with the third cranial nerve paresis, ptosis was the first to be recovered and adduction limitation was the last to be recovered. Of the 3 patients who had iridoplegia, one patient with complete iridoplegia did not recover completely until 9 months whereas 2 patients with incomplete iridoplegia had complete recovery after one and two months, respectively. Seventy-three point seven percent of patients with ischemic ophthalmoplegia completely recovered 4.3 months after onset, and there was no difference in the recovery time among the paralyzed nerves. CONCLUSIONS: There was no difference in the frequency of the paralyzed nerve according to the causative disease, and the complete iridoplegia showed slower recovery than incomplete one. Most patients with ischemic ophthalmoplegia caused by DM or HT recovered spontaneously and did not need any further treatment.

Leber's Hereditary Optic Neuropathy with 3460 Mitochondrial DNA Mutation

Leber's hereditary optic neuropathy (LHON) is a maternally transmitted disease causing acute or subacute, bilateral optic atrophy mainly in young men. It is found to be a mitochondrial disorder with the primary mitochondrial DNA (mtDNA) mutations at 11778, 3460, and 14484. The incidence of each mutation is reported to be race-dependent. Point mutations at mtDNA nucleotide position 11778 and 14484 have been reported in Korean patients with LHON, however there has been no report of mtDNA mutation at nucleotide position 3460. Molecular genetic analyses at four primary sites (11778, 14484, 15257, and 3460) of mitochondrial DNA using the polymerase chain reaction, restriction enzyme digestion, and direct sequencing were performed in a 35-yr-old man with severe visual loss. A point mutation in the mtDNA at nucleotide position 3460 was identified and a conversion of a single alanine to a threonine was confirmed. To our knowledge, this is the first report confirming mtDNA mutation at nucleotide position 3460 in Korean patients with LHON. Detailed molecular analyses would be very helpful for the correct diagnosis of optic neuropathy of unknown etiology and for genetic counseling.

Monocanalicular Lacrimal Silicone Intubation for the Treatment of Pediatric Lacrimal Duct Obstruction

PURPOSE: To assess the clinical efficacy of monocanalicular lacrimal silicone intubation in the pediatric patients with lacrimal duct obstruction. METHODS: The medical records of 14 children with 14 eyes who underwent this procedure were reviewed retrospectively. RESULTS: Monoka(r) silicone tube was used in 3 eyes and Ritleng Self-threading Monoka(r) tube, in 11 eyes. Postoperatively, epiphora was resolved in all cases between one week and 7 months. Early postoperative extrusion of silicone tube occurred in 3 eyes(21.4%). Corneal erosion in 1 eye(7.1%), and granuloma formation in another eye(7.1%) were noticed but disappeared after removal of tubes. Removal of silicone tube was easily performed postoperatively between 3 and 7 months(mean, 4.6 months) in the clinic without sedation in all cases. CONCLUSIONS: Monocanalicular lacrimal intubation using especially Ritleng Self-threading Monoka(r) silicone tube is an easy technique for intubation and removal, and an effective method for the treatment of pediatric lacrimal duct obstruction.

The Surgical Outcome of Bilateral Lateral Rectus Recession in Large Angle Exotropia

To evaluate the results of bilateral recession in large angle exotropia we examined medical records of 73 patients who had exotropia larger than 35PD and underwent bilateral lateral rectus recession. The mean of follow-up period was 16months. Successful alignment, defined as a final alignment of orthophoria, esotropia less than 5PD or exotropia less than 10PD was achieved in 44 patients(60.3%). There were no differences in age, refractive error, preoperative angle of deviation, prevalence of amblyopia, the presence and concurrent correction of vertical or cyclodeviation, the development of diplopia and the duration of follow-up period between the successful alignment group and failure group. The esodeviation on postoperative one-day tended to ensure a more satisfactory result, but it was not statistically significant. There were no statistically significant differences in stereoacuity and postoperative angle of deviation among the different fusional ability groups. The stereoacuity and postoperative angle of deviation did not show a positive correlation. However, on the two separate examinations of the stereoacuity and fusional ability, the latter results showed improvement in both parameters. This result suggests that the correction of exodeviation may play a role in improving binocular visual function in patients with large angle exotropia.

The Effect of Cyclosporin A on Delayed Adjustable Strabismus Surgery in Rabbits

The delayed adjustable strabismus surgery may be desirable because the angle of strabismus can be changed after the strabismus surgery. We have studied the effect of 2% cyclosporin A on the delayed adjustable strabismus surgery in rabbits. Two percent cyclosporin A was soaked for 5 minutes for group 4 and 10 minutes for group 5 between the conjunctiva and sclera during the adjustable strabismus surgery on the eyes of New Zealand white rabbits. The eyes in group 1 received only adjustable strabismus surgery, and those in group 2 and 3 received the surgery including 5 minutes and 10 minutes soaking with castor oil, respectively. We evaluated the time of adjustability and measured the traction force and length during adjustment after the adjustable strabismus surgery. We could adjust in all of the 6 eyes in group 4 and 5 two weeks after the surgery. At 1 week, the traction forces were 30.7+/-14.0 (mean+/-SD), 42.0+/-39.6, 31.7+/-7.5, 24.0+/-7.5, and 21.8+/-6.0 gm in group 1, 2, 3, 4, and 5, respectively. The forces in group 4 and 5 were not significantly different from those in group 1, 2, and 3. At 2 weeks, the degrees of adhesion between the conjunctiva and superior rectus muscle, and those between the muscle and sclera were significantly lower in group 4 and 5 than those in group 1, 2, and 3. These results suggest that 2% cyclosporin A soaking is useful to obtain the better results due to the delayed adjustment by decreasing the adhesion around the muscle (J KoreanOphthalmol Soc 41:2115~2123, 2000).

Clinical Manifestations of Lebers Here ditary Optic Neuropathy with 11778 mitochondrial DNA Mutation in Koreans

Lebers hereditary optic neuropathy(LHON)is caused by a single nucleotide change in the mitochondrial deoxynucleic acid(mtDNA)and accounts for 30% of bilateral optic atrophy of unknown etiology. In order to define the clinical features of LHON associated with the 11778 mtDNA mutation, clinical and historical data were collected from 60 visually symptomatic patients with the molecularly confirmed mtDNA 11778 mutation. Forty-nine(82%)of the 60 patients were male. Onset of visual loss was between 6 and 63 years of age. Worst visual acuity ranged from light perception to 0.8. In most patients, visual acuities deteriorated to worse than 0.1 and remained at that level. Final visual acuities ranged from light perception to 1.2.Five(8.3%)out of 60 patients showed improvement of visual acuity up to 0.5 or better in at least one eye. Ishihara test revealed severe color vision impairment in most patients. Optic atrophy was the most common ophthalmoscopic finding.However, increased C/D ratio or normal disc was also observed. Central scotoma was the most frequent visual field defect, but normal visual field was also found. LHON should be considered in the differential diagnosis of optic neuropathy in a young man with visual and color deterioration as well as with a central scotoma. However, various phenotypes also exist in an atypical LHON case.

Clinical Analysis of Seventeen Korean Families of Hereditary Congenital Cataract

To elucidate genetic traits, clinical findings and treatment outcomes in Korean families with hereditary congenital cataract, 24 patients(17 families)were retrospectively analysed. Genetic trait was analysed by family pedigree. Chief complaints, ages at diagnosis, bilaterality, types of lens opacity, associated systemic or ocular anomalies were examined. The final best-corrected visual acuity was compared among groups according to the presence of surgery or the age at diagnosis. Among 17 families, 15 belonged to an autosomal dominant trait and two an autosomal recessive trait. Bilateral cataracts were shown in all patients. Twelve(50.0%)out of 24 patients who had cataracts were diagnosed before 3 months of age. Five(29.4%)out of 17 patients who received surgery were done before 3 months of age. Final best-corrected visual acuity was not different between surgery group before 3 months of age and that of after 3 months of age. Associated ocular anomalies were microphthalmia(4 patients), nystagmus(4 patients), and esotropia(3 patients), but no systemic anomalies were found. These results show that most Korean families with hereditary congenital cataract have an autosomal dominant genetic trait and the age at diagnosis or surgery is too late to treat them properly.

Clinical Analysis of Strabismus between Siblings

To investigate the clinical similarity between the siblings, we retrospectively studied the medical records of 64 patients, 32 pairs. 31 pairs showed the similar entity of strabismus between siblings. There was exotropia in 22 pairs, esotropia in 5 pairs, bilateral superior obliqre palsy in 2 pairs, exotropia, esotropia and Duane`s retraction syndrome in 1 pair. One was exotropia and the other was exotropia and Duane`s retraction syndrome in one pair. One pair was bilateral supperior obliqre palsy and esotropia and the other was right gypertropia and exotropia. The difference in the amount of deviation was less than 10 prism diopter in 23 pairs. There was no association between the strabismic siblings in refractive anomaly, amblyopia, and anisometropea. The surgical results were similar in 7 pairs of siblings among 8 pairs who underwent corrective operations.

Clinical Analysis of Strabismus between Siblings

To investigate the clinical similarity between the siblings, we retrospectively studied the medical records of 64 patients, 32 pairs. 31 pairs showed the similar entity of strabismus between siblings. There was exotropia in 22 pairs, esotropia in 5 pairs, bilateral superior obliqre palsy in 2 pairs, exotropia, esotropia and Duane`s retraction syndrome in 1 pair. One was exotropia and the other was exotropia and Duane`s retraction syndrome in one pair. One pair was bilateral supperior obliqre palsy and esotropia and the other was right gypertropia and exotropia. The difference in the amount of deviation was less than 10 prism diopter in 23 pairs. There was no association between the strabismic siblings in refractive anomaly, amblyopia, and anisometropea. The surgical results were similar in 7 pairs of siblings among 8 pairs who underwent corrective operations.

The Combined Effect of Physical Barriers and 5-Fluorouracil on Delayed Adjustable Strabismus Surgery

In order to prevent the formation of postoperative adhesions and delay the time of adjustment, the authors tried 5-fluorouracil and physical barriers of polytetrafluoroethylene, Interceed, Viscoat in rabbits. Fluorouracil delayed the adjustment for up to one week after surgery in three out of four eyes. Combined use of Interceed and 5-fluorouracil of addition of Viscoat could delay the adjustment for up to two weeks after surgery I one out of four eyes. Combined use of pophtetrafluoroethylene and 5-fluorouracil of addition of Viscoat could delay the adjustment for up to four weeks after surgery in four out of five eyes. In conclusion, combined use of polytetrafluoroethylene, 5-fluorouracil and Viscoat could be more helpful for delayine adjustment in rabbits.